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Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
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1

High efficiency solar heater  

SciTech Connect

This patent describes a solar oven comprising canted side-walls defining a heating chamber of inverted pyramidal configuration having a rectangular upper aperture for admitting solar radiation into the chamber, and a closed bottom, the side walls having four blackened non-reflective interior surfaces and translucent means closing the upper aperture for containing heated air with the chamber. The four interior surfaces are exposed to radiation entering the chamber through the translucent means. A frusto-pyramidal reflector is removably mounted externally of the heating chamber and including four reflector surfaces diverging from each other at a somewhat greater angle than the interior surfaces such that light falling onto the external reflector substantially normally to the translucent means is reflected onto an opposite one of the interior surfaces substantially at right angles thereto; and temperature responsive means arranged for opening a vent into the chamber in response to temperature rising in the chamber beyond a predetermined level. The temperature responsive means comprises spring means retained in a compressed state by structural means selected to lose structural integrity near the predetermined level. The spring means is released upon the structural means losing structural integrity near the predetermined level and failing under load imposed by the spring means, whereby the spring means is free to operate to open the vent.

Varney, J.A.; Varney, F.M.

1987-01-20T23:59:59.000Z

2

High Efficiency Solar Integrated Roof Membrane Product  

SciTech Connect

This project was designed to address the Solar Energy Technology Program objective, to develop new methods to integrate photovoltaic (PV) cells or modules within a building-integrated photovoltaic (BIPV) application that will result in lower installed cost as well as higher efficiencies of the encapsulated/embedded PV module. The technology assessment and development focused on the evaluation and identification of manufacturing technologies and equipment capable of producing such low-cost, high-efficiency, flexible BIPV solar cells on single-ply roofing membranes.

Partyka, Eric; Shenoy, Anil

2013-05-15T23:59:59.000Z

3

High-efficiency concentrator silicon solar cells  

DOE Green Energy (OSTI)

This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

1990-11-01T23:59:59.000Z

4

Highly Efficient Multigap Solar Cell Materials  

Scientists at Berkeley Lab have invented multiband gap semiconducting materials for developing solar cells that could achieve power conversion efficiencies of 50 percent or higher.

5

High efficiency, radiation-hard solar cells  

DOE Green Energy (OSTI)

The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is a less significant effect at large x. Evidence of p-type activity below the surface in Mg-doped InN was obtained; this is a significant step toward achieving photovoltaic action and, ultimately, a solar cell using this material.

Ager III, J.W.; Walukiewicz, W.

2004-10-22T23:59:59.000Z

6

Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs  

Wladek Walukiewicz, Joel Ager, and Kin Man Yu of Berkeley Lab have developed high-efficiency solar cells that leverage the well-established design and ...

7

High efficiency, radiation-hard solar cells  

E-Print Network (OSTI)

x Ga x N alloys: a full-solar-spectrum photovoltaic materialto the useful part of the solar spectrum. In fact, current

Ager III, J.W.; Walukiewicz, W.

2004-01-01T23:59:59.000Z

8

SOLAR POWERING OF HIGH EFFICIENCY ABSORPTION CHILLER  

SciTech Connect

This is the Final Report for two solar cooling projects under this Cooperative Agreement. The first solar cooling project is a roof-integrated solar cooling and heating system, called the Power Roof{trademark}, which began operation in Raleigh, North Carolina in late July 2002. This system provides 176 kW (50 ton) of solar-driven space cooling using a unique nonimaging concentrating solar collector. The measured performance of the system during its first months of operation is reported here, along with a description of the design and operation of this system. The second solar cooling system, with a 20-ton capacity, is being retrofit to a commercial office building in Charleston, South Carolina but has not yet been completed.

Randy C. Gee

2004-11-15T23:59:59.000Z

9

High-Efficiency Solar Cell Concepts: Physics, Materials, and Devices  

DOE Green Energy (OSTI)

Over the past three decades, significant progress has been made in the area of high-efficiency multijunction solar cells, with the effort primarily directed at current-matched solar cells in tandem. The key materials issues here have been obtaining semiconductors with the required bandgaps for sequential absorption of light in the solar spectrum and that are lattice matched to readily available substrates. The GaInP/GaAs/Ge cell is a striking example of success achieved in this area. Recently, several new approaches for high-efficiency solar cell design have emerged, that involve novel methods for tailoring alloy bandgaps, as well as alternate technologies for hetero-epitaxy of III-V's on Si. The advantages and difficulties expected to be encountered with each approach will be discussed, addressing both the materials issues and device physics whilst contrasting them with other fourth-generation solar cell concepts.

Mascarenhas, A.; Francoeur, S.; Seong, M. J.; Fluegel, B.; Zhang, Y.; Wanlass, M. W.

2005-01-01T23:59:59.000Z

10

Properties of High Efficiency CIGS Thin Film Solar Cells  

DOE Green Energy (OSTI)

We present experimental results in three areas. Solar cells with an efficiency of 19% have been fabricated with an absorber bandgap in the range of 1.1-1.2 eV. Properties of solar cells fabricated with and without an undoped ZnO layer were compared. The data show that high efficiency cells can be fabricated without using the high-resistivity or undoped ZnO layer. Properties of CIGS solar cells were fabricated from thin absorbers (1 {micro}m) deposited by the three-stage process and simultaneous co-deposition of all the elements. In both cases, solar cells with efficiencies of 16%-17% are obtained.

Ramanathan, K.; Keane, J.; Noufi, R.

2005-02-01T23:59:59.000Z

11

High Efficiency Solar Power via Separated Photo and Voltaic Pathways  

DOE Green Energy (OSTI)

This project demonstrates a novel nanostructured solar cell architecture capable of achieving high efficiency levels that is relatively simple and inexpensive to manufacture. The high efficiency will be achieved by the novel structure that separates the path of the photons from the path of the generated charge carriers. In this way, the photon path can be long for maximum light absorption, while the path for carriers can be short for maximum electronic energy harvesting. The combination of maximum light absorption coupled with maximum carrier harvesting is the basis for the expected high efficiency. The project will develop high efficiency solar cell prototypes utilizing this unique nanostructured architecture. The project addresses the fundamental limitation inherent in all current solar cell designs, and which opens a pathway to development for high efficiency solar cells at low cost. Realizing this goal will result in a levelized cost of electricity in the range of 10¢/kWh, which would achieve the long-sought goal of making photovoltaic electricity cost competitive with fossil-fuel generated electricity without any governmental subsidies. This breakthrough would spur the already rapid growth in the photovoltaic industry to an explosive pace, with significant, widespread benefit to the national economy and the nation’s energy security. The initial target of the program is to develop single-junction solar cells using ultrathin amorphous silicon with the performance approaching that of single crystal silicon cells.

Michael J. Naughton

2009-02-17T23:59:59.000Z

12

High-efficiency solar cell and method for fabrication  

DOE Patents (OSTI)

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

Hou, H.Q.; Reinhardt, K.C.

1999-08-31T23:59:59.000Z

13

High-efficiency solar cell and method for fabrication  

DOE Patents (OSTI)

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

Hou, Hong Q. (Albuquerque, NM); Reinhardt, Kitt C. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

14

Conversion Tower for Dispatchable Solar Power: High-Efficiency Solar-Electric Conversion Power Tower  

Science Conference Proceedings (OSTI)

HEATS Project: Abengoa Solar is developing a high-efficiency solar-electric conversion tower to enable low-cost, fully dispatchable solar energy generation. Abengoa’s conversion tower utilizes new system architecture and a two-phase thermal energy storage media with an efficient supercritical carbon dioxide (CO2) power cycle. The company is using a high-temperature heat-transfer fluid with a phase change in between its hot and cold operating temperature. The fluid serves as a heat storage material and is cheaper and more efficient than conventional heat-storage materials, like molten salt. It also allows the use of a high heat flux solar receiver, advanced high thermal energy density storage, and more efficient power cycles.

None

2012-01-11T23:59:59.000Z

15

Modelling and fabrication of high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

This report covers the research conducted on modelling and development of high-efficiency silicon solar cells during the period May 1989 to August 1990. First, considerable effort was devoted toward developing a ray-tracing program for the photovoltaic community to quantify and optimize surface texturing for solar cells. Second, attempts were made to develop a hydrodynamic model for device simulation. Such a model is somewhat slower than drift-diffusion type models like PC-1D, but it can account for more physical phenomena in the device, such as hot carrier effects, temperature gradients, thermal diffusion, and lattice heat flow. In addition, Fermi-Dirac statistics have been incorporated into the model to deal with heavy doping effects more accurately. Third and final component of the research includes development of silicon cell fabrication capabilities and fabrication of high-efficiency silicon cells. 84 refs., 46 figs., 10 tabs.

Rohatgi, A.; Smith, A.W.; Salami, J. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical Engineering] [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical Engineering

1991-10-01T23:59:59.000Z

16

High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells  

E-Print Network (OSTI)

of a triple cell showing 10.7% stable efficiency. Figure 4-1 Schematic diagram of the Hot Wire CVD deposition. Task 7: High-rate deposition of a-Si based solar cells We have conducted extensive research using a hot1 High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells PHASE I Annual

Deng, Xunming

17

Design and global optimization of high-efficiency solar thermal systems with tungsten cermets  

E-Print Network (OSTI)

Solar thermal, thermoelectric, and thermophotovoltaic (TPV) systems have high maximum theoretical efficiencies; experimental systems fall short because of losses by selective solar absorbers and TPV selective emitters. To ...

Chester, David A.

18

Integration of High Efficiency Solar Cells on Carriers for Concentrating System Applications .  

E-Print Network (OSTI)

??High efficiency multi-junction (MJ) solar cells were packaged onto receiver systems. The efficiency change of concentrator cells under continuous high intensity illumination was done. Also,… (more)

Chow, Simon Ka Ming

2011-01-01T23:59:59.000Z

19

Available Technologies: Highly Efficient Multigap Solar Cell Materials  

Scientists at Berkeley Lab have invented multiband gap semiconducting materials for developing solar cells that could achieve power conversion efficiencies of 50 ...

20

High Efficiency Multiple-Junction Solar Cells - Energy ...  

Technology Marketing Summary Single junction solar cells have limited efficiency and fail to extract maximum energy from photons outside of a specific ...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Processes for producing low cost, high efficiency silicon solar cells  

SciTech Connect

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. Silicon solar cell efficiencies of 16.9% have been achieved. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x.

Rohatgi, Ajeet (Marietta, GA); Chen, Zhizhang (Duluth, GA); Doshi, Parag (Atlanta, GA)

1996-01-01T23:59:59.000Z

22

High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells  

E-Print Network (OSTI)

High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells Brian E soluble energy relay dyes with high molar extinction coefficients. KEYWORDS Solar cell, energy transfer-sensitized solar cells, the excited ERDs must be able to efficiently transfer energy to the sensitizing dyes

McGehee, Michael

23

HIGH EFFICIENCY BIFACIAL BACK SURFACE FIELD SOLAR CELLS  

E-Print Network (OSTI)

The first high efficiency p÷-n-n + bifacial solar cells are presented. Efficiencies of 15.7 % and 13.6 % were measured under front and back air mass one illumination respectively at 28 °C. At 7 air mass one illumination and 28 °C the front efficiency increases to 16.5%. A pilot production of 200 cells was made following a fabrication process as simple as that for conventional back surface field cells. Mean efficiencies of 13.4 % and 10.7 % were obtained under front and back illumination respectively. The production yield is higher than 80%. The advantages that bifacial cells present in some applications, compared with conventional cells, have been pointed out for static [1] and quasi-static [2] concentrating systems, for luminescent concentrators [3] and also for flat panels. A transistor-like structure (n+-p-n +) has already been developed as a bifacial cell [4]. We have also suggested [5] and theoretically analysed [6] the use of a back surface field (BSF) structure (n+-p-p ÷ or p+-n-n +) as a bifacial cell. The purpose here is to demonstrate the feasibility of high efficiency bifacial BSF solar cells. p+-n-n ÷ bifacial cells with a 5 cm 2 area were made on float-zone silicon wafers. The resistivity of the n-type base region was 10 ~2 cm and the thickness was 260 pm. The p ÷ and n + regions were formed by open-tube diffusions using BBr3 and POC13 sources, the resulting sheet resistance being 45- 60 ~2/[:] for the p ÷ layer and 20- 30 ~2/[:] for the n ÷ layer. A TiOx antireflection (AR) coating was spun onto both sides of the cell; Ti-Pd-Ag grids were sputtered and lift-off defined also on both faces. The metallization pattern was designed for the cells to operate inside static compound parabolic mirrors with a concentration factor of 5 and a non-uniform distribution of light intensity on the cell surface. The optimum grid has ten fingers per centimetre (each finger is 50- 70 pm wide) and produces a coverage factor in the illuminated area of about 5.5%.

A. Cuevas; A. Luque; J. Eguren; J. Del Alamo

1980-01-01T23:59:59.000Z

24

Processes for producing low cost, high efficiency silicon solar cells  

DOE Patents (OSTI)

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure.

Rohatgi, Ajeet (Marietta, GA); Doshi, Parag (Altanta, GA); Tate, John Keith (Lawrenceville, GA); Mejia, Jose (Atlanta, GA); Chen, Zhizhang (Duluth, GA)

1998-06-16T23:59:59.000Z

25

Processes for producing low cost, high efficiency silicon solar cells  

DOE Patents (OSTI)

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime {tau} and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime {tau} and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO{sub x}. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure. 28 figs.

Rohatgi, A.; Doshi, P.; Tate, J.K.; Mejia, J.; Chen, Z.

1998-06-16T23:59:59.000Z

26

Scientists Confirm Robustness of Key Component in Ultra-High-Efficiency Solar Cell (Fact Sheet)  

DOE Green Energy (OSTI)

Scientists developed and tested a new, stable 1-eV metamorphic junction for a high efficiency multijunction III-V solar cell for CPV application.

Not Available

2011-05-01T23:59:59.000Z

27

High-efficiency solar cells using HEM silicon  

DOE Green Energy (OSTI)

Developments in Heat Exchanger Method (HEM) technology for production of multicrystalline silicon ingot production have led to growth of larger ingots (55 cm square cross section) with lower costs and reliability in production. A single reusable crucible has been used to produce 18 multicrystalline 33 cm square cross section 40 kg ingots, and capability to produce 44 cm ingots has been demonstrated. Large area solar cells of 16.3% (42 cm{sup 2}) and 15.3% (100 cm{sup 2}) efficiency have been produced without optimization of the material production and the solar cell processing.

Khattak, C.P.; Schmid, F. [Crystal Systems, Inc., Salem, MA (United States); Schubert, W.K. [Sandia National Labs., Albuquerque, NM (United States)

1994-12-31T23:59:59.000Z

28

High-Efficiency Solar Cells for Large-Scale Electricity Generation  

DOE Green Energy (OSTI)

One strategy for helping the solar industry to grow faster is to use very high efficiency cells under concentrating optics. By using lenses or mirrors to concentrate the light, very small solar cells can be used, reducing the amount of semiconductor material and allowing use of higher efficiency cells, which are now >40% efficient.

Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A.; Wanlass, M.; Kibbler, A.; Kramer, C.; Bertness, K.; Ward, S.; Duda, A.; Young, M.; Carapella, J.; Steiner, M.

2008-09-26T23:59:59.000Z

29

New approaches for high-efficiency solar cells. Final report  

DOE Green Energy (OSTI)

This report summarizes the activities carried out in this subcontract. These activities cover, first the atomic layer epitaxy (ALE) growth of GaAs, AlGaAs and InGaP at fairly low growth temperatures. This was followed by using ALE to achieve high levels of doping both n-type and p-type required for tunnel junctions (Tj) in the cascade solar cell structures. Then the authors studied the properties of AlGaAs/InGaP and AlGaAs/GaAs tunnel junctions and their performances at different growth conditions. This is followed by the use of these tunnel junctions in stacked solar cell structures. The effect of these tunnel junctions on the performance of stacked solar cells was studied at different temperatures and different solar fluences. Finally, the authors studied the effect of different types of black surface fields (BSF), both p/n and n/p GaInP solar cell structures, and their potential for window layer applications. Parts of these activities were carried in close cooperation with Dr. Mike Timmons of the Research Triangle Institute.

Bedair, S.M.; El-Masry, N.A. [North Carolina State Univ., Raleigh, NC (United States)

1997-12-01T23:59:59.000Z

30

Power efficiency for very high temperature solar thermal cavity receivers  

DOE Patents (OSTI)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatures are attained.

McDougal, Allan R. (LaCanada-Flintridge, CA); Hale, Robert R. (Upland, CA)

1984-01-01T23:59:59.000Z

31

Quantum Dot Solar Cells: High Efficiency through Multiple Exciton Generation  

DOE Green Energy (OSTI)

Impact ionization is a process in which absorbed photons in semiconductors that are at least twice the bandgap can produce multiple electron-hole pairs. For single-bandgap photovoltaic devices, this effect produces greatly enhanced theoretical thermodynamic conversion efficiencies that range from 45-85%, depending upon solar concentration, the cell temperature, and the number of electron-hole pairs produced per photon. For quantum dots (QDs), electron-hole pairs exist as excitons. We have observed astoundingly efficient multiple exciton generation (MEG) in QDs of PbSe (bulk Eg = 0.28 eV), ranging in diameter from 3.9 to 5.7nm (Eg = 0.73, 0.82, and 0.91 eV, respectively). The effective masses of electron and holes are about equal in PbSe, and the onset for efficient MEG occurs at about three times the QD HOMO-LUMO transition (its ''bandgap''). The quantum yield rises quickly after the onset and reaches 300% at 4 x Eg (3.64 eV) for the smallest QD; this means that every QD in the sample produces three electron-hole pairs/photon.

Hanna, M. C.; Ellingson, R. J.; Beard, M.; Yu, P.; Micic, O. I.; Nozik, A. J.; c.

2005-01-01T23:59:59.000Z

32

Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs  

iency solar cells that leverage the well-established design and manufacturing technology of silicon cells while delivering the performance previously achievable only by far more complex and expensive tandem solar cells. 

33

High-Efficiency 6?? Multicrystalline Black Solar Cells Based on Metal-Nanoparticle-Assisted Chemical Etching  

E-Print Network (OSTI)

Multicrystalline silicon (mc-Si) photovoltaic (PV) solar cells with nanoscale surface texturing by metal-nanoparticle-assisted etching are proposed to achieve high power efficiency. The investigation of average nanorod ...

Hsu, W. Chuck

2012-01-01T23:59:59.000Z

34

Full-Spectrum Semiconducting Material for Affordable, Highly Efficient Solar Cells  

Wladyslaw Walukiewicz and Kin Man Yu of Berkeley Lab have designed a new semiconducting material that will enable the fabrication of high efficiency solar cells at a fraction of the price of other technologies. 

35

High-Efficiency, Self-Concentrating Nanoscale Solar Cell  

While solar cells have the potential to provide clean energy for a large portion of the earth's population, no one technology has provided the right ...

36

Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N. [SunPower Corp., Sunnyvale, CA (United States)

1996-10-01T23:59:59.000Z

37

Light Trapping for High Efficiency Heterojunction Crystalline Si Solar Cells: Preprint  

DOE Green Energy (OSTI)

Light trapping plays an important role to achieve high short circuit current density (Jsc) and high efficiency for amorphous/crystalline Si heterojunction solar cells. Si heterojunction uses hydrogenated amorphous Si for emitter and back contact. This structure of solar cell posses highest open circuit voltage of 0.747 V at one sun for c-Si based solar cells. It also suggests that over 25% record-high efficiency is possible with further improvement of Jsc. Light trapping has two important tasks. The first one is to reduce the surface reflectance of light to zero for the solar spectrum that Si has a response. The second one is to increase the effective absorption length to capture all the photon. For Si heterojunction solar cell, surface texturing, anti-reflectance indium tin oxides (ITO) layer at the front and back are the key area to improve the light trapping.

Wang, Q.; Xu, Y.; Iwaniczko, E.; Page, M.

2011-04-01T23:59:59.000Z

38

High-Efficiency, Self-Concentrating Nanoscale Solar Cell - Energy ...  

While solar cells have the potential to provide clean energy for a large portion of the earth’s population, no one technology has provided the right combination of ...

39

High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers  

DOE Green Energy (OSTI)

Reported are the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Silicon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to complete the fabrication of the Silicon Ink high efficiency solar cells. Also reported are the development and demonstration of a 18.5% efficient 125mm x 125mm monocrystalline Silicon cell, and a 17% efficient 125mm x 125mm multicrystalline Silicon cell, by utilizing high throughput Ink-jet and screen printing technologies. To achieve these objectives, Innovalight developed new high throughput processing tools to print and fuse both p and n type particle Silicon Inks in a predetermined pat-tern applied either on the front or the back of the cell. Additionally, a customized Ink-jet and screen printing systems, coupled with customized substrate handling solution, customized printing algorithms, and a customized ink drying process, in combination with a purchased turn-key line, were used to complete the high efficiency solar cells. This development work delivered a process capable of high volume producing 18.5% efficient crystalline Silicon solar cells and enabled the Innovalight to commercialize its technology by the summer of 2010.

Antoniadis, H.

2011-03-01T23:59:59.000Z

40

Rational Device Design for Highly Efficient Organic Photovoltaic Solar Cells.  

E-Print Network (OSTI)

??Abundant, scalable, environmentally-friendly organic photovoltaic (OPV) technology is increasingly promising in recent years. The power conversion efficiency (PCE) of OPVs has been raised to around… (more)

Yang, Bin

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Design for the fabrication of high efficiency solar cells  

DOE Patents (OSTI)

A method and apparatus for a photo-active region for generation of free carriers when a first surface is exposed to optical radiation. The photo-active region includes a conducting transparent matrix and clusters of semiconductor materials embedded within the conducting transparent matrix. The clusters are arranged in the matrix material so as to define at least a first distribution of cluster sizes ranging from those with the highest bandgap energy near a light incident surface of the photo-active region to those with the smallest bandgap energy near an opposite second surface of the photo-active region. Also disclosed is a method and apparatus for a solar cell. The solar cell includes a photo-active region containing a plurality of semiconductor clusters of varying sizes as described.

Simmons, Joseph H. (Gainesville, FL)

1998-01-01T23:59:59.000Z

42

Fundamental understanding and development of low-cost, high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

The overall objectives of this program are (1) to develop rapid and low-cost processes for manufacturing that can improve yield, throughput, and performance of silicon photovoltaic devices, (2) to design and fabricate high-efficiency solar cells on promising low-cost materials, and (3) to improve the fundamental understanding of advanced photovoltaic devices. Several rapid and potentially low-cost technologies are described in this report that were developed and applied toward the fabrication of high-efficiency silicon solar cells.

ROHATGI,A.; NARASIMHA,S.; MOSCHER,J.; EBONG,A.; KAMRA,S.; KRYGOWSKI,T.; DOSHI,P.; RISTOW,A.; YELUNDUR,V.; RUBY,DOUGLAS S.

2000-05-01T23:59:59.000Z

43

Current-matched high-efficiency, multijunction monolithic solar cells  

DOE Patents (OSTI)

The efficiency of a two-junction (cascade) tandem photovoltaic device is improved by adjusting (decreasing) the top cell thickness to achieve current matching. An example of the invention was fabricated out of Ga.sub.0.52 In.sub.0.48 P and GaAs. Additional lattice-matched systems to which the invention pertains include Al.sub.x Ga.sub.1-x /GaAS (x= 0.3-0.4), GaAs/Ge and Ga.sub.y In.sub.l-y P/Ga.sub.y+0.5 In.sub.0.5-y As (0

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

1993-01-01T23:59:59.000Z

44

New concepts for high efficiency energy conversion: The avalanche heterostructure and superlattice solar cells  

DOE Green Energy (OSTI)

This report describes investigation into the theory and technology of a novel heterojunction or superlattice, single-junction solar cell, which injects electrons across the heterointerface to produce highly efficient impact ionization of carriers in the lowband-gap side of the junction, thereby conserving their total energy. Also, the superlattice structure has the advantage of relaxing the need for perfect lattice matching at the p-n interface and will inhibit the cross diffusion of dopant atoms that typically occurs in heavy doping. This structure avoids the use of tunnel junctions that make it very difficult to achieve the predicted efficiencies in cascade cells, thus making it possible to obtain energy efficiencies that are competitive with those predicted for cascade solar cells with reduced complexity and cost. This cell structure could also be incorporated into other solar cell structures designed for wider spectral coverage.

Summers, C.J.; Rohatgi, A.; Torabi, A.; Harris, H.M. (Georgia Tech Research Inst., Atlanta, GA (United States))

1993-01-01T23:59:59.000Z

45

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

46

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

47

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

48

High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application  

DOE Green Energy (OSTI)

The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong potential for net gains in efficiency at high concentration.

Hubbard, Seth

2012-09-12T23:59:59.000Z

49

Simulation of Device Parameters of High Efficiency Multicrystalline Silicon Solar Cells  

Science Conference Proceedings (OSTI)

The results of the simulation of the reported experimental results of high efficiency multicrystalline silicon (mc-Si) solar cells, using PC1D software, are reported in this study. Results obtained by various groups have been incorporated and compared in this study. The highest efficiency reported so far for mc-Si solar cells is 20{center_dot}4% and 17-18% by research laboratories and commercial houses, respectively. The efficiency can be further enhanced if passivation characteristics on both the front and back surface are improved. The role of back surface recombination has become more significant in light of the use of thin mc-Si wafers by the solar cell industry. Based on the passivation characteristics and considering the understanding of the past three decades of studies, the authors have proposed and simulated a structure for mc-Si solar cells to improve the performance of the same. The results of our modeled structure of mc-Si solar cell show an efficiency of 21{center_dot}88% with short-circuit current density, J{sub sc} = 39{center_dot}39 mA/cm2, and open circuit voltage, V{sub oc} = 0{center_dot}666 V.

Budhraja, V.; Misra, D.; Ravindra, N. M.

2011-11-01T23:59:59.000Z

50

Novel wide band gap materials for highly efficient thin film tandem solar cells  

SciTech Connect

Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PV�s goal in Phase I of the DOE SBIR was to 1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and 2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin films using a mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.

Brian E. Hardin, Stephen T. Connor, Craig H. Peters

2012-06-11T23:59:59.000Z

51

Highly-Efficient Thermoelectronic Conversion of Solar Energy and Heat into Electric Power  

E-Print Network (OSTI)

Electric power may, in principle, be generated in a highly efficient manner from heat created by focused solar irradiation, chemical combustion, or nuclear decay by means of thermionic energy conversion. As the conversion efficiency of the thermionic process tends to be degraded by electron space charges, the efficiencies of thermionic generators have amounted to only a fraction of those fundamentally possible. We show that this space-charge problem can be resolved by shaping the electric potential distribution of the converter such that the static electron space-charge clouds are transformed into an output current. Although the technical development of practical generators will require further substantial efforts, we conclude that a highly efficient transformation of heat to electric power may well be achieved.

Meir, S; Geballe, T H; Mannhart, J

2013-01-01T23:59:59.000Z

52

Low cost, single crystal-like substrates for practical, high efficiency solar cells  

Science Conference Proceedings (OSTI)

It is well established that high efficiency (20%) solar cells can be routinely fabricated using single crystal photovoltaic (PV) materials with low defect densities. Polycrystalline materials with small grain sizes and no crystallographic texture typically result in reduced efficiences. This has been ascribed primarily to the presence of grain boundaries and their effect on recombination processes. Furthermore, lack of crystallographic texture can result in a large variation in dopant concentrations which critically control the electronic properties of the material. Hence in order to reproducibly fabricate high efficiency solar cells a method which results in near single crystal material is desirable. Bulk single crystal growth of PV materials is cumbersome, expensive and difficult to scale up. We present here a possible route to achieve this if epitaxial growth of photovoltaic materials on rolling-assisted-biaxially textured-substrates (RABiTS) can be achieved. The RABiTS process uses well-established, industrially scaleable, thermomechanical processing to produce a biaxially textured or single-crystal-like metal substrate with large grains (50-100 {mu}m). This is followed by epitaxial growth of suitable buffer layers to yield chemically and structurally compatible surfaces for epitaxial growth of device materials. Using the RABiTS process it should be possible to economically fabricate single-crystal-like substrates of desired sizes. Epitaxial growth of photovoltaic devices on such substrates presents a possible route to obtaining low-cost, high performance solar cells.

Goyal, A.; Specht, E.D.; List, F.A. [and others

1997-09-01T23:59:59.000Z

53

Highly efficient solar collector including means for preventing cover plate fluid condensation  

SciTech Connect

A solar energy collector of low cost and high thermal efficiency is disclosed having a heat trap produced by zigzagging a thin strip of polyethylene terephthalate between opposite sides of the trap while wrapping the strip about rows of dowels positioned at opposite sides of the frame of the solar collector. A window of soda lime glass filters uv radiation to inhibit discoloration of the plastic heat trap walls. An absorber plate having fluid pipes therein is positioned underneath the heat trap and a first layer of fiberglass, and a second layer of polyurethane foam are positioned below the absorber plate. The fiberglass layer prevents overheating of the polyurethane foam layer to in turn inhibit the formation of toxic fluids, which may condense upon the underside of the window to reduce the efficiency of the collector.

Root, E.F.; Kunica, S.; Simmons, H.M.

1977-09-06T23:59:59.000Z

54

Rapid thermal processing of high-efficiency silicon solar cells with controlled in-situ annealing  

DOE Green Energy (OSTI)

Silicon solar cell efficiencies of 17.1%, 16.4%, 14.8%, and 14.9% have been achieved on FZ, Cz, multicrystalline (mc-Si), and dendritic web (DW) silicon, respectively, using simplified, cost-effective rapid thermal processing (RTP). These represent the highest reported efficiencies for solar cells processed with simultaneous front and back diffusion with no conventional high-temperature furnace steps. Appropriate diffusion temperature coupled with the added in-situ anneal resulted in suitable minority-carrier lifetime and diffusion profiles for high-efficiency cells. The cooling rate associated with the in-situ anneal can improve the lifetime and lower the reverse saturation current density (J{sub 0}), however, this effect is material and base resistivity specific. PECVD antireflection (AR) coatings provided low reflectance and efficient front surface and bulk defect passivation. Conventional cells fabricated on FZ silicon by furnace diffusions and oxidations gave an efficiency of 18.8% due to greater short wavelength response and lower J{sub 0}.

Doshi, P.; Rohatgi, A.; Ropp, M.; Chen, Z. [Georgia Institute of Technology, Atlanta, GA (United States). Univ. Center of Excellence for Photovoltaics Research and Education; Ruby, D. [Sandia National Labs., Albuquerque, NM (United States); Meier, D.L. [EBARA Solar, Inc., Large, PA (United States)

1995-01-01T23:59:59.000Z

55

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print Wednesday, 27 March 2013 00:00 The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

56

Development of high-efficiency silicon solar cells and modeling the impact of system parameters on levelized cost of electricity .  

E-Print Network (OSTI)

??The objective of this thesis is to develop low-cost high-efficiency crystalline silicon solar cells which are at the right intersection of cost and performance to… (more)

Kang, Moon Hee

2013-01-01T23:59:59.000Z

57

High efficiency thin film CdTe and a-Si based solar cells  

DOE Green Energy (OSTI)

This report describes work done by the University of Toledo during the first year of this subcontract. During this time, the CdTe group constructed a second dual magnetron sputter deposition facility; optimized reactive sputtering for ZnTe:N films to achieve 10 ohm-cm resistivity and {approximately}9% efficiency cells with a copper-free ZnTe:N/Ni contact; identified Cu-related photoluminescence features and studied their correlation with cell performance including their dependence on temperature and E-fields; studied band-tail absorption in CdS{sub x}Te{sub 1{minus}x} films at 10 K and 300 K; collaborated with the National CdTe PV Team on (1) studies of high-resistivity tin oxide (HRT) layers from ITN Energy Systems, (2) fabrication of cells on the HRT layers with 0, 300, and 800-nm CdS, and (3) preparation of ZnTe:N-based contacts on First Solar materials for stress testing; and collaborated with Brooklyn College for ellipsometry studies of CdS{sub x}Te{sub 1{minus}x} alloy films, and with the University of Buffalo/Brookhaven NSLS for synchrotron X-ray fluorescence studies of interdiffusion in CdS/CdTe bilayers. The a-Si group established a baseline for fabricating a-Si-based solar cells with single, tandem, and triple-junction structures; fabricated a-Si/a-SiGe/a-SiGe triple-junction solar cells with an initial efficiency of 9.7% during the second quarter, and 10.6% during the fourth quarter (after 1166 hours of light-soaking under 1-sun light intensity at 50 C, the 10.6% solar cells stabilized at about 9%); fabricated wide-bandgap a-Si top cells, the highest Voc achieved for the single-junction top cell was 1.02 V, and top cells with high FF (up to 74%) were fabricated routinely; fabricated high-quality narrow-bandgap a-SiGe solar cells with 8.3% efficiency; found that bandgap-graded buffer layers improve the performance (Voc and FF) of the narrow-bandgap a-SiGe bottom cells; and found that a small amount of oxygen partial pressure ({approximately}2 {times} 10{sup {minus}5} torr) was beneficial for growing high-quality films from ITO targets.

Compaan, A. D.; Deng, X.; Bohn, R. G.

2000-01-04T23:59:59.000Z

58

High Efficiency Single Crystal CdTe Solar Cells: November 19, 2009 - January 31, 2011  

DOE Green Energy (OSTI)

The goal of the program was to develop single crystal CdTe-based top cells grown on Si solar cells as a platform for the subsequent manufacture of high efficiency tandem cells for CPV applications. The keys to both the single junction and the tandem junction cell architectures are the ability to grow high quality single-crystal CdTe and CdZnTe layers on p-type Si substrates, to dope the CdTe and CdZnTe controllably, both n and p-type, and to make low resistance ohmic front and back contacts. EPIR demonstrated the consistent MBE growth of CdTe/Si and CdZnTe/Si having high crystalline quality despite very large lattice mismatches; epitaxial CdTe/Si and CdZnTe/Si consistently showed state-of-the-art electron mobilities and good hole mobilities; bulk minority carrier recombination lifetimes of unintentionally p-doped CdTe and CdZnTe grown by MBE on Si were demonstrated to be consistently of order 100 ns or longer; desired n- and p-doping levels were achieved; solar cell series specific resistances <10 ?-cm2 were achieved; A single-junction solar cell having a state-of-the-art value of Voc and a unverified 16.4% efficiency was fabricated from CdZnTe having a 1.80 eV bandgap, ideal for the top junction in a tandem cell with a Si bottom junction.

Carmody, M.; Gilmore, A.

2011-05-01T23:59:59.000Z

59

NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar...  

NLE Websites -- All DOE Office Websites (Extended Search)

Low-bandgap cells can lose 25% of their power output and efficiency ratings as solar cell operating temperatures climb to 75C or more, a common occurrence in hot and arid...

60

High efficiency thin film silicon solar cells with novel light trapping : principle, design and processing  

E-Print Network (OSTI)

One major efficiency limiting factor in thin film solar cells is weak absorption of long wavelength photons due to the limited optical path length imposed by the thin film thickness. This is especially severe in Si because ...

Zeng, Lirong, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells  

DOE Green Energy (OSTI)

This document describes the progress made in obtaining stable, a-Si-based submodules that have a large area and high efficiency. Conversion efficiencies of up to 11.95% were obtained in small-area, single-junction a-Si solar cells using textured TiO{sub 2}, superlattice p-layers, graded carbon concentrations near the p/i interface, and highly reflective ITO/silver back contacts. Single- junction a-SiC and a-SiGe p-i-n cells were also fabricated that had conversion efficiencies of 9%--11%, and some recently fabricated stacked-junction cells had conversion efficiencies of about 10%. In materials research boron-doped microcrystalline SiC films were recently developed containing up to 6 at. % carbon with conductivities of 3 {times} 10{sup {minus}3}/{Omega}-cm at room temperature and activation energies of 0.11 eV. Microcrystalline film growth was shown to be strongly influenced by the nature of the substrate, with nucleation occurring more readily on a-Si substrates than on TiO{sub 2}. Stability studies show that light-induced degradation is usually enhanced by the presence of carbon grading near the p/i interface. In general, adding either germanium (from GeH{sub 4}) or carbon (from CH{sub 4}) to the i-layer of a p-i-n cell leads to enhanced light-induced degradation. 13 refs., 80 figs., 17 tabs.

Catalano, A.W.; Carlson, D.E.; Ayra, R.R.; Bennett, M.S.; D'Aiello, R.V.; Dickson, C.R.; Fortmann, C.M.; Goldstein, B.; McVeigh, J.; Morris, J.; Newton, J.L.; Wiedeman, S. (Solarex Corp., Newtown, PA (USA). Thin Film Div.)

1989-10-01T23:59:59.000Z

62

The effects of concentrated ultraviolet light on high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

The importance of stability in the performance of solar cells is clearly recognized as fundamental. Some of the highest efficiency silicon solar cells demonstrated to date, such as the Point Contact solar cell and the Passivated Emitter solar cell, rely upon the passivation of cell surfaces in order to minimize recombination, which reduces cell power output. Recently, it has been shown that exposure to ultraviolet (UV) light of wavelengths present in the terrestrial solar spectrum can damage a passivating silicon-oxide interface and increase recombination. In this study, we compared the performance of Point Contact and Passivated Emitter solar cells after exposure to UV light. We also examined the effect of UV exposure on oxide-passivated silicon wafers. We found that current Passivated Emitter designs are stable at both one-sun and under concentrated sunlight. The evolution of Point Contact concentrator cell performance shows a clear trend towards more stable cells. 15 refs., 18 figs.

Ruby, D.S.; Schubert, W.K.

1991-01-01T23:59:59.000Z

63

Development of high efficiency (14%) solar cell array module. Final report, November 1979-June 1980  

DOE Green Energy (OSTI)

More effort was concentrated on development of procedures to provide large area (3 in. dia) high efficiency (16.5% AM1, 28/sup 0/C) P+NN+ solar cells. Intensive tests with 3 in. slices gave consistently lower efficiency (13.5%). The problems were identified as incomplete formation of an optimum back surface field (BSF), and interaction of the BSF process and the shallow P+ junction. The problem was shown not to be caused by reduced quality of silicon near the edges of the larger slices. A promising process sequence was identified. A reasonably large number of fairly efficient (13.5% average) 3 in. P+NN+ cells were made and combined with no problems with the module design developed for this project. In the module, one hundred and twenty (120) cells were connected, eight (8) in parallel and fifteen (15) in series. Six (6) modules were delivered with an average power output (per total module area of 6890 cm/sup 2/) of 75.3 watts and a module overall average efficiency of 10.9%.

Iles, P.A.; Khemthong, S.; Olah, S.; Sampson, W.J.; Ling, K.S.

1980-01-01T23:59:59.000Z

64

High-efficiency cadmium and zinc-telluride-based thin-film solar cells  

DOE Green Energy (OSTI)

This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.

Rohatgi, A.; Sudharsanan, R.; Ringel, S. (Georgia Inst. of Tech., Atlanta, GA (United States))

1992-02-01T23:59:59.000Z

65

Solar bowl component efficiencies  

Science Conference Proceedings (OSTI)

Battelle Pacific Northwest Laboratory has published two volumes on the economic evaluation of various proposed configurations and plant sizes for the four solar thermal technologies. These are the latest in a series of publications sponsored by the Department of Energy (DOE) on plant and operational costs and are more complete in that they include calculations of electrical output. These latest Battelle volumes use the 1976 solar data from Barstow, Calif., and by calculating or estimating the energy conversion efficiency of each element in the process from sun to electricity predict the output and cost of electricity from different plant sizes for each of the four technologies. In this paper a comparison is presented of the component efficiencies developed by Battelle and those of the solar bowl at Crosbyton, Tex.

O'Hair, E.A.; Green, B.L. (College of Engineering, Texas Tech. Univ., Lubbock, TX (United States))

1992-11-01T23:59:59.000Z

66

Solar ADEPT: Efficient Solar Energy Systems  

DOE Green Energy (OSTI)

Solar ADEPT Project: The 7 projects that make up ARPA-E's Solar ADEPT program, short for 'Solar Agile Delivery of Electrical Power Technology,' aim to improve the performance of photovoltaic (PV) solar energy systems, which convert the sun's rays into electricity. Solar ADEPT projects are integrating advanced electrical components into PV systems to make the process of converting solar energy to electricity more efficient.

None

2011-01-01T23:59:59.000Z

67

NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells (Fact Sheet)  

Science Conference Proceedings (OSTI)

Researchers at the National Renewable Energy Laboratory (NREL) are finding new ways to manufacture thin-film solar cells made from copper, indium, gallium, and selenium - called CIGS cells - that are different than conventional CIGS solar cells. Their use of high-temperature glass, designed by SCHOTT AG, allows higher fabrication temperatures, opening the door to new CIGS solar cells employing light-absorbing materials with wide 'bandgaps.'

Not Available

2012-09-01T23:59:59.000Z

68

High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges  

Science Conference Proceedings (OSTI)

Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se{sub 2} (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. These two thin-film technologies have a common device/module structure: substrate, base electrode, absorber, junction layer, top electrode, patterning steps for monolithic integration, and encapsulation. The monolithic integration of thin-film solar cells can lead to significant manufacturing cost reduction compared to crystalline Si technology. The CdTe and CIGS modules share common structural elements. In principle, this commonality should lead to similar manufacturing cost per unit area, and thus, the module efficiency becomes the discriminating factor that determines the cost per watt. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

Noufi, R.; Zweibel, K.

2006-01-01T23:59:59.000Z

69

Low temperature metal-organic chemical vapor deposition growth processes for high-efficiency solar cells  

DOE Green Energy (OSTI)

This report describes the results of a program to develop a more complete understanding of the physical and chemical processes involved in low-temperature growth of III-V compounds by metal-organic chemical vapor deposition (MOCVD) and to develop a low-temperature process that is suitable for the growth of high-efficiency solar cells. The program was structured to develop a better understanding of the chemical reactions involved in MOCVD growth, to develop a model of the processes occurring in the gas phase, to understand the physical kinetics and reactions operative on the surface of the growing crystal, and to develop an understanding of the means by which these processes may be altered to reduce the temperature of growth and the utilization of toxic hydrides. The basic approach was to develop the required information about the chemical and physical kinetics operative in the gas phase and on the surface by the direct physical measurement of the processes whenever possible. The program included five tasks: (1) MOCVD growth process characterization, (2) photoenhanced MOCVD studies, (3) materials characterization, (4) device fabrication and characterization, and (5) photovoltaic training. Most of the goals of the program were met and significant progress was made in defining an approach that would allow both high throughput and high uniformity growth of compound semiconductors at low temperatures. The technical activity was focused on determining the rates of thermal decomposition of trimethyl gallium, exploring alternate arsenic sources for use MOCVD, and empirical studies of atomic layer epitaxy as an approach.

Dapkus, P.D. (University of Southern California, Los Angeles, CA (United States))

1993-02-01T23:59:59.000Z

70

Turning Bacteria into Fuel: Cyanobacteria Designed for Solar-Powered Highly Efficient Production of Biofuels  

SciTech Connect

Broad Funding Opportunity Announcement Project: ASU is engineering a type of photosynthetic bacteria that efficiently produce fatty acids—a fuel precursor for biofuels. This type of bacteria, called Synechocystis, is already good at converting solar energy and carbon dioxide (CO2) into a type of fatty acid called lauric acid. ASU has modified the organism so it continuously converts sunlight and CO2 into fatty acids—overriding its natural tendency to use solar energy solely for cell growth and maximizing the solar-to-fuel conversion process. ASU’s approach is different because most biofuels research focuses on increasing cellular biomass and not on excreting fatty acids. The project has also identified a unique way to convert the harvested lauric acid into a fuel that can be easily blended with existing transportation fuels.

2010-01-01T23:59:59.000Z

71

A high-efficiency indirect lighting system utilizing the solar 1000 sulfur lamp  

SciTech Connect

High-lumen light sources represent unique challenges and opportunities for the design of practical and efficient interior lighting systems. High-output sources require a means of large-scale distribution and avoidance of high-luminance glare while providing efficient delivery. An indirect lighting system has been developed for use with a 1,000 Watt sulfur lamp that efficiently utilizes the high-output source to provide quality interior lighting. This paper briefly describes the design and initial testing of this new system.

Siminovitch, M.; Gould, C.; Page, E.

1997-06-01T23:59:59.000Z

72

High efficiency epitaxial optical reflector solar cells. Final subcontract report, 1 January 1990--31 October 1992  

DOE Green Energy (OSTI)

This report describes work to test the feasibility of a new solar cell concept -- the epitaxial optical reflector (EOR) solar cell. This cell concept alters current designs for high efficiency cells by changing the optical absorption efficiency of single cells. The change is introduced by the use an epitaxial multilayer reflector as an integral part of the cell to increase the optical path length of certain wavelengths of light in the cell. These changes are expected to increase the open circuit voltage at which power is extracted from the cell. The program is designed to test the feasibility of the use of a broad band epitaxial multilayer reflector grown as an integral part of the device structure to reflect the near-band-edge light back through the device for a second absorption pass. This second pass allows the design of a solar cell with a thinner base, and the use of the epitaxial reflector as a heterojunction carrier-reflecting barrier at the rear of the device. The thinner cell design and altered carrier profile that results from the light- and carrier-reflecting barrier will decrease the carrier concentration gradient and increase the open circuit voltage. The program is structured to have three tasks: (1) Solar Cell and Reflector Modeling, (2) Materials Growth and Optimization, and (3) Solar Cell Fabrication and Characterization.

Dapkus, P.D.; Hummel, S.G. [University of Southern California, Los Angeles, CA (United States)

1993-08-01T23:59:59.000Z

73

High efficiency thin-film GaAs solar cells. First interim report, March 1--August 30, 1977  

DOE Green Energy (OSTI)

The objective is to demonstrate the feasibility of producing high-efficiency (15% or greater) thin-film GaAs solar cells with costs suitable for terrestrial solar electric power generation. The approach is that of growing GaAs by organio-metallic chemical vapor deposition on recrystallized germanium (Ge) films previously deposited on metal substrates and fabricating AMOS (Antireflecting Metal-Oxide-Semiconductor) solar cells on the GaAs. Previously it had been determined that a water vapor-grown native oxide (temperature = 25/sup 0/C) was the most useful native oxide for AMOS cells. A new chemical surface preparation prior to oxide growth led to more uniform oxides and reduced interface contamination, yielding lower reverse saturation current densities, a near-unity diode ideality factor, and better reproducibility. Substituting silver (Ag) for gold metallization showed no change in starting cell efficiency, but did greatly improve high temperature stability of the AMOS solar cell. A new study was completed on antireflection coatings on AMOS GaAs solar cells, taking into account the spectral response of the cell and nature of the solar spectra, and the results submitted for publication. XPS (X-ray Photoelectron Spectroscopy) studies had found earlier that the more efficient native oxides had primarily As/sub 2/O/sub 3/ and Ga/sub 2/O/sub 3/ with little GaAsO/sub 4/. A new chemical step etching was developed which can be used to profile the oxide in 5- to 7-A/sup 0/ steps without modifying the oxide chemistry as does ion sputtering. A new Schottky barrier structure is described which can give cell efficiencies up to 16% without oxide interfacial layer effects and 20 to 22% with a moderate interfacial layer effect. AMOS solar cells fabricated on sliced polycrystalline GaAs wafers with 100- to 500-..mu..m grains using Sb/sub 2/O/sub 3/ deposited oxides showed 14% cell efficiency compared to 16.2% in a region with few grains.

Stirn, R.J.

1977-12-01T23:59:59.000Z

74

High efficiency resonant dc/dc converter for solar power applications  

E-Print Network (OSTI)

This thesis presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across ...

Inam, Wardah

2013-01-01T23:59:59.000Z

75

Improved power efficiency for very-high-temperature solar-thermal-cavity receivers  

DOE Patents (OSTI)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatues are attained.

McDougal, A.R.; Hale, R.R.

1982-04-14T23:59:59.000Z

76

Solar efficient structure  

Science Conference Proceedings (OSTI)

A solar efficient structure is disclosed which comprises a central chase positioned vertically within the structure and connected in fluid communication with a duct network positioned in thermal contact with the ground and with the attic of the structure. A fan is provided for circulating air through a perforated attic duct, through the various rooms of the structure, and through the duct network and the chase. In one embodiment, the fan is reversible so as to circulate the air in one direction, or in the other direction. When operating in the heating mode, the ground acts as a heat source to heat the air circulating through the duct network. Conversely, when operating in the cooling mode, the ground acts as a heat sink to cool the airflow circulating therethrough. A dehumidifier, and a heating or cooling means is provided for assisting in the conditioning of the circulating airflow. In one embodiment, the heating means comprises a greenhouse room which permits ultraviolet radiation to enter and heat the air contained therein, and a damper means for controlling the flow rate of the air circulating through the greenhouse room. The structure is fully insulated and includes a vent skin positioned about the exterior walls and the roof thereof. A method is disclosed for insulating the roof line with loose insulation.

Arenas, F.B.

1985-02-12T23:59:59.000Z

77

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology  

DOE Green Energy (OSTI)

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, [approximately] 1 [times] 10[sup 5] cm[sup [minus]5], as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 [times]10[sup 7] cm[sup [minus]2]. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. (Spire Corp., Bedford, MA (United States))

1993-04-01T23:59:59.000Z

78

High-efficiency one-sun photovoltaic module demonstration using solar-grade CZ silicon. Final report  

DOE Green Energy (OSTI)

This work was performed jointly by Sandia National Laboratories (Albuquerque, NM) and Siemens Solar Industries (Camarillo, CA) under a Cooperative Research and Development Agreement (CRADA 1248). The work covers the period May 1994 to March 1996. The purpose of the work was to explore the performance potential of commercial, photovoltaic-grade Czochralski (Cz) silicon, and to demonstrate this potential through fabrication of high-efficiency cells and a module. Fabrication of the module was omitted in order to pursue further development of advanced device structures. The work included investigation of response of the material to various fabrication processes, development of advanced cell structures using the commercial material, and investigation of the stability of Cz silicon solar cells. Some important achievements of this work include the following: post-diffusion oxidations were found to be a possible source of material contamination; bulk lifetimes around 75 pts were achieved; efficiencies of 17.6% and 15.7% were achieved for large-area cells using advanced cell structures (back-surface fields and emitter wrap-through); and preliminary investigations into photodegradation in Cz silicon solar cells found that oxygen thermal donors might be involved. Efficiencies around 20% should be possible with commercial, photovoltaic-grade silicon using properly optimized processes and device structures.

Gee, J.M.

1996-10-01T23:59:59.000Z

79

High-efficiency silicon solar cells for use with a prismatic cover at 160 suns  

DOE Green Energy (OSTI)

For this program, Solarex developed a process sequence that could be used in a manufacturing environment to produce high-efficiency silicon concentrator cells. The cells had large gridlines to minimize series resistance losses and a prismatic cover to minimize shadowing. The front surface of the cell was textured to improve absorption of light and passivated to reduce front-surface recombination. Two separate diffusions steps were used: a deep emitter with a light surface concentration and a heavy diffusion to reduce recombination under the front contacts. Cell efficiencies as high as 22.25% were demonstrated at 75 suns and over 21.5% at 150 suns air mass 1.5 illumination. 16 refs., 31 figs., 10 tabs.

Silver, J.R.; Patel, B. (Solarex Corp., Rockville, MD (USA))

1990-08-01T23:59:59.000Z

80

Novel InGaAsN pn Junction for High-Efficiency Multiple-Junction Solar Cells  

DOE Green Energy (OSTI)

We report the application of a novel material, InGaAsN, with bandgap energy of 1.05 eV as a junction in an InGaP/GaAs/InGaAsN/Ge 4-junction design. Results of the growth and structural, optical, and electrical properties were demonstrated, showing the promising perspective of this material for ultra high efficiency solar cells. Photovoltaic properties of an as-grown pn diode structure and improvement through post growth annealing were also discussed.

Allerman, A.A.; Chang, P.C.; Gee, J.M.; Hammons, B.E.; Hou, H.Q.; Jones, E.D.; Kurtz, S.R.; Reinhardt, K.C.

1999-03-26T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Technology Development for High-Efficiency Solar Cells and Modules Using Thin (<80 um) Single-Crystal Silicon Wafers Produced by Epitaxy: June 11, 2011 - April 30, 2013  

DOE Green Energy (OSTI)

Final technical progress report of Crystal Solar subcontract NEU-31-40054-01. The objective of this 18-month program was to demonstrate the viability of high-efficiency thin (less than 80 um) monocrystalline silicon (Si) solar cells and modules with a low-cost epitaxial growth process.

Ravi, T. S.

2013-05-01T23:59:59.000Z

82

Advanced laser processing and photoluminescence characterisation of high efficiency silicon solar cells.  

E-Print Network (OSTI)

??Many current technologies used in solar cell fabrication have been successfully adapted from the integrated circuits industry. The success of laser processing applications in this… (more)

Abbott, Malcolm David

2006-01-01T23:59:59.000Z

83

High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells: Final Technical Report, 1 September 2001--6 March 2005  

SciTech Connect

The objectives for the University of Toledo are to: (1) establish a transferable knowledge and technology base for fabricating high-efficiency triple-junction a-Si-based solar cells, and (2) develop high-rate deposition techniques for the growing a-Si-based and related alloys, including poly-Si, c-Si, a-SiGe, and a-Si films and photovoltaic devices with these materials.

Deng, X.

2006-01-01T23:59:59.000Z

84

Simulation and analysis of high efficiency absorption systems for solar cooling  

DOE Green Energy (OSTI)

A flexible modular computer code was developed for simulation of absorption systems. The code is capable to investigate, on a comparable basis, various cycles configurations with a variety of working fluids. In Phase 1 of the program, two open cycle absorption systems for solar energy were successfully simulated. Modifications which were applied to the code in Phase 2, allowed the analysis of systems with volatile absorbents, as used in advanced, high COP, absorption systems such as the GAX cycle. Ammonia-water database was developed into equation form and introduced to the code. That eliminated discontinuities in evaluating differentials used in the solver. Properties calculated with these equations fit well the tabulated data. This and other modifications allowed to model absorption cycles using ammonia-water. Single effect cycles converged in most ranges. Direct analysis of the code to advanced cycles, such as GAX, still encountered some convergence problems. It was, however, possible to analyze the GAX cycle in groups. The results show that high COP's are obtainable and are compatible with those reached by LBL. The properties of two additional pairs, that were developed in BG Univ., are reported. 27 refs., 13 figs., 13 tabs.

Shavit, A.; Haim, I. (Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering); Borde, I.; Jelinek, M. (Ben-Gurion Univ. of the Negev, Beersheba (Israel). Applied Research Inst.)

1989-05-31T23:59:59.000Z

85

Development of high efficiency (14%) solar cell array module. Third quarterly report, July 15, 1979-November 15, 1979  

DOE Green Energy (OSTI)

Most effort was concentrated on development of procedures to provide large area (3'' diameter) high efficiency (approx. 15.5% AM1, 28/sup 0/C) P/N solar cells. These efficiencies had been obtained for 2 x 2 cm area cells, but tests showed that the problem was not reduced silicon quality near the edges of the larger slices. The problems were in optimizing the back-surface field (BSF) process, and its possible interaction with the shallow P+ layer formation. Towards the end of this reporting period a promising process sequence had been identified and is being tested. The module design has been finalized. One hundred and twenty (120) cells will be connected eight (8) in parallel and fifteen (15) in series. The designs and tooling phases have been completed and are awaiting completion of the cells.

Iles, P.A.; Khemthong, S.; Olah, S.; Sampson, W.J.; Ling, K.S.

1980-01-01T23:59:59.000Z

86

Development of high efficiency cascade solar cells. Quarterly technical progress report No. 2  

DOE Green Energy (OSTI)

Research has continued in the development of selected ternary and quaternary III-V materials that are potential candidates for cascade solar cell applications. In addition, various simple and multi-junction cascade solar cell components have been fabricated and evaluated in a continuing study of several different solar cell designs (materials combinations). During the present reporting period, work has concentrated on the following major areas: GaAlAs/GaAs cell development; AlGaAsSb/GaAsSb materials development; GaInP materials development via VPE; inverted structure development; and MO/CVD growth system work at NCSU. Progress in each of these areas is summarized.

Not Available

1979-12-31T23:59:59.000Z

87

Silicon Ink for High-Efficiency Solar Cells Captures a Share of the Market (Fact Sheet)  

DOE Green Energy (OSTI)

Fact sheet on 2011 R&D 100 Award winner Silicon Ink. Liquid silicon has arrived, and with it comes a power boost for solar cells and dramatic cost savings for cell manufacturers.

Not Available

2011-08-01T23:59:59.000Z

88

Earth abundant materials for high efficiency heterojunction thin film solar cells  

E-Print Network (OSTI)

We investigate earth abundant materials for thin-film solar cells that can meet tens of terawatts level deployment potential. Candidate materials are identified by combinatorial search, large-scale electronic structure ...

Buonassisi, Tonio

89

MOVPE Growth of High Efficiency Inverted Metamorphic 1.1eV Solar ...  

Science Conference Proceedings (OSTI)

This paper focuses on the 1.1ev Ga0.77In0.23As inverted metamorphic solar cell grown with AlGaInAs quarternary step graded buffer on 6o miscut (001) thin Ge ...

90

A market analysis for high efficiency multi-junction solar cells grown on SiGe  

E-Print Network (OSTI)

Applications, markets and a cost model are presented for III-V multi-junction solar cells built on compositionally graded SiGe buffer layers currently being developed by professors Steven Ringell of Ohio State University ...

Judkins, Zachara Steele

2007-01-01T23:59:59.000Z

91

Silicon sheet with molecular beam epitaxy for high efficiency solar cells. Final technical report, March 22, 1982-April 30, 1984  

DOE Green Energy (OSTI)

A two-year program has been carried out for the Jet Propulsion Laboratory in which the UCLA silicon MBE facility has been used to attempt to grow silicon solar cells of high efficiency. MBE ofers the potential of growing complex and arbitrary doping profiles with 10 A depth resolution. It is the only technique taht can readily grow built-in front and back surface fields of any desired depth and value in silicon solar cells, or the more complicated profiles needed for a double junction cascade cell, all in silicon, connected in series by a tunnel junction. Although the dopant control required for such structures has been demonstrated in silicon by UCLA, crystal quality at the p-n junctions is still too poor to allow the other advantages to be exploited. Results from other laboratories indicate that this problem will soon be overcome. A computer analysis of the double cascade all in silicon shows that efficiencies can be raised over that of any single silicon cell by 1 or 2%, and that open circuit voltage of almost twice that of a single cell should be possible.

Not Available

1984-01-01T23:59:59.000Z

92

High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water  

SciTech Connect

The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector entities. The photoelectrochemical hydrogen task included formal collaborations with three universities and one national laboratory. The formal participants in these two tasks are listed above. Informal collaborations in both projects included one additional university (the University of Nevada, Reno) and two additional national laboratories (Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory).

Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

2011-09-29T23:59:59.000Z

93

III-V-N materials for super high-efficiency multijunction solar cells  

Science Conference Proceedings (OSTI)

We have been studying concentrator multi-junction solar cells under Japanese Innovative Photovoltaic R and D program since FY2008. InGaAsN is one of appropriate materials for 4-or 5-junction solar cell configuration because this material can be lattice-matched to GaAs and Ge substrates. However, present InGaAsN single-junction solar cells have been inefficient because of low minority-carrier lifetime due to N-related recombination centers and low carrier mobility due to alloy scattering and non-homogeneity of N. This paper presents our major results in the understanding of majority and minority carrier traps in GaAsN grown by chemical beam epitaxy and their relationships with the poor electrical properties of the materials.

Yamaguchi, Masafumi; Bouzazi, Boussairi; Suzuki, Hidetoshi; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio [Toyota Technological Institute, Nagoya 468-8511 (Japan)

2012-10-06T23:59:59.000Z

94

Development of high, stable-efficiency triple-junction a-Si alloy solar cells. Final technical report  

DOE Green Energy (OSTI)

This report summarizes Energy Conversion Devices, Inc.`s (ECD) research under this program. ECD researchers explored the deposition of a-Si at high rates using very-high-frequency plasma MHz, and compared these VHF i-layers with radio-frequency (RF) plasma-deposited i-layers. ECD conducted comprehensive research to develop a {mu}c-Si p{sup +} layer using VHF deposition process with the objectives of establishing a wider process window for the deposition of high-quality p{sup +} materials and further enhancing their performance of a-Si solar cells by improving its p-layers. ECD optimized the deposition of the intrinsic a-Si layer and the boron-doped {mu}c-Si p{sup +} layer to improve the V{sub oc}. Researchers deposited wide-bandgap a-Si films using high hydrogen dilution; investigated the deposition of the ZnO layer (for use in back-reflector) using a sputter deposition process involving metal Zn targets; and obtained a baseline fabrication for single-junction a-Si n-i-p devices with 10.6% initial efficiency and a baseline fabrication for triple-junction a-Si devices with 11.2% initial efficiency. ECD researchers also optimized the deposition parameters for a-SiGe with high Ge content; designed a novel structure for the p-n tunnel junction (recombination layer) in a multiple-junction solar cell; and demonstrated, in n-i-p solar cells, the improved stability of a-Si:H:F materials when deposited using a new fluorine precursor. Researchers investigated the use of c-Si(n{sup +})/a-Si alloy/Pd Schottky barrier device as a tool for the effective evaluation of photovoltaic performance on a-Si alloy materials. Through alterations in the deposition conditions and system hardware, researchers improved their understanding for the deposition of uniform and high-quality a-Si and a-SiGe films over large areas. ECD researchers also performed extensive research to optimize the deposition process of the newly constructed 5-MW back-reflector deposition machine.

Deng, X.; Jones, S.J.; Liu, T.; Izu, M. [Energy Conversion Devices, Inc., Troy, MI (United States)

1998-04-01T23:59:59.000Z

95

Ultra High Efficiency Thermo-Photovoltaic Solar Cells Using Metallic Photonic Crystals As Intermediate Absorber and Emitter  

E-Print Network (OSTI)

, a material with a high melting point, since many solar thermal applications, especially solar thermal photovolatics,6,7 require absorbers that can withstand high temperatures. While there is significant amount-difference time-domain method.15 To describe the effect of material dispersion and absorption in the time

Nur, Amos

96

Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells: Annual subcontract report, May 1985 - Jul 1986  

DOE Green Energy (OSTI)

A study was undertaken of the optoelectronic properties of amorphous silicon-hydrogen thin films deposited from disilane at high deposition rates. The information derived from this study was used to fabricate amorphous silicon solar cells with efficiencies exceeding 7%. The intrinsic layer of these solar cells was deposited at 15 angstroms/second. Material properties investigated included dark conductivity, photoconductivity, minority carrier diffusion length, and density of states. The solar cells properties characterized were absolute quantum yield and simulated global AM 1.5 efficiencies. Investigations were undertaken utilizing optical and infrared spectroscopy to optimize the microstructures of the intrinsic amorphous silicon. That work was sponsored by the New York State Energy Research and Development Authority. The information was used to optimize the intrinsic layer of amorphous silicon solar cells, resulting in AM 1.5 efficiencies exceeding 7%.

Wiesmann, H.; Dolan, J.; Fricano, G.; Danginis, V.

1987-02-01T23:59:59.000Z

97

Research on the basic understanding of high efficiency in silicon solar cells. Annual report, 1 December 1982-30 November 1983  

DOE Green Energy (OSTI)

This report presents results of research designed to develop a basic understanding of high-efficiency silicon solar cells and achieve cell efficiencies greater than 17% by employing innovative concepts of material preparation, cell design, and fabrication technology. The research program consisted of a theoretical effort to develop models for very high-efficiency cell designs, experimental verification of the designs, and improved understanding of efficiency-limiting mechanisms such as heavy doping effects and bulk and surface recombination. Research was performed on high-lifetime float-zone silicon, the baseline materials, low-resistivity gallium-doped czochralski silicon, and boron-doped float-zone silicon.

Rohatgi, A.; Rai-Choudhury, P.

1984-09-01T23:59:59.000Z

98

Development of high, stable-efficiency triple-junction a-Si alloy solar cells. Annual technical progress report, October 1995--October 1996  

DOE Green Energy (OSTI)

The overall objective of this amorphous silicon research program is to develop high efficiency a-Si solar cells and to develop and improve processes for large area deposition of a-Si solar cells and modules. The knowledge obtained and technologies demonstrated in this program will be incorporated into ECD`s continuous roll-to-roll deposition process to further enhance its photovoltaic manufacturing technology.

Deng, X.; Izu, M.; Jones, S.J.; Kopf, R. [Energy Conversion Devices, Troy, MI (United States)] [and others

1997-04-01T23:59:59.000Z

99

High Efficiency Organic Solar Cells: December 16, 2009 - February 2, 2011  

DOE Green Energy (OSTI)

Details on the development of novel organic solar cells incorporating Trimetasphere based acceptors are presented including: baseline performance for Lu-PCBEH acceptor blended with P3HT demonstrated at 4.89% PCE exceeding the 4.5% PCE goal; an increase of over 250mV in Voc was demonstrated for Lu-PCBEH blended with low band gap polymers compared to a comparable C60-PCBM device. The actual Voc was certified at 260mV higher for a low band gap polymer device using the Lu-PCBEH acceptor; and the majority of the effort was focused on development of a device with over 7% PCE. While low current and fill factors suppressed overall device performance for the low band gap polymers tested, significant discoveries were made that point the way for future development of these novel acceptor materials.

Walker, K.; Joslin, S.

2011-05-01T23:59:59.000Z

100

Development of high-efficiency solar cells on silicon web. First quarterly progress report, April 20-July 15, 1984  

DOE Green Energy (OSTI)

The major objective of the work reported is to improve web base material with a goal toward obtaining solar cell efficiencies in excess of 18% (AM1). The program consists of the investigation of carrier loss mechanisms in web silicon, development of techniques to reduce carrier recombination in web, and web cell fabrication using effective surface passivation. Web surfaces have been bevelled with the intention of measuring the electrical activity of the twin plane. Web crystals have been intentionally contaminated with vanadium and titanium to examine the twin-plane-assisted internal gettering by DLTS. Model calculations were done to see the effect of twin-plane activity on V/sub oc/ as a function of resistivity of the web material. Experiments were initiated to study the effect of heat treatment and gettering on the minority carrier diffusion length in webs. Fabrication of high-efficiency web cells using several web crystals was initiated. These cells will include surface passivation and double-layer antireflection coating. (LEW)

Rohatgi, A.; Meier, D.L.; Campbell, R.B.; Rai-Choudhury, P.

1984-08-09T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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101

Plasma analysis and diagnostics for high efficiency amorphous solar cell production. Final report  

DOE Green Energy (OSTI)

This is a project that sought to improve the amorphous silicon-germanium (SiGe) thin film deposition process in the production of solar cells. To accomplish this, the electron cyclotron resonance (ECR) plasma discharge, employed for the thin film deposition, was modified. Changes in the parameters of the plasma were monitored with diagnostic techniques, similar to those used in fusion plasma studies. That was the primary contribution from ORNL. Only one phase was contained in the statement of work, with the following tasks: (1) Develop a detailed program for plasma characterization. (2) Carry-out plasma modeling and analysis to support deposition systems design. (3) Operate experimental deposition systems for the purpose of plasma characterization. (4) Analyze data. (5) Modify deposition as directed by measurements. (6) This final report, which was deemed to be the only deliverable of this small project. And while the modified ECR discharge did not show measurable improvement of the conditions relevant to the deposition process, much was learned about the plasma parameters in the process. Some ideas on alternative designs are being discuss and funding options for testing such designed are being sought.

Klepper, C.C.

1994-12-21T23:59:59.000Z

102

Development of high stable-efficiency, triple-junction a-Si alloy solar cells. Annual subcontract report, July 18, 1994--July 17, 1995  

DOE Green Energy (OSTI)

This report describes work performed by Energy Conversion Devices, Inc. (ECD) under a 3-year, cost-shared amorphous silicon (a-Si) research program to develop advanced technologies and to demonstrate stable 14%-efficient, triple-junction a-Si alloy solar cells. The technologies developed under the program will then be incorporated into ECD`s continuous roll-to-roll deposition process to further enhance ECD`s photovoltaic manufacturing technology. In ECD`s solar cell design, triple-junction a-Si alloy solar cells are deposited onto stainless-steel substrates coated with Ag/ZnO back-reflector layers. This type of cell design enabled ECD to use a continuous roll- to-roll deposition process to manufacture a-Si PV materials in high volume at low cost. Using this cell design, ECD previously achieved 13.7% initial solar cell efficiency using the following features: (1) a triple-junction, two-band-gap, spectrum-splitting solar cell design; (2) a microcrystalline silicon p-layer; (3) a band-gap-profiled a- SiGe alloy as the bottom cell i-layer; (4) a high-performance AgZnO back-reflector; and (5) a high-performance tunnel junction between component cells. ECD also applied the technology into its 2-MW/yr a- Si production line and achieved the manufacturing of 4-ft{sup 2} PV modules with 8% stable efficiency. During this program, ECD is also further advancing its existing PV technology toward the goal of 14% stable solar cells by performing the following four tasks: (1) improving the stability of the intrinsic a-Si alloy materials; (2) improving the quality of low-band-gap a-SiGe alloy; (3) improving p{sup +} window layers, and (4) developing high stable-efficiency triple-junction a-Si alloy solar cells.

Deng, X. [Energy Conversion Devices, Inc., Troy, MI (United States)

1996-02-01T23:59:59.000Z

103

High efficiency cadmium and zinc telluride-based thin film solar cells  

DOE Green Energy (OSTI)

Polycrystalline Cd{sub 1-x}Zn{sub x}Te and Cd{sub 1-x}Mn{sub x}Te films with a band gap of 1.7 eV were successfully grown on glass/SnO{sub 2}/CdS substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), respectively. Polycrystalline Cd{sub 1-x}Zn{sub x}Te films grown by MBE resulted in uniform composition and sharp interfaces. However, polycrystalline Cd{sub 1-x}Mn{sub x}Te films grown by MOCVD showed nonuniform compositions and evidence of manganese accumulation at the Cd{sub 1-x}Mn{sub x}Te/CdS interface. We found that manganese interdiffuses and replaces cadmium in the CdS film. By improving the CdTe/CdS interface and, thus, reducing the collection function effects, the efficiency of the MOCVD CdTe cell can be improved to about 13.5%. MBE-grown CdTe cells also produced 8%--9% efficiencies. The standard CdTe process was not optimum for ternary films and resulted in a decrease in the band gap. Recent results indicate that CdCl{sub 2} + ZnCl{sub 2} chemical treatment may prevent the band-gap reduction, and that chromate etch (rather than bromine etch) may provide the solution to contact resistance in the ternary cells.

Rohatgi, A.; Summers, C.J.; Erbil, A.; Sudharsanan, R.; Ringel, S. (Georgia Inst. of Tech., Atlanta, GA (USA). School of Electrical Engineering)

1990-10-01T23:59:59.000Z

104

High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges; Preprint  

DOE Green Energy (OSTI)

Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

Noufi, R.; Zweibel, K.

2006-05-01T23:59:59.000Z

105

New concepts for high efficiency energy conversion: The avalanche heterostructure and superlattice solar cells. Subcontract report, 1 June 1987--31 January 1990  

DOE Green Energy (OSTI)

This report describes investigation into the theory and technology of a novel heterojunction or superlattice, single-junction solar cell, which injects electrons across the heterointerface to produce highly efficient impact ionization of carriers in the lowband-gap side of the junction, thereby conserving their total energy. Also, the superlattice structure has the advantage of relaxing the need for perfect lattice matching at the p-n interface and will inhibit the cross diffusion of dopant atoms that typically occurs in heavy doping. This structure avoids the use of tunnel junctions that make it very difficult to achieve the predicted efficiencies in cascade cells, thus making it possible to obtain energy efficiencies that are competitive with those predicted for cascade solar cells with reduced complexity and cost. This cell structure could also be incorporated into other solar cell structures designed for wider spectral coverage.

Summers, C.J.; Rohatgi, A.; Torabi, A.; Harris, H.M. [Georgia Tech Research Inst., Atlanta, GA (United States)

1993-01-01T23:59:59.000Z

106

Current-matched, high-efficiency, multi-junction monolithic solar cells  

DOE Patents (OSTI)

In this invention, the efficiency of a two-junction (cascade) tandem photovoltaic device is improved by adjusting (decreasing) the top cell thickness to achieve current matching. An example of the invention was fabricated out of Ga{sub 0.52}In{sub 0.48}P and GaAs. Additional lattice-matched systems to which the invention pertains include Al{sub x}Ga{sub l-x}/GaAs (x=0.3 {minus} 0.4), GaAs/Ge and Ga{sub y}In{sub 1-y}P/Ga{sub y+0.5}In{sub 0.5-{sub Y}} As (O

Olson, J.M.; Kurtz, S.R.

1991-02-11T23:59:59.000Z

107

High-Efficiency Neutron Detection and Spectroscopy  

Science Conference Proceedings (OSTI)

High-Efficiency Neutron Detection and Spectroscopy. ... such as searches for WIMP dark matter, neutrinoless double beta decay, and solar neutrinos. ...

2013-07-22T23:59:59.000Z

108

InGaAsN: A Novel Material for High-Efficiency Solar Cells and Advanced Photonic Devices  

DOE Green Energy (OSTI)

This report represents the completion of a 6 month Laboratory-Directed Research and Development (LDRD) program that focused on research and development of novel compound semiconductor, InGaAsN. This project seeks to rapidly assess the potential of InGaAsN for improved high-efficiency photovoltaic. Due to the short time scale, the project focused on quickly investigating the range of attainable compositions and bandgaps while identifying possible material limitations for photovoltaic devices. InGaAsN is a new semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the bandgap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low temperature photoluminescence energy of the material for pressures between ambient and 110 kbar. We describe a simple, density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low concentration alloys. The theoretically predicted pressure dependence of the bandgap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for the strongly non-linear pressure dependence of the bandgap that, surprisingly, does not involve a nitrogen impurity band. Additionally, conduction-band mass measurements, measured by three different techniques, will be described and finally, the magnetoluminescence determined pressure coefficient for the conduction-band mass is measured. The design, growth by metal-organic chemical vapor deposition, and processing of an In{sub 0.07}Ga{sub 0.93}As{sub 0.98}N{sub 0.02} solar cell, with 1.0 eV bandgap, lattice matched to GaAs is described. The hole diffusion length in annealed, n-type InGaAsN is 0.6-0.8 pm, and solar cell internal quantum efficiencies >70% are obtained. Optical studies indicate that defects or impurities, from doping and nitrogen incorporation, limit cell performance.

Allerman, Andrew A.; Follstaedt, David M.; Gee, James M.; Jones, Eric D.; Kurtz, Steven R.; Modine, Norman A.

1999-07-01T23:59:59.000Z

109

High Efficiency Thin Film CdTe and a-Si Based Solar Cells: Final Technical Report, 4 March 1998--15 October 2001  

DOE Green Energy (OSTI)

This is the final report covering about 42 months of this subcontract for research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Phases I and II have been extensively covered in two Annual Reports. For this Final Report, highlights of the first two Phases will be provided and then detail will be given on the last year and a half of Phase III. The effort on CdTe-based materials is led by Prof. Compaan and emphasizes the use of sputter deposition of the semiconductor layers in the fabrication of CdS/CdTe cells. The effort on high-efficiency a-Si materials is led by Prof. Deng and emphasizes plasma-enhanced chemical vapor deposition for cell fabrication with major efforts on triple-junction devices.

Compaan, A. D.; Deng, X.; Bohn, R. G.

2003-10-01T23:59:59.000Z

110

The Growth of InGaAsN for High Efficiency Solar Cells by Metalorganic Chemical Vapor Deposition  

SciTech Connect

InGaAsN alloys are a promising material for increasing the efficiency of multi-junction solar cells now used for satellite power systems. However, the growth of these dilute N containing alloys has been challenging with further improvements in material quality needed before the solar cell higher efficiencies are realized. Nitrogen/V ratios exceeding 0.981 resulted in lower N incorporation and poor surface morphologies. The growth rate was found to depend on not only the total group III transport for a fixed N/V ratio but also on the N/V ratio. Carbon tetrachloride and dimethylzinc were effective for p-type doping. Disilane was not an effective n-type dopant while SiCl4 did result in n-type material but only a narrow range of electron concentrations (2-5e17cm{sup -3}) were achieved.

ALLERMAN,ANDREW A.; BANKS,JAMES C.; GEE,JAMES M.; JONES,ERIC D.; KURTZ,STEVEN R.

1999-09-16T23:59:59.000Z

111

High efficiency low cost thin film silicon solar cell design and method for making  

DOE Patents (OSTI)

A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer.

Sopori, Bhushan L. (Denver, CO)

1999-01-01T23:59:59.000Z

112

High efficiency, low cost, thin film silicon solar cell design and method for making  

DOE Patents (OSTI)

A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer.

Sopori, Bhushan L. (Denver, CO)

2001-01-01T23:59:59.000Z

113

High efficiency low cost thin film silicon solar cell design and method for making  

DOE Patents (OSTI)

A semiconductor device is described having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer. 9 figs.

Sopori, B.L.

1999-04-27T23:59:59.000Z

114

High-Efficiency Amorphous Silicon Alloy Based Solar Cells and Modules; Final Technical Progress Report, 30 May 2002--31 May 2005  

DOE Green Energy (OSTI)

The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low manufacturing cost and high reliability. Our strategy has been to use the spectrum-splitting triple-junction structure, a-Si:H/a-SiGe:H/a-SiGe:H, to improve solar cell and module efficiency, stability, and throughput of production. The methodology used to achieve the objectives included: (1) explore the highest stable efficiency using the triple-junction structure deposited using RF glow discharge at a low rate, (2) fabricate the devices at a high deposition rate for high throughput and low cost, and (3) develop an optimized recipe using the R&D batch large-area reactor to help the design and optimization of the roll-to-roll production machines. For short-term goals, we have worked on the improvement of a-Si:H and a-SiGe:H alloy solar cells. a-Si:H and a-SiGe:H are the foundation of current a-Si:H based thin-film photovoltaic technology. Any improvement in cell efficiency, throughput, and cost reduction will immediately improve operation efficiency of our manufacturing plant, allowing us to further expand our production capacity.

Guha, S.; Yang, J.

2005-10-01T23:59:59.000Z

115

Highly Efficient 32.3% Monolithic GaInP/GaAs/Ge Triple Junction Concentrator Solar Cells  

DOE Green Energy (OSTI)

Based on recent cell improvements for space applications, multijunction cells apear to be ideal candidates for high efficiency, cost effective, PV concentrator systems.

Cotal, H. L.; Lillington, D. R.; Ermer, J. H.; King, R. R.; Karam, N. H.; Kurtz, S. R.; Friedman, D. J.; Olson, J. M.; Ward, S.; Duda, A.; Emery, K. A.; Moriarty, T.

2000-01-01T23:59:59.000Z

116

Efficient Polymer Solar Cells - Energy Innovation Portal  

Ames Laboratory researchers have developed a process for producing more efficient polymer solar cells by increasing light absorption through a thin ...

117

"Approaches to Ultrahigh Efficiency Solar Energy Conversion"...  

Office of Science (SC) Website

"Approaches to Ultrahigh Efficiency Solar Energy Conversion" Webinar Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights News & Events EFRC News...

118

High-Efficiency Amorphous Silicon and Nanocrystalline Silicon Based Solar Cells and Modules: Annual Technical Progress Report, 30 January 2006 - 29 January 29, 2007  

DOE Green Energy (OSTI)

United Solar used a-Si:H/a-SiGe:H/a-SiGe:H in two manufacturing plants and improved solar efficiency and reduced manufacturing cost by new deposition methods, optimized deposition parameters, and new materials and cell structures.

Guha, S.; Yang, J.

2007-07-01T23:59:59.000Z

119

High Throughput, Low Toxic Processing of Very Thin, High Efficiency CIGSS Solar Cells: Final Report, December 2008  

DOE Green Energy (OSTI)

The work carried out during this project presents the use of diethylselenium or other organometallic precursors as low-toxicity alternative selenium sources for preparing a high-quality absorber.

Dhere, N. G.

2009-04-01T23:59:59.000Z

120

High external quantum efficiency and fill-factor InGaN/GaN heterojunction solar cells grown by NH{sub 3}-based molecular beam epitaxy  

SciTech Connect

High external quantum efficiency (EQE) p-i-n heterojunction solar cells grown by NH{sub 3}-based molecular beam epitaxy are presented. EQE values including optical losses are greater than 50% with fill-factors over 72% when illuminated with a 1 sun AM0 spectrum. Optical absorption measurements in conjunction with EQE measurements indicate an internal quantum efficiency greater than 90% for the InGaN absorbing layer. By adjusting the thickness of the top p-type GaN window contact layer, it is shown that the short-wavelength (<365 nm) quantum efficiency is limited by the minority carrier diffusion length in highly Mg-doped p-GaN.

Lang, J. R.; Hurni, C. A.; Cruz, S. C.; Matioli, E.; Speck, J. S. [Department of Materials, University of California, Santa Barbara, California 93106 (United States); Neufeld, C. J.; Mishra, U. K. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

2011-03-28T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Advanced high efficiency concentrator cells  

DOE Green Energy (OSTI)

This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

Gale, R. (Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center)

1992-06-01T23:59:59.000Z

122

Efficiency of luminescence in luminescent solar concentrators  

Science Conference Proceedings (OSTI)

The power effiency of luminescence excited by solar radiation in luminescent solar collectors is calculated for a glass sheet doped with CR/sup 3 +/. The achievable chemical potential for an optically thick absorber irradiated by diluted blackbody radiation as a function of Cr/sup 3 +/ concentration, sheet thickness, sunlight dilution, and luminescence quantum yield leads directly to overall conversion efficiency of solar power to luminescence power.

Lempicki, A.

1983-04-15T23:59:59.000Z

123

Nanofluid-based receivers for high-temperature, high-flux direct solar collectors  

E-Print Network (OSTI)

Solar power plants with surface receivers have low overall energy conversion efficiencies due to large emissive losses at high temperatures. Alternatively, volumetric receivers promise increased performance because solar ...

Lenert, Andrej

2010-01-01T23:59:59.000Z

124

Solar Cell Efficiency Tables (Version 39)  

Science Conference Proceedings (OSTI)

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since July 2011 are reviewed.

Green, M. A.; Emery, K.; Hishikawa, Y.; Warta, W.; Dunlop, E. D.

2012-01-01T23:59:59.000Z

125

Theoretical efficiency of solar thermoelectric energy generators  

E-Print Network (OSTI)

This paper investigates the theoretical efficiency of solar thermoelectric generators (STEGs). A model is established including thermal concentration in addition to optical concentration. Based on the model, the maximum ...

Chen, Gang

126

Process for Fabrication of Efficient Solar Cells - Energy ...  

Ames Laboratory researchers have developed a process for fabrication of solar cells with increased efficiency.

127

Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells: Phase II annual subcontract report, 1 January 1985--31 January 1986  

DOE Green Energy (OSTI)

This report presents results of the second phase of research on high-efficiency, single-junction, monolithic, thin-film a-Si solar cells. Five glow-discharge deposition systems, including a new in-line, multichamber system, were used to grow both doped and undoped a-Si:H. A large number of silane and disilane gas cylinders were analyzed with a gas chromatography/mass spectroscopy system. Strong correlations were found between the breakdown voltage, the deposition rate, the diffusion length, and the conversion efficiency for varying cathode-anode separations in a DC glow-discharge deposition mode. Tin oxide films were grown by chemical vapor deposition with either tetramethyl tin (TMT) or tin tetrachloride (TTC). The best were grown with TMT, but TTC films had a more controlled texture for light trapping and provided a better contact to the p-layer. The best results were obtained with 7059 glass substrates. Efficiencies as high as 10.86% were obtained in p-i-n cells with superlattice p-layers and as high as 10.74% in cells with both superlattice p- and n-layers. Measurements showed that the boron-doping level in the p-layer can strongly affect transport in the i-layer, which can be minimized by reactive flushing before i-layer deposition. Stability of a-Si:H cells is improved by light doping. 51 refs., 64 figs., 21 tabs.

Carlson, D.E.; Ayra, R.R.; Bennett, M.S.; Catalano, A.; D'Aiello, R.V.; Dickson, C.R.; McVeigh, J.; Newton, J.; O'Dowd, J.; Oswald, R.S.; Rajan, K.

1988-09-01T23:59:59.000Z

128

Preparation of copper-indium-gallium-diselenide precursor films by electrodeposition for fabricating high efficiency solar cells  

DOE Patents (OSTI)

A photovoltaic cell exhibiting an overall conversion efficiency of 13.6% is prepared from a copper-indium-gallium-diselenide precursor thin film. The film is fabricated by first simultaneously electrodepositing copper, indium, gallium, and selenium onto a glass/molybdenum substrate (12/14). The electrodeposition voltage is a high frequency AC voltage superimposed upon a DC voltage to improve the morphology and growth rate of the film. The electrodeposition is followed by physical vapor deposition to adjust the final stoichiometry of the thin film to approximately Cu(In.sub.1-n Ga.sub.x)Se.sub.2, with the ratio of Ga/(In+Ga) being approximately 0.39.

Bhattacharya, Raghu N. (Littleton, CO); Hasoon, Falah S. (Arvada, CO); Wiesner, Holm (Golden, CO); Keane, James (Lakewood, CO); Noufi, Rommel (Golden, CO); Ramanathan, Kannan (Golden, CO)

1999-02-16T23:59:59.000Z

129

High-efficiency cadmium and zinc-telluride-based thin-film solar cells. Annual subcontract report, 1 March 1990--28 February 1991  

DOE Green Energy (OSTI)

This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.

Rohatgi, A.; Sudharsanan, R.; Ringel, S. [Georgia Inst. of Tech., Atlanta, GA (United States)

1992-02-01T23:59:59.000Z

130

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic...

131

Titania Coated Silica Microspheres for High Efficiency Dye ...  

Science Conference Proceedings (OSTI)

These microspheres, if used in DSSCs, can boost the efficiency of solar cell ... In- situ Characterization of Intercalation-induced Damage of High Purity Graphite ...

132

Boiler efficiency methodology for solar heat applications  

DOE Green Energy (OSTI)

This report contains a summary of boiler efficiency measurements which can be applied to evaluate the performance of steam-generating boilers via both the direct and indirect methods. This methodology was written to assist industries in calculating the boiler efficiency for determining the applicability and value of thermal industrial heat, as part of the efforts of the Solar Thermal Design Assistance Center (STDAC) funded by Sandia National Laboratories. Tables of combustion efficiencies are enclosed as functions of stack temperatures and the amount of carbon dioxide and carbon monoxide in the gas stream.

Maples, D.; Conwell, J.C. [Louisiana State Univ., Baton Rouge, LA (United States). Boiler Efficiency Inst.; Pacheco, J.E. [Sandia National Labs., Albuquerque, NM (United States)

1992-08-01T23:59:59.000Z

133

Development of high-efficiency, thin-film CdTe solar cells. Annual subcontract report, January 1, 1993--December 31, 1993  

DOE Green Energy (OSTI)

Polycrystalline thin film CdTe solar cells are one of the leading candidates for terrestrial photovoltaic applications. Theoretical calculations project an efficiency of 27% for single crystal, single junction CdTe cells, and the practically achievable efficiency for polycrystalline CdTe cells is 18-20%. Polycrystalline CdTe cells made by different groups show a significant variation in short circuit currents, open circuit voltages, and cell efficiencies. A better understanding of carrier loss and transport mechanism is crucial for explaining these differences, improving the yield, and bridging the gap between current and practically achievable limits in CdTe cell efficiencies. The goal of this program is to improve the understanding of the loss mechanisms in thin film CdS/CdTe solar cells and to improve their efficiency by characterizing the properties of the films as well as the finished devices.

Rohatgi, A.; Chou, H.C.; Kamra, S.; Bhat, A. [Georgia Institute of Technology, Atlanta, GA (United States)

1994-09-01T23:59:59.000Z

134

Growth and development of GaInAsP for use in high-efficiency solar cells. Final subcontract report, 1 July 1991--30 December 1993  

DOE Green Energy (OSTI)

This report describes accomplishments during Phase 3 of this subcontract. The overall goals of the subcontract were (1) to develop the necessary technology to grow high-efficiency GaInAsP layers that are lattice-matched to GaAs and Ge; (2) to demonstrate highefficiency GaInAsP single-junction solar cells; and (3) to demonstrate GaInAsP/Ge cascade solar cells suitable for operation under concentrated (500X) sunlight. The major accomplishments during Phase 3 include (1) demonstrating a GaInAsP tunnel diode for use as an interconnect in the GaInAsP/Ge cascade cell, and (2) demonstrating a GaInAsP/Ge cascade cell. The development of the GaInAsP tunnel diode is a major accomplishment because it allows for the GaInAsP and Ge cells to be connected without optical losses for the bottom Ge cell, such as a Ge tunnel diode would cause. The GaInAsP/Ge cascade cell development is significant because of the demonstration of a cascade cell with a new materials system.

Sharps, P.R. [Research Triangle Inst., Research Triangle Park, NC (United States)

1994-10-01T23:59:59.000Z

135

High-Efficiency Solar Cells for Large-Scale Electricity Generation & Design Considerations for the Related Optics (Presentation)  

SciTech Connect

The photovoltaic industry has been growing exponentially at an average rate of about 35%/year since 1979. Recently, multijunction concentrator cell efficiencies have surpassed 40%. Combined with concentrating optics, these can be used for electricity generation.

Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A.; Wanlass, M.k; Kibbler, A.; Kramer, C.; Ward, S.; Duda, A.; Young, M.; Carapella, J.

2007-09-17T23:59:59.000Z

136

Liquid Metal, a Heat Transport Fluid for High Temperature Solar ...  

Science Conference Proceedings (OSTI)

The need for high efficiency and direct heat conversion into hydrogen, process heat and energy storage pushes the temperature for solar concentrator systems.

137

High Efficiency, Clean Combustion  

DOE Green Energy (OSTI)

Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high-efficiency clean combustion (HECC) technologies. To demonstrate the technology is compatible with B2

Donald Stanton

2010-03-31T23:59:59.000Z

138

Growth and development of GaInAsP for use in high-efficiency solar cells  

DOE Green Energy (OSTI)

This report describes work done during Phase II of the subcontract. Goals for Phase II include the following: (1) Optimize the GaInAsP cell on GaAs and demonstrate a 500-sun at air mass (AM) 1.5 efficiency of >23%. (2) Develop a window layer, including the evaluation of AlGaAs, GaInP, AlGaAsP, AlGaInP, and GaP. (3) Develop a front-surface contact, with a grid designed for 500-sun concentration, and a goal of a contact resistivity of [approximately]10[sup 5] ohm-cm[sup 2]. (4) Grow GaInAsP cells on Ge, with a goal of a 1-sun (AM 1.5) efficiency of >15%. Accomplishments reported herein include (1) the fabrication of p-on-n and n-on-p GaInAsP cells on GaAs, with the n-on-p cell demonstrating a 10-sun (AM 1.5) active-area efficiency of 23.4% as measured at NREL (2) the evaluation of Al[sub x]Ga([sub 1-x])As, GaInP[sub 2], and AlInP[sub 2] window layers; and (3) the fabrication of GaInAsP cells on Ge, with the demonstration of a p-on-n GaInAsP cell grown on Ge with a 1-sun (AM 1.5) active-area efficiency of 14.4%.

Sharps, P.R. (Research Triangle Inst., Research Triangle Park, NC (United States))

1993-04-01T23:59:59.000Z

139

EERE Roofus' Solar and Efficient Home: More Search Options  

NLE Websites -- All DOE Office Websites (Extended Search)

More Search Options Roofus' Solar and Efficient Home Site Search Search EERE Kids Site Search Search Energy Efficiency and Renewable Energy Site Search Search Search Help Printable...

140

Low temperature metal-organic chemical vapor deposition growth processes for high-efficiency solar cells. Final technical report, 1 September 1985--30 November 1989  

DOE Green Energy (OSTI)

This report describes the results of a program to develop a more complete understanding of the physical and chemical processes involved in low-temperature growth of III-V compounds by metal-organic chemical vapor deposition (MOCVD) and to develop a low-temperature process that is suitable for the growth of high-efficiency solar cells. The program was structured to develop a better understanding of the chemical reactions involved in MOCVD growth, to develop a model of the processes occurring in the gas phase, to understand the physical kinetics and reactions operative on the surface of the growing crystal, and to develop an understanding of the means by which these processes may be altered to reduce the temperature of growth and the utilization of toxic hydrides. The basic approach was to develop the required information about the chemical and physical kinetics operative in the gas phase and on the surface by the direct physical measurement of the processes whenever possible. The program included five tasks: (1) MOCVD growth process characterization, (2) photoenhanced MOCVD studies, (3) materials characterization, (4) device fabrication and characterization, and (5) photovoltaic training. Most of the goals of the program were met and significant progress was made in defining an approach that would allow both high throughput and high uniformity growth of compound semiconductors at low temperatures. The technical activity was focused on determining the rates of thermal decomposition of trimethyl gallium, exploring alternate arsenic sources for use MOCVD, and empirical studies of atomic layer epitaxy as an approach.

Dapkus, P.D. [University of Southern California, Los Angeles, CA (United States)

1993-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

On second-law efficiency of solar collectors  

SciTech Connect

Traditionally, the performance of solar collectors has been examined from the standpoint of energy-balance approach (Hahne, 1985; Francy et al., 1985; Lund, 1985; Satyamurty, 1985; Proctor, 1984a; Proctor; 1984b; Proctor, 1984c). It is important to note that this approach gives a very poor indication of how well a particular energy resource is being utilized by a given system to accomplish a specific objective. For example, it is difficult to examine the performance of solar thermal collectors versus solar-photovoltaic panels, strictly based on the first law of thermodynamics. A photovoltaic panel having ten percent first-law efficiency may be better than a solar collector converting 50 percent of useful energy by raising the water temperature from 30 to 50 C. Thus, it has been necessary to resort to the second law of thermodynamics for evaluation of solar systems, particularly collection devices. The second-law efficiency addresses the quality of energy. The quality of energy may be defined as its available portion; that portion which may be used for producing shaft work. It is important to note that the energy be conserved, but the manner in which energy is used must be examined. To use high quality energy for low-quality energy tasks is wasteful. This type of indication can only be examined from the second-law point of view. In this paper, measurements obtained from an experimental solar collector test facility are presented. Analysis of the performance of two flat-plate thermal solar collectors and one photovoltaic panel are analyzed based on both the first and second law of thermodynamics. The measurements presented, indicate very low second-law efficiency (maximum of 17 percent for photovoltaic panel and 11 percent for solar thermal flat-plate collectors), but are merely used as a vehicle for discussion.

Said, S.A.M.; Zubair, S.M. (King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia))

1993-02-01T23:59:59.000Z

142

Development of high-efficiency, thin-film CdTe solar cells. Final subcontract report, 1 February 1992--30 November 1995  

DOE Green Energy (OSTI)

This report describes work performed by the Georgia Institute of Technology (GIT) to bring the polycrystalline CdTe cell efficiency a step closer to the practically achievable efficiency of 18% through fundamental understanding of detects and loss mechanisms, the role of chemical and heat treatments, and investigation of now process techniques. The objective was addressed by a combination of in-depth characterization, modeling, materials growth, device fabrication, and `transport analyses of Au/Cu/CdTe/CdS/SnO {sub 2} glass front-wall heterojunction solar cells. GiT attempted to understand the loss mechanism(s) in each layer and interface by a step-by-step investigation of this multilayer cell structure. The first step was to understand, quantify, and reduce the reflectance and photocurrent loss in polycrystalline CdTe solar calls. The second step involved the investigation of detects and loss mechanisms associated with the CdTe layer and the CdTe/CdS interface. The third stop was to investigate the effect of chemical and heat treatments on CdTe films and cells. The fourth step was to achieve a better and reliable contact to CdTe solar cells by improving the fundamental understanding. Of the effects of Cu on cell efficiency. Finally, the research involved the investigation of the effect of crystallinity and grain boundaries on Cu incorporation in the CdTe films, including the fabrication of CdTe solar calls with larger CdTe grain size.

Rohatgi, A.; Chou, H.C.; Kamra, S.; Bhat, A. [Georgia Inst. of Tech., Atlanta, GA (United States)

1996-01-01T23:59:59.000Z

143

Manufacturing of High-Efficiency Bi-Facial Tandem Concentrator Solar Cells: February 20, 2009--August 20, 2010  

DOE Green Energy (OSTI)

Spire Semiconductor made concentrator photovoltaic (CPV) cells using a new bi-facial growth process and met both main program goals: a) 42.5% efficiency 500X (AM1.5D, 25C, 100mW/cm2); and b) Ready to supply at least 3MW/year of such cells at end of program. We explored a unique simple fabrication process to make a N/P 3-junction InGaP/GaAs/InGaAs tandem cells . First, the InGaAs bottom cell is grown on the back of a GaAs wafer. The wafers are then loaded into a cassette, spin-rinsed to remove particles, dipped in dilute NH4OH and spin-dried. The wafers are then removed from the cassette loaded the reactor for GaAs middle and InGaP top cell growth on the opposite wafer face (bi-facial growth). By making the epitaxial growth process a bit more complex, we are able to avoid more complex processing (such as large area wafer bonding or epitaxial liftoff) used in the inverted metamorphic (IMM) approach to make similar tandem stacks. We believe the yield is improved compared to an IMM process. After bi-facial epigrowth, standard III-V cell steps (back metal, photolithography for front grid, cap etch, AR coat, dice) are used in the remainder of the process.

Wojtczuk , S.

2011-06-01T23:59:59.000Z

144

EERE Roofus' Solar and Efficient Home: Appliances  

NLE Websites -- All DOE Office Websites (Extended Search)

Appliances Front-Loading Washing Machine Electric Meter Lights Solar Car Solar Hot Water Solar Panels Walls Windows Activities Printable Version Appliances Illustration of Roofus,...

145

PERFORMANCE ANALYSIS OF A WINDOWED HIGH TEMPERATURE GAS RECEIVER USING A SUSPENSION OF ULTRAFINE CARBON PARTICLES AS THE SOLAR ABSORBER  

E-Print Network (OSTI)

efficiency. INTRODUCTION Recently, there has been renewed interest in windowed high temperature receivers for solar thermal

Fisk, William J.

2012-01-01T23:59:59.000Z

146

High efficiency photoionization detector  

DOE Patents (OSTI)

A high efficiency photoionization detector is described using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 [+-] 0.02 eV, and a vapor pressure of 0.35 torr at 20 C. 6 figs.

Anderson, D.F.

1984-01-31T23:59:59.000Z

147

High efficiency photoionization detector  

DOE Patents (OSTI)

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36.+-.0.02 eV, and a vapor pressure of 0.35 torr at 20.degree. C.

Anderson, David F. (3055 Trinity, Los Alamos, NM 87544)

1984-01-01T23:59:59.000Z

148

High efficiency thin film CdTe solar cells. Second quarterly progress report, June 19-September 18, 1979  

DOE Green Energy (OSTI)

During the second quarter of this program primary emphasis was put into depositing and evaluating both n and p-type CdTe films on a variety of conducting and non-conducting substrates. Improvements in the deposition apparatus permitted preparation of a large number of CdTe films and numerous analytic techniques available at Tufts University were utilized to examine these films. It was found that the introduction of a thin (100 A). In layer between the ITO and the CdTe significantly reduced the previously observed barrier present at the ITO/n-CdTe interface without adversely reducing optical transmission. While the resistivity of the films is still rather high, very recent results show that proper changes in procedure are capable of markedly lowering the resistivity. Preliminary Schottky barrier devices have been made which show promising photovoltaic characteristics.

Serreze, H.B.; Entine, G.; Goldner, R.B.

1979-10-01T23:59:59.000Z

149

Low Cost High Efficiency InP-Based Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-09-344  

DOE Green Energy (OSTI)

NREL will develop a method of growing and fabricating single junction InP solar cells on 2-inch InP substrates on which a release layer has been deposited by MicroLink Devices. NREL will transfer to MicroLink the details of the InP solar cell layer structure and test results in order that the 2-inch results can be replicated on 4-inch InP substrates. NREL will develop a method of growing and fabricating single junction InP solar cells, including a metamorphic layer, on 2-inch GaAs substrates on which a release layer has been deposited by MicroLink Devices. NREL will transfer to MicroLink the details of the InP solar cell layer structure and test results in order that the 2-inch results can be replicated on 6-inch GaAs substrates. NREL will perform characterization measurements of the solar cells, including I-V and quantum efficiency measurements at AM1.5 1-sun.

Wanlass, M.

2012-07-01T23:59:59.000Z

150

Solar Junction | Open Energy Information  

Open Energy Info (EERE)

Junction Jump to: navigation, search Name Solar Junction Place San Jose, California Zip CA 95131 Sector Efficiency, Solar Product Solar Junction is developing high efficiency solar...

151

HIGH EFFICIENCY SYNGAS GENERATION  

DOE Green Energy (OSTI)

This project investigated an efficient and low cost method of auto-thermally reforming natural gas to hydrogen and carbon monoxide. Reforming is the highest cost step in producing products such as methanol and Fisher Tropsch liquids (i.e., gas to liquids); and reducing the cost of reforming is the key to reducing the cost of these products. Steam reforming is expensive because of the high cost of the high nickel alloy reforming tubes (i.e., indirectly fired reforming tubes). Conventional auto-thermal or Partial Oxidation (POX) reforming minimizes the size and cost of the reformers and provides a near optimum mixture of CO and hydrogen. However POX requires pure oxygen, which consumes power and significantly increases the cost to reforming. Our high efficiency process extracts oxygen from low-pressure air with novel oxygen sorbent and transfers the oxygen to a nickel-catalyzed reformer. The syngas is generated at process pressure (typically 20 to 40 bar) without nitrogen dilution and has a 1CO to 2H{sub 2} ratio that is near optimum for the subsequent production of Fisher-Tropsch liquid to liquids and other chemicals (i.e., Gas to Liquids, GTL). Our high process efficiency comes from the way we transfer the oxygen into the reformer. All of the components of the process, except for the oxygen sorbent, are commonly used in commercial practice. A process based on a longlived, regenerable, oxygen transfer sorbent could substantially reduce the cost of natural gas reforming to syngas. Lower cost syngas (CO + 2H{sub 2}) that is the feedstock for GTL would reduce the cost of GTL and for other commercial applications (e.g., methanol, other organic chemicals). The vast gas resources of Alaska's North Slope (ANS) offer more than 22 Tcf of gas and GTL production in this application alone, and could account for as much as 300,000 to 700,000 bpd for 20 to 30+ years. We developed a new sorbent, which is an essential part of the High Efficiency Oxygen Process (HOP). We tested the sorbent and observed that it has both a good oxygen capacity and operates as a highly effective reforming catalyst. We conducted a long duration tests of the sorbent (1,500 hours of continuous operation in the HOP cycle). Although the sorbent lost some oxygen capacity with cycling, the sorbent oxygen capacity stabilized after 1,000 hours and remained constant to the end of the test, 1,500 hour. The activity of the catalyst to reform methane to a hydrogen and carbon monoxide mixture was unchanged through the oxidation/reduction cycling. Our cost and performance analyses indicated a significant reduction in the cost of GTL production when using the HOP process integrated into a GTL plant.

Robert J. Copeland; Yevgenia Gershanovich; Brian Windecker

2005-02-01T23:59:59.000Z

152

High Efficiency Steam Electrolyzer  

SciTech Connect

A novel steam electrolyzer has been developed. In conventional electrolyzers, oxygen produced from electrolysis is usually released in the air stream. In their novel design, natural gas is used to replace air in order to reduce the chemical potential difference across the electrolyzer, thus minimizing the electrical consumption. The oxygen from the electrolysis is consumed in either a total oxidation or a partial oxidation reaction with natural gas. Experiments performed on single cells shown a voltage reduction as much as 1 V when compared to conventional electrolyzers. Using thin film materials and high performance cathode and anode, electrolysis could be done at temperatures as low as 700 C with electrolytic current as high as 1 A/cm{sup 2} at a voltage of 0.5 V only. The 700 C operating temperature is favorable to the total oxidation of natural gas while minimizing the need for steam that is otherwise necessary to avoid carbon deposition. A novel tubular electrolyzer stack has been developed. The system was designed to produce hydrogen at high pressures, taking advantage of the simplicity and high efficiency of the electrochemical compressors. A complete fabrication process was developed for making electrolyzer tubes with thin film coatings. A 100 W stack is being built.

Pham, A.Q.

2000-06-19T23:59:59.000Z

153

Studies of basic mechanisms influencing solar-cell efficiency for terrestrial applications  

DOE Green Energy (OSTI)

The research activities include determination of the basic mechanisms that control and limit solar-cell efficiency, engineering design of solar cells, and the improvement of cell design to increase the power conversion efficiency and to define the maximum efficiency expected from a given material technology. Experimental methods for determining the basic mechanisms in the highly-doped emitter region and for determining diffusion length and lifetime in the base region of p-n junction solar cells are discussed. The evolution of three different silicon solar cell structures proposed to yield efficiencies greater than 20% for illumination levels in the 25 to 100 sun range is discussed.

None

1978-01-01T23:59:59.000Z

154

INCREASED CELL EFFICIENCY IN InGaAs THIN FILM SOLAR CELLS WITH DIELECTRIC AND METAL BACK REFLECTORS  

E-Print Network (OSTI)

solar cells enable very high photovoltaic efficiencies by virtue of employing different band gap to increase the short circuit current and the photovoltaic efficiency of solar cells. INTRODUCTION Multi-junction solar cells based on III-V compound semiconductors are the most efficient photovoltaic devic- es

Heaton, Thomas H.

155

Efficiency of silicon solar cells containing chromium  

DOE Patents (OSTI)

Efficiency of silicon solar cells containing about 10.sup.15 atoms/cm.sup.3 of chromium is improved about 26% by thermal annealing of the silicon wafer at a temperature of 200.degree. C. to form chromium precipitates having a diameter of less than 1 Angstrom. Further improvement in efficiency is achieved by scribing laser lines onto the back surface of the wafer at a spacing of at least 0.5 mm and at a depth of less than 13 micrometers to preferentially precipitate chromium near the back surface and away from the junction region of the device. This provides an economical way to improve the deleterious effects of chromium, one of the impurities present in metallurgical grade silicon material.

Frosch, Robert A. Administrator of the National Aeronautics and Space (New Port Beach, CA); Salama, Amal M. (New Port Beach, CA)

1982-01-01T23:59:59.000Z

156

High efficiency diamond solar cells  

SciTech Connect

A photovoltaic device and method of making same. A layer of p-doped microcrystalline diamond is deposited on a layer of n-doped ultrananocrystalline diamond such as by providing a substrate in a chamber, providing a first atmosphere containing about 1% by volume CH.sub.4 and about 99% by volume H.sub.2 with dopant quantities of a boron compound, subjecting the atmosphere to microwave energy to deposit a p-doped microcrystalline diamond layer on the substrate, providing a second atmosphere of about 1% by volume CH.sub.4 and about 89% by volume Ar and about 10% by volume N.sub.2, subjecting the second atmosphere to microwave energy to deposit a n-doped ultrananocrystalline diamond layer on the p-doped microcrystalline diamond layer. Electrodes and leads are added to conduct electrical energy when the layers are irradiated.

Gruen, Dieter M. (Downers Grove, IL)

2008-05-06T23:59:59.000Z

157

Holographic technology could increase solar efficiency | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Holographic technology could increase solar efficiency Holographic technology could increase solar efficiency Holographic technology could increase solar efficiency October 12, 2010 - 1:00pm Addthis Luminit's co-generation technology could combine photovoltaics (shown in this file photo) and solar thermal energy. | File photo Luminit's co-generation technology could combine photovoltaics (shown in this file photo) and solar thermal energy. | File photo Lorelei Laird Writer, Energy Empowers Co-generation technology could combine photovoltaics and solar thermal Luminit's technology bends and redirects sunlight to produce energy Research funded by Small Business Innovation Research grant There are two major technologies in solar energy: photovoltaics and solar thermal. Most people are more familiar with photovoltaics (PV) - the flat solar

158

Solar thermophotovoltaic efficiency potentials : surpassing photovoltaic device efficiencies  

E-Print Network (OSTI)

Solar energy has gained more attention in recent years due to increased concerns about the continued use of fossil fuels. Solar energy is a form of renewable energy, and solar energy technology does not release greenhouse ...

Barnes, Kathryn M

2012-01-01T23:59:59.000Z

159

High-efficiency photovoltaic cells  

DOE Patents (OSTI)

High efficiency solar converters comprised of a two cell, non-lattice matched, monolithic stacked semiconductor configuration using optimum pairs of cells having bandgaps in the range 1.6 to 1.7 eV and 0.95 to 1.1 eV, and a method of fabrication thereof, are disclosed. The high band gap subcells are fabricated using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxy (LPE) or molecular beam epitaxy (MBE) to produce the required AlGaAs layers of optimized composition, thickness and doping to produce high performance, heteroface homojunction devices. The low bandgap subcells are similarly fabricated from AlGa(As)Sb compositions by LPE, MBE or MOCVD. These subcells are then coupled to form a monolithic structure by an appropriate bonding technique which also forms the required transparent intercell ohmic contact (IOC) between the two subcells. Improved ohmic contacts to the high bandgap semiconductor structure can be formed by vacuum evaporating to suitable metal or semiconductor materials which react during laser annealing to form a low bandgap semiconductor which provides a low contact resistance structure.

Yang, H.T.; Zehr, S.W.

1982-06-21T23:59:59.000Z

160

Berkeley Lab Sheds Light on Improving Solar Cell Efficiency  

DOE Green Energy (OSTI)

Typical manufacturing methods produce solar cells with an efficiency of 12-15%; and 14% efficiency is the bare minimum for achieving a profit. In work performed at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley, CA, 5 10-486-577 1)--a US Department of Energy national laboratory that conducts unclassified scientific research and is managed by the University of California--scientist Scott McHugo has obtained keen insights into the impaired performance of solar cells manufactured from polycrystalline silicon. The solar cell market is potentially vast, according to Berkeley Lab. Lightweight solar panels are highly beneficial for providing electrical power to remote locations in developing nations, since there is no need to build transmission lines or truck-in generator fuel. Moreover, industrial nations confronted with diminishing resources have active programs aimed at producing improved, less expensive solar cells. 'In a solar cell, there is a junction between p-type silicon and an n-type layer, such as diffused-in phosphorous', explained McHugo, who is now with Berkeley Lab's Accelerator and Fusion Research Division. 'When sunlight is absorbed, it frees electrons, which start migrating in a random-walk fashion toward that junction. If the electrons make it to the junction; they contribute to the cell's output of electric current. Often, however, before they reach the junction, they recombine at specific sites in the crystal' (and, therefore, cannot contribute to current output). McHugo scrutinized a map of a silicon wafer in which sites of high recombination appeared as dark regions. Previously, researchers had shown that such phenomena occurred not primarily at grain boundaries in the polycrystalline material, as might be expected, but more often at dislocations in the crystal. However, the dislocations themselves were not the problem. Using a unique heat treatment technique, McHugo performed electrical measurements to investigate the material at the dislocations. He was purportedly the first to show that they were 'decorated' with iron.

Lawrence Berkeley National Laboratory

2007-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

EERE: Roofus' Solar and Efficient Home Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

Roofus' Solar and Efficient Home Illustration showing Roofus' home. Roofus, a golden retriever wearing a baseball cap, sunglasses, and large gold dog tag, is sitting on a couch...

162

Air-stable Nanomaterials for Efficient OLEDs and Solar Cells  

Air-stable Nanomaterials for Efficient OLEDs and Solar Cells . IB-2044, IB-2231 . ... U.S. DEPARTMENT OF ENERGY • OFFICE OF SCIENCE • UNIVERSITY OF CALIFORNIA.

163

More Efficient Polymer Solar Cells by Doping with Ferroelectric ...  

Science Conference Proceedings (OSTI)

Presentation Title, More Efficient Polymer Solar Cells by Doping with ... Mixture for Predicting the Ideal Solubility of Thermally Stable and Unstable Compounds.

164

"Increasing Solar Panel Efficiency And Reliability By Evaporative...  

NLE Websites -- All DOE Office Websites (Extended Search)

Increasing Solar Panel Efficiency And Reliability By Evaporative Cooling" Inventors..--.. Lewis Meixler, Charles Gentile, Patricia Hillyer, Dylan Carpe, Jason Wang, Caroline Brooks...

165

Solar and Energy Efficiency Justice | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Energy Efficiency Justice and Energy Efficiency Justice Solar and Energy Efficiency Justice June 24, 2010 - 3:00pm Addthis The roof of the justice center where a solar panel array will be installed to power a solar thermal water-heating system | Photo courtesy of Blount County, Tenn. The roof of the justice center where a solar panel array will be installed to power a solar thermal water-heating system | Photo courtesy of Blount County, Tenn. A solar thermal water-heating system at the justice center in Maryville, Tenn., is helping to reduce energy consumption and cut costs for Blount County. Funded by $300,000 of the $501,600 Energy Efficiency and Conservation Block Grant (EECBG) awarded to Blount County through the Recovery Act, the solar thermal water-heating system will retrofit the detention facility's

166

The Importance of Domain Size and Purity in High-Efficiency Organic...  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymerorganic photovoltaic cells hinges on excitons-electronhole pairs...

167

SunShot Initiative: High-Efficiency Thermal Storage System for...  

NLE Websites -- All DOE Office Websites (Extended Search)

Efficiency Thermal Storage System for Solar Plants to someone by E-mail Share SunShot Initiative: High-Efficiency Thermal Storage System for Solar Plants on Facebook Tweet about...

168

High-efficiency silicon concentrator cell commercialization  

SciTech Connect

This report summarizes the first phase of a forty-one month program to develop a commercial, high-efficiency concentrator solar cell and facility for manufacturing it. The period covered is November 1, 1990 to December 31, 1991. This is a joint program between the Electric Power Research Institute (EPRI) and Sandia National Laboratories. (This report is also published by EPRI as EPRI report number TR-102035.) During the first year of the program, SunPower accomplished the following major objectives: (1) a new solar cell fabrication facility, which is called the Cell Pilot Line (CPL), (2) a baseline concentrator cell process has been developed, and (3) a cell testing facility has been completed. Initial cell efficiencies are about 23% for the baseline process. The long-range goal is to improve this efficiency to 27%.

Sinton, R.A.; Swanson, R.M. [SunPower Corp., Sunnyvale, CA (US)

1993-05-01T23:59:59.000Z

169

High flux solar energy transformation  

DOE Patents (OSTI)

Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes. 7 figures.

Winston, R.; Gleckman, P.L.; O' Gallagher, J.J.

1991-04-09T23:59:59.000Z

170

High flux solar energy transformation  

DOE Patents (OSTI)

Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.

Winston, Roland (Chicago, IL); Gleckman, Philip L. (Chicago, IL); O' Gallagher, Joseph J. (Flossmoor, IL)

1991-04-09T23:59:59.000Z

171

Maximizing efficiency of solar-powered systems by load matching  

Science Conference Proceedings (OSTI)

Solar power is an important source of renewable energy for many low-power systems. Matching the power consumption level with the supply level can make a great difference in the efficiency of power utilization. This paper proposes a source-tracking power ... Keywords: load matching, photovoltaics, power management, power model, solar energy, solar-aware

Dexin Li; Pai H. Chou

2004-08-01T23:59:59.000Z

172

Unleashing Rooftop Solar Energy through More Efficient Government |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Unleashing Rooftop Solar Energy through More Efficient Government Unleashing Rooftop Solar Energy through More Efficient Government Unleashing Rooftop Solar Energy through More Efficient Government June 1, 2011 - 11:45am Addthis Solar panels on the roof of the Department of Energy Forrestal Building in Washington, D.C. | Credit: DOE photo Solar panels on the roof of the Department of Energy Forrestal Building in Washington, D.C. | Credit: DOE photo Ramamoorthy Ramesh Former Director, SunShot Initiative & Solar Energy Technologies Program How can I participate? Teams can include large individual cities or metropolitan areas, regional groups of local governments, states, and Indian Tribes. The Department anticipates providing funding for up to 25 awardees. Learn more here: http://www.eere.energy.gov/solarchallenge/ Across the country, the race is on to drive down the cost of solar energy.

173

Solar, Wind, and Energy Efficiency Easements and Rights Laws | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solar, Wind, and Energy Efficiency Easements and Rights Laws Solar, Wind, and Energy Efficiency Easements and Rights Laws Solar, Wind, and Energy Efficiency Easements and Rights Laws < Back Eligibility Residential Savings Category Appliances & Electronics Commercial Lighting Lighting Heating & Cooling Commercial Heating & Cooling Solar Heating Buying & Making Electricity Water Heating Wind Program Info State Colorado Program Type Solar/Wind Access Policy Provider Colorado Energy Office Colorado's solar access laws, which date back to 1979, prohibit any residential covenants that restrict solar access. [http://www.leg.state.co.us/CLICS/CLICS2008A/csl.nsf/fsbillcont3/3F45E0C8... HB 1270] of 2008 extended the law to protect installations of wind turbines that meet the state's interconnection standards, and certain

174

Solar Energy Materials & Solar Cells 91 (2007) 15991610 Improving solar cell efficiency using photonic band-gap materials  

E-Print Network (OSTI)

Solar Energy Materials & Solar Cells 91 (2007) 1599­1610 Improving solar cell efficiency using Propulsion Laboratory, California Institute of Technology, Mail Stop T1714 106, 4800 Oak Grove Drive and reliable solar-cell devices is presented. We show that due their ability to modify the spectral and angular

Dowling, Jonathan P.

175

Current NIST Research: Building Energy Efficiency Solar ...  

Science Conference Proceedings (OSTI)

... Characterize solar cells & modules => improve module ratings and computer models Page 16. ... PV accelerated weathering facility. ... usage, weather ...

2013-10-31T23:59:59.000Z

176

Durable and Highly Efficient Energy-harvesting Electrochromic ...  

Science Conference Proceedings (OSTI)

The resulting device performed three states: solar cell, transparent, and dark, and ... Anatase Nanostructures for High Efficiency Photocatalysis Application ... EBSD Study of Electromigration Damage in Idealized SnAgCu 305 Interconnects.

177

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology. Annual subcontract report, 1 August 1991--31 July 1992  

DOE Green Energy (OSTI)

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, {approximately} 1 {times} 10{sup 5} cm{sup {minus}5}, as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 {times}10{sup 7} cm{sup {minus}2}. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. [Spire Corp., Bedford, MA (United States)

1993-04-01T23:59:59.000Z

178

Crystal Growth and Wafer Processing for High Yield and High Efficiency Solar Cells: Final Report, 1 October 2003 - 15 January 2008  

DOE Green Energy (OSTI)

Hardness, elastic modulus, and fracture toughness of low and high carrier-lietime regions in polycrystalline silicon were evaluated using the nanoindentation technique.

Rozgonyi, G. A.; Youssef, K.

2008-11-01T23:59:59.000Z

179

Upside-Down Solar Cell Achieves Record Efficiencies (Fact Sheet)  

DOE Green Energy (OSTI)

The inverted metamorphic multijunction (IMM) solar cell is an exercise in efficient innovation - literally, as the technology boasted the highest demonstrated efficiency for converting sunlight into electrical energy at its debut in 2005. Scientists at the National Renewable Energy Laboratory (NREL) inverted the conventional photovoltaic (PV) structure to revolutionary effect, achieving solar conversion efficiencies of 33.8% and 40.8% under one-sun and concentrated conditions, respectively.

Not Available

2010-12-01T23:59:59.000Z

180

Advanced processing technology for high-efficiency, thin-film CuInSe{sub 2} and CdTe solar cells. Annual subcontract report, 1 March 1993--28 February 1994  

Science Conference Proceedings (OSTI)

This annual report details activities in research on advanced processing technology for high-effiency, thin-film solar cells.

Morel, D.L.; Ferekides, C.S. [University of South Florida, Tampa, FL (United States)

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

High efficiency solar air heaters with novel built-in heat storage for use in a humidification-dehumidification desalination cycle  

E-Print Network (OSTI)

Compared to solar water heaters, solar air heaters have received relatively little investigation and have resulted in few commercial products. However, in the context of a Humidification-Dehumidification (HD) Desalination ...

Summers, Edward K

2010-01-01T23:59:59.000Z

182

EERE Roofus' Solar and Efficient Home: Solar Hot Water  

NLE Websites -- All DOE Office Websites (Extended Search)

of Roofus, a golden retriever, sitting in front of three black, rectangular solar collectors. Sunshine is really hot, and it makes my roof get hot, too So I use a...

183

EERE Roofus' Solar and Efficient Home: Solar Panels  

NLE Websites -- All DOE Office Websites (Extended Search)

of Roofus, a golden retriever, sitting in front of three black, rectangular solar panels. When you turn on a light in your home, electricity flows through wires up to...

184

EERE Roofus' Solar and Efficient Home: Solar Car  

NLE Websites -- All DOE Office Websites (Extended Search)

Car Illustration of Roofus, a golden retriever, sitting in a solar car, which is dome-shaped and has a small compartment for the driver. Almost all cars today use gasoline, but my...

185

Parabolic trough solar collectors : design for increasing efficiency  

E-Print Network (OSTI)

Parabolic trough collectors are a low cost implementation of concentrated solar power technology that focuses incident sunlight onto a tube filled with a heat transfer fluid. The efficiency and cost of the parabolic trough ...

Figueredo, Stacy L. (Stacy Lee), 1981-

2011-01-01T23:59:59.000Z

186

EERE Roofus' Solar and Efficient Home: Windows  

NLE Websites -- All DOE Office Websites (Extended Search)

or you can use a compass to find out. Where I live, it gets cold in the winter, so my solar house uses the sun to help me stay warm. On a nice sunny day, you can see for yourself...

187

EERE Roofus' Solar and Efficient Home: Activities  

NLE Websites -- All DOE Office Websites (Extended Search)

some fun activities for you to do while you visit my house Learn how to build your own solar oven using a pizza box. Use it to heat a treat on your own Learn how to build your...

188

EERE Roofus' Solar and Efficient Home: Lights  

NLE Websites -- All DOE Office Websites (Extended Search)

by buying energy-saving light bulbs. I use these light bulbs to save energy in my solar house Most people have incandescent (IN-CAN-DE-SENT) light bulbs in their house. If...

189

High Efficiency Particulate Air Filters  

NLE Websites -- All DOE Office Websites (Extended Search)

High Efficiency Particulate Air (HEPA) Filters High Efficiency Particulate Air (HEPA) Filters Home Standards DOE Workshops Nuclear Air Cleaning Conference Proceedings Qualified Filter List News Items Related Sites HEPA Related Lessons Learned Contact Us HSS Logo High Efficiency Particulate Air Filters The HEPA Filter web site provides a forum for informing and reporting department-wide activities related to filtration and ventilation issues with special reference to the High Efficiency Particulate Air (HEPA) Filters' use, inspection, and testing. This site contains essentials of DOE HEPA filter test program, procedures, requirements and quality assurance aspects applicable to HEPA filters used in DOE facilities. This site contains information about the DOE-accepted Filter Test Facility and its management, operation and quality assuranceprogram.

190

New GaInP/GaAs/GaInAs, Triple-Bandgap, Tandem Solar Cell for High-Efficiency Terrestrial Concentrator Systems  

DOE Green Energy (OSTI)

GaInP/GaAs/GaInAs three-junction cells are grown in an inverted configuration on GaAs, allowing high quality growth of the lattice matched GaInP and GaAs layers before a grade is used for the 1-eV GaInAs layer. Using this approach an efficiency of 37.9% was demonstrated.

Kurtz, S.; Wanlass, M.; Kramer, C.; Young, M.; Geisz, J.; Ward, S.; Duda, A.; Moriarty, T.; Carapella, J.; Ahrenkiel, P.; Emery. K.; Jones, K.; Romero, M.; Kibbler, A.; Olson, J.; Friedman, D.; McMahon, W.; Ptak, A.

2005-11-01T23:59:59.000Z

191

High Speed AB-Solar Sail  

E-Print Network (OSTI)

The Solar sail is a large thin film used to collect solar light pressure for moving of space apparatus. Unfortunately, the solar radiation pressure is very small about 9 mkN/sq.m at Earth's orbit. However, the light force significantly increases up to 0.2 - 0.35 N/sq.m near the Sun. The author offers his research on a new revolutionary highly reflective solar sail which flyby (after special maneuver) near Sun and attains velocity up to 400 km/sec and reaching far planets of the Solar system in short time or enable flights out of Solar system. New, highly reflective sail-mirror allows avoiding the strong heating of the solar sail. It may be useful for probes close to the Sun and Mercury and Venus. Key words: AB-solar sail, highly reflective solar sail, high speed propulsion.

A. Bolonkin

2007-01-08T23:59:59.000Z

192

High-Efficiency Steam Electrolyzer  

SciTech Connect

We are developing a novel high-efficiency, high-temperature steam electrolyzer. Although water or steam electrolysis is well known to be one of the cleanest ways to produce hydrogen, widespread utilization is hindered by high operational costs because of high electricity consumption. To decrease the electrical power input requirements in electrolysis, our approach uses natural gas as an anode depolarizer. This approach essentially replaces one unit of electricity with one equivalent-energy unit of natural gas at much lower cost. The direct use of natural gas on the electrolyzer enables very high system efficiency with respect to primary energy. Experiments performed on single cells have shown a voltage reduction as much as 1 V when compared to conventional electrolyzers. System efficiency has been estimated to be 50 to 80%, depending on the electrolytic current. A 200-W prototype unit is being developed.

Pham, A Q

2001-06-20T23:59:59.000Z

193

Estimating the Cost and Energy Efficiency of a Solar Water Heater...  

NLE Websites -- All DOE Office Websites (Extended Search)

Estimating the Cost and Energy Efficiency of a Solar Water Heater Estimating the Cost and Energy Efficiency of a Solar Water Heater May 30, 2012 - 3:09pm Addthis Solar water...

194

Solar Decathlon: How Do WE Do Efficiency? | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Decathlon: How Do WE Do Efficiency? Decathlon: How Do WE Do Efficiency? Solar Decathlon: How Do WE Do Efficiency? August 31, 2009 - 4:06pm Addthis Drew Bittner Web Manager, Office of Energy Efficiency and Renewable Energy October is a great time of year in Washington, D.C. The weather is cooling off, the trees look gorgeous and (every other year) the National Mall turns into a beehive of activity when the Solar Decathlon comes to town. Well, it doesn't really "come to town." It's an event that the Department of Energy sponsors every other year. Twenty college and university teams come to D.C. with solar-powered homes that they have designed, built, and transported here-some across the Atlantic Ocean, no less-in order to compete. That's dedication, folks; these college teams put in two years of

195

NREL Researchers Demonstrate External Quantum Efficiency Surpassing 100% in a Quantum Dot Solar Cell (Fact Sheet)  

DOE Green Energy (OSTI)

A new device that produces and collects multiple electrons per photon could yield inexpensive, high-efficiency photovoltaics. A new device developed through research at the National Renewable Energy Laboratory (NREL) reduces conventional losses in photovoltaic (PV) solar cells, potentially increasing the power conversion efficiency-but not the cost-of the solar cells. Solar cells convert optical energy from the sun into usable electricity; however, almost 50% of the incident energy is lost as heat with present-day technologies. High-efficiency, multi-junction cells reduce this heat loss, but their cost is significantly higher. NREL's new device uses excess energy in solar photons to create extra charges rather than heat. This was achieved using 5-nanometer-diameter quantum dots of lead selenide (PbSe) tightly packed into a film. The researchers chemically treated the film, and then fabricated a device that yielded an external quantum efficiency (number of electrons produced per incident photon) exceeding 100%, a value beyond that of all current solar cells for any incident photon. Quantum dots are known to efficiently generate multiple excitons (a bound electron-hole pair) per absorbed high-energy photon, and this device definitively demonstrates the collection of multiple electrons per photon in a PV cell. The internal quantum efficiency corrects for photons that are not absorbed in the photoactive layer and shows that the PbSe film generates 30% to 40% more electrons in the high-energy spectral region than is possible with a conventional solar cell. While the unoptimized overall power conversion efficiency is still low (less than 5%), the results have important implications for PV because such high quantum efficiency can lead to more electrical current produced than possible using present technologies. Furthermore, this fabrication is also amenable to inexpensive, high-throughput roll-to-roll manufacturing.

Not Available

2011-12-01T23:59:59.000Z

196

High Efficiency Engine Technologies Program  

Science Conference Proceedings (OSTI)

Caterpillar's Product Development and Global Technology Division carried out a research program on waste heat recovery with support from DOE (Department of Energy) and the DOE National Energy Technology Laboratory. The objective of the program was to develop a new air management and exhaust energy recovery system that would demonstrate a minimum 10% improvement in thermal efficiency over a base heavy-duty on-highway diesel truck engine. The base engine for this program was a 2007 C15 15.2L series-turbocharged on-highway truck engine with a LPL (low-pressure loop) exhaust recirculation system. The focus of the program was on the development of high efficiency turbomachinery and a high efficiency turbocompound waste heat recovery system. The focus of each area of development was as follows: (1) For turbine stages, the focus was on investigation and development of technologies that would improve on-engine exhaust energy utilization compared to the conventional radial turbines in widespread use today. (2) For compressor stages, the focus was on investigating compressor wheel design parameters beyond the range typically utilized in production, to determine the potential efficiency benefits thereof. (3) For turbocompound, the focus was on the development of a robust bearing system that would provide higher bearing efficiencies compared to systems used in turbocompound power turbines in production. None of the turbocharger technologies investigated involved addition of moving parts, actuators, or exotic materials, thereby increasing the likelihood of a favorable cost-value tradeoff for each technology. And the turbocompound system requires less hardware addition than competing bottoming cycle technologies, making it a more attractive solution from a cost and packaging standpoint. Main outcomes of the program are as follows: (1) Two turbine technologies that demonstrated up to 6% improvement in turbine efficiency on gas stand and 1-3% improvement in thermal efficiency in on-engine testing. (2) A compressor technology that demonstrated 1.5% improvement in compressor efficiency on gas stand compared to production available compressors. (3) A power turbine with high efficiency bearing system that demonstrated excellent rotordynamic stability throughout the required speed range, up to 60,000 rpm. (4) A predicted improvement (using engine simulation) in engine thermal efficiency of 7% at the peak torque design point, when combining the technologies developed in this program.

Rich Kruiswyk

2010-07-13T23:59:59.000Z

197

Enabling High Efficiency Ethanol Engines  

Science Conference Proceedings (OSTI)

Delphi Automotive Systems and ORNL established this CRADA to explore the potential to improve the energy efficiency of spark-ignited engines operating on ethanol-gasoline blends. By taking advantage of the fuel properties of ethanol, such as high compression ratio and high latent heat of vaporization, it is possible to increase efficiency with ethanol blends. Increasing the efficiency with ethanol-containing blends aims to remove a market barrier of reduced fuel economy with E85 fuel blends, which is currently about 30% lower than with petroleum-derived gasoline. The same or higher engine efficiency is achieved with E85, and the reduction in fuel economy is due to the lower energy density of E85. By making ethanol-blends more efficient, the fuel economy gap between gasoline and E85 can be reduced. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has extensive knowledge and experience in powertrain components and subsystems as well as overcoming real-world implementation barriers. ORNL has extensive knowledge and expertise in non-traditional fuels and improving engine system efficiency for the next generation of internal combustion engines. Partnering to combine these knowledge bases was essential towards making progress to reducing the fuel economy gap between gasoline and E85. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, usually on a bi-weekly basis, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided substantial hardware support to the project by providing components for the single-cylinder engine experiments, engineering support for hardware modifications, guidance for operational strategies on engine research, and hardware support by providing a flexible multi-cylinder engine to be used for optimizing engine efficiency with ethanol-containing fuels.

Szybist, J.; Confer, K. (Delphi Automotive Systems)

2011-03-01T23:59:59.000Z

198

Search for Factors Determining the Photodegradation in High-Efficiency a-Si:H-Based Solar Cells; Annual Technical Progress Report, 16 January 1998-15 January 1999  

DOE Green Energy (OSTI)

This report describes studies on glow discharge (GD) and hot-wire a-Si-based samples by the University of North Carolina-Chapel Hill during Phase I. We have characterized H-bonding and its light-induced changes by using infrared (IR) and differential IR (DIR). For the less stable film, there is a simultaneous decrease {approx} 2040 cm{sup -1} and increase {approx} 1880 cm{sup -1}; for the more-stable samples, the DIR near 2000 cm{sup -1} increases upon light-soaking. Nuclear magnetic resonance (NMR) dipolar relaxation time T{sub 1D} of the clustered H is slightly shorter, but the T{sub 1D} of the isolated H is 4 times longer in hot-wire (HW) film than that in GD films. The results indicate that the local motion of the isolated H is much slower in HW compared to that in GD film. High-Temperature NMR results show a second narrow line (less than 1 kHz wide) as the temperature is raised. In stress measurements, it is clearly shown that HW films with lower hydrogen content show lower compression. A photoinduced increase of the compression on the order of 10{sup -4} of the initial value upon light-soaking was found to be similar in all a-Si:H films which exhibit different amounts of Staebler-Wronski (SW) degradation. Hence, the volume expansion is not directly related to SW effect. Also, we have measured the electric field profile in a-Si:H and a-SiGe:H solar cells, and the results agreed with computer simulation.

Han, D.

1999-06-18T23:59:59.000Z

199

Evaluating High Efficiency Motor Retrofit  

E-Print Network (OSTI)

In the petrochemical and refining Industries, and most manufacturing plants, the reliable operation of AC motors always has been crucial to the continuous operation of the process. Now, the cost of operating these motors has also become a significant factor. Engineers Involved In motor specification can help lower plant operating costs and reduce electrical energy consumption dramatically by a relatively simple technique: retrofit of existing, standard-efficiency motors with new, high efficiency models. This article demonstrates strong reasons for motor retrofit, and explains step-by step how process and manufacturing engineering personnel can fully evaluate a retrofit decision.

Evans, T. A.

1984-01-01T23:59:59.000Z

200

High-Efficiency Steam Electrolyzer  

SciTech Connect

We are developing a novel high-efficiency, high-temperature steam electrolyzer. Although water or steam electrolysis is well known to be one of the cleanest ways to produce hydrogen, widespread utilization is hindered by high operational costs because of high electricity consumption. To decrease the electrical power input requirements in electrolysis, our approach uses natural gas as an anode depolarizer. This approach essentially replaces one unit of electricity with one equivalent-energy unit of natural gas at much lower cost. The direct use of natural gas on the electrolyzer enables very high system efficiency with respect to primary energy. Experiments performed on single cells have shown a voltage reduction as much as 1 V when compared to conventional electrolyzers. System efficiency has been estimated to be 50 to 80%, depending on the electrolytic current density. During FY02, we have accomplished several major milestones, including the development of a metal-to-ceramic seal that withstands 150 psi differential, the fabrication of the electrolyzer tubes of up to 16 inches in length, the improvement of single tube performance and the demonstration of the first electrolyzer stack.

Pham, A Q; See, E; Lenz, D; Martin, P; Glass, R

2002-07-03T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Search for the Factors Determining the Photodegradation in High Efficiency a-Si:H Solar Cells: Final Subcontract Report, 28 January 1998 - 15 August 2001  

DOE Green Energy (OSTI)

This report describes continuing studies on photoluminescence (PL), electroluminescence (EL), Raman, and nuclear magnetic resonance (NMR) by the University of North Carolina-Chapel Hill during the three years and the extension period. Systematic studies on the transition materials and their solar cells and a review of the photo-induced structural changes in correlation to the electronic degradation have led to better understanding of the factors determining the photodegradation in a-Si:H solar cells. NHR established significant differences, as in the bonding of hydrogen in the hot-wire- and plasma-deposited amorphous silicon.

Han, D.

2002-03-01T23:59:59.000Z

202

An efficient solar energy harvester for wireless sensor nodes  

E-Print Network (OSTI)

Solar harvesting circuits have been recently proposed to increase the autonomy of embedded systems. One key design challenge is how to optimize the efficiency of solar energy collection under non stationary light conditions. This paper proposes a scavenger that exploits miniaturized photovoltaic modules to perform automatic maximum power point tracking at a minimum energy cost. The system adjusts dynamically to the light intensity variations and its measured power consumption is less than 1mW. Experimental results show increments of global efficiency up to 80%, diverging from ideal situation by less than 10%, and demonstrate the flexibility and the robustness of our approach. 1.

Davide Brunelli; Luca Benini; Clemens Moser; Lothar Thiele

2008-01-01T23:59:59.000Z

203

Sunshot Initiative High Penetration Solar Portal  

DOE Data Explorer (OSTI)

The DOE SunShot Initiative is a collaborative national initiative to make solar energy cost-competitive with other forms of energy by the end of the decade. Reducing the installed cost of solar energy systems by about 75% will drive widespread large-scale adoption of this renewable energy and restore U.S. leadership in the global clean energy race. The High Penetration Solar Portal was created as a resource to aggregate the most relevant and timely information related to high penetration solar scenarios and integrating solar into the grid. The site is designed so that utilities, grant awardees, regulators, researchers, and other solar professionals can easily share data, case studies, lessons learned, and demonstration project findings. [copied from https://solarhighpen.energy.gov/about_the_high_penetration_solar_portal

204

High-Efficiency Amorphous Silicon and Nanocrystalline Silicon-Based Solar Cells and Modules: Final Technical Progress Report, 30 January 2006 - 29 January 2008  

DOE Green Energy (OSTI)

United Solar Ovonic successfully used its spectrum-splitting a-Si:H/a-SiGe:H/a-SiGe:H triple-junction structure in their manufacturing plants, achieving a manufacturing capacity of 118 MW in 2007, and set up a very aggressive expansion plan to achieve grid parity.

Guha, S.; Yang, J.

2008-05-01T23:59:59.000Z

205

AEROSPACE TECHNOLOGY REVIEW FOR LBL WINDOW/PASSIVE SOLAR PROGRAM FINAL REPORT  

E-Print Network (OSTI)

F. Uno, "High Efficiency Solar Panel (HESP)! ', N78 10572,High Efficiency, Long Life Terrestrial Solar Panel", 7 8Ncapabilities, the efficiency of the solar panels, co-

Viswanathan, R.

2011-01-01T23:59:59.000Z

206

Low-cost, Efficient, Flexible Solar Cells with 3D Nanopillar ...  

The technology was also used to produce solar modules on flexible substrates that offer more efficient light ... Solar panels; Consumer electronics; More Information ...

207

Assessing solar energy and water use efficiencies in winter wheat  

SciTech Connect

The water use and solar energy conversion efficiencies of two cultivars of winter wheat (Triticum aestivum L., vars, Centurk and Newton) planted at three densities, were examined during a growing season. Water use, based on soil moisture depletion, was the lowest under the light, and the highest under the heavy planting densities of both cultivars. Water use efficiency of medium and heavy planting densities were greater than the light planting densities in both cultivars. The canopy radiation extinction coefficients of both cultivars increased with increases in planting density. Efficiency of operation interception of photosynthetically active radiation by both cultivars improved from the time of jointing until anthesis, and then decreased during senescence. The efficiency of the conversion of intercepted radiation to dry matter (biochemical efficiency) decreased throughout the growing season both cultivars. The interception, biochemical, and photosynthetic efficiencies improved as planting density increased.

Asrar, G.; Hipps, L.E.; Kanemasu, E.T.

1982-09-01T23:59:59.000Z

208

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Structure of All-Polymer Solar Cells Impedes Efficiency Structure of All-Polymer Solar Cells Impedes Efficiency Print Wednesday, 27 October 2010 00:00 Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material combinations (polymer/fullerene, polymer/inorganic, all-polymer, and dye-sensitized cells), seeking a deeper understanding of their fundamental structure, operation, and limitations. A team of researchers from North Carolina State University and the UK has now found, through microscopy and resonant scattering and reflectivity studies at ALS Beamlines 6.3.2 and 5.3.2, that the low rate of energy conversion in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials.

209

High-efficiency photoionization detector  

DOE Patents (OSTI)

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 +- 0.02 eV, and a vapor pressure of 0.35 torr at 20/sup 0/C.

Anderson, D.F.

1981-05-12T23:59:59.000Z

210

Efficient Solar Concentrators: Affordable Energy from Water and Sunlight  

Science Conference Proceedings (OSTI)

Broad Funding Opportunity Announcement Project: Teledyne is developing a liquid prism panel that tracks the position of the sun to help efficiently concentrate its light onto a solar cell to produce power. Typically, solar tracking devices have bulky and expensive mechanical moving parts that require a lot of power and are often unreliable. Teledyne’s liquid prism panel has no bulky and heavy supporting parts—instead it relies on electrowetting. Electrowetting is a process where an electric field is applied to the liquid to control the angle at which it meets the sunlight above and to control the angle of the sunlight to the focusing lensthe more direct the angle to the focusing lens, the more efficiently the light can be concentrated to solar panels and converted into electricity. This allows the prism to be tuned like a radio to track the sun across the sky and steer sunlight into the solar cell without any moving mechanical parts. This process uses very little power and requires no expensive supporting hardware or moving parts, enabling efficient and quiet rooftop operation for integration into buildings.

None

2010-01-01T23:59:59.000Z

211

SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Solar Foundational Program to Solar Foundational Program to Advance Cell Efficiency to someone by E-mail Share SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency on Facebook Tweet about SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency on Twitter Bookmark SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency on Google Bookmark SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency on Delicious Rank SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency on Digg Find More places to share SunShot Initiative: Solar Foundational Program to Advance Cell Efficiency on AddThis.com... Concentrating Solar Power Photovoltaics Research & Development Competitive Awards Diversity in Science and Technology Advances National Clean Energy

212

Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies  

E-Print Network (OSTI)

1.1 Solar Energy . . . . . . . . .on ?uorescent glass-?lms. Solar Energy Materials and SolarHo?mann. Photovoltaic Solar Energy Gen- eration. Optical

Wang, Chunhua

2011-01-01T23:59:59.000Z

213

High Efficiency Fans and High Efficiency Electrical Motors  

E-Print Network (OSTI)

Replacing nominal efficient electrical motors with premium efficiency can save on electrical power costs in cotton gins. Connected horsepower load on industrial air fans is approximately 60% of the total horsepower in a typical cotton gin. By replacing old inefficient centrifugal fans with new higher efficiency fans, additional power savings can be achieved.

Breedlove, C. W.

1989-09-01T23:59:59.000Z

214

Non-tracking solar concentrator with a high concentration ratio  

DOE Patents (OSTI)

A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

Hinterberger, Henry (Batavia, IL)

1977-01-01T23:59:59.000Z

215

Scientists at ALS Find New Path to More Efficient Organic Solar...  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists at ALS Find New Path to More Efficient Organic Solar Cells Scientists at ALS Find New Path to More Efficient Organic Solar Cells Print Monday, 07 January 2013 00:00...

216

Growth and development of GaInAsP for use in high-efficiency solar cells. Annual subcontract report, 1 July 1991--30 June 1992  

DOE Green Energy (OSTI)

This report describes work done during Phase II of the subcontract. Goals for Phase II include the following: (1) Optimize the GaInAsP cell on GaAs and demonstrate a 500-sun at air mass (AM) 1.5 efficiency of >23%. (2) Develop a window layer, including the evaluation of AlGaAs, GaInP, AlGaAsP, AlGaInP, and GaP. (3) Develop a front-surface contact, with a grid designed for 500-sun concentration, and a goal of a contact resistivity of {approximately}10{sup 5} ohm-cm{sup 2}. (4) Grow GaInAsP cells on Ge, with a goal of a 1-sun (AM 1.5) efficiency of >15%. Accomplishments reported herein include (1) the fabrication of p-on-n and n-on-p GaInAsP cells on GaAs, with the n-on-p cell demonstrating a 10-sun (AM 1.5) active-area efficiency of 23.4% as measured at NREL (2) the evaluation of Al{sub x}Ga({sub 1-x})As, GaInP{sub 2}, and AlInP{sub 2} window layers; and (3) the fabrication of GaInAsP cells on Ge, with the demonstration of a p-on-n GaInAsP cell grown on Ge with a 1-sun (AM 1.5) active-area efficiency of 14.4%.

Sharps, P.R. [Research Triangle Inst., Research Triangle Park, NC (United States)

1993-04-01T23:59:59.000Z

217

Advanced processing technology for high-efficiency thin-film CuInSe{sub 2} solar cells. Annual subcontract report, 1 March 1992--28 February 1993  

DOE Green Energy (OSTI)

This report describes work to develop novel fabrication for CuInSe{sub 2} (CIS) solar cells that will result in improved performance and cost effectiveness at the manufacturing level. The primary approach involves all solid-state processing for CIS. This was augmented by work to provide novel alternatives for the formation of the window layer/heterojunction contact. Inherent to the project was the need to develop a generic understanding of the relationship between processing and performance so that broad-based transfer to industry can be facilitated. We achieved good-electronic-quality CIS by the use of two selenization procedures for predeposited metal layers. We achieved good stoichiometry throughout the bulk of the film, attained grain sizes of up to 1 {mu}m, and measured electron mobilities of up to 60 cm{sup 2}V-s. However, there is a complex relationship between grain size, adhesion, and performance. Our primary approach to characterization was to fabricate ZnO/CIS test devices and measure as many properties as possible in device format. We are also developing reactive sputtering of ZnO as an alternative window layer technology.

Morel, D.L.; Attar, G.; Karthikeyan, S.; Muthaiah, A.; Zafar, A. [University of South Florida, Tampa, FL (United States)

1993-08-01T23:59:59.000Z

218

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material combinations (polymer/fullerene, polymer/inorganic, all-polymer, and dye-sensitized cells), seeking a deeper understanding of their fundamental structure, operation, and limitations. A team of researchers from North Carolina State University and the UK has now found, through microscopy and resonant scattering and reflectivity studies at ALS Beamlines 6.3.2 and 5.3.2, that the low rate of energy conversion in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials.

219

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material combinations (polymer/fullerene, polymer/inorganic, all-polymer, and dye-sensitized cells), seeking a deeper understanding of their fundamental structure, operation, and limitations. A team of researchers from North Carolina State University and the UK has now found, through microscopy and resonant scattering and reflectivity studies at ALS Beamlines 6.3.2 and 5.3.2, that the low rate of energy conversion in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials.

220

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material combinations (polymer/fullerene, polymer/inorganic, all-polymer, and dye-sensitized cells), seeking a deeper understanding of their fundamental structure, operation, and limitations. A team of researchers from North Carolina State University and the UK has now found, through microscopy and resonant scattering and reflectivity studies at ALS Beamlines 6.3.2 and 5.3.2, that the low rate of energy conversion in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials.

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material combinations (polymer/fullerene, polymer/inorganic, all-polymer, and dye-sensitized cells), seeking a deeper understanding of their fundamental structure, operation, and limitations. A team of researchers from North Carolina State University and the UK has now found, through microscopy and resonant scattering and reflectivity studies at ALS Beamlines 6.3.2 and 5.3.2, that the low rate of energy conversion in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials.

222

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material combinations (polymer/fullerene, polymer/inorganic, all-polymer, and dye-sensitized cells), seeking a deeper understanding of their fundamental structure, operation, and limitations. A team of researchers from North Carolina State University and the UK has now found, through microscopy and resonant scattering and reflectivity studies at ALS Beamlines 6.3.2 and 5.3.2, that the low rate of energy conversion in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials.

223

Estimating the Cost and Energy Efficiency of a Solar Water Heater |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Estimating the Cost and Energy Efficiency of a Solar Water Heater Estimating the Cost and Energy Efficiency of a Solar Water Heater Estimating the Cost and Energy Efficiency of a Solar Water Heater May 30, 2012 - 3:09pm Addthis Solar water heaters are more efficient the gas or electric heaters. | Chart credit ENERGY STAR Solar water heaters are more efficient the gas or electric heaters. | Chart credit ENERGY STAR What does this mean for me? Solar water heaters cost more to purchase and install but may save you money in the long run. Estimate the annual operating costs and compare several solar water heaters to determine whether it is worth investing in a more efficient system. Solar water heating systems usually cost more to purchase and install than conventional water heating systems. However, a solar water heater can

224

Estimating the Cost and Energy Efficiency of a Solar Water Heater |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Estimating the Cost and Energy Efficiency of a Solar Water Heater Estimating the Cost and Energy Efficiency of a Solar Water Heater Estimating the Cost and Energy Efficiency of a Solar Water Heater May 30, 2012 - 3:09pm Addthis Solar water heaters are more efficient the gas or electric heaters. | Chart credit ENERGY STAR Solar water heaters are more efficient the gas or electric heaters. | Chart credit ENERGY STAR What does this mean for me? Solar water heaters cost more to purchase and install but may save you money in the long run. Estimate the annual operating costs and compare several solar water heaters to determine whether it is worth investing in a more efficient system. Solar water heating systems usually cost more to purchase and install than conventional water heating systems. However, a solar water heater can

225

Lithographic antennas for enhancement of solar cell efficiency  

DOE Green Energy (OSTI)

This report documents proof-of-concept demonstration of the use of lithographic antennas for enhancement of solar-cell efficiency. A micro-sized lithographic antenna array was theoretically modeled, designed and fabricated. Experimental research was performed to validate the ability of the antenna array to concentrate infrared and visible energy onto photovoltaic (PV) materials. The research will serve as the basis for the design of a miniature power source for remote sensors.

Kotter, D.K. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States); Boreman, G. [Univ. of Central Florida, Orlando, FL (United States). Center for Research and Education in Optics and Lasers

1998-04-01T23:59:59.000Z

226

Energy-Efficient Path Planning for Solar-Powered Mobile Robots  

E-Print Network (OSTI)

Energy-Efficient Path Planning for Solar-Powered Mobile Robots Patrick A. Plonski Department@cs.umn.edu Abstract We explore the problem of energy-efficient, time-constrained path planning of a solar pow- ered circuit and basic GPS localization, and this solar map can be used for energy-efficient navigation

Minnesota, University of

227

High efficiency shale oil recovery  

SciTech Connect

The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical conditions (heating, mixing, pyrolysis, oxidation) exist in both systems.The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed this quarter. (1) Twelve pyrolysis runs were made on five different oil shales. All of the runs exhibited a complete absence of any plugging, tendency. Heat transfer for Green River oil shale in the rotary kiln was 84.6 Btu/hr/ft[sup 2]/[degrees]F, and this will provide for ample heat exchange in the Adams kiln. (2) One retorted residue sample was oxidized at 1000[degrees]F. Preliminary indications are that the ash of this run appears to have been completely oxidized. (3) Further minor equipment repairs and improvements were required during the course of the several runs.

Adams, D.C.

1993-04-22T23:59:59.000Z

228

High efficiency shale oil recovery  

SciTech Connect

The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated at bench-scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although a batch oil shale sample will be sealed in the batch kiln from the start until the end of the run, the process conditions for the batch will be the same as the conditions that an element of oil shale would encounter in a large continuous process kiln. For example, similar conditions of heat-up rate (20 deg F/min during the pyrolysis), oxidation of the residue and cool-down will prevail for the element in both systems. This batch kiln is a unit constructed in a 1987 Phase I SBIR tar sand retorting project. The kiln worked fairly well in that project; however, the need for certain modifications was observed. These modifications are now underway to simplify the operation and make the data and analysis more exact. The agenda for the first three months of the project consisted of the first of nine tasks and was specified as the following four items: 1. Sample acquisition and equipment alteration: Obtain seven oil shale samples, of varying grade each 10 lb or more, and samples of quartz sand. Order equipment for kiln modification. 3. Set up and modify kiln for operation, including electric heaters on the ends of the kiln. 4. Connect data logger and make other repairs and changes in rotary batch kiln.

Adams, D.C.

1992-01-01T23:59:59.000Z

229

High efficiency shale oil recovery  

SciTech Connect

The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical (heating, mixing) conditions exist in both systems. The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed and is reported on this quarter: (1) A software routine was written to eliminate intermittently inaccurate temperature readings. (2) We completed the quartz sand calibration runs, resolving calibration questions from the 3rd quarter. (3) We also made low temperature retorting runs to identify the need for certain kiln modifications and kiln modifications were completed. (4) Heat Conductance data on two Pyrolysis runs were completed on two samples of Occidental oil shale.

Adams, D.C.

1992-01-01T23:59:59.000Z

230

Productization and Manufacturing Scaling of High-Efficiency Solar Cell and Module Products Based on a Disruptive Low-Cost, Mono-Crystalline Technology: Final Technical Progress Report, April 1, 2009 - December 30, 2010  

DOE Green Energy (OSTI)

Final report for PV incubator subcontract with Solexel, Inc. The purpose of this project was to develop Solexel's Unique IP, productize it, and transfer it to manufacturing. Silicon constitutes a significant fraction of the total solar cell cost, resulting in an industry-wide drive to lower silicon usage. Solexel's disruptive Solar cell structure got around these challenges and promised superior light trapping, efficiency and mechanical strength, despite being significantly thinner than commercially available cells. Solexel's successful participation in this incubator project became evident as the company is now moving into commercial production and position itself to be competitive for the next Technology Pathway Partnerships (TPP) funding opportunity.

Fatemi, H.

2012-07-01T23:59:59.000Z

231

High-Efficiency Polycrystalline CdTe Thin-Film Solar Cells with an Oxygenated Amorphous CdS (a-CdS:O) Window Layer: Preprint  

DOE Green Energy (OSTI)

In the conventional CdS/CdTe device structure, the poly-CdS window layer has a bandgap of {approx}2.4 eV, which causes absorption in the short-wavelength region. Higher short-circuit current densities (Jsc) can be achieved by reducing the CdS thickness, but this can adversely impact device open-circuit voltage (Voc) and fill factor (FF). Also, poly-CdS film has about 10% lattice mismatch related to the CdTe film, which limits the improvement of device Voc and FF. In this paper, we report a novel window material: oxygenated amorphous CdS film (a-CdS:O) prepared at room temperature by rf sputtering. The a-CdS:O film has a higher optical bandgap (2.5-3.1 eV) than the poly-CdS film and an amorphous structure. The preliminary device results have demonstrated that Jsc of the CdTe device can be greatly improved while maintaining higher Voc and FF. We have fabricated a CdTe cell demonstrating an NREL-confirmed Jsc of 25.85 mA/cm2 and a total-area efficiency of 15.4%.

Wu, X.; Dhere, R. G.; Yan, Y.; Romero, M. J.; Zhang, Y.; Zhou, J.; DeHart, C.; Duda, A.; Perkins, C.; To, B.

2002-05-01T23:59:59.000Z

232

High Aspect Ratio Semiconductor Heterojunction Solar Cells  

E-Print Network (OSTI)

High Aspect Ratio Semiconductor Heterojunction Solar Cells Haoting Shen Prof. Redwing's Research and in-situ dopant for Si nanowires Y. Ke, X.J. Weng, J.M. Redwing, C.M. Eichfeld, T.R. Swisher, S

Yener, Aylin

233

A low cost high flux solar simulator  

E-Print Network (OSTI)

A low cost, high flux, large area solar simulator has been designed, built and characterized for the purpose of studying optical melting and light absorption behavior of molten salts. Seven 1500 W metal halide outdoor ...

Codd, Daniel S.

234

SunShot Initiative: High Penetration Solar Deployment  

NLE Websites -- All DOE Office Websites (Extended Search)

High Penetration Solar Deployment High Penetration Solar Deployment to someone by E-mail Share SunShot Initiative: High Penetration Solar Deployment on Facebook Tweet about SunShot Initiative: High Penetration Solar Deployment on Twitter Bookmark SunShot Initiative: High Penetration Solar Deployment on Google Bookmark SunShot Initiative: High Penetration Solar Deployment on Delicious Rank SunShot Initiative: High Penetration Solar Deployment on Digg Find More places to share SunShot Initiative: High Penetration Solar Deployment on AddThis.com... Concentrating Solar Power Photovoltaics Systems Integration Research, Development, & Demonstration Competitive Awards Solar Utility Networks: Replicable Innovations in Solar Energy High Penetration Solar Deployment Grid Integration Advanced Concepts

235

Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.  

DOE Green Energy (OSTI)

Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures >600 C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.05) in the IR region, be stable in air, and be low-cost and readily manufacturable. We propose to utilize solution-based synthesis techniques to prepare intrinsic absorbers for use in central receiver applications.

Stechel, Ellen Beth; Ambrosini, Andrea; Hall, Aaron Christopher; Lambert, Timothy L.; Staiger, Chad Lynn; Bencomo, Marlene

2010-09-01T23:59:59.000Z

236

High-flux solar photon processes  

DOE Green Energy (OSTI)

This study was commissioned by the National Renewable Energy Laboratory (NREL) for the purpose of identifying high-flux photoprocesses that would lead to beneficial national and commercial applications. The specific focus on high-flux photoprocesses is based on the recent development by NREL of solar concentrator technology capable of delivering record flux levels. We examined photolytic and photocatalytic chemical processes as well as photothermal processes in the search for processes where concentrated solar flux would offer a unique advantage. 37 refs.

Lorents, D C; Narang, S; Huestis, D C; Mooney, J L; Mill, T; Song, H K; Ventura, S [SRI International, Menlo Park, CA (United States)

1992-06-01T23:59:59.000Z

237

Basic studies of 3-5 high efficiency cell components  

DOE Green Energy (OSTI)

This project's objective is to improve our understanding of the generation, recombination, and transport of carriers within III-V homo- and heterostructures. The research itself consists of fabricating and characterizing solar cell building blocks'' such as junctions and heterojunctions as well as basic measurements of material parameters. A significant effort is also being directed at characterizing loss mechanisms in high-quality, III-V solar cells fabricated in industrial research laboratories throughout the United States. The project's goal is to use our understanding of the device physics of high-efficiency cell components to maximize cell efficiency. A related goal is the demonstration of new cell structures fabricated by molecular beam epitaxy (MBE). The development of measurement techniques and characterization methodologies is also a project objective. This report describes our progress during the fifth and final year of the project. During the past five years, we've teamed a great deal about heavy doping effects in p[sup +] and n[sup +] GaAs and have explored their implications for solar cells. We have developed an understanding of the dominant recombination losses in present-day, high-efficiency cells. We've learned to appreciated the importance of recombination at the perimeter of the cell and have developed techniques for chemically passivating such edges. Finally, we've demonstrated that films grown by molecular beam epitaxy are suitable for high-efficiency cell research.

Lundstrom, M.S.; Melloch, M.R.; Pierret, R.F.; Carpenter, M.S.; Chuang, H.L.; Dodd, P.E.; Keshavarzi, A.; Klausmeier-Brown, M.E.; Lush, G.B.; Stellwag, T.B. (Purdue Univ., Lafayette, IN (United States))

1993-01-01T23:59:59.000Z

238

Bringing Energy Efficiency to High Performance Computing  

NLE Websites -- All DOE Office Websites (Extended Search)

Bringing Energy Efficiency to High Performance Computing Oak Ridge National Laboratory's Jaguar Supercomputer William Tschudi September 2013 The ability of high performance...

239

Thermodynamics, Entropy, Information and the Efficiency of Solar Cells  

E-Print Network (OSTI)

Steinborn, Exergy of solar radiation: information approach.detailed in Chapter II. Solar radiation is split into athe spectrum of the solar radiation. The first is the data-

Abrams, Zeev R.

2012-01-01T23:59:59.000Z

240

Impact of High Solar Penetration in the Western Interconnection  

NLE Websites -- All DOE Office Websites (Extended Search)

Impact of High Solar Penetration Impact of High Solar Penetration in the Western Interconnection Debra Lew National Renewable Energy Laboratory Nicholas Miller, Kara Clark, Gary Jordan, and Zhi Gao GE Energy Technical Report NREL/TP-5500-49667 December 2010 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Impact of High Solar Penetration in the Western Interconnection Debra Lew National Renewable Energy Laboratory Nicholas Miller, Kara Clark, Gary Jordan, and Zhi Gao GE Energy Prepared under Task No. SM101610

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Highly Efficient Modeling of Dynamic Coronal Loops  

E-Print Network (OSTI)

Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated quasi-independently by nanoflares. It is therefore an enormous undertaking to model an entire active region or the global corona. Three-dimensional MHD codes have inadequate spatial resolution, and 1D hydro codes are too slow to simulate the many thousands of elemental strands that must be treated in a reasonable representation. Fortunately, thermal conduction and flows tend to smooth out plasma gradients along the magnetic field, so "0D models" are an acceptable alternative. We have developed a highly efficient model called Enthalpy-Based Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of the average temperature, pressure, and density along a coronal strand. It improves significantly upon earlier models of this type--in accuracy, flexibility, and capability. It treats both slowly varying and highly impulsive coronal heating; it provides the differential emission measure distribution, DEM(T), at the transition region footpoints; and there are options for heat flux saturation and nonthermal electron beam heating. EBTEL gives excellent agreement with far more sophisticated 1D hydro simulations despite using four orders of magnitude less computing time. It promises to be a powerful new tool for solar and stellar studies.

J. A. Klimchuk; S. Patsourakos; P. J. Cargill

2007-10-01T23:59:59.000Z

242

Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies  

E-Print Network (OSTI)

by one-sun solar simulator. . . . . . . . . . . . . . .is characterized by one-sun solar simulator as shown in Fig.is characterized by one-sun solar simulator. rials to solar

Wang, Chunhua

2011-01-01T23:59:59.000Z

243

Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies  

E-Print Network (OSTI)

Process 3.2.2 Solar Simulator Spectrum . . . . . . . . . .500nm to 600nm over the solar spectrum, while QDS like CdSe/e?cient use of the solar spectrum. Solar Energy Materials

Wang, Chunhua

2011-01-01T23:59:59.000Z

244

U.S. Department of Energy Solar Decathlon: Challenging Students to Build Energy Efficient, Cost-Effective, and Attractive Solar-Powered Houses  

DOE Green Energy (OSTI)

The U.S. Department of Energy Solar Decathlon challenges collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. The winner of the competition is the team that best blends affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency. The paper discusses the solutions developed for the event. We believe that the solutions implemented for Solar Decathlon 2011 represent current trends and that by analyzing, critiquing, and exposing the solutions pursued, the industry can become better suited to address challenges of the future. Constructing a solar community using high-efficiency design and unique materials while remaining code compliant, safe, and effective results in solutions that are market relevant, important, and interesting to the industry as a whole.

Simon, J.

2012-01-01T23:59:59.000Z

245

High Energy Particles in the Solar Corona  

E-Print Network (OSTI)

Collective Ampere law interactions producing magnetic flux tubes piercing through sunspots into and then out of the solar corona allow for low energy nuclear reactions in a steady state and high energy particle reactions if a magnetic flux tube explodes in a violent event such as a solar flare. Filamentous flux tubes themselves are vortices of Ampere currents circulating around in a tornado fashion in a roughly cylindrical geometry. The magnetic field lines are parallel to and largely confined within the core of the vortex. The vortices may thereby be viewed as long current carrying coils surrounding magnetic flux and subject to inductive Faraday and Ampere laws. These laws set the energy scales of (i) low energy solar nuclear reactions which may regularly occur and (ii) high energy electro-weak interactions which occur when magnetic flux coils explode into violent episodic events such as solar flares or coronal mass ejections.

A. Widom; Y. N. Srivastava; L. Larsen

2008-04-16T23:59:59.000Z

246

Variation of collector efficiency and receiver thermal loss as a function of solar irradiance  

DOE Green Energy (OSTI)

Efficiency and thermal loss of a parabolic trough concentrating solar collector have been measured for values of solar irradiance between 400 W/m/sup 2/ and 1000 W/m/sup 2/. Both parameters are shown to vary significantly with changing solar irradiance. Significant errors can result from improper use of currently published efficiency data.

Dudley, V.E.; Workhoven, R.M.

1982-01-01T23:59:59.000Z

247

High Volume Method of Making Low Cost, Lightweight Solar Materials ...  

A critical challenge for solar energy is the high cost (>$1/W) of quality solar materials. Researchers at ORNL have invented an approach for producing large volumes ...

248

Efficiency of a solar collector with internal boiling  

DOE Green Energy (OSTI)

The behavior of a solar collector with a boiling fluid is analyzed to provide a simple algebraic model for future systems simulations, and to provide guidance for testing. The efficiency equation is developed in a form linear in the difference between inlet and saturation (boiling) temperatures, whereas the expression upon which ASHRAE Standard 109P is based utilizes the difference between inlet and ambient temperatures. The coefficient of the revised linear term is a weak function of collector parameters, weather, and subcooling of the working fluid. For a glazed flat-plate collector with metal absorber, the coefficient is effectively constant. Therefore, testing at multiple values of insolation and subcooling, as specified by ASHRAE 109P, should not be necessary for most collectors. The influences of collector properties and operating conditions on efficiency are examined.

Neeper, D.A.

1986-01-01T23:59:59.000Z

249

Efficiency of a solar collector with internal boiling  

DOE Green Energy (OSTI)

The behavior of a solar collector with a boiling fluid is analyzed to provide a simple algebraic model for future systems simulations, and to provide guidance for testing. The efficiency equation is developed in a form linear in the difference between inlet and saturation (boiling) temperatures, whereas the expression upon which ASHRAE Standard 109P is based utilizes the difference between inlet and ambient temperatures. The coefficient of the revised linear term is a week function of collector parameters, weather, and subcooling of the working fluid. For a glazed flat-plate collector with metal absorber, the coefficient is effectively constant. Therefore, testing at multiple values of insolation and subcooling, as specified by ASHRAE 109P, should not be necessary for most collectors. The influences of collector properties and operating conditions on efficiency are examined.

Neeper, D.A.

1986-06-01T23:59:59.000Z

250

Zero energy homes: Combining energy efficiency and solar energy technologies  

DOE Green Energy (OSTI)

In a typical Florida house, air-conditioning accounts for about 35% of all the electricity the home uses. As the largest single source of energy consumption in Florida, a home's air-conditioning load represents the biggest energy challenge facing Florida residents. The Florida Solar Energy Center designed a project to meet this challenge. Two homes were built with the same floor plan on near-by lots. The difference was that one (the control home) conformed to local residential building practices, and the other (the Zero Energy home) was designed with energy efficiency in mind and a solar technology system on the roof. The homes were then monitored carefully for energy use. The projects designers were looked to answer two questions: (1) could a home in a climate such as central Florida be engineered and built so efficiently that a relatively small PV system would serve the majority of its cooling needs--and even some of its daytime electrical needs; and (2) would that home be as comfortable and appealing as the conventional model built alongside it? The answer was yes, even though it was conducted in the summer of 1998--one of the hottest summers on record in Florida.

NREL

2000-03-09T23:59:59.000Z

251

Efficiency-improvement study for GaAs solar cells. Final report, March 31, 1980-September 30, 1981  

DOE Green Energy (OSTI)

High-yield fabrication of good quality AlGaAs/GaAs concentration solar cells has been a limiting factor in widespread utilization of these high conversion efficiency (22 to 24%) photovoltaic cells. Reported is a series of investigations to correlate solar cell yield with substrate quality, growth techniques, layer composition, and metallization processes. In addition, several diagnostic techniques are described to aid in device characterization.

Cape, J.A.; Oliver, J.R.; Zehr, S.W.

1982-04-01T23:59:59.000Z

252

High-Efficiency Neutron Detection and Spectroscopy ...  

Science Conference Proceedings (OSTI)

... are also working on a large volume detector to use in the underground environment where high efficiency is more important that energy resolution. ...

2013-07-22T23:59:59.000Z

253

SunShot Initiative: Development and Productization of High-Efficiency,  

NLE Websites -- All DOE Office Websites (Extended Search)

Development and Productization of Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells to someone by E-mail Share SunShot Initiative: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells on Facebook Tweet about SunShot Initiative: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells on Twitter Bookmark SunShot Initiative: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells on Google Bookmark SunShot Initiative: Development and Productization of

254

Collector efficiency of the double-pass solar air collectors with fins  

Science Conference Proceedings (OSTI)

The experimental study on a forced-convective double-pass solar air collector with fins in the second channel has been conducted. The experiments were conducted by changing the parameters that influence the thermal efficiency of the collector. The efficiency ... Keywords: collector efficiency, double-pass solar air collector, fins absorbers

A. Fudholi; M. H. Ruslan; M. Y. Othman; M. Yahya; Supranto Supranto; A. Zaharim; K. Sopian

2010-10-01T23:59:59.000Z

255

Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies  

E-Print Network (OSTI)

and V.U. Ho?mann. Photovoltaic Solar Energy Gen- eration.e?ciency for photovoltaic solar energy collections, reviewedenergy sources, the manufacturing of solar cells and photovoltaic

Wang, Chunhua

2011-01-01T23:59:59.000Z

256

Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies  

E-Print Network (OSTI)

dyes. Photovoltaic (PV) solar cells are used to attach atis fa- vored by the silicon PV solar cells for the LSC PVemission properties for PV solar cells. We studied e?ect of

Wang, Chunhua

2011-01-01T23:59:59.000Z

257

Sandia National Laboratories High Efficiency Multiple-Junction ...  

Sandia National Laboratories TECHNOLOGY SUMMARY Single junction solar cells have limited efficiency and fail to extract maximum energy from photons outside of a specific

258

Development of an Efficient Solar Powered Unmanned Aerial Vehicle with an Onboard Solar Tracker.  

E-Print Network (OSTI)

??Methods were developed for the design of a solar powered UAV capable of tracking the sun to achieve maximum solar energy capture. A single-axis solar… (more)

Tegeder, Troy Dixon 1979-

2007-01-01T23:59:59.000Z

259

Searching for the Optimal Mix of Solar and Efficiency in Zero Net Energy Buildings: Preprint  

SciTech Connect

Zero net energy buildings employ efficiency to reduce energy consumption and solar technologies to produce as much energy on site as is consumed on an annual basis.

Horowitz, S.; Christensen, C.; Anderson, R.

2008-08-01T23:59:59.000Z

260

NREL: News Feature - New Solar Cell Is More Efficient, Less Costly  

NLE Websites -- All DOE Office Websites (Extended Search)

it comes to squeezing more efficiency and lower costs out of silicon, the workhorse of solar photovoltaic (PV) cells and modules worldwide. A recent breakthrough - the product...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Phase II Final Project Report SBIR Project: "A High Efficiency PV to Hydrogen Energy System"  

Science Conference Proceedings (OSTI)

The innovative research conducted for this project contributed greatly to the understanding of generating low-cost hydrogen from solar energy. The project’s research identified two highly leveraging and complementary pathways. The first pathway is to dramatically increase the efficiency of converting sunlight into electricity. Improving solar electric conversion efficiency directly increases hydrogen production. This project produced a world record efficiency for silicon solar cells and contributed to another world record efficiency for a solar concentrator module using multijunction solar cells. The project’s literature review identified a second pathway in which wasted heat from the solar concentration process augments the electrolysis process generating hydrogen. One way to do this is to use a “heat mirror” that reflects the heat-producing infrared and transmits the visible spectrum to the solar cells; this also increases solar cell conversion efficiency. An economic analysis of this concept confirms that, if long-term concentrator photovoltaic (CPV) and solid-oxide electrolyzer cost goals can be achieved, hydrogen will be produced from solar energy cheaper than the cost of gasoline. The potential public benefits from this project are significant. The project has identified a potential energy source for the nation’s future electricity and transportation needs that is entirely “home grown” and carbon free. As CPV enter the nation’s utility markets, the opportunity for this approach to be successful is greatly increased. Amonix strongly recommends further exploration of this project’s findings.

Slade, A; Turner, J; Stone, K; McConnell, R

2008-09-02T23:59:59.000Z

262

Efficient high density train operations  

DOE Patents (OSTI)

The present invention provides methods for preventing low train voltages and managing interference, thereby improving the efficiency, reliability, and passenger comfort associated with commuter trains. An algorithm implementing neural network technology is used to predict low voltages before they occur. Once voltages are predicted, then multiple trains can be controlled to prevent low voltage events. Further, algorithms for managing inference are presented in the present invention. Different types of interference problems are addressed in the present invention such as "Interference. During Acceleration", "Interference Near Station Stops", and "Interference During Delay Recovery." Managing such interference avoids unnecessary brake/acceleration cycles during acceleration, immediately before station stops, and after substantial delays. Algorithms are demonstrated to avoid oscillatory brake/acceleration cycles due to interference and to smooth the trajectories of closely following trains. This is achieved by maintaining sufficient following distances to avoid unnecessary braking/accelerating. These methods generate smooth train trajectories, making for a more comfortable ride, and improve train motor reliability by avoiding unnecessary mode-changes between propulsion and braking. These algorithms can also have a favorable impact on traction power system requirements and energy consumption.

Gordon, Susanna P. (Oakland, CA); Evans, John A. (Hayward, CA)

2001-01-01T23:59:59.000Z

263

Bilayer Polymer Solar Cells with Improved Power Conversion Efficiency and Enhanced Spectrum Coverage  

SciTech Connect

We demonstrate the construction of an efficient bilayer polymer solar cell comprising of Poly(3-hexylthiophene)(P3HT) as a p-type semiconductor and asymmetric fullerene (C{sub 70}) as n-type counterparts. The bilayer configuration was very efficient compared to the individual layer performance and it behaved like a regular p-n junction device. The photovoltaic characteristic of the bilayers were studied under AM 1.5 solar radiation and the optimized device parameters are the following: Voc = 0.5V, Jsc = 10.1 mA/cm{sup 2}, FF = 0.60 and power conversion efficiency of 3.6 %. A high fill factor of {approx}0.6 was achieved, which is only slightly reduced at very intense illumination. Balanced mobility between p-and n-layers is achieved which is essential for achieving high device performance. Correlation between the crystallinity, morphology and the transport properties of the active layers is established. The External quantum efficiency (EQE) spectral distribution of the bilayer devices with different processing solvents correlates well with the trends of short circuit current densities (J{sub sc}) measured under illumination. Efficiency of the bilayer devices with rough P3HT layer was found to be about 3 times higher than those with a planar P3HT surface. Hence it is desirable to have a larger grains with a rough surface of P3HT layer for providing larger interfacial area for the exciton dissociation.

Kekuda, Dhananjaya [Department of Physics, Manipal Institute of Technology, Manipal University, Manipal, India 576 104 (India); Chu, Chih-Wei [Research Center for Applied Science, Academia Sinica, Taipei, Taiwan 300 13 (China)

2011-10-20T23:59:59.000Z

264

High Efficiency New Metallurgical Technology  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... The alumina leaching rate of calcium aluminate in residue is over 80%. .... Different types of plasma torches including a high power steam plasma torch ... for about 50% of the total NOX emissions in the iron and steel industry.

265

Development and Testing of High-Temperature Solar Selective Coatings  

DOE Green Energy (OSTI)

The Solar Energy Technologies Program is working to reduce the cost of parabolic trough solar power technology. System studies show that increasing the operating temperature of the solar field from 390 to >450 C will result in improved performance and cost reductions. This requires the development of new more-efficient selective coatings that have both high solar absorptance (>0.96) and low thermal emittance (<0.07) and are thermally stable above 450 C, ideally in air. Potential selective coatings were modeled, identified for laboratory prototyping, and manufactured at NREL. Optimization of the samples and high-temperature durability testing will be performed. Development of spectrally selective materials depends on reliable characterization of their optical properties. Protocols for testing the thermal/optical properties of selective coatings were developed and a round-robin experiment was conducted to verify and document the reflectance and high-temperature emittance measurements. The development, performance, and durability of these materials and future work will be described.

Kennedy, C.; Price, H.

2005-01-01T23:59:59.000Z

266

Research on stable, high-efficiency amorphous silicon multijunction modules  

DOE Green Energy (OSTI)

This report describes the progress made during Phase 1 of research and development program to obtain high-efficiency amorphous silicon alloy multijunction modules. Using a large-area deposition system, double-and triple-junction cells were made on stainless steel substrates of over 1 ft{sup 2} area with Ag and ZnO predeposited back reflector. Modules of over 1 ft{sup 2} were produced with between 9.2% and 9.9 initial aperture-area efficiencies as measured under a USSC Spire solar simulator. Efficiencies as measured under the NREL Spire solar simulator were found to be typically 15% to 18% lower. The causes for this discrepancy are now being investigated. The modules show about 15% degradation after 600 hours of one-sun illumination at 50{degrees}C. To optimize devices for higher stabilized efficiency, a new method was developed by which the performance of single-junction cells after long-term, one-sun exposure at 50{degrees}C can be predicted by exposing cells to short-term intense light at different temperatures. This method is being used to optimize the component cells of the multijunction structure to obtain the highest light-degraded efficiency.

Banerjee, A.; Chen, E.; Clough, R.; Glatfelter, T.; Guha, S.; Hammond, G.; Hopson, M.; Jackett, N.; Lycette, M.; Noch, J.; Palmer, T.; Pawlikiewicz, A.; Rosenstein, I.; Ross, R.; Wolf, D.; Xu, X.; Yang, J.; Younan, K.

1992-04-01T23:59:59.000Z

267

Multicolor, High Efficiency, Nanotextured LEDs  

SciTech Connect

We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and green for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) heteroepitaxy of nitrogen-polar LEDs on sapphire, (ii) heteroepitaxy of semipolar (11{bar 2}2) green LEDs on sapphire, (iii) synthesis of quantum-dot loaded nanoporous GaN that emits white light without phosphor conversion, (iv) demonstration of the highest quality semipolar (11{bar 2}2) GaN on sapphire using orientation-controlled epitaxy, (v) synthesis of nanoscale GaN and InGaN medium, and (vi) development of a novel liftoff process for manufacturing GaN thin-film vertical LEDs. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

Jung Han; Arto Nurmikko

2011-09-30T23:59:59.000Z

268

High Rate Laser Pitting Technique for Solar Cell Texturing  

SciTech Connect

High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a production tool and process. The developed technique will have an reducing impact on product pricing. As efficiency has a substantial impact on the economics of solar cell production due to the high material cost content; in essence, improved efficiency through cost-effective texturing reduces the material cost component since the product is priced in terms of $/W. The project is a collaboration between Fraunhofer USA, Inc. and a c-Si PV manufacturer.

Hans J. Herfurth; Henrikki Pantsar

2013-01-10T23:59:59.000Z

269

Author's personal copy Maximizing the solar to H2 energy conversion efficiency  

E-Print Network (OSTI)

Author's personal copy Maximizing the solar to H2 energy conversion efficiency of outdoor, Cockrell School of Engineering, The University of Texas at Austin ­ Austin, TX 78712, USA b Mechanical t A numerical study is presented aiming to maximize the solar to hydrogen energy conversion efficiency

Pilon, Laurent

270

EERE Roofus' Solar and Efficient Home: Find-a-Word  

NLE Websites -- All DOE Office Websites (Extended Search)

Windows Activities Pizza Box Solar Oven Sundial Word Game Coloring Page Printable Version Find-a-Word Can you help Roofus find the words that he uses in his solar house? Find the...

271

EERE: Roofus' Solar and Efficient Home Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

smart, too' The illustration shows an electric meter on the side of the house, a solar car in the driveway, a washer and dryer in the house, a solar panel on the house roof,...

272

SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Efficiency Thermal Energy High-Efficiency Thermal Energy Storage System for CSP to someone by E-mail Share SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Facebook Tweet about SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Twitter Bookmark SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Google Bookmark SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Delicious Rank SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Digg Find More places to share SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards CSP Research & Development Thermal Storage CSP Recovery Act

273

NREL: News Feature - Super-Efficient Cells Key to Low-Cost Solar Power  

NLE Websites -- All DOE Office Websites (Extended Search)

Super-Efficient Cells Key to Low-Cost Solar Power Super-Efficient Cells Key to Low-Cost Solar Power February 16, 2011 This photo shows eight Amonix 7700 solar power generators, those in front tilted horizontally, those in the rear tilted near vertically. Each is a huge rectangle divided into hundreds of squares holding cells and lenses. Enlarge image The Amonix 7700 Concentrated Photovoltaic (CPV) Solar Power Generators are showcasing reliability and undergoing validation-of-performance measurements at the SolarTAC facility in Aurora, Colo. Credit: Dennis Schroeder In this photo, a man in an orange safety vest and hardhat is using a laptop, with large concentrated photovoltaic generators in the background. Enlarge image A technician at SolarTAC in Aurora, CO, enters some numbers into a laptop as he monitors validation of the Amonix 7700 Solar Power Generators.

274

The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Mission  

E-Print Network (OSTI)

The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Mission R. P. fla B. Dennis, G mission is to investigate the physics of particle acceleration and energy release in solar flares, through-ray/gamma-ray spectroscopy 1. INTRODUCTION The primary scientific objective of the Reuven Ramaty High Energy Solar

California at Berkeley, University of

275

Documentation of high resolution solar resource assessment (10km...  

Open Energy Info (EERE)

resolution solar resource assessment for China provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global...

276

Documentation of high resolution solar resource assessment (10km...  

Open Energy Info (EERE)

solar resource assessment for Ethiopia provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global...

277

Documentation of high resolution solar resource assessment for...  

Open Energy Info (EERE)

solar resource assessment for Sri Lanka provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global...

278

Documentation of high resolution solar resource assessment (10km...  

Open Energy Info (EERE)

resolution solar resource assessment for Nepal provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global...

279

Documentation of high resolution solar resource assessment (10km...  

Open Energy Info (EERE)

resolution solar resource assessment for Kenya provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global...

280

Documentation of high resolution solar resource assessment for...  

Open Energy Info (EERE)

resolution solar resource assessment for Ghana provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Residential Solar and Efficiency Tax Credit - Personal (Massachusetts...  

Open Energy Info (EERE)

Programmable Thermostats, DuctAir sealing, Building Insulation, Windows, Solar Water Heat, Other Unspecified Technologies Active Incentive No Implementing Sector State...

282

Residential Solar and Efficiency Tax Credit - Corporate (Massachusetts...  

Open Energy Info (EERE)

Programmable Thermostats, DuctAir sealing, Building Insulation, Windows, Solar Water Heat, Other Unspecified Technologies Active Incentive No Implementing Sector State...

283

Improved Solar Power Plant Efficiency: Low Cost Vaccine ...  

Background Photovoltaic (PV) systems are of great interest to the efforts of sustainable energy. Solar irradiance is a measure of the sun’s ...

284

Available Technologies: Low-cost, Efficient, Flexible Solar ...  

3D solar cell of nanopillars. ... Layered Nanocrystal Photovoltaic Cells, IB-2511 . Hot Electron Photovoltaics Using Low Cost Materials and Simple Cel ...

285

An Upside-Down Solar Cell Achieves Record Efficiencies (Fact...  

NLE Websites -- All DOE Office Websites (Extended Search)

by the Federal Laboratory Consortium. The cell's inventors pioneered a new class of solar cells with marked advantages in performance, engineering design, operation, and...

286

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

device technology that will help realize the intrinsic potential of these materials. Solar Panels To Go Photovoltaic cells are a key component of most visions of a...

287

Thermodynamics, Entropy, Information and the Efficiency of Solar Cells  

E-Print Network (OSTI)

and P.T. Landsberg, Thermodynamics and reciprocity of solar59. E. Yablonovitch, Thermodynamics of the fluorescentC. 139. E. Yablonovitch, Thermodynamics of the fluorescent

Abrams, Zeev R.

2012-01-01T23:59:59.000Z

288

Parabolic trough solar collectors : design for increasing efficiency.  

E-Print Network (OSTI)

??Parabolic trough collectors are a low cost implementation of concentrated solar power technology that focuses incident sunlight onto a tube filled with a heat transfer… (more)

Figueredo, Stacy L. (Stacy Lee), 1981-

2011-01-01T23:59:59.000Z

289

New Funding Boosts Carbon Capture, Solar Energy and High Gas Mileage Cars  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

New Funding Boosts Carbon Capture, Solar Energy and High Gas New Funding Boosts Carbon Capture, Solar Energy and High Gas Mileage Cars and Trucks New Funding Boosts Carbon Capture, Solar Energy and High Gas Mileage Cars and Trucks June 11, 2009 - 12:00am Addthis WASHINGTON D.C. --- U.S. Energy Secretary Steven Chu today announced more than $300 million worth of investments that will boost a range of clean energy technologies - including carbon capture from coal, solar power, and high efficiency cars and trucks. The move reflects the Obama Administration's commitment to a broad based strategy that will create millions of jobs while transforming the way we use and produce energy. "There's enormous potential for new jobs and reduced carbon pollution just by implementing existing technologies like energy efficiency and wind

290

Measure Guideline: High Efficiency Natural Gas Furnaces  

SciTech Connect

This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

Brand, L.; Rose, W.

2012-10-01T23:59:59.000Z

291

Effect of water storage tanks design in solar combisystems efficiency  

Science Conference Proceedings (OSTI)

One of the key components of a solar combisystem is the heat store. In the international literature the matter of storage necessity for solar systems is well justified. We build an experimental system assisted by a stratified storage tank and we estimate ... Keywords: fractional savings, storage tank, stratification

Nikolaos Taoussanidis

2007-05-01T23:59:59.000Z

292

New Fabrication Method Improves the Efficiency and Economics of Solar Cells (Fact Sheet)  

DOE Green Energy (OSTI)

Synthetic fabrication strategy optimizes the illumination geometry and transport properties of dye-sensitized solar cells. Using oriented titanium oxide (TiO{sub 2}) nanotube (NT) arrays has shown promise for dye-sensitized solar cells (DSSCs). High solar conversion efficiency requires that the incident light enters the cell from the photoelectrode side. However, for NT-based DSSCs, the light normally enters the cell through the counter electrode because a nontransparent titanium foil is typically used as the substrate for forming the aligned NTs and for making electrical contact with them. It has been synthetically challenging to prepare transparent TiO{sub 2} NT electrodes by directly anodizing Ti metal films on transparent conducting oxide (TCO) substrates because it is difficult to control the synthetic conditions. National Renewable Energy Laboratory (NREL) researchers have developed a general synthetic strategy for fabricating transparent TiO{sub 2} NT films on TCO substrates. With the aid of a conducting Nb-doped TiO{sub 2} (NTO) layer between the Ti film and TCO substrate, the Ti film can be anodized completely without degrading the TCO. The NTO layer protects the TCO from degradation through a self-terminating mechanism by arresting the electric field-assisted dissolution process at the NT-NTO interface. NREL researchers found that the illumination direction and wavelength of the light incident on the DSSCs strongly influenced the incident photon-to-current conversion efficiency, light-harvesting, and charge-collection properties, which, in turn, affect the photocurrent density, photovoltage, and solar energy conversion efficiency. Researchers also examined the effects of NT film thickness on the properties and performance of DSSCs and found that illuminating the cell from the photoelectrode side substantially increased the conversion efficiency compared with illuminating it from the counter-electrode side. This method solves a key challenge in fabricating NT-based DSSCs and determines an optimal illumination direction to use in these cells. The synthetic fabrication strategy will improve the economics and conversion efficiency of DSSCs.

Not Available

2012-07-01T23:59:59.000Z

293

Highly efficient photochemical HCOOH production from CO{sub 2} and water using an inorganic system  

SciTech Connect

We have constructed a system that uses solar energy to react CO{sub 2} with water to generate formic acid (HCOOH) at an energy conversion efficiency of 0.15%. It consists of an AlGaN/GaN anode photoelectrode and indium (In) cathode that are electrically connected outside of the reactor cell. High energy conversion efficiency is realized due to a high quantum efficiency of 28% at 300 nm, attributable to efficient electron-hole separation in the semiconductor's heterostructure. The efficiency is close to that of natural photosynthesis in plants, and what is more, the reaction product (HCOOH) can be used as a renewable energy source.

Yotsuhashi, Satoshi; Hashiba, Hiroshi; Deguchi, Masahiro; Zenitani, Yuji; Hinogami, Reiko; Yamada, Yuka [Advanced Technology Research Laboratory, Panasonic Corporation, Soraku-gun, Kyoto 619-0237 (Japan); Deura, Momoko; Ohkawa, Kazuhiro [Department of Applied Physics, Tokyo University of Science, Shinjuku, Tokyo 162-8601 (Japan)

2012-12-15T23:59:59.000Z

294

Preparation of cuxinygazsen (X=0-2, Y=0-2, Z=0-2, N=0-3) precursor films by electrodeposition for fabricating high efficiency solar cells  

DOE Patents (OSTI)

High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

Bhattacharya, Raghu N. (Littleton, CO); Contreras, Miguel A. (Golden, CO); Keane, James (Lakewood, CO); Tennant, Andrew L. (Denver, CO); Tuttle, John R. (Denver, CO); Ramanathan, Kannan (Lakewood, CO); Noufi, Rommel (Golden, CO)

1998-03-24T23:59:59.000Z

295

Absorber and emitter for solar thermo-photovoltaic systems to achieve efficiency  

E-Print Network (OSTI)

Pbs photovoltaic cells," Int. J. Energy Res. 16(6), 481­487 (1992). 7. V. Badescu, "ThermodynamicAbsorber and emitter for solar thermo- photovoltaic systems to achieve efficiency exceeding, provides a sharp emissivity peak at the solar cell band-gap while suppressing emission at lower frequencies

Fan, Shanhui

296

Better Solar Cells and Manufacturing Processes Using NREL's Ultrafast Quantum Efficiency Method (Fact Sheet)  

DOE Green Energy (OSTI)

Fact sheet on the FlashQE system, a 2011 R&D 100 Award winner. A solid-state optical system by NREL and Tau Science measures solar cell quantum efficiency in less than a second, enabling a suite of new capabilities for solar cell manufacturers.

Not Available

2011-08-01T23:59:59.000Z

297

EERE Roofus' Solar and Efficient Home: Build a Pizza Box Solar...  

NLE Websites -- All DOE Office Websites (Extended Search)

Activities Pizza Box Solar Oven Sundial Word Game Coloring Page Printable Version Build a Pizza Box Solar Oven Illustration of a pizza box. The sun is hot enough to bake food....

298

Impact of High Solar Penetration in the Western Interconnection  

DOE Green Energy (OSTI)

This paper presents an overview of the variable characteristics of solar power, as well as the accompanying grid dynamic performance and operational economics for a system with significant solar generation. The paper will show results of economic operational simulations of a very high solar generation future for the western half of the United States.

Lew, D.; Miller, N.; Clark, K.; Jordan, G.; Gao, Z.

2010-12-01T23:59:59.000Z

299

Microscopic Mechanism of the Staebler-Wronski Effect in a-Si Films and High-Efficiency Solar Cells: Final Subcontract Report, 1 October 2001--30 September 2004  

DOE Green Energy (OSTI)

In high growth rate ({ge} 50 {angstrom}/s) HW-CVD a-Si:H films, for the first time, we show gaseous molecules in nanovoids ({approx}2% volume fraction of tube-like nanoscale voids), and demonstrate that confinement on the nanometer scale generates NMR effects that have never been observed in macroscopic systems. In the same system we found the PL peak red shift. We suggest that highly strained bonds on the inner surfaces of the nanoscale voids form broad conduction-band tail states that are responsible for the PL red shift. We characterized the structural transition from a- to nc-Si as function of H-dilution, thickness and T{sub s} of both HW- and PE-CVD films using IR, Raman, PL, CPM/PDS and E{sub a} et al. We found not only the c-Si volume fraction but also the g.b. and microstructures play an important role in the properties of the i-layer and their solar cell performance. We found a narrow structural transition zone in which the bond-angle variation, {Delta}{Theta}, decreases from 10{sup o} to 8{sup o}. For nc-Si samples, we found a characteristic low energy PL peak and proved that is originated from the g.b. regions. Using micro-Raman, we found the structural non-uniformity in the mixed-phase solar cells that showed V{sub oc} enhancement after light soaking. Using micro-Raman, we also found the slight increase of crystallinity in M/{mu}c-Si/M devices after current forming.

Han, D.

2005-05-01T23:59:59.000Z

300

Improving PbS Quantum Dot Solar Cell Power Conversion Efficiency...  

NLE Websites -- All DOE Office Websites (Extended Search)

research team developed a new process that improves the efficiency of PbS quantum dot solar power conversion. Key Result By using a transition metal oxide in the quantum dot...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

EERE Roofus' Solar and Efficient Home: Build a Sundial  

NLE Websites -- All DOE Office Websites (Extended Search)

Activities Pizza Box Solar Oven Sundial Word Game Coloring Page Printable Version Build a Sundial Illustration of a sundial, which is a round disk with a triangular piece that...

302

Efficient light trapping structure in thin film silicon solar cells  

E-Print Network (OSTI)

Thin film silicon solar cells are believed to be promising candidates for continuing cost reduction in photovoltaic panels because silicon usage could be greatly reduced. Since silicon is an indirect bandgap semiconductor, ...

Sheng, Xing

303

Brunswick EMC - Residential Energy Efficiency and Solar Water...  

Open Energy Info (EERE)

insulation, and solar water heaters. The loans of up to 6,000 are available to homeowners served by BEMC for at least one year and who have a good credit history. Incentive...

304

High voltage series connected tandem junction solar battery  

DOE Patents (OSTI)

A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

Hanak, Joseph J. (Lawrenceville, NJ)

1982-01-01T23:59:59.000Z

305

High Performance Solar Control Office Windows  

E-Print Network (OSTI)

Solar Control Office Windows William King December 1977 C'eSOLAR CONTROL OFFICE WINDOWS Wm. J. King KINETIC COATINGS,R. Berman. Consultation on window characteristics and aid in

King, William J.

2011-01-01T23:59:59.000Z

306

High Resolution Solar Energy Resource Assessment within the UNEP Project  

Open Energy Info (EERE)

High Resolution Solar Energy Resource Assessment within the UNEP Project High Resolution Solar Energy Resource Assessment within the UNEP Project SWERA Dataset Summary Description (Abstract): To expand the world wide use of renewable energy a consistent, reliable, verifiable, and easily accessible database of solar energy resources is needed. Within the UNEP (United Nations Environment Programme) Project SWERA (Solar and Wind Energy Resource Assessment, http://swera.unep.net), funded by GEF (Global Environment Facility), a global database of solar and wind energy resources will be set up. SWERA will provide, beside the wind products, global horizontal irradiance, which is mostly used to plan photovoltaic systems, and direct normal irradiance, which is needed for solar concentrating systems. For selected countries throughout the world, additionally high resolution data will be produced which is required to plan solar energy systems in detail. Within SWERA, the partners DLR, SUNY and INPE calculate solar irradiance with high temporal resolution of 1 hour and with a spatial resolution of 10km x 10km. By processing data from geostationary satellites we provide solar irradiance data for Cuba, El Salvador, Honduras, Nicaragua, Guatemala, Brazil, Ghana, Ethiopia, Kenya, China, Sri Lanka, Nepal, and Bangladesh. In this paper we describe the ongoing work of developing this high resolution solar irradiance tx_metadatatool and cross-checking of the used solar irradiance algorithms for various satellite data.

307

Building Technologies Office: Highly Energy Efficient Wall Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

Highly Energy Efficient Wall Systems Research Project to someone by E-mail Share Building Technologies Office: Highly Energy Efficient Wall Systems Research Project on Facebook...

308

Vehicle Technologies Office: Materials for High Efficiency Combustion...  

NLE Websites -- All DOE Office Websites (Extended Search)

High Efficiency Combustion Engines to someone by E-mail Share Vehicle Technologies Office: Materials for High Efficiency Combustion Engines on Facebook Tweet about Vehicle...

309

Energy Efficiency Opportunities in Federal High Performance Computing...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy Efficiency Opportunities in Federal High Performance Computing Data Centers Energy Efficiency Opportunities in Federal High Performance Computing Data Centers Case study...

310

High Resolution Solar Energy Resource Assessment within the UNEP...  

Open Energy Info (EERE)

High Resolution Solar Energy Resource Assessment within the UNEP Project SWERA

(Abstract):  To expand the world wide use of renewable energy a consistent,...

311

High Volume Method of Making Low Cost, Lightweight Solar Materials  

ORNL 2010-G00644/jcn UT-B ID 201002380 High Volume Method of Making Low Cost, Lightweight Solar Materials Technology Summary A critical challenge for ...

312

High Efficiency Adsorption Chillers: High Efficiency Adsorption Cooling Using Metal Organic Heat Carriers  

SciTech Connect

BEETIT Project: PNNL is incorporating significant improvements in materials that adsorb liquids or gases to design more efficient adsorption chillers. An adsorption chiller is a type of air conditioner that is powered by heat, solar or waste heat, or combustion of natural gas. Unlike typical chillers, this type has few moving parts and uses almost no electricity to operate. PNNL is designing adsorbent materials at the molecular level with at least 3 times higher refrigerant capacity and up to 20 times faster kinetics than adsorbents used in current chillers. By using the new adsorbent, PNNL is able to create a chiller that is significantly smaller, has twice the energy efficiency, and lower costs for materials and assembly time compared to conventional adsorption chillers.

None

2010-10-01T23:59:59.000Z

313

Thermal-Electric Conversion Efficiency of the Dish/AMTEC Solar Thermal Power System in Wind Condition  

Science Conference Proceedings (OSTI)

The dish/AMTEC solar thermal power system is a newly proposed solar energy utilization system that enables the direct thermal-electric conversion. The performance of the solar dish/AMTEC system in wind condition has been theoretically evaluated in addition ... Keywords: dish/AMTEC solar thermal power system, efficiency, thermal-electric conversion, wind condition

Lan Xiao; Shuang-Ying Wu; You-Rong Li

2012-07-01T23:59:59.000Z

314

High efficiency inverter and ballast circuits  

SciTech Connect

A high efficiency push-pull inverter circuit employing a pair of relatively high power switching transistors is described. The switching on and off of the transistors is precisely controlled to minimize power losses due to common-mode conduction or due to transient conditions that occur in the process of turning a transistor on or off. Two current feed-back transformers are employed in the transistor base drives; one being saturable for providing a positive feedback, and the other being non-saturable for providing a subtractive feedback.

Nilssen, O.K.

1984-02-07T23:59:59.000Z

315

Multi-band high efficiency power amplifier  

E-Print Network (OSTI)

Baseline) Output Power (Transformer) Drain Efficiency (Performance Frequency (GHz) Output Power (Transformer) DrainEfficiency (Transformer) Output Power (Baseline) Drain

Besprozvanny, Randy-Alexander Randolph

2011-01-01T23:59:59.000Z

316

Building Technologies Office: High Efficiency, Low Emission Supermarket  

NLE Websites -- All DOE Office Websites (Extended Search)

High Efficiency, Low High Efficiency, Low Emission Supermarket Refrigeration Research Project to someone by E-mail Share Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Facebook Tweet about Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Twitter Bookmark Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Google Bookmark Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Delicious Rank Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Digg Find More places to share Building Technologies Office: High

317

Toward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power  

E-Print Network (OSTI)

. Building Technologies Program, 2007 Buildings Energy Data Book (Washington, DC: Office of Energy Efficiency Annual Energy Outlook with Projections to 2030 (Washington, DC, 2008). 17. VentureSource data as citedToward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power By Merrian C. Fuller

Kammen, Daniel M.

318

Overcoming the Efficiency-Limiting Mechanisms in Commercial Si Solar Cells  

DOE Green Energy (OSTI)

A brief review of performance-limiting processes in a commercial solar cell fabricated on low-cost substrate is given. Higher efficiencies require effective gettering of precipitated impurities present at the defect clusters, and improved cell and process designs. Overcoming these limitations is expected to lead to 18%-20% cell efficiencies.

Sopori, B.; Chen, W. (National Renewable Energy Laboratory); Tan, T.; Plekhanov, P. (Duke University, Raleigh, NC)

1998-11-19T23:59:59.000Z

319

Highly Efficient Silicon Light Emitting Diode  

E-Print Network (OSTI)

In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a local strain field that is formed by dislocation loop arrays. The dependence of device electroluminescent properties on the annealing conditions is carefully examined as a high temperature process has profound influence on these dislocations. Increased luminescent intensity at higher device temperature, together with pure diffusion current conduction mechanism evidently shows the influence of the dislocation loops. The electrical properties of the diode are reasonable with low leakage reverse current.

Leminh Holleman Wallinga; P. Leminh; J. Holleman; H. Wallinga

2000-01-01T23:59:59.000Z

320

High performance solar control office windows  

SciTech Connect

Investigations conducted over a 9 month period on the use of ion beam sputtering methods for the fabrication of solar control windows for energy conservation are described. Principal emphasis was placed on colored, reflecting, heat rejecting, office building windows for reducing air conditioning loads and to aid in the design of energy conserving buildings. The coating techniques were developed primarily for use with conventional absorbing plate glass such as PPG solarbronze, but were also demonstrated on plastic substrates for retrofit applications. Extensive material investigations were conducted to determine the optimum obtainable characteristics, with associated weathering studies as appropriate aimed at achieving a 20 year minimum life. Conservative estimates indicate that successful commercialization of the windows developed under this program would result in energy savings of 16,000,000 barrels of oil/year by 1990 if installation were only 10 percent of new commercial building stock. These estimates are relative to existing design for energy conserving windows. Installation in a greater percentage of new stock and for retrofit applications could lead to proportionately greater energy savings. All such installations are projected as cost effective as well as energy effective. A secondary program was carried out to modify the techniques to yield thermal control windows for residential applications. These windows were designed to provide a high heat retention capability without seriously affecting their transmission of incident solar radiation, thereby enhancing the greenhouse effect. This part of the program was successful in producing a window form which could be interchanged for standard residential window material in a cost and energy effective manner. The only variation from standard stock in appearance is a very light rose or neutral gray coloring.

King, W.J.

1977-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

NREL: News - NREL Reports 31.1% Efficiency for III-V Solar Cell  

NLE Websites -- All DOE Office Websites (Extended Search)

913 913 NREL Reports 31.1% Efficiency for III-V Solar Cell Conversion-efficiency mark is a world record for a two-junction solar cell measured under one-sun illumination June 24, 2013 The Energy Department's National Renewable Energy Lab has announced a world record of 31.1% conversion efficiency for a two-junction solar cell under one sun of illumination. NREL Scientist Myles Steiner announced the new record June 19 at the 39th IEEE Photovoltaic Specialists Conference in Tampa, Fla. The previous record of 30.8% efficiency was held by Alta Devices. The tandem cell was made of a gallium indium phosphide cell atop a gallium arsenide cell, has an area of about 0.25 square centimeters and was measured under the AM1.5 global spectrum at 1,000 W/m2. It was grown inverted, similar to the NREL-developed inverted metamorphic multi-junction

322

Thermodynamics, Entropy, Information and the Efficiency of Solar Cells  

E-Print Network (OSTI)

state-of-the-art photovoltaic cells. Prog. Photovolt: Res.efficiency of an ideal photovoltaic cell with charge carrierefficiency of photovoltaic and photoelectrolysis cells with

Abrams, Zeev R.

2012-01-01T23:59:59.000Z

323

City of Long Beach - Residential Energy Efficiency and Solar...  

Open Energy Info (EERE)

condominiums, and livework units who purchase certain energy efficient appliances. Homeowners who install Energy Star certified windows, doors, skylights, roofs, tankless water...

324

Energy Efficiency Opportunities in Federal High Performance Computing Data Centers  

Energy.gov (U.S. Department of Energy (DOE))

Case study describes an outline of energy efficiency opportunities in federal high performance computing data centers.

325

High efficiency compressor uses direct drive  

Science Conference Proceedings (OSTI)

This article focuses on the high efficiency of a compressor which uses only direct drive. This compressor was evaluated by judges and won Top Honors in the 1982 Chemical Processing magazine Vaaler Awards category of compressors, blowers and fans. Applications for the compressor include combustion air, process air and gas booster, incineration, fermentation, and vacuum filtration systems. In addition to a 50% reduction in power comsumption, the use of the compressor eliminated the need for a water seal, thus saving 200 gpm of water. And, since the elimination of the water seal reduced the necessary downtime for seal maintenance, on stream time was increased by 5%.

Not Available

1982-11-01T23:59:59.000Z

326

19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 QUANTUM EFFICIENCY OF CdTe SOLAR CELLS IN FORWARD BIAS  

E-Print Network (OSTI)

19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 QUANTUM EFFICIENCY OF Cd;19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 Figure 2 shows the numerical as #12;19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 CE V( )= J V,100%( )- J V

Sites, James R.

327

Structure, dynamics and power conversion efficiency correlations in a new low bandgap polymer : PCBM solar cell.  

DOE Green Energy (OSTI)

Molecular packing structures and photoinduced charge separation dynamics have been investigated in a recently developed bulk heterojunction (BHJ) organic photovoltaic (OPV) material based on poly(thienothiophene-benzodithiophene) (PTB1) with a power conversion efficiency (PCE) of >5% in solar cell devices. Grazing incidence X-ray scattering (GIXS) measurements of the PTB1:PCBM ([6,6]-phenyl-C{sub 61}-butyric acid methyl ester) films revealed {pi}-stacked polymer backbone planes oriented parallel to the substrate surface, in contrast to the {pi}-stacked polymer backbone planes oriented perpendicular to the substrate surface in regioregular P3HT [poly(3-hexylthiophene)]:PCBM films. A {approx}1.7 times higher charge mobility in the PTB1:PCBM film relative to that in P3HT:PCBM films is attributed to this difference in stacking orientation. The photoinduced charge separation (CS) rate in the pristine PTB1:PCBM film is more than twice as fast as that in the annealed P3HT:PCBM film. The combination of a small optical gap, fast CS rate, and high carrier mobility in the PTB1:PCBM film contributes to its relatively high PCE in the solar cells. Contrary to P3HT:PCBM solar cells, annealing PTB1:PCBM films reduced the device PCE from 5.24% in the pristine film to 1.92% due to reduced interfacial area between the electron donor and the acceptor. Consequently, quantum yields of exciton generation and charge separation in the annealed film are significantly reduced compared to those in the pristine film.

Guo, J.; Liang, Y.; Szarko, J.; Lee, B.; Son, H. J.; Rolczynski, B. S.; Yu, L.; Chen, L. X.; Univ.of Chicago; Northwestern Univ.

2010-01-21T23:59:59.000Z

328

High Efficiency, Illumination Quality OLEDs for Lighting  

SciTech Connect

The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown. In 2003, a large area, OLED based illumination source was demonstrated that could provide light with a quality, quantity, and efficiency on par with what can be achieved with traditional light sources. The demonstration source was made by tiling together 16 separate 6-inch x 6-inch blue-emitting OLEDs. The efficiency, total lumen output, and lifetime of the OLED based illumination source were the same as what would be achieved with an 80 watt incandescent bulb. The devices had an average efficacy of 15 LPW and used solution-processed OLEDs. The individual 6-inch x 6-inch devices incorporated three technology strategies developed specifically for OLED lighting -- downconversion for white light generation, scattering for outcoupling efficiency enhancement, and a scalable monolithic series architecture to enable large area devices. The downconversion approach consists of optically coupling a blue-emitting OLED to a set of luminescent layers. The layers are chosen to absorb the blue OLED emission and then luminescence with high efficiency at longer wavelengths. The composition and number of layers are chosen so that the unabsorbed blue emission and the longer wavelength re-emission combine to make white light. A downconversion approach has the advantage of allowing a wide variety of colors to be made from a limited set of blue emitters. In addition, one does not have to carefully tune the emission wavelength of the individual electro-luminescent species within the OLED device in order to achieve white light. The downconversion architecture used to develop the 15LPW large area light source consisted of a polymer-based blue-emitting OLED and three downconversion layers. Two of the layers utilized perylene based dyes from BASF AG of Germany with high quantum efficiency (>98%) and one of the layers consisted of inorganic phosphor particles (Y(Gd)AG:Ce) with a quantum efficiency of {approx}85%. By independently varying the optical density of the downconversion layers, the overall emission spectrum could be adjusted to maximize performance for lighting (e.g. blackbody temp

Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

2008-03-31T23:59:59.000Z

329

A High Efficiency PSOFC/ATS-Gas Turbine Power System  

DOE Green Energy (OSTI)

A study is described in which the conceptual design of a hybrid power system integrating a pressurized Siemens Westinghouse solid oxide fuel cell generator and the Mercury{trademark} 50 gas turbine was developed. The Mercury{trademark} 50 was designed by Solar Turbines as part of the US. Department of Energy Advanced Turbine Systems program. The focus of the study was to develop the hybrid power system concept that principally would exhibit an attractively-low cost of electricity (COE). The inherently-high efficiency of the hybrid cycle contributes directly to achieving this objective, and by employing the efficient, power-intensive Mercury{trademark} 50, with its relatively-low installed cost, the higher-cost SOFC generator can be optimally sized such that the minimum-COE objective is achieved. The system cycle is described, major system components are specified, the system installed cost and COE are estimated, and the physical arrangement of the major system components is discussed. Estimates of system power output, efficiency, and emissions at the system design point are also presented. In addition, two bottoming cycle options are described, and estimates of their effects on overall-system performance, cost, and COE are provided.

W.L. Lundberg; G.A. Israelson; M.D. Moeckel; S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann

2001-02-01T23:59:59.000Z

330

Enhanced Efficiency of Light-Trapping Nanoantenna Arrays for Thin Film Solar Cells  

E-Print Network (OSTI)

We suggest a novel concept of efficient light-trapping structures for thin-film solar cells based on arrays of planar nanoantennas operating far from plasmonic resonances. The operation principle of our structures relies on the excitation of chessboard-like collective modes of the nanoantenna arrays with the field localized between the neighboring metal elements. We demonstrated theoretically substantial enhancement of solar-cell short-circuit current by the designed light-trapping structure in the whole spectrum range of the solar-cell operation compared to conventional structures employing anti-reflecting coating. Our approach provides a general background for a design of different types of efficient broadband light-trapping structures for thin-film solar-cell technologically compatible with large-area thin-film fabrication techniques.

Simovski, Constantin R; Voroshilov, Pavel M; Guzhva, Michael E; Belov, Pavel A; Kivshar, Yuri S

2013-01-01T23:59:59.000Z

331

Progress Toward Developing a Durable High-Temperature Solar Selective Coating (Poster)  

DOE Green Energy (OSTI)

Increasing the operating temperature of parabolic trough solar fields from 400 C to >450 C will increase their efficiency and reduce the cost of electricity. Current coatings do not have the stability and performance necessary to move to higher operating temperatures. The objective is to develop new, more efficient selective coatings with both high solar absoprtance ({alpha} > 0.96) and low thermal emittance ({var_epsilon} < 0.07) that are thermally stable above 450 C, ideally in air, with improved durability and manufacturability, and reduced cost.

Kennedy, C.; Price, H. W.

2007-03-01T23:59:59.000Z

332

Improved Energy Conversion Efficiency in Wide-Bandgap Cu(In,Ga)Se2 Solar Cells: Preprint  

DOE Green Energy (OSTI)

This report outlines improvements to the energy conversion efficiency in wide bandgap (Eg>1.2 eV) solar cells based on CuIn1-xGaxSe2. Using (a) alkaline containing high temperature glass substrates, (b) elevated substrate temperatures 600?C-650?C and (c) high vacuum evaporation from elemental sources following NREL's three-stage process, we have been able to improve the performance of wider bandgap solar cells with 1.2efficiencies >18% for absorber bandgaps ~1.30 eV and efficiencies ~16% for bandgaps up to ~1.45 eV. In comparing J-V parameters in similar materials, we establish gains in the open-circuit voltage and, to a lesser degree, the fill factor value, as the reason for the improved performance. The higher voltages seen in these wide gap materials grown at high substrate temperatures may be due to reduced recombination at the grain boundary of such absorber films. Solar cell results, absorber materials characterization, and experimental details are reported.

Contreras, M.; Mansfield, L.; Egaas, B.; Li, J.; Romero, M.; Noufi, R.; Rudiger-Voigt, E.; Mannstadt, W.

2011-07-01T23:59:59.000Z

333

White LED with High Package Extraction Efficiency  

Office of Scientific and Technical Information (OSTI)

WHITE LED WITH HIGH PACKAGE WHITE LED WITH HIGH PACKAGE EXTRACTION EFFICIENCY Final Report Report Period Start Date: 10/01/2006 Report Period End Date: 09/30/2008 Authors: Yi Zheng and Matthew Stough Report Submission Date: November 2008 DOE Award Number: DE-FC26-06NT42935 Project Manager: Ryan Egidi OSRAM SYLVANIA Product Inc Central Research and Service Laboratory 71 Cherry Hill Dr., Beverly, MA 01915 2 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor an agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus,

334

Efficient Switches for Solar Power Conversion: Four Quadrant GaN Switch Enabled Three Phase Grid-Tied Microinverters  

Science Conference Proceedings (OSTI)

Solar ADEPT Project: Transphorm is developing power switches for new types of inverters that improve the efficiency and reliability of converting energy from solar panels into useable electricity for the grid. Transistors act as fast switches and control the electrical energy that flows in an electrical circuit. Turning a transistor off opens the circuit and stops the flow of electrical current; turning it on closes the circuit and allows electrical current to flow. In this way a transistor can be used to convert DC from a solar panel into AC for use in a home. Transphorm’s transistors will enable a single semiconductor device to switch electrical currents at high-voltage in both directions—making the inverter more compact and reliable. Transphorm is using Gallium Nitride (GaN) as a semiconductor material in its transistors instead of silicon, which is used in most conventional transistors, because GaN transistors have lower losses at higher voltages and switching frequencies.

None

2012-02-13T23:59:59.000Z

335

Review of Mid- to High-Temperature Solar Selective Absorber Materials  

DOE Green Energy (OSTI)

This report describes the concentrating solar power (CSP) systems using solar absorbers to convert concentrated sunlight to thermal electric power. It is possible to achieve solar absorber surfaces for efficient photothermal conversion having high solar absorptance (a) for solar radiation and a low thermal emittance (e) at the operational temperature. A low reflectance (?'' 0) at wavelengths (?) 3 mm and a high reflectance (?'' 1) at l 3 mm characterize spectrally selective surfaces. The operational temperature ranges of these materials for solar applications can be categorized as low temperature (T< 100 C), mid-temperature (100 C< T< 400 C), and high-temperature (T> 400 C). High- and mid-temperature applications are needed for CSP applications. For CSP applications, the ideal spectrally selective surface would be low-cost and easy to manufacture, chemically and thermally stable in air at elevated operating temperatures (T= 500 C), and have a solar absorptance= 0.98 and a thermal emittance= 0.05 at 500 C.

Kennedy, C. E.

2002-07-01T23:59:59.000Z

336

High heat flux engineering in solar energy applications  

DOE Green Energy (OSTI)

Solar thermal energy systems can produce heat fluxes in excess of 10,000 kW/m{sup 2}. This paper provides an introduction to the solar concentrators that produce high heat flux, the receivers that convert the flux into usable thermal energy, and the instrumentation systems used to measure flux in the solar environment. References are incorporated to direct the reader to detailed technical information.

Cameron, C.P.

1993-07-01T23:59:59.000Z

337

Antireflection and SiO2 Surface Passivation by Liquid-Phase Chemistry for Efficient Black Silicon Solar Cells: Preprint  

Science Conference Proceedings (OSTI)

We report solar cells with both black Si antireflection and SiO2 surface passivation provided by inexpensive liquid-phase chemistry, rather than by conventional vacuum-based techniques. Preliminary cell efficiency has reached 16.4%. Nanoporous black Si antireflection on crystalline Si by aqueous etching promises low surface reflection for high photon utilization, together with lower manufacturing cost compared to vacuum-based antireflection coating. Ag-nanoparticle-assisted black Si etching and post-etching chemical treatment recently developed at NREL enables excellent control over the pore diameter and pore separation. Performance of black Si solar cells, including open-circuit voltage, short-circuit current density, and blue response, has benefited from these improvements. Prior to this study, our black Si solar cells were all passivated by thermal SiO2 produced in tube furnaces. Although this passivation is effective, it is not yet ideal for ultra-low-cost manufacturing. In this study, we report, for the first time, the integration of black Si with a proprietary liquid-phase deposition (LPD) passivation from Natcore Technology. The Natcore LPD forms a layer of solar cells with LPD SiO2 with a spectrum-weighted average reflection lower than 5%, similar to the more costly thermally grown SiO2 approach. However, LPD SiO2 provides somewhat better surface-passivation quality according to the lifetime analysis by the photo-conductivity decay measurement. Moreover, black Si solar cells with LPD SiO2 passivation exhibit higher spectral response at short wavelength compared to those passivated by thermally grown SiO2. With further optimization, the combination of aqueous black Si etching and LPD could provide a pathway for low-cost, high-efficiency crystalline Si solar cells.

Yuan, H. C.; Oh, J.; Zhang, Y.; Kuznetsov, O. A.; Flood, D. J.; Branz, H. M.

2012-06-01T23:59:59.000Z

338

Antireflection and SiO2 Surface Passivation by Liquid-Phase Chemistry for Efficient Black Silicon Solar Cells: Preprint  

DOE Green Energy (OSTI)

We report solar cells with both black Si antireflection and SiO2 surface passivation provided by inexpensive liquid-phase chemistry, rather than by conventional vacuum-based techniques. Preliminary cell efficiency has reached 16.4%. Nanoporous black Si antireflection on crystalline Si by aqueous etching promises low surface reflection for high photon utilization, together with lower manufacturing cost compared to vacuum-based antireflection coating. Ag-nanoparticle-assisted black Si etching and post-etching chemical treatment recently developed at NREL enables excellent control over the pore diameter and pore separation. Performance of black Si solar cells, including open-circuit voltage, short-circuit current density, and blue response, has benefited from these improvements. Prior to this study, our black Si solar cells were all passivated by thermal SiO2 produced in tube furnaces. Although this passivation is effective, it is not yet ideal for ultra-low-cost manufacturing. In this study, we report, for the first time, the integration of black Si with a proprietary liquid-phase deposition (LPD) passivation from Natcore Technology. The Natcore LPD forms a layer of <10-nm SiO2 on top of the black Si surface in a relatively mild chemical bath at room temperature. We demonstrate black Si solar cells with LPD SiO2 with a spectrum-weighted average reflection lower than 5%, similar to the more costly thermally grown SiO2 approach. However, LPD SiO2 provides somewhat better surface-passivation quality according to the lifetime analysis by the photo-conductivity decay measurement. Moreover, black Si solar cells with LPD SiO2 passivation exhibit higher spectral response at short wavelength compared to those passivated by thermally grown SiO2. With further optimization, the combination of aqueous black Si etching and LPD could provide a pathway for low-cost, high-efficiency crystalline Si solar cells.

Yuan, H. C.; Oh, J.; Zhang, Y.; Kuznetsov, O. A.; Flood, D. J.; Branz, H. M.

2012-06-01T23:59:59.000Z

339

Available Technologies: Thinner Film Silicon Solar Cells  

Berkeley Lab scientists have designed a new approach to create highly efficient thin film silicon solar cells. This technology promises to lower solar cell material ...

340

Geek-Up[4.29.2011]: Boosting the Efficiency of Wind and Solar Power |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Geek-Up[4.29.2011]: Boosting the Efficiency of Wind and Solar Power Geek-Up[4.29.2011]: Boosting the Efficiency of Wind and Solar Power Geek-Up[4.29.2011]: Boosting the Efficiency of Wind and Solar Power April 29, 2011 - 5:14pm Addthis Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs It's a big month for the National Wind Technology Center. Earlier this week, the Department of Energy's National Renewable Energy Laboratory (NREL) commemorated the successful installation and full capacity operation of a 3 megawatt Alstom ECO 100 wind turbine at the center. As part of a long-term collaboration between NREL and Alstom, engineers from the two institutions will perform a series of analyses and tests to evaluate Alstom's unique drive train configuration technology. After this initial testing is complete, the joint team will continue

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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341

Intense Internal and External Fluorescence as Solar Cells Approach the Shockley-Queisser Efficiency Limit  

E-Print Network (OSTI)

Absorbed sunlight in a solar cell produces electrons and holes. But, at the open circuit condition, the carriers have no place to go. They build up in density and, ideally, they emit external fluorescence that exactly balances the incoming sunlight. Any additional non-radiative recombination impairs the carrier density buildup, limiting the open-circuit voltage. At open-circuit, efficient external fluorescence is an indicator of low internal optical losses. Thus efficient external fluorescence is, counter-intuitively, a necessity for approaching the Shockley-Queisser efficiency limit. A great Solar Cell also needs to be a great Light Emitting Diode. Owing to the narrow escape cone for light, efficient external emission requires repeated attempts, and demands an internal luminescence efficiency >>90%.

Miller, Owen D; Kurtz, Sarah R

2012-01-01T23:59:59.000Z

342

Improved Solar Cell Efficiency Through the Use of an Additive Nanostructure-Based Optical Downshifter: Final Subcontract Report, January 28, 2010 -- February 28, 2011  

DOE Green Energy (OSTI)

This final report summarizes all SpectraWatt's progress in achieving a boost in solar cell efficiency using an optical downshifter. Spectrawatt's downshifting technology is based on a nanostructured material system which absorbs high energy (short wavelength) light and reemits it at a lower energy (long wavelength) with high efficiency. This system has shown unprecedented performance parameters including near unity quantum yield and high thermal stability.

Kurtin, J.

2011-05-01T23:59:59.000Z

343

Novel Nanophosphors for High Efficiency Fluorescent Lamps  

SciTech Connect

This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation, which are detailed in this report. Within the program we have carried out fundamental investigations into the physical processes that determine the quantum splitting behavior of the Pr{sup 3+} ion in solids. Specifically, we have investigated the quantum splitting luminescence of this ion in the LaPO{sub 4}, SrAl{sub 12}O{sub 19} and LiLaP{sub 4}O{sub 12} host lattices. In this final report we summarize the technical work completed under the Program, summarize our findings about the performance limits of the various technologies we investigated, and outline promising paths for future work.

Alok Srivatava

2007-03-31T23:59:59.000Z

344

Improving Real World Efficiency of High Performance Buildings  

E-Print Network (OSTI)

Improving Real World Efficiency of High Performance Buildings Buildings End-Use Energy Efficiency Research www.energy.ca.gov/research/buildings February 2012 The Issue Highperformance buildings efficiency in highperformance buildings, however, are not always realized in practice. Addressing

345

Highly Efficient Modeling of Dynamic Coronal Loops  

E-Print Network (OSTI)

Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated quasi-independently by nanoflares. It is therefore an enormous undertaking to model an entire active region or the global corona. Three-dimensional MHD codes have inadequate spatial resolution, and 1D hydro codes are too slow to simulate the many thousands of elemental strands that must be treated in a reasonable representation. Fortunately, thermal conduction and flows tend to smooth out plasma gradients along the magnetic field, so "0D models" are an acceptable alternative. We have developed a highly efficient model called Enthalpy-Based Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of the average temperature, pressure, and density along a coronal strand. It improves significantly upon earlier models of this type--in accuracy, flexibility, and capability. It ...

Klimchuk, J A; Cargill, P J

2007-01-01T23:59:59.000Z

346

High efficiency Brayton cycles using LNG  

DOE Patents (OSTI)

A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.

Morrow, Charles W. (Albuquerque, NM)

2006-04-18T23:59:59.000Z

347

New III-V cell design approaches for very high efficiency  

DOE Green Energy (OSTI)

This report describes to examine new solar cell desip approaches for achieving very high conversion efficiencies. The program consists of two elements. The first centers on exploring new thin-film approaches specifically designed for M-III semiconductors. Substantial efficiency gains may be possible by employing light trapping techniques to confine the incident photons, as well as the photons emitted by radiative recombination. The thin-film approach is a promising route for achieving substantial performance improvements in the already high-efficiency, single-junction, III-V cell. The second element of the research involves exploring desip approaches for achieving high conversion efficiencies without requiring extremely high-quality material. This work has applications to multiple-junction cells, for which the selection of a component cell often involves a compromise between optimum band pp and optimum material quality. It could also be a benefit manufacturing environment by making the cell's efficiency less dependent on materialquality.

Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; Patkar, M.P.; Young, M.P. (Purdue Univ., Lafayette, IN (United States))

1993-04-01T23:59:59.000Z

348

White LED with High Package Extraction Efficiency  

Science Conference Proceedings (OSTI)

The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W{sub e} using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat generated in the package may cause a deterioration of encapsulant materials, affecting the performance of both the LED die and phosphor, leading to a decrease in the luminous efficacy over lifetime. Recent studies from research groups at Rensselaer Polytechnic Institute found that, under the condition to obtain a white light, about 40% of the light is transmitted outward of the phosphor layer and 60% of the light is reflected inward.1,2 It is claimed that using scattered photon extraction (SPE) technique, luminous efficacy is increased by 60%. In this project, a transparent/translucent monolithic phosphor was used to replace the powdered phosphor layer. In the normal pcLED package, the powdered phosphor is mixed with silicone either to be deposited on the top of LED die forming a chip level conversion (CLC) white LED or to be casted in the package forming a volume conversion white LED. In the monolithic phosphors there are no phosphor powder/silicone interfaces so it can reduce the light scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is inserted in the white LED package between the blue LED die and phosphor layer. It will selectively transmit the blue light from the LED die and reflect the phosphor's yellow inward emission outward. The two technologies try to recover backward light to the outward direction in the pcLED package thereby improving the package extraction efficiency.

Yi Zheng; Matthew Stough

2008-09-30T23:59:59.000Z

349

Tailored Materials for High Efficiency CIDI Engines  

DOE Green Energy (OSTI)

The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in. deep that showed significant grain refinement and homogeneous microstructures favorable to increased fracture toughness and fatigue performance. The final tasks of the project demonstrated that the FSP concept can be applied to a relevant part geometry by fabricating diesel piston crowns with FSP regions applied selectively to the edge of the bowl rim. This area of the piston typically suffers from conditions at high PCP that cause severe thermal fatigue issues. It is expected that, given the data from coupon testing, the durability of pistons modified by FSP will allow much higher fatigue lifetime and potentially also greater resistance to elevated stress-level effects on fatigue.

Grant, G.J.; Jana, S.

2012-03-30T23:59:59.000Z

350

Documentation of high resolution solar resource assessment for Sri Lanka  

Open Energy Info (EERE)

Sri Lanka Sri Lanka provided by DLR Dataset Summary Description (Abstract): Documentation of the satellite-based high resolution solar resource assessment for Sri Lanka provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global horizontal and direct normal irradiance (GHI and DNI) for the year 2000, 2002 and 2003. Additionally, for selected sites hourly values of GHI and DNI are provided.The Documentation gives an overview about the used input data and used methodology, shows example maps and describes a comparison with ground data (if provided by the country) (Purpose): The data are helpful for the assessment of the solar potential of the country and can give project developer a first impression of the solar resource of the country. For the selected sites, the hourly time series can be used for the simulation of Photovoltaic (PV)-systems or Concentrating Solar Power (CSP)-systems.

351

High temperature solar thermal technology: The North Africa Market  

DOE Green Energy (OSTI)

High temperature solar thermal (HTST) technology offers an attractive option for both industrialized and non-industrialized countries to generate electricity and industrial process steam. The purpose of this report is to assess the potential market for solar thermal applications in the North African countries of Algeria, Egypt, Morocco and Tunisia. North Africa was selected because of its outstanding solar resource base and the variety of applications to be found there. Diminishing oil and gas resources, coupled with expanding energy needs, opens a large potential market for the US industry. The US high temperature solar trough industry has little competition globally and could build a large market in these areas. The US is already familiar with certain solar markets in North Africa due to the supplying of substantial quantities of US-manufactured flat plate collectors to this region.

Not Available

1990-12-01T23:59:59.000Z

352

Means of increasing efficiency of CPC solar energy collector  

DOE Patents (OSTI)

A device is provided for improving the thermal efficiency of a cylindrical radiant energy collector. A channel is placed next to and in close proximity to the nonreflective side of an energy reflective wall of a cylindrical collector. A coolant is piped through the channel and removes a portion of the nonreflective energy incident on the wall which is absorbed by the wall. The energy transferred to the coolant may be utilized in a useful manner.

Chao, Bei Tse (Urbana, IL); Rabl, Ari (Downers Grove, IL)

1977-02-15T23:59:59.000Z

353

Means of increasing efficiency of CPC solar energy collector  

DOE Patents (OSTI)

A device is provided for improving the thermal efficiency of a cylindrical radiant energy collector. A channel is placed next to and in close proximity to the nonreflective side of an energy reflective wall of a cylindrical collector. A coolant is piped through the channel and removes a portion of the nonreflective energy incident on the wall which is absorbed by the wall. The energy transferred to the coolant may be utilized in a useful manner.

Chao, B.T.; Rabl, A.

1975-06-27T23:59:59.000Z

354

Compressor performance at high suction temperatures with application to solar heat pump  

DOE Green Energy (OSTI)

As part of the study of Solar Assisted Heat Pump (SAHP) Systems, the performance of the heat pump itself and its components under conditions attendant to series solar input to the evaporator is being investigated at Brookhaven National Laboratory (BNL). Particular emphasis has been placed on the details of the compressor performance, since in order to properly exploit the thermodynamic potential of high solar input temperatures (40 to 100/sup 0/F), the compressor must operate efficiently over a wide range of (saturated) suction temperatures most of which are well above those for which present compressors are designed. A systematic series of experiments is being conducted at evaporating temperatures in the range from 45 to 100/sup 0/F using a Solar Heat Pump Simulator and a specially designed Laboratory Model Heat Pump assembled from off-the-shelf components. Two reciprocating compressors have been tested thus far - an open type driven by a 2-speed motor and a hermetic 2-speed, the multi-speed feature providing capacity control, which is a virtual necessity for effective use of solar source. Thorough and highly accurate instrumentation is used in the simulator and in the heat pump refrigeration loop. The results to date of the compressor aspects of the solar heat pump experiments at BNL are described, and the general application of heat pumps and their compressors to use with solar input are discussed.

Kush, E A

1980-01-01T23:59:59.000Z

355

High efficiency thin-film multiple-gap photovoltaic device  

SciTech Connect

A photovoltaic device includes at least two solar cells made from Group IV elements or their alloys in the amorphous state mounted on a substrate. The outermost or first cell has a larger bandgap than the second cell. Various techniques are utilized to improve the efficiency of the device.

Dalal, Vikram L. (Newark, DE)

1983-01-01T23:59:59.000Z

356

High throughput solar cell ablation system  

SciTech Connect

A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

2012-09-11T23:59:59.000Z

357

High efficiency photodetection below the quantum noise limit  

E-Print Network (OSTI)

Two low-noise, high quantum efficiency, high bandwidth photodetectors have constructed to form a balanced homodyne detector to detect squeezed light. The detectors have quantum efficiencies of 85% and 90%, a bandwidth of ...

Bullard, Elizabeth Caryn

2005-01-01T23:59:59.000Z

358

Finite element strategies for the efficient analysis and evaluation of solar collector structures  

DOE Green Energy (OSTI)

Concentrating or reflecting structures for solar energy systems must be evaluated as to their structural integrity and optical performance. Computer studies can be used as an integral part of these evaluations. The computer studies make use of finite element structural codes coupled with post-processors that calculate optical data. If the analysis of a solar structure is to be carried out in an efficient manner, these computer codes must have certain capabilities. A number of solar energy projects at Sandia National Laboratories have made extensive use of finite element analyses. The analyses have been useful in evaluating design concepts which hold promise for large scale use in solar energy projects. Analysis procedures have been developed for some structures so that evaluations can be carried out in a straightforward manner.

Koteras, J. R.

1980-01-01T23:59:59.000Z

359

High Efficiency Organic Light Emitting Devices for Lighting  

SciTech Connect

Incorporate internal scattering layers and microlens arrays in high efficiency OLED to achieve up to 70% EQE.

So, Franky; Tansu, Nelson; Gilchrist, James

2013-06-30T23:59:59.000Z

360

High Efficiency Electrical Energy Storage Using Reversible Solid ...  

Science Conference Proceedings (OSTI)

Symposium, Energy Storage III: Materials, Systems and Applications Symposium. Presentation Title, High Efficiency Electrical Energy Storage Using Reversible ...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

High Efficiency Low Emission Supermarket Refrigeration Research Project  

Energy.gov (U.S. Department of Energy (DOE))

The U.S. Department of Energy (DOE) is currently conducting research into high efficiency, low emission supermarket refrigeration technologies.

362

High Plains Ranch Solar Power Plant | Open Energy Information  

Open Energy Info (EERE)

High Plains Ranch Solar Power Plant High Plains Ranch Solar Power Plant Jump to: navigation, search Name High Plains Ranch Solar Power Plant Facility High Plains Ranch Sector Solar Facility Type Photovoltaic Developer Sun Power Location Carizzo Plain, California Coordinates 35.1913858°, -119.7260983° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":35.1913858,"lon":-119.7260983,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

363

Apparatus for preventing high temperatures in a glazed solar collector  

DOE Patents (OSTI)

Venting the glazing (i.e., transparent cover) of a solar collector can be used to prevent the collector's absorber surface from reaching too high a temperature.

Buckley, Bruce S. (410 Memorial Dr., #154, Cambridge, MA 02139)

1979-01-01T23:59:59.000Z

364

High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems  

DOE Green Energy (OSTI)

This document is the sixth volume of the Building America Best Practices Series. It presents information that is useful throughout the United States for enhancing the energy efficiency practices in the specific climate zones that are presented in the first five Best Practices volumes. It provides an introduction to current photovoltaic and solar thermal building practices. Information about window selection and shading is included.

Baechler, M.; Gilbride, T.; Ruiz, K.; Steward, H.; Love, P.

2007-06-01T23:59:59.000Z

365

Indium oxide/n-silicon heterojunction solar cells  

DOE Patents (OSTI)

A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

1982-12-28T23:59:59.000Z

366

An Efficient Method for Computing the Absorption of Solar Radiation by Water Vapor  

Science Conference Proceedings (OSTI)

An efficient method has been developed to compute the absorption of solar radiation by water vapor. The method is based on the molecular line parameters compiled by McClatchey et al. (1973) and makes use of the far-wing scaling approximation and ...

Ming-Dah Chou; Albert Arking

1981-04-01T23:59:59.000Z

367

Increasing the efficiency of organic solar cells by photonic and electrostatic-field enhancements  

SciTech Connect

Organic photovoltaic (OPV) technology is an attractive solar-electric conversion paradigm due to the promise of low cost roll-to-roll production and amenability to flexible substrates. Power conversion efficiency (PCE) exceeding 7% has recently been achieved. OPV cells suffer from low charge carrier mobilities of polymers, leading to recombination losses, higher series resistances and lower fill-factors. Thus, it is imperative to develop fabrication methodologies that can enable efficient optical absorption in films thinner than optical absorption length. Active layers conformally deposited on light-trapping, microscale textured, grating-type surfaces is one possible approach to achieve this objective. In this study, 40% theoretical increase in photonic absorption over flat OPVs is shown for devices with textured geometry by the simulation results. For verifying this theoretical result and improving the efficiency of OPVs by light trapping, OPVs were fabricated on grating-type textured substrates possessing t pitch and -coat PV active-layer on these textured substrates led to over filling of the valleys and shunts at the crest, which severely affected the performance of the resultant PV devices. Thus, it is established that although the optical design is important for OPV performance but the potential of light trapping can only be effectively tapped if the textures are amenable for realizing a conformal active layer. It is discovered that if the height of the underlying topographical features is reduced to sub-micron regime (e.g. 300 nm) and the pitch is increased to more than a micron (e.g. 2 ?m), the textured surface becomes amenable to coating a conformal PV active-layer. The resultant PV cells showed 100% increase in average light absorption near the band edge due to trapping of higher wavelength photons, and 20% improvement in power conversion efficiency as compared with the flat PV cell. Another factor that severely limits the performance of OPVs is recombination of charge carriers. Thus it becomes imperative to understand the effect of processing conditions such as spin coating speed and drying rate on defect density and hence induced carrier recombination mechanism. In this study, It is shown that slow growth (longer drying time) of the active-layer leads to reduction of sub-bandgap traps by an order of magnitude as compared to fast grown active-layer. By coupling the experimental results with simulations, it is demonstrated that at one sun condition, slow grown device has bimolecular recombination as the major loss mechanism while in the fast grown device with high trap density, the trap assisted recombination dominates. It has been estimated that non-radiative recombination accounts nearly 50% of efficiency loss in modern OPVs. Generally, an external bias (electric field) is required to collect all the photogenerated charges and thus prevent their recombination. The motivation is to induce additional electric field in otherwise low mobility conjugated polymer based active layer by incorporating ferroelectric dipoles. This is expected to facilitate singlet exciton dissociation in polymer matrix and impede charge transfer exciton (CTE) recombination at polymer:fullerene interface. For the first time, it is shown that the addition of ferroelectric dipoles to modern bulk heterojunction (BHJ) can significantly improve exciton dissociation, resulting in a ~50% enhancement of overall solar cell efficiency. The devices also exhibit the unique ferroelectric-photovoltaic effect with polarization-controlled power conversion efficiency.

Nalwa, Kanwar

2012-11-03T23:59:59.000Z

368

High performance hydrogenated amorphous silicon solar cells made at a high deposition rate by glow discharge of disilane  

SciTech Connect

The deposition rate, electronic and optical properties of hydrogenated amorphous silicon films prepared from rf glow discharge decomposition of disilane (Si/sub 2/H/sub 6/) diluted in helium have been measured. These films show excellent electrical and optical properties and, most importantly, a high deposition rate coupled with satisfactory solar cell application was realized for the first time. At a deposition rate of 11 A/s, 5.47% and 6.5% conversion efficiencies were obtained with a first trial of n-i-p type solar cells deposited on SnO/sub 2//ITO glass and metal substrates, respectively.

Ohashi, Y.; Kenne, J.; Konagai, M.; Takahashi, K.

1983-06-15T23:59:59.000Z

369

High-efficiency photovoltaics based on semiconductor nanostructures  

SciTech Connect

The objective of this project was to exploit a variety of semiconductor nanostructures, specifically semiconductor quantum wells, quantum dots, and nanowires, to achieve high power conversion efficiency in photovoltaic devices. In a thin-film device geometry, the objectives were to design, fabricate, and characterize quantum-well and quantum-dot solar cells in which scattering from metallic and/or dielectric nanostructures was employed to direct incident photons into lateral, optically confined paths within a thin (~1-3um or less) device structure. Fundamental issues concerning nonequilibrium carrier escape from quantum-confined structures, removal of thin-film devices from an epitaxial growth substrate, and coherent light trapping in thin-film photovoltaic devices were investigated. In a nanowire device geometry, the initial objectives were to engineer vertical nanowire arrays to optimize optical confinement within the nanowires, and to extend this approach to core-shell heterostructures to achieve broadspectrum absorption while maintaining high opencircuit voltages. Subsequent work extended this approach to include fabrication of nanowire photovoltaic structures on low-cost substrates.

Yu, Paul K.L. [University of California, San Diego; Yu, Edward T. [University of Texas at Austin; Wang, Deli [University of California, San Diego

2011-10-31T23:59:59.000Z

370

Development of efficient photoreactors for solar hydrogen production  

Science Conference Proceedings (OSTI)

The rate of hydrogen evolution from a photocatalytic process depends not only on the activity of a photocatalyst, but also on photoreactor design. Ideally, a photoreactor should be able to absorb the incident light, promoting photocatalytic reactions in an effective manner with minimal photonic losses. There are numerous technical challenges and cost related issues when designing a large-scale photoreactor for hydrogen production. Active stirring of the photocatalyst slurry within a photoreactor is not practical in large-scale applications due to cost related issues. Rather, the design should allow facile self-mixing of the flow field within the photoreactor. In this paper two types of photocatalytic reactor configurations are studied: a batch type design and another involving passive self-mixing of the photolyte. Results show that energy loss from a properly designed photoreactor is mainly due to reflection losses from the photoreactor window. We describe the interplay between the reaction and the photoreactor design parameters as well as effects on the rate of hydrogen evolution. We found that a passive self-mixing of the photolyte is possible. Furthermore, the use of certain engineering polymer films as photoreactor window materials has the potential for substantial cost savings in large-scale applications, with minimal reduction of photon energy utilization efficiency. Eight window materials were tested and the results indicate that Aclar trademark polymer film used as the photoreactor window provides a substantial cost saving over other engineering polymers, especially with respect to fused silica glass at modest hydrogen evolution rates. (author)

Huang, Cunping; Yao, Weifeng; T-Raissi, Ali; Muradov, Nazim [University of Central Florida, Florida Solar Energy Center, 1679 Clearlake Road, Cocoa, Fl 32922-5703 (United States)

2011-01-15T23:59:59.000Z

371

Process Development for High Voc CdTe Solar Cells  

DOE Green Energy (OSTI)

This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

Ferekides, C. S.; Morel, D. L.

2011-05-01T23:59:59.000Z

372

Smart Solar Rooftops  

competing with fossil fuels on the energy market, so producing high-efficiency while maintaining a low cost is a major priority for the solar industry.

373

Solar | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the ENERGY STAR refrigerators, high efficiency central air conditioning systems, and solar electric photovoltaic systems. This loan is being offered to encourage the...

374

Documentation of high resolution solar resource assessment for Ghana  

Open Energy Info (EERE)

Ghana Ghana provided by DLR Dataset Summary Description (Abstract): Documentation of the satellite-based high resolution solar resource assessment for Ghana provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global horizontal and direct normal irradiance (GHI and DNI) for the year 2000, 2001 and 2002. Additionally, for selected sites hourly values of GHI and DNI are provided.The Documentation gives an overview about the used input data and used methodology, shows example maps and describes a comparison with ground data (if provided by the country) (Purpose): The data are helpful for the assessment of the solar potential of the country and can give projet developer a first impression of the solar resource of the country. For the selected

375

Documentation of high resolution solar resource assessment (10km) for  

Open Energy Info (EERE)

for for Ethiopia provided by DLR Dataset Summary Description (Abstract): Documentation of the satellite-based high resolution solar resource assessment for Ethiopia provided by DLR. The high resolution solar data (10kmx10km) provide country maps of the annual and monthly sums of hourly global horizontal and direct normal irradiance (GHI and DNI) for the year 2000, 2001 and 2002. Additionally, for selected sites hourly values of GHI and DNI are provided.The Documentation gives an overview about the used input data and used methodology, shows example maps and describes a comparison with ground data (if provided by the country) (Purpose): The data are helpful for the assessment of the solar potential of the country and can give project developer a first impression of the solar resource of the country. For the selected

376

Solar Wind Sources in the Late Declining Phase of Cycle 23: Effects of the Weak Solar Polar Field on High Speed Streams  

E-Print Network (OSTI)

Isenberg, P.A. (eds. ) Solar Wind Nine, AIP Conf. Proc. 471,AT SOLAR MINIMUM Solar Wind Sources in the Late Decliningfor their high speed solar wind streams that dominate the

2009-01-01T23:59:59.000Z

377

ENGINEERED ELECTRODES AND ELECTRODE-ORGANIC INTERFACES FOR HIGH-EFFICIENCY ORGANIC PHOTOVOLTAICS  

DOE Green Energy (OSTI)

Organic photovoltaic (OPV) cells offer the ultimate promise of low cost, readily manufacturable, and durable solar power. While recent advances have led to cells with impressive performance levels, OPV cells have yet to break the double-digit efficiency barrier. Further gains in efficiency and durability, to that competitive with high-performance inorganic photovoltaics will require breakthroughs in transparent electrode and interfacial materials science and engineering. This project involved an integrated basic research effort carried out by an experienced and highly collaborative interdisciplinary team to address in unconventional ways, critical electrode-interfacial issues underlying OPV performance--controlling band offsets between transparent electrodes and organics, addressing current loss/leakage problems at interfaces, enhancing adhesion, interfacial stability, and device durability while minimizing cost. It synergistically combined materials and interfacial reagent synthesis, nanostructural and photovoltaic characterization, and high level quantum theory. The research foci were: 1) understanding of/development of superior transparent electrode materials and materials morphologies--i.e., better matched electronically and chemically to organic active layers, 2) understanding-based development of inorganic interfacial current-collecting/charge-blocking layers, and 3) understanding-based development of self-assembled adhesion/current-collecting/charge-blocking/cross-linking layers for high-efficiency OPV interfaces. Pursing the goal of developing the fundamental scientific understanding needed to design, fabricate, prototype and ultimately test high-efficiency OPV cells incorporating these new concepts, we achieved a record power conversion efficiency of 5.2% for an organic bulk-heterjunction solar cell.

Tobin J. Marks; R.P.H. Chang; Tom Mason; Ken Poeppelmeier; Arthur J. Freeman

2008-11-13T23:59:59.000Z

378

High-Efficiency Nitride-Base Photonic Crystal Light Sources  

DOE Green Energy (OSTI)

The research activities performed in the framework of this project represent a major breakthrough in the demonstration of Photonic Crystals (PhC) as a competitive technology for LEDs with high light extraction efficiency. The goals of the project were to explore the viable approaches to manufacturability of PhC LEDS through proven standard industrial processes, establish the limits of light extraction by various concepts of PhC LEDs, and determine the possible advantages of PhC LEDs over current and forthcoming LED extraction concepts. We have developed three very different geometries for PhC light extraction in LEDs. In addition, we have demonstrated reliable methods for their in-depth analysis allowing the extraction of important parameters such as light extraction efficiency, modal extraction length, directionality, internal and external quantum efficiency. The information gained allows better understanding of the physical processes and the effect of the design parameters on the light directionality and extraction efficiency. As a result, we produced LEDs with controllable emission directionality and a state of the art extraction efficiency that goes up to 94%. Those devices are based on embedded air-gap PhC - a novel technology concept developed in the framework of this project. They rely on a simple and planar fabrication process that is very interesting for industrial implementation due to its robustness and scalability. In fact, besides the additional patterning and regrowth steps, the process is identical as that for standard industrially used p-side-up LEDs. The final devices exhibit the same good electrical characteristics and high process yield as a series of test standard LEDs obtained in comparable conditions. Finally, the technology of embedded air-gap patterns (PhC) has significant potential in other related fields such as: increasing the optical mode interaction with the active region in semiconductor lasers; increasing the coupling of the incident light into the active region of solar cells; increasing the efficiency of the phosphorous light conversion in white light LEDs etc. In addition to the technology of embedded PhC LEDs, we demonstrate a technique for improvement of the light extraction and emission directionality for existing flip-chip microcavity (thin) LEDs by introducing PhC grating into the top n-contact. Although, the performances of these devices in terms of increase of the extraction efficiency are not significantly superior compared to those obtained by other techniques like surface roughening, the use of PhC offers some significant advantages such as improved and controllable emission directionality and a process that is directly applicable to any material system. The PhC microcavity LEDs have also potential for industrial implementation as the fabrication process has only minor differences to that already used for flip-chip thin LEDs. Finally, we have demonstrated that achieving good electrical properties and high fabrication yield for these devices is straightforward.

James Speck; Evelyn Hu; Claude Weisbuch; Yong-Seok Choi; Kelly McGroddy; Gregor Koblmuller; Elison Matioli; Elizabeth Rangel; Fabian Rol; Dobri Simeonov

2010-01-31T23:59:59.000Z

379

Solar dish/engine systems  

DOE Green Energy (OSTI)

Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun's rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.

NONE

1998-04-01T23:59:59.000Z

380

New and Underutilized Technology: Efficient High Bay Fluorescent Lighting |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Efficient High Bay Fluorescent Efficient High Bay Fluorescent Lighting New and Underutilized Technology: Efficient High Bay Fluorescent Lighting October 7, 2013 - 8:54am Addthis The following information outlines key deployment considerations for efficient high bay fluorescent lighting within the Federal sector. Benefits Efficient high bay fluorescent lighting can include either T5 or T8 fluorescent lighting systems for high-bay applications currently using metal halide fixtures. Fluorescent fixtures offer better light distribution, better light maintenance over the life of the lamp, improved color quality, and on-off control (re-strike time) with lower energy consumption. Application Efficient high bay fluorescent lighting is applicable for facilities containing high bay areas. Key Factors for Deployment

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Advanced high efficiency concentrator cells. Final subcontractor report, 1 October 1988--31 March 1990  

DOE Green Energy (OSTI)

This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the ``reverse`` side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

Gale, R. [Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center

1992-06-01T23:59:59.000Z

382

High efficiency pulse motor drive for robotic propulsion  

E-Print Network (OSTI)

The goal of this research is to improve the power efficiency of robotic locomotion through the use of series elastic actuation, with a focus on swimming motion. To achieve high efficiency, electromechanical drives need to ...

Sun, Zhen, M.S. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

383

Techniques for high-efficiency outphasing power amplifiers  

E-Print Network (OSTI)

A trade-off between linearity and efficiency exists in conventional power amplifiers (PAs). The outphase amplifying concept overcomes this trade-off by enabling the use of high efficiency, non-linear power amplifiers for ...

Godoy, Philip (Philip Andrew)

2011-01-01T23:59:59.000Z

384

Energy efficiency indicators for high electric-load buildings  

Science Conference Proceedings (OSTI)

Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

Aebischer, Bernard; Balmer, Markus A.; Kinney, Satkartar; Le Strat, Pascale; Shibata, Yoshiaki; Varone, Frederic

2003-06-01T23:59:59.000Z

385

Design of high efficiency Mid IR QCL lasers  

E-Print Network (OSTI)

The proposed research is a study of designing high-efficiency Mid-IR quantum cascade lasers (QCL). This thesis explores "injector-less" designs for achieving lower voltage defects and improving wall plug efficiencies through ...

Hsu, Allen Long

2008-01-01T23:59:59.000Z

386

Efficient Organic Excitonic Solar Cells with Carbon Nanotubes Replacing In2O3:Sn as the Transparent Electrode (Presentation)  

DOE Green Energy (OSTI)

The conclusions of this report are that: (1) organic solar cells with efficiencies of up to 1.43% conversion efficiency that use no ITO and no PEDOT:PSS, are demonstrated; (2) a cell without ITO, but with PEDOT:PSS gave 2.6% conversion efficiency; (3) due to porous nature of SWCNT substrates, optimization of the active layer is essential; and (4) SWCNT electrodes bring one step closer the goal of a fully printable, organic solar cell.

van de Lagemaat, J.; Barnes, T.; Rumbles, G.; Shaheen, S.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.

2006-05-01T23:59:59.000Z

387

Solar Energy Materials & Solar Cells 83 (2004) 263271 Improving power efficiencies in  

E-Print Network (OSTI)

blend device, made with indium-tin oxide and Ca electrodes, gives a power conversion efficiency Zp=1 indium tin oxide (ITO) and gold electrodes in a sandwich structure. The TiO2 solgel precursor, prepared.orholdc a National Renewable Energy Laboratory, Golden, CO 80401, USA b Physics Department, University of California

Carter, Sue

388

Design of Zinc Oxide Based Solid-State Excitonic Solar Cell with Improved Efficiency  

E-Print Network (OSTI)

Excitonic photovoltaic devices, including organic, hybrid organic/inorganic, and dye-sensitized solar cells, are attractive alternatives to conventional inorganic solar cells due to their potential for low cost and low temperature solution-based processing on flexible substrates in large scale. Though encouraging, they are currently limited by the efficiency from not yet optimized structural and material parameters and poor overall knowledge regarding the fundamental details. This dissertation aims to achieve improved performance of hybrid solar cells by enhancing material property and designing new device architecture. The study begins with the addition of XD-grade single-walled carbon nanotube (XDSWNT) into poly(3-hexylthiophene) (P3HT) to improve the current density. By having a weight ratio of XDSWNT and P3HT equaled to 0.1:1, short-circuit current was quadrupled from 0.12 mA cm-2 to 0.48 mA cm-2 and solar cell efficiency was tripled from 0.023% to 0.07%, compared to devices with pure P3HT as a hole transport material. Secondly, a significant improvement in device efficiency with 250 nm long ZnO nanorod arrays as photoanodes has been achieved by filling the interstitial voids of the nanorod arrays with ZnO nanoparticles. The overall power conversion efficiency increased from 0.13% for a nanorod-only device to 0.34% for a device with combined nanoparticles and nanorod arrays. The higher device efficiency in solid-state DSSCs with hybrid nanorod/nanoparticle photoanodes is originated from both large surface area provided by nanoparticles for dye adsorption and efficient charge transport provided by the nanorod arrays to reduce the recombinations of photogenerated carriers. Followed by the novel layer-by-layer self-assembly deposition process, the hybrid photoanode study was extended to the longer ZnO nanorod arrays. The best performance, 0.64%, was achieved when the thickness of the photoanodes equaled to 1.2 ?m. Finally, the photovoltaic devices were modified by adding ZnO nanoarpticles into P3HT to increase interfacial area between ZnO and P3HT. The efficiency was enhanced from 0.18% to 0.45% when the ZnO nanorod arrays were 625 nm in length. Our successful design of the device morphology significantly contributes to the performance of solid-state hybrid solar cells.

Lee, Tao Hua

2011-12-01T23:59:59.000Z

389

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS  

E-Print Network (OSTI)

process efficiency (UoK, GA) · Estimate the size and cost of the process equipment (All) #12;s NERI H2 6 cycle analysis (SNL) · Develop detailed chemical flowsheet for selected process and determine projected UT-3 process is conceptually simple. . . l Invented at Univ. of Tokyo, being pursued in Japan, SI

390

Scientists at ALS Find New Path to More Efficient Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists at ALS Find New Path to Scientists at ALS Find New Path to More Efficient Organic Solar Cells Scientists at ALS Find New Path to More Efficient Organic Solar Cells Print Monday, 07 January 2013 00:00 Harald Ade, a physicist at North Carolina State University, led a study at the Advanced Light Source that revealed a second pathway to improved performances of polymer/organic solar cells. Whereas the first pathway demands crystals of ultrapure domains, the new pathway shows that impure domains if sufficiently small can also lead to improved photovoltaic performances. Also working on this project were Brian Collins, Zhe Li, John Tumbleston, Eliot Gann and Christopher McNeill. Read the News Release Molecular view of polymer/fullerene solar film showing an interface between acceptor and donor domains. Red dots are PC71BM molecules and blue lines represent PTB7 chains. Excitons are shown as yellow dots, purple dots are electrons and green dots represent holes

391

Quantum Dots Promise to Significantly Boost Solar Cell Efficiencies (Fact Sheet)  

DOE Green Energy (OSTI)

In the search for a third generation of solar-cell technologies, a leading candidate is the use of 'quantum dots' -- tiny spheres of semiconductor material measuring only about 2-10 billionths of a meter in diameter. Quantum dots have the potential to dramatically increase the efficiency of converting sunlight into energy -- perhaps even doubling it in some devices -- because of their ability to generate more than one bound electron-hole pair, or exciton, per incoming photon. NREL has produced quantum dots using colloidal suspensions; then, using molecular self-assembly, they have been fabricated into the first-ever quantum-dot solar cells. While these devices operate with only 4.4% efficiency, they demonstrate the capability for low-cost manufacturing.

Not Available

2013-08-01T23:59:59.000Z

392

High deposition rate preparation of amorphous silicon solar cells by rf glow discharge decomposition of disilane  

SciTech Connect

The optical and electrical properties of hydrogenated amorphous silicon films produced by rf glow discharge decomposition of disilane diluted in helium (Si/sub 2/H/sub 6//He = 1/9) have been studied while systematically varying the film deposition rate. The properties and composition of the films were monitored by measuring the optical band gap, IR vibrational spectrum, dark conductivity, and the photoconductivity as a function of the deposition rate. The photoluminescence of the high deposition rate films gave a peak at 1.33 eV. These films, whose properties are rather similar to those of the conventional a-Si:H films prepared from monosilane, have been used to fabricate nip-type a-Si:H solar cells. At a deposition rate of 11 A/sec, a conversion efficiency of 6.86% was obtained. This high efficiency shows that disilane is applicable for mass production fabrication of a-Si:H solar cells.

Kenne, J.; Ohashi, Y.; Matsushita, T.; Konagai, M.; Takahashi, K.

1984-01-15T23:59:59.000Z

393

Solar Energy Education. Renewable energy activities for junior high/middle school science  

DOE Green Energy (OSTI)

Some basic topics on the subject of solar energy are outlined in the form of a teaching manual. The manual is geared toward junior high or middle school science students. Topics include solar collectors, solar water heating, solar radiation, insulation, heat storage, and desalination. Instructions for the construction of apparatus to demonstrate the solar energy topics are provided. (BCS)

Not Available

1985-01-01T23:59:59.000Z

394

Heat Transfer Interface for Thermo-Solar Energy - Energy ...  

Technology Marketing Summary Alex Zettl of Berkeley Lab has invented a high efficiency solar energy collector and converter. By addressing both solar absorption and ...

395

Design and Performance of Solar Decathlon 2011 High-Penetration Microgrid: Preprint  

DOE Green Energy (OSTI)

The U.S. Department of Energy Solar Decathlon challenges collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. The Solar Decathlon 2011 was held in Washington, D.C., from September 23 to October 2, 2011 . A high-penetration microgrid was designed, installed, and operated for the Solar Decathlon 2011 to grid-connect 19 highly energy-efficient, solar-powered competition houses to a single utility connection point. The capacity penetration of this microgrid (defined as maximum PV generation divided by maximum system load over a two-week period) was 74% based on 1-minute averaged data. Temporary, ground-laid conductors and electrical distribution equipment were installed to grid-connect the Solar Decathlon village, which included the houses as well as other electrical loads used by the event organizers. While 16 of the houses were connected to the 60 Hz microgrid, three houses from Belgium, China, and New Zealand were supplied with 50 Hz power. The design of the microgrid, including the connection of the houses powered by 50 Hz and a standby diesel generator, is discussed in this paper. In addition to the utility-supplied net energy meters at each house, a microgrid monitoring system was installed to measure and record energy consumption and PV energy production at 1-second intervals at each house. Bidirectional electronic voltage regulators were installed for groups of competition houses, which held the service voltage at each house to acceptable levels. The design and successful performance of this high-penetration microgrid is presented from the house, microgrid operator, and utility perspectives.

Stafford, B.; Coddington, M.; Butt, R.; Solomon, S.; Wiegand, G.; Wagner, C.; Gonzalez, B.

2012-04-01T23:59:59.000Z

396

High Efficiency Low Emission Supermarket Refrigeration Research Project |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Efficiency Low Emission Supermarket High Efficiency Low Emission Supermarket Refrigeration Research Project High Efficiency Low Emission Supermarket Refrigeration Research Project The U.S. Department of Energy (DOE) is currently conducting research into high efficiency, low emission supermarket refrigeration technologies. Project Description The project involves the development of a supermarket refrigeration system that can reduce greenhouse gas emissions and energy consumption when compared to existing systems. The challenge is to design a system that is capable of achieving low refrigerant leak rates while significantly reducing both the energy consumption and the refrigerant charge size. Project Partners Research is being undertaken between DOE and Oak Ridge National Laboratory. Project Goals

397

High-Efficiency Photovoltaics at Thin Film Costs  

Time (Years) 0-+ 5. 10. 15. 20. 25. Opportunity. Technology. ... • 15 years renewable energy business development ... High-Efficiency Photovoltaics at ...

398

Available Technologies: High Efficiency Spiral RF-Induction ...  

The spiral antennas efficient use of source geometry also ... Neutron and high energy gamma ... A typical RF-induction plasma generator with a ...

399

Energy Efficiency in Mineral Processing Industry Using High ...  

Science Conference Proceedings (OSTI)

Presentation Title, Energy Efficiency in Mineral Processing Industry Using High ... These studies were prepared by Tetra Tech on eight different projects at ...

400

Complex Oxides for Highly Efficient Solid-State Energy ...  

Complex Oxides for Highly Efficient Solid-State Energy ... Using complex oxides to directly convert thermal to electrical energy is both ... Thermal P ...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Available Technologies: High Quantum Efficiency Charge-Coupled ...  

Scientists at Berkeley Lab have developed a p-channel CCD with high quantum efficiency in the blue and near infrared wavelengths by combining a ...

402

Novel High Efficiency Photovoltaic Devices Based on the III-N Material System: Final Technical Report, 7 December 2005 - 29 August 2008  

DOE Green Energy (OSTI)

The research shows that InGaN material system can be used to realize high-efficiency solar cells, making contributions to growth, modeling, understanding of loss mechanisms, and process optimization.

Hornsberg, C.; Doolittle, W. A.; Ferguson, I.

2008-10-01T23:59:59.000Z

403

Northview Junior High solar energy demonstration project. Final report, 16 May 1974--16 May 1975  

DOE Green Energy (OSTI)

This report covers a one-year test and evaluation of the Northview Junior High School Solar Energy Demonstration Project. The system provided about 5 percent of the school's energy requirements for the year. This energy was used for space heating, domestic water heating, and pool water heating for a total of 629,000,000 solar supplied Btu's. Average collector efficiency for the year was 44 percent. Operating costs were less than 5 percent of the value of the collected energy. Solar insolation data and system performance data are presented for the various operating modes. Results and conclusions indicate that the supplemental heating of large-scale buildings is feasible and economical. An optimum performance requires a careful matching of load, collectors, and distribution system.

Merrill, G.; Dib, A.

1976-05-01T23:59:59.000Z

404

Northview Junior High solar energy demonstration project. Final report, 16 May 1974--16 May 1975  

SciTech Connect

This report covers a one-year test and evaluation of the Northview Junior High School Solar Energy Demonstration Project. The system provided about 5 percent of the school's energy requirements for the year. This energy was used for space heating, domestic water heating, and pool water heating for a total of 629,000,000 solar supplied Btu's. Average collector efficiency for the year was 44 percent. Operating costs were less than 5 percent of the value of the collected energy. Solar insolation data and system performance data are presented for the various operating modes. Results and conclusions indicate that the supplemental heating of large-scale buildings is feasible and economical. An optimum performance requires a careful matching of load, collectors, and distribution system.

Merrill, G.; Dib, A.

1976-05-01T23:59:59.000Z

405

Candidate Alloys for Cost-Effective, High-Efficiency, High ...  

Science Conference Proceedings (OSTI)

the efficiency of heat exchange in these fuel cells require both development and careful ..... 3rd EPRI Conference on Advances in Materials Technology for Fossil.

406

High Spatial Resolution Observations of Loops in the Solar Corona  

E-Print Network (OSTI)

Understanding how the solar corona is structured is of fundamental importance to determining how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in July 2012. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270km. We also use Atmospheric Imaging Assembly (AIA) data for a subset of 79 of these loops and find that their temperature distributions are narrow. These observations provide further evidence that loops in the solar corona are structured at a scale of several hundred kilometers, well above the spatial scale of proposed physical mechanisms.

Brooks, David H; Ugarte-Urra, Ignacio; Winebarger, Amy R

2013-01-01T23:59:59.000Z

407

Creating systems that effectively convert energy, such as efficient solar cells and electrochemical batteries, has been a  

E-Print Network (OSTI)

SEMTE abstract Creating systems that effectively convert energy, such as efficient solar cells stimuli, the solar energy from sunlight, and the mechanical motion is commonplace, indeed fundamental and electrochemical batteries, has been a longstanding scientific pursuit, especially given the global energy

Reisslein, Martin

408

Efficiency improvement of solar cells by importing microdome-shaped anti-reflective structures as a surface protection layer  

Science Conference Proceedings (OSTI)

A novel dome-shaped and anti-reflective microdome array (MDA) was developed for a solar cell surface protection layer with the aim to improve the cell efficiency. Uniform microdomes in the array were obtained by isotropic wet-etching of quartz. The microdome ... Keywords: Anti-reflective coating, Isotropic etching, Microdome array (MDA), Polymer replica molding, Solar cell, Surface protection layer

Minwoo Nam; Jaejin Lee; Kee-Keun Lee

2011-08-01T23:59:59.000Z

409

"Tuning" microalgae for high photosynthesis efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

"Tuning" Microalgae For High Photosynthesis Efficiency "Tuning" Microalgae For High Photosynthesis Efficiency "Tuning" microalgae for high photosynthesis efficiency Los Alamos scientist Richard Sayre and his team of researchers have recently developed more efficient microalgae. March 25, 2013 Shown here is a model for light absorption and use by algae as a function of antenna size. Shown here is a model for light absorption and use by algae as a function of antenna size. The team's work in this area is reported in a paper published in the journal Algal Research. Los Alamos scientist Richard Sayre of Bioenergy and Biome Sciences (B-11) and his team of researchers have recently developed more efficient microalgae. Microalgae have large rates of biomass accumulation due to their high photosynthetic efficiencies. This makes them attractive candidates for

410

"Tuning" microalgae for high photosynthesis efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

"Tuning" Microalgae For High Photosynthesis Efficiency "Tuning" Microalgae For High Photosynthesis Efficiency "Tuning" microalgae for high photosynthesis efficiency Los Alamos scientist Richard Sayre and his team of researchers have recently developed more efficient microalgae. March 25, 2013 Shown here is a model for light absorption and use by algae as a function of antenna size. Shown here is a model for light absorption and use by algae as a function of antenna size. The team's work in this area is reported in a paper published in the journal Algal Research. Los Alamos scientist Richard Sayre of Bioenergy and Biome Sciences (B-11) and his team of researchers have recently developed more efficient microalgae. Microalgae have large rates of biomass accumulation due to their high photosynthetic efficiencies. This makes them attractive candidates for

411

Hathaway ''Solar Patriot'' House: A Case Study in Efficiency and Renewable Energy  

DOE Green Energy (OSTI)

This report details the monitored and modeled performance of a solar home outside of Washington, D.C. We modeled the home energy performance using DOE2.2, performed numerous short-terms tests on the home and monitored its occupied performance for 29 months. The home uses modular construction, solar water heating, a ground-coupled heat pump, efficient appliances and compact fluorescent lighting to reduce its energy consumption by 35% compared to the Building America research benchmark home. The addition of 6kW of photovoltaics increases the savings to 67% compared to the Building America research benchmark. A more efficient shell to reduce space conditioning loads would have brought the home closer to its zero energy goals. However, even with efficient lighting and appliances, the lights, appliance and plug loads are a significant energy consumer. About 4 kW of PV are required to meet the needs of these loads alone. To achieve the zero energy goal with no further efficiency increases, the Hathaway house would need about 2.6 kW of PV in addition to the 6.0 kW it now has.

Norton, P.; Hancock, E.; Barker, G.; Reeves, P.

2005-05-01T23:59:59.000Z

412

Evaluation of a High-Performance Solar Home in Loveland, Colorado: Preprint  

DOE Green Energy (OSTI)

Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, Colorado, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium (BSC) conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 35 l/s (75 cfm), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (>83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict whole-house source energy savings of 54% compared to the BA Benchmark. The largest contributors to energy savings beyond McStain's standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package.

Hendron, R.; Eastment, M.; Hancock, E.; Barker, G.; Reeves, P.

2006-08-01T23:59:59.000Z

413

Evaluation of a High-Performance Solar Home in Loveland, Colorado  

DOE Green Energy (OSTI)

Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, Colorado, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR? appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium (BSC) conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 75 cfm (35 l/s), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (>83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict whole-house source energy savings of 54% compared to the BA Benchmark [1]. The largest contributors to energy savings beyond McStain's standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package.

Hendron, R.; Eastment, M.; Hancock, E.; Barker, G.; Reeves, P.

2006-01-01T23:59:59.000Z

414

The role of Förster Resonance Energy Transfer in luminescent solar concentrator efficiency and color tunability  

E-Print Network (OSTI)

greenhouse collector for solar radiation," Applied OpticsOn the conversion of solar radiation with fluorescent planarmaterial which absorbs solar radiation and isotropically

Balaban, Benjamin

2013-01-01T23:59:59.000Z

415

The Design of Organic Polymers and Small Molecules to Improve the Efficiency of Excitonic Solar Cells  

E-Print Network (OSTI)

broadly across the solar spectrum, have functional groupsbroadly across the solar spectrum. Open circuit voltages (Vabsorbing 80% of the solar spectrum from 350-900 nm would

Armstrong, Paul Barber

2010-01-01T23:59:59.000Z

416

Optimal Materials and Deposition Technique Lead to Cost-Effective Solar Cell with Best-Ever Conversion Efficiency (Fact Sheet)  

DOE Green Energy (OSTI)

This fact sheet describes how the SJ3 solar cell was invented, explains how the technology works, and why it won an R&D 100 Award. Based on NREL and Solar Junction technology, the commercial SJ3 concentrator solar cell - with 43.5% conversion efficiency at 418 suns - uses a lattice-matched multijunction architecture that has near-term potential for cells with {approx}50% efficiency. Multijunction solar cells have higher conversion efficiencies than any other type of solar cell. But developers of utility-scale and space applications crave even better efficiencies at lower costs to be both cost-effective and able to meet the demand for power. The SJ3 multijunction cell, developed by Solar Junction with assistance from foundational technological advances by the National Renewable Energy Laboratory, has the highest efficiency to date - almost 2% absolute more than the current industry standard multijunction cell-yet at a comparable cost. So what did it take to create this cell having 43.5% efficiency at 418-sun concentration? A combination of materials with carefully designed properties, a manufacturing technique allowing precise control, and an optimized device design.

Not Available

2012-07-01T23:59:59.000Z

417

High-flux solar photon processes: Opportunities for applications  

DOE Green Energy (OSTI)

The overall goal of this study was to identify new high-flux solar photon (HFSP) processes that show promise of being feasible and in the national interest. Electric power generation and hazardous waste destruction were excluded from this study at sponsor request. Our overall conclusion is that there is promise for new applications of concentrated solar photons, especially in certain aspects of materials processing and premium materials synthesis. Evaluation of the full potential of these and other possible applications, including opportunities for commercialization, requires further research and testing. 100 refs.

Steinfeld, J.I.; Coy, S.L.; Herzog, H.; Shorter, J.A.; Schlamp, M.; Tester, J.W.; Peters, W.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1992-06-01T23:59:59.000Z

418

Method for forming indium oxide/n-silicon heterojunction solar cells  

DOE Patents (OSTI)

A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

1984-03-13T23:59:59.000Z

419

Enabling Technologies for High Penetration of Wind and Solar Energy  

Science Conference Proceedings (OSTI)

High penetration of variable wind and solar electricity generation will require modifications to the electric power system. This work examines the impacts of variable generation, including uncertainty, ramp rate, ramp range, and potentially excess generation. Time-series simulations were performed in the Texas (ERCOT) grid where different mixes of wind, solar photovoltaic and concentrating solar power provide up to 80% of the electric demand. Different enabling technologies were examined, including conventional generator flexibility, demand response, load shifting, and energy storage. A variety of combinations of these technologies enabled low levels of surplus or curtailed wind and solar generation depending on the desired penetration of renewable sources. At lower levels of penetration (up to about 30% on an energy basis) increasing flexible generation, combined with demand response may be sufficient to accommodate variability and uncertainty. Introduction of load-shifting through real-time pricing or other market mechanisms further increases the penetration of variable generation. The limited time coincidence of wind and solar generation presents increasing challenges as these sources provide greater than 50% of total demand. System flexibility must be increased to the point of virtually eliminating must-run baseload generators during periods of high wind and solar generation. Energy storage also becomes increasingly important as lower cost flexibility options are exhausted. The study examines three classes of energy storage - electricity storage, including batteries and pumped hydro, hybrid storage (compressed-air energy storage), and thermal energy storage. Ignoring long-distance transmission options, a combination of load shifting and storage equal to about 12 hours of average demand may keep renewable energy curtailment below 10% in the simulated system.

Denholm, P.

2011-01-01T23:59:59.000Z

420

Compact and highly efficient laser pump cavity  

SciTech Connect

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, Jim J. (Dublin, CA); Bass, Isaac L. (Castro Valley, CA); Zapata, Luis E. (Livermore, CA)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Compact and highly efficient laser pump cavity  

SciTech Connect

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, J.J.; Bass, I.L.; Zapata, L.E.

1999-11-02T23:59:59.000Z

422

Advances in solar assisted drying systems for agricultural produce  

Science Conference Proceedings (OSTI)

The technical directions in the development of solar assisted drying systems system for agricultural produce are compact collector design, high efficiency, integrated storage, and long-life drying system. Air based solar collectors are not the only available ... Keywords: V-groove solar collector, double-pass solar collector, photovoltaic thermal collectors, solar assisted chemical heat pump system, solar dehumidification system

Kamaruzzaman Sopian; Mohd Yusof Sulaiman; Mohd Yusof Othman; Sohif Mat; Muhamad Yahya; Mohamad A. Alghoul; Baharudin Ali; Lim Chin Haw; Mohd Hafidz Ruslan; Azami Zaharim

2009-02-01T23:59:59.000Z

423

CdTe portfolio offers commercial ready high efficiency solar ...  

This characteristic is due partly to the single-phase nature of the absorber layer and the ease with which the CdTe source ... Wind Energy; Partners (27) Visual ...

424

High Efficiency Materials for Dye-Sensitized Solar Cells  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Energy Storage III: Materials, Systems and Applications Symposium.

425

Highlighting High Performance: The Solar Energy Research Facility, Golden, Colorado  

DOE Green Energy (OSTI)

The National Renewable Energy Laboratory's Solar Energy Research Facility in Golden, Colorado, uses a stair-step configuration to allow daylight and heat into the office areas, while the laboratories in the back of the building are in a more controlled environment where tight levels of ventilation, humidity, temperature, and light are critical. A unique mechanical system makes the most of the natural environment and the building's design to efficiently heat and cool the building at an annual utility bill savings of almost $200,000 per year.

Torcellini, P.; Epstein, K.

2001-06-26T23:59:59.000Z

426

Highly Energy Efficient Wall Systems Research Project | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Highly Energy Efficient Wall Systems Highly Energy Efficient Wall Systems Research Project Highly Energy Efficient Wall Systems Research Project The Department of Energy is currently conducting research into highly energy efficient wall systems. Walls with high R-values are better insulators, and their development can help buildings come closer to having zero net energy consumption. Project Description This project seeks to develop a commercially viable wall system up to R-40 through integration of vacuum technology with the exterior insulated façade system (EIFS). Dow Corning will develop a wall system configuration of expanded polystyrene vacuum isolation panels that can be specified for R-values of 20, 30, and 40. This project also aims to develop a unitized protection system of vacuum isolation panels and to validate current code

427

Department of Energy Lauds Highly Efficient Industrial Technology |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Department of Energy Lauds Highly Efficient Industrial Technology Department of Energy Lauds Highly Efficient Industrial Technology Department of Energy Lauds Highly Efficient Industrial Technology November 30, 2007 - 4:45pm Addthis DOE Celebrates One-Year Anniversary of Operation of the Energy Efficient "Super Boiler" WASHINGTON, DC - Representing important technology transfer from Department of Energy (DOE) labs to the marketplace, DOE today announced the successful one-year operation of the first generation "Super Boiler," which can deliver 94 percent thermal efficiency, while producing fewer emissions than conventional boiler technologies. By 2020, this technology could save more than 185 trillion British Thermal Units (Btus) of energy - equivalent to the natural gas consumed by more than two million households. The

428

Department of Energy Lauds Highly Efficient Industrial Technology |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Lauds Highly Efficient Industrial Technology Lauds Highly Efficient Industrial Technology Department of Energy Lauds Highly Efficient Industrial Technology November 30, 2007 - 4:45pm Addthis DOE Celebrates One-Year Anniversary of Operation of the Energy Efficient "Super Boiler" WASHINGTON, DC - Representing important technology transfer from Department of Energy (DOE) labs to the marketplace, DOE today announced the successful one-year operation of the first generation "Super Boiler," which can deliver 94 percent thermal efficiency, while producing fewer emissions than conventional boiler technologies. By 2020, this technology could save more than 185 trillion British Thermal Units (Btus) of energy - equivalent to the natural gas consumed by more than two million households. The

429

Energy Efficiency Indicators for High Electric-Load Buildings  

NLE Websites -- All DOE Office Websites (Extended Search)

Energy Efficiency Indicators for High Electric-Load Buildings Energy Efficiency Indicators for High Electric-Load Buildings Speaker(s): Bernard Aebischer Date: February 6, 2003 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Kristina LaCommare Energy per unit of floor area is not an adequate indictor for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed. Prerequisites in order to be able to use these indicators in energy efficiency programmes are discussed. The opportunity of an internationally coordinated research activity is also presented. Since 1999, Dr. Bernard Aebischer has served as a senior scientist at CEPE (Centre for Energy Policy and Economics) of the Swiss Federal Institutes of

430

High Performance Photovoltaic Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-05-169  

DOE Green Energy (OSTI)

NREL will provide certified measurements of the conversion efficiency at high concentration for several multijunction solar cells that were fabricated by Cyrium Technologies. In an earlier phase of the CRADA, Cyrium provided epitaxially-grown material and NREL processed the samples into devices and measured the performance.

Steiner, M.

2012-07-01T23:59:59.000Z

431

Improving efficiency of high-concentrator photovoltaics by cooling with  

NLE Websites -- All DOE Office Websites (Extended Search)

Improving efficiency of high-concentrator photovoltaics by cooling with Improving efficiency of high-concentrator photovoltaics by cooling with two-phase forced convection Title Improving efficiency of high-concentrator photovoltaics by cooling with two-phase forced convection Publication Type Journal Article Year of Publication 2010 Authors Ho, Tony, Samuel S. Mao, and Ralph Greif Journal International Journal of Energy Research Volume 34 Start Page 1257 Issue 14 Pagination 1257-1271 Date Published 11/2010 Keywords high-concentrator photovoltaic efficiency, two-phase flow cooling applications Abstract The potential of increasing high-concentrator photovoltaic cell efficiency by cooling with two-phase flow is analyzed. The governing energy equations were used to predict cell temperature distributions and cell efficiencies for a photovoltaic cell under 100 suns' concentration. Several design conditions were taken into consideration in the analysis, including cooling channel height, working fluid type (between water and R134a), working fluid inlet temperature, pressure, and mass flow rate. It was observed that the dominant parameter for increasing cell efficiency was the working fluid saturation temperature, which itself is affected by a number of the aforementioned design parameters. The results show R134a at low inlet pressures to be highly effective in this two-phase cooling design.

432

Kauai, Hawaii: Solar Resource Analysis and High-Penetration PV Potential  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

956 956 April 2010 Kauai, Hawaii: Solar Resource Analysis and High-Penetration PV Potential Chris Helm and Kari Burman National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Operated by the Alliance for Sustainable Energy, LLC Contract No. DE-AC36-08-GO28308 Technical Report NREL/TP-7A2-47956 April 2010 Kauai, Hawaii: Solar Resource Analysis and High-Penetration PV Potential Chris Helm and Kari Burman Prepared under Task No. IDHW.9170 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any

433

SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Efficiency Thermal Energy Storage System for CSP High-Efficiency Thermal Energy Storage System for CSP ANL logo Photo of a black and white porous material magnified 50 times by a microscope. Microstructure of the highly thermal conductive foam that will be used for the prototype TES system. Image from ANL Argonne National Laboratory and project partner Ohio Aerospace Institute, under the National Laboratory R&D competitive funding opportunity, will design, develop, and test a prototype high-temperature and high-efficiency thermal energy storage (TES) system with rapid charging and discharging times. By increasing the efficiency of TES systems, this project aims to lower the capital costs of concentrating solar power (CSP) systems. Approach The research team is developing and evaluating a novel approach for TES at temperatures greater than 700ËšC for CSP systems. The approach uses high thermal conductivity and high-porosity graphite foams infiltrated with a phase change material (PCM) to provide TES in the form of latent heat.

434

Energy Efficiency Indicators for High Electric-Load Buildings  

NLE Websites -- All DOE Office Websites (Extended Search)

Energy Efficiency Indicators for High Electric-Load Buildings Speaker(s): Bernard Aebischer Date: February 6, 2003 - 12:00pm Location: Bldg. 90 Seminar HostPoint of Contact:...

435

Conversion efficiency, scaling and global optimization of high harmonic generation  

E-Print Network (OSTI)

Closed form expressions for the high harmonic generation (HHG) conversion efficiency in the plateau and cut-off region are derived showing agreement with previous observations. Application of these results to optimal ...

Falcao-Filho, Edilson L.

436

III-V High-Efficiency Multijunction Photovoltaics (Fact Sheet)  

Science Conference Proceedings (OSTI)

Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for III-V High-Efficiency Multijunction Photovoltaics at the National Center for Photovoltaics.

Not Available

2011-06-01T23:59:59.000Z

437

City of High Point Electric- Residential Energy Efficiency Rebate Program  

Energy.gov (U.S. Department of Energy (DOE))

The City of High Point offers the Hometown Green Program to help customers reduce energy use. Under this program, rebates are available for newly constructed energy efficient homes, heat pumps, and...

438

Highly efficient blue polyfluorene-based polymer light-emitting...  

NLE Websites -- All DOE Office Websites (Extended Search)

of Physics Volume 42 Pagination 5 Abstract A highly efficient blue polymer light-emitting diode based on poly(9,9-di(2-(2-(2-methoxy-ethoxy)ethoxy)ethyl)fluorenyl-2,7-diyl)...

439

Interfacial Engineering for Highly Efficient-Conjugated Polymer-Based Bulk Heterojunction Photovoltaic Devices  

Science Conference Proceedings (OSTI)

The aim of our proposal is to apply interface engineering approach to improve charge extraction, guide active layer morphology, improve materials compatibility, and ultimately allow the fabrication of high efficiency tandem cells. Specifically, we aim at developing: i. Interfacial engineering using small molecule self-assembled monolayers ii. Nanostructure engineering in OPVs using polymer brushes iii. Development of efficient light harvesting and high mobility materials for OPVs iv. Physical characterization of the nanostructured systems using electrostatic force microscopy, and conducting atomic force microscopy v. All-solution processed organic-based tandem cells using interfacial engineering to optimize the recombination layer currents vi. Theoretical modeling of charge transport in the active semiconducting layer The material development effort is guided by advanced computer modeling and surface/ interface engineering tools to allow us to obtain better understanding of the effect of electrode modifications on OPV performance for the investigation of more elaborate device structures. The materials and devices developed within this program represent a major conceptual advancement using an integrated approach combining rational molecular design, material, interface, process, and device engineering to achieve solar cells with high efficiency, stability, and the potential to be used for large-area roll-to-roll printing. This may create significant impact in lowering manufacturing cost of polymer solar cells for promoting clean renewable energy use and preventing the side effects from using fossil fuels to impact environment.

Alex Jen; David Ginger; Christine Luscombe; Hong Ma

2012-04-02T23:59:59.000Z

440

SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature  

NLE Websites -- All DOE Office Websites (Extended Search)

A Small-Particle Solar Receiver A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles to someone by E-mail Share SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles on Facebook Tweet about SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles on Twitter Bookmark SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles on Google Bookmark SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles on Delicious Rank SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles on Digg Find More places to share SunShot Initiative: A Small-Particle Solar Receiver for High-Temperature Brayton Power Cycles on AddThis.com...

Note: This page contains sample records for the topic "high efficiency solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials |  

Office of Science (SC) Website

Design of Bulk Nanocomposites as High Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights Highlight Archives News & Events Publications Contact BES Home 04.27.12 Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials Print Text Size: A A A RSS Feeds FeedbackShare Page Scientific Achievement A newly synthesized bulk thermoelectric material that contains nanocrystals with the same orientation and structure as the host material breaks thermoelectric efficiency records by blocking thermal, but not electrical, conductivity. Significance and Impact A new strategy to design inexpensive materials that more efficiently convert heat to electricity. Research Details Thermoelectric materials directly generate electrical power from heat, but

442

Laclede Gas Company - Residential High Efficiency Heating Rebate Program |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Residential High Efficiency Heating Rebate Residential High Efficiency Heating Rebate Program Laclede Gas Company - Residential High Efficiency Heating Rebate Program < Back Eligibility Multi-Family Residential Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Appliances & Electronics Water Heating Maximum Rebate Heating System: 2 maximum Programmable Thermostats: 2 maximum Multi-Family Property Owners: 50 thermostat rebates, 50 furnace rebates over the life of the program Program Info State Missouri Program Type Utility Rebate Program Rebate Amount Gas Furnace: $150 - $200 Gas Boiler: $150 Programmable Setback Thermostat: $25 Gas Water Heater: $50 - $200 Provider Laclede Gas Company Laclede Gas Company offers various rebates to residential customers for investing in energy efficient equipment and appliances. Residential

443

Solar wind acceleration in coronal holes. [High speed solar wind streams  

SciTech Connect

Past attempts to explain the large solar wind velocities in high speed streams by theoretical models of the expansion have invoked either extended nonthermal heating of the corona, heat flux inhibition, or direct addition of momentum to the expanding coronal plasma. Several workers have shown that inhibiting the heat flux at low coronal densities is probably not adequate to explain quantitatively the observed plasma velocities in high speed streams. It stressed that, in order to account for both these large plasma velocities and the low densities found in coronal holes (from which most high speed streams are believed to emanate), extended heating by itself will not suffice. One needs a nonthermal mechanism to provide the bulk acceleration of the high wind plasma close to the sun, and the most likely candidate at present is direct addition of the momentum carried by outward-propagating waves to the expanding corona. Some form of momentum addition appears to be absolutely necessary if one hopes to build quantitatively self-consistent models of coronal holes and high speed solar wind streams.

Kopp, R.A.

1978-01-01T23:59:59.000Z

444

Solar  

Energy.gov (U.S. Department of Energy (DOE))

The U.S. Department of Energy (DOE) leads a large network of researchers and other partners to deliver innovative solar photovoltaic and concentrating solar power technologies that will make solar...

445

Immersion Cooling of Photovoltaic Cells in Highly Concentrated Solar Beams.  

E-Print Network (OSTI)

??Concentrated solar radiation can be utilized to generate electrical power from photovoltaic cells, but concentrated solar radiation increases the photovoltaic cell’s temperature. This increase in… (more)

Darwish, Ahmed

2011-01-01T23:59:59.000Z

446

Highly Mismatched Alloys for Intermediate Band Solar Cells  

E-Print Network (OSTI)

edges span much of the solar spectrum, demonstrating thatthat fall within the solar energy spectrum, Zn 1-x Mn x O y

2005-01-01T23:59:59.000Z

447

Principles of energy efficiency in high performance computing  

Science Conference Proceedings (OSTI)

High Performance Computing (HPC) is a key technology for modern researchers enabling scientific advances through simulation where experiments are either technically impossible or financially not feasible to conduct and theory is not applicable. However, ... Keywords: HPC, PUE, energy efficiency, high performance computing, power usage effectiveness

Axel Auweter; Arndt Bode; Matthias Brehm; Herbert Huber; Dieter Kranzlmüller

2011-08-01T23:59:59.000Z

448

Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems  

E-Print Network (OSTI)

in thermal energy conversion efficiency over present solarsolar thermal- photovoltaic co-generation scheme could have potentially very high solar-to-electric efficiency.solar-to-electric conversion efficiencies are attained and no thermal

Ho, Tony

2012-01-01T23:59:59.000Z

449

A Scheduling Algorithm for Consistent Monitoring Results with Solar Powered High-Performance Wireless Embedded Systems  

E-Print Network (OSTI)

A Scheduling Algorithm for Consistent Monitoring Results with Solar Powered High but critical task for solar powered wireless high power embedded systems. Our algorithm relies on an energy Few bytes per second Up to 2MB per second Peak power (mW) 198 2200 Solar harvesting is one of the most

Simunic, Tajana

450

Design of a High Temperature Small Particle Solar Receiver for Powering a Gas Turbine Engine  

E-Print Network (OSTI)

Design of a High Temperature Small Particle Solar Receiver for Powering a Gas Turbine Engine Dr. Fletcher Miller SDSU Department of Mechanical Engineering Abstract Solar thermal power for electricity will describe the design of a high temperature solar receiver capable of driving a gas turbine for power

Ponce, V. Miguel

451

Heterojunction solar cell  

DOE Patents (OSTI)

A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

Olson, J.M.

1994-08-30T23:59:59.000Z

452

Basic studies of 3-5 high efficiency cell components. Annual subcontract report, 15 August 1989--14 August 1990  

DOE Green Energy (OSTI)

This project`s objective is to improve our understanding of the generation, recombination, and transport of carriers within III-V homo- and heterostructures. The research itself consists of fabricating and characterizing solar cell ``building blocks`` such as junctions and heterojunctions as well as basic measurements of material parameters. A significant effort is also being directed at characterizing loss mechanisms in high-quality, III-V solar cells fabricated in industrial research laboratories throughout the United States. The project`s goal is to use our understanding of the device physics of high-efficiency cell components to maximize cell efficiency. A related goal is the demonstration of new cell structures fabricated by molecular beam epitaxy (MBE). The development of measurement techniques and characterization methodologies is also a project objective. This report describes our progress during the fifth and final year of the project. During the past five years, we`ve teamed a great deal about heavy doping effects in p{sup +} and n{sup +} GaAs and have explored their implications for solar cells. We have developed an understanding of the dominant recombination losses in present-day, high-efficiency cells. We`ve learned to appreciated the importance of recombination at the perimeter of the cell and have developed techniques for chemically passivating such edges. Finally, we`ve demonstrated that films grown by molecular beam epitaxy are suitable for high-efficiency cell research.

Lundstrom, M.S.; Melloch, M.R.; Pierret, R.F.; Carpenter, M.S.; Chuang, H.L.; Dodd, P.E.; Keshavarzi, A.; Klausmeier-Brown, M.E.; Lush, G.B.; Stellwag, T.B. [Purdue Univ., Lafayette, IN (United States)

1993-01-01T23:59:59.000Z

453

A high-efficiency thermoelectric converter for space applications  

DOE Green Energy (OSTI)

This paper presents a concept for using high-temperature superconducting materials in thermoelectric generators (SCTE) to produce electricity at conversion efficiencies approaching 50% of the Carrot efficiency. The SCTE generator is applicable to systems operating in temperature ranges of high-temperature superconducting materials and thus would be a low-grade converter. Operating in cryogenic temperature ranges provides the advantage of inherently increasing the limits of the Carrot efficiency. Potential applications are for systems operating in space where the ambient temperatures are in the cryogenic temperature range. The advantage of using high-temperature superconducting material in a thermoelectric converter is that it would significantly reduce or eliminate the Joule heating losses in a thermoelectric element. This paper investigates the system aspects and the material requirements of the SCTE converter concept, and presents a conceptual design and an application for a space power system.

Metzger, J.D. [Westinghouse Savannah River Co., Aiken, SC (United States); El-Genk, M.S. [New Mexico Univ., Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies

1990-12-31T23:59:59.000Z

454

Southwest Gas Corporation - Commercial High-Efficiency Equipment Rebate  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Southwest Gas Corporation - Commercial High-Efficiency Equipment Southwest Gas Corporation - Commercial High-Efficiency Equipment Rebate Program Southwest Gas Corporation - Commercial High-Efficiency Equipment Rebate Program < Back Eligibility Commercial Industrial Savings Category Other Appliances & Electronics Commercial Weatherization Commercial Heating & Cooling Water Heating Maximum Rebate General: 50% of price Boiler Steam Trap: 25% of price Program Info State Arizona Program Type Utility Rebate Program Rebate Amount Modulating Burner Control: $10,000 Boiler O2 Trim Control Pad: $10,000 Boiler Steam Trap: $250 Non-condensing Boiler: $1/MBtuh Condensing Boiler: $1.25/MBtuh Storage Water Heater: 50% of cost, up to $1,100 Tankless Water Heater: 50% of cost, up to $450 Griddle: 50% of cost, up to $600 Fryer: 50% of cost, up to $1,350

455

Home Performance with Energy Star High Efficiency Measure Incentive (HEMI)  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Home Performance with Energy Star High Efficiency Measure Incentive Home Performance with Energy Star High Efficiency Measure Incentive (HEMI) Home Performance with Energy Star High Efficiency Measure Incentive (HEMI) < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Home Weatherization Commercial Weatherization Cooling Appliances & Electronics Sealing Your Home Ventilation Manufacturing Commercial Lighting Lighting Water Heating Maximum Rebate $3,000 Program Info State New York Program Type State Rebate Program Rebate Amount 10% of project costs Provider New York State Energy Research and Development Authority The New York State Research and Development Authority (NYSERDA) offers an incentive for homeowners of 1-4 homes that participate in the Home Performance with Energy Star program. The program entitles the participant

456

A high-efficiency thermoelectric converter for space applications  

DOE Green Energy (OSTI)

This paper presents a concept for using high-temperature superconducting materials in thermoelectric generators (SCTE) to produce electricity at conversion efficiencies approaching 50% of the Carrot efficiency. The SCTE generator is applicable to systems operating in temperature ranges of high-temperature superconducting materials and thus would be a low-grade converter. Operating in cryogenic temperature ranges provides the advantage of inherently increasing the limits of the Carrot efficiency. Potential applications are for systems operating in space where the ambient temperatures are in the cryogenic temperature range. The advantage of using high-temperature superconducting material in a thermoelectric converter is that it would significantly reduce or eliminate the Joule heating losses in a thermoelectric element. This paper investigates the system aspects and the material requirements of the SCTE converter concept, and presents a conceptual design and an application for a space power system.

Metzger, J.D. (Westinghouse Savannah River Co., Aiken, SC (United States)); El-Genk, M.S. (New Mexico Univ., Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies)

1990-01-01T23:59:59.000Z

457

Application of CIS to high-efficiency PV module fabrication. Annual technical progress report, April 1, 1995--March 31, 1996  

DOE Green Energy (OSTI)

The authors investigated the interactions between the soda-lime glass substrate, the Mo contract film and the CIS absorber layer. Excessive Na diffusion through the Mo layer was found to be the reason for excessive interaction between the substrate and the CIS layers obtained by the H{sub 2}Se selenization technique. This chemical interaction influenced the stoichiometric uniformity of the absorbers. Addition of Ga into the CIS layers by the two-stage selenization technique yielded graded absorber structures with higher Ga content near the Mo/absorber interface. Gallium was later diffused through the absorber film by a high-temperature annealing step, and large bandgap alloys were obtained. Solar cells with active-area efficiencies of close to 12% were fabricated on these CIGS layers. Sulfur addition experiments were also carried out during this period. By controlling the Se and S availability to the precursors during the reaction step of the process, various S profiles were obtained in high-bandgap absorber layers. The highest-efficiency cell made on S-containing absorbers was about 10% efficient. A low-cost, non-vacuum technique was successful