Sample records for high efficiency solar

  1. Webinar: Highly Efficient Solar Thermochemical Reaction Systems

    Broader source: Energy.gov [DOE]

    Video recording and text version of the Fuel Cell Technologies Office webinar titled "Highly Efficient Solar Thermochemical Reaction Systems," originally presented on January 13, 2015.

  2. Very High Efficiency Solar Cell Modules

    SciTech Connect (OSTI)

    Barnett, A.; Kirkpatrick, D.; Honsberg, C.; Moore, D.; Wanlass, M.; Emery, K.; Schwartz, R.; Carlson, D.; Bowden, S.; Aiken, D.; Gray, A.; Kurtz, S.; Kazmerski, L., et al

    2009-01-01T23:59:59.000Z

    The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system - PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42.7 {+-} 2.5% are described.

  3. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

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

    2004-01-01T23:59:59.000Z

    J. F. Geisz, “Superior radiation resistance of In 1-x Ga x Nand H. Itoh, “Proton radiation analysis of multi-junction56326 High efficiency, radiation-hard solar cells Final

  4. Highly Efficient Solar Thermochemical Reaction Systems

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Highly Efficient, Solar Thermochemical Reaction Systems (2014 R&D 100 Award Winner) U.S. Department of Energy Fuel Cell Technologies Office 2 Question and Answer * Please type your...

  5. Webinar: Highly Efficient Solar Thermochemical Reaction Systems

    Broader source: Energy.gov [DOE]

    The Fuel Cell Technologies Office will present a live webinar titled "Highly Efficient Solar Thermochemical Reaction Systems" on Tuesday, January 13, from 12:00 to 1:00 p.m. Eastern Standard Time.

  6. Integrated Solar Thermochemical Reaction System for High Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Integrated Solar Thermochemical Reaction System for High Efficiency Production of Electricity Integrated Solar Thermochemical Reaction System for High Efficiency Production of...

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search High-Efficiency, Self-Concentrating Nanoscale Solar Cell Lawrence Berkeley National Laboratory Contact...

  8. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

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

    2004-01-01T23:59:59.000Z

    Solar Energy Mat. and Solar Cells 75, 261-9 (2003) andD. J. , “Advanced Space Solar Cells,” Prog. Photovolt: Res.Igari, and W. Warta, “Solar Cell Efficiency Tables (Version

  9. High Efficiency Solar Integrated Roof Membrane Product

    SciTech Connect (OSTI)

    Partyka, Eric; Shenoy, Anil

    2013-05-15T23:59:59.000Z

    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.

  10. Highly efficient light management for perovskite solar cells

    E-Print Network [OSTI]

    Wang, Dong-Lin; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2015-01-01T23:59:59.000Z

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  11. Solar Cells, 3 (1981) 337 -340 337 HIGH EFFICIENCY BIFACIAL BACK SURFACE FIELD SOLAR CELLS

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    . CUEVAS, A. LUQUE, J. EGUREN and J. DEL ALAMO Instituto de Energia Solar, Escuela Tdcnica Superior deSolar Cells, 3 (1981) 337 - 340 337 HIGH EFFICIENCY BIFACIAL BACK SURFACE FIELD SOLAR CELLS A solar cells are presented. Effi- ciencies of 15.7% and 13.6% were measured under front and back air mass

  12. SOLAR POWERING OF HIGH EFFICIENCY ABSORPTION CHILLER

    SciTech Connect (OSTI)

    Randy C. Gee

    2004-11-15T23:59:59.000Z

    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.

  13. High-Efficiency Solar Cogeneration with Thermophotovoltaic &...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    system are produced, including, Lighting Luminary Fixtures, weatherized building-mounted solar receiver, fiber cables, IR electricity generation. System performance will be...

  14. High Efficiency Solar Fuels Reactor Concept

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

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

    SciTech Connect (OSTI)

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

    2005-01-01T23:59:59.000Z

    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.

  16. High Efficiency Solar Power via Separated Photo and Voltaic Pathways

    SciTech Connect (OSTI)

    Michael J. Naughton

    2009-02-17T23:59:59.000Z

    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.

  17. Sandia National Laboratories: high-efficiency solar cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cells Sandia and EMCORE: Solar Photovoltaics, Fiber Optics, MODE, and Energy Efficiency On March 29, 2013, in Concentrating Solar Power, Energy, Partnership, Photovoltaic,...

  18. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

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

    1999-08-31T23:59:59.000Z

    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.

  19. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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).

  20. Emerging High-Efficiency Low-Cost Solar Cell Technologies

    E-Print Network [OSTI]

    McGehee, Michael

    Emerging High-Efficiency Low-Cost Solar Cell Technologies Mike McGehee Materials Science and Engineering Center for Advanced Molecular Photovoltaics Bay Area Photovoltaic Consortium Precourt Institute for Energy Stanford University #12;Source: US DOE report "$1/W Photovoltaic Systems," August 2010. DOE

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

    SciTech Connect (OSTI)

    None

    2012-01-11T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Chester, David A.

    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 ...

  3. Ultrathin, high-efficiency, broad-band, omni-acceptance, organic solar cells enhanced by

    E-Print Network [OSTI]

    Ultrathin, high-efficiency, broad-band, omni- acceptance, organic solar cells enhanced by plasmonic: Three of central challenges in solar cells are high light coupling into solar cell, high light trapping and demonstration of a new ultra-thin high- efficiency organic solar cell (SC), termed "plasmonic cavity

  4. High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical...

    Office of Environmental Management (EM)

    High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle - FY13 Q1 High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2...

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

    E-Print Network [OSTI]

    McGehee, Michael

    High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells Brian E, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3 be efficiently implemented in optimized dye-sensitized solar cells, but also highlights the need to design highly

  6. Development of a high-efficiency solar micro-inverter

    E-Print Network [OSTI]

    Hayman, Alexander Khaled

    2009-01-01T23:59:59.000Z

    In typical solar power installations, multiple modules are connected to the grid through a single high-power inverter. However, an alternative approach is to connect each solar module directly to the grid through a ...

  7. Review paper: Toward highly efficient quantum-dot-and dye-sensitized solar cells

    E-Print Network [OSTI]

    Park, Byungwoo

    Review paper: Toward highly efficient quantum-dot- and dye-sensitized solar cells Hongsik Choi Interface control Light harvesting Tandem solar cell a b s t r a c t Dye- and quantum-dot-sensitized solar technologies of silicon-based solar cells should be resolved [7]. Dye-sensitized solar cells (DSSCs) have been

  8. Webinar January 13: Highly Efficient Solar Thermochemical Reaction...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    69% solar-to-chemical energy conversion efficiency, converting methane and water into syngas-a mix of hydrogen and carbon monoxide-and the technology received an R&D 100 Award in...

  9. Processes for producing low cost, high efficiency silicon solar cells

    DOE Patents [OSTI]

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

    1996-01-01T23:59:59.000Z

    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.

  10. Advanced Nanomaterials for High-Efficiency Solar Cells

    SciTech Connect (OSTI)

    Chen, Junhong [University of Wisconsin-Milwaukee] [University of Wisconsin-Milwaukee

    2013-11-29T23:59:59.000Z

    Energy supply has arguably become one of the most important problems facing humankind. The exponential demand for energy is evidenced by dwindling fossil fuel supplies and record-high oil and gas prices due to global population growth and economic development. This energy shortage has significant implications to the future of our society, in addition to the greenhouse gas emission burden due to consumption of fossil fuels. Solar energy seems to be the most viable choice to meet our clean energy demand given its large scale and clean/renewable nature. However, existing methods to convert sun light into electricity are not efficient enough to become a practical alternative to fossil fuels. This DOE project aims to develop advanced hybrid nanomaterials consisting of semiconductor nanoparticles (quantum dots or QDs) supported on graphene for cost-effective solar cells with improved conversion efficiency for harvesting abundant, renewable, clean solar energy to relieve our global energy challenge. Expected outcomes of the project include new methods for low-cost manufacturing of hybrid nanostructures, systematic understanding of their properties that can be tailored for desired applications, and novel photovoltaic cells. Through this project, we have successfully synthesized a number of novel nanomaterials, including vertically-oriented graphene (VG) sheets, three-dimensional (3D) carbon nanostructures comprising few-layer graphene (FLG) sheets inherently connected with CNTs through sp{sup 2} carbons, crumpled graphene (CG)-nanocrystal hybrids, CdSe nanoparticles (NPs), CdS NPs, nanohybrids of metal nitride decorated on nitrogen-doped graphene (NG), QD-carbon nanotube (CNT) and QD-VG-CNT structures, TiO{sub 2}-CdS NPs, and reduced graphene oxide (RGO)-SnO{sub 2} NPs. We further assembled CdSe NPs onto graphene sheets and investigated physical and electronic interactions between CdSe NPs and the graphene. Finally we have demonstrated various applications of these nanomaterials in solar cells (both as photoanodes and counter electrodes), gas sensors, and energy storage devices. This research is potentially transformative since the availability of affordable hybrid nanostructures and their fundamental properties will enable various innovative applications of the multifunctional hybrid nanostructures and thus will accelerate new discoveries and inventions in nanoscience and nanotechnology.

  11. Highly-Efficient Selective Metamaterial Absorber for High-Temperature Solar Thermal Energy Harvesting

    E-Print Network [OSTI]

    Wang, Hao; Mitchell, Arnan; Rosengarten, Gary; Phelan, Patrick; Wang, Liping

    2014-01-01T23:59:59.000Z

    In this work, a metamaterial selective solar absorber made of nanostructured titanium gratings deposited on an ultrathin MgF2 spacer and a tungsten ground film is proposed and experimentally demonstrated. Normal absorptance of the fabricated solar absorber is characterized to be higher than 90% in the UV, visible and, near infrared (IR) regime, while the mid-IR emittance is around 20%. The high broadband absorption in the solar spectrum is realized by the excitation of surface plasmon and magnetic polariton resonances, while the low mid-IR emittance is due to the highly reflective nature of the metallic components. Further directional and polarized reflectance measurements show wide-angle and polarization-insensitive high absorption within solar spectrum. Temperature-dependent spectroscopic characterization indicates that the optical properties barely change at elevated temperatures up to 350{\\deg}C. The solar-to-heat conversion efficiency with the fabricated metamaterial solar absorber is predicted to be 78%...

  12. EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Ceder, Gerbrand

    materials for thin film solar cells such as CdTe and CIGS suffer from concerns over resource scarcity (eEARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS Yun Seog Lee 1 conversion efficiencies should be increased. In terms of reducing module cost, thin film solar cells

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

    SciTech Connect (OSTI)

    Not Available

    2011-05-01T23:59:59.000Z

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

  14. Processes for producing low cost, high efficiency silicon solar cells

    DOE Patents [OSTI]

    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

    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.

  15. Processes for producing low cost, high efficiency silicon solar cells

    DOE Patents [OSTI]

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

    1998-06-16T23:59:59.000Z

    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.

  16. High-Efficiency Solar Cells for Large-Scale Electricity Generation

    SciTech Connect (OSTI)

    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

    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.

  17. A highly efficient (>6%) Cd1xMnxSe quantum dot sensitized solar cell

    E-Print Network [OSTI]

    Cao, Guozhong

    A highly efficient (>6%) Cd1ÀxMnxSe quantum dot sensitized solar cell Jianjun Tian,*a Lili Lv,a Chengbin Fei,b Yajie Wang,b Xiaoguang Liua and Guozhong Cao*bc Quantum dot sensitized solar cells (QDSCs-effective solar cell. The design and synthesis of quantum dots (QDs) for achieving high photoelectric performance

  18. Development of a solar receiver for a high-efficiency thermionic/thermoelectric conversion system

    SciTech Connect (OSTI)

    Naito, H.; Kohsaka, Y.; Cooke, D.; Arashi, H. [Tohoku Univ., Aramaki (Japan)] [Tohoku Univ., Aramaki (Japan)

    1996-10-01T23:59:59.000Z

    Solar energy is one of the most promising energy resources on Earth and in space, because it is clean and inexhaustible. Therefore, we have been developing a solar-powered high-efficiency thermionic-thermoelectric conversion system which combines a thermionic converter (TIC) with a thermoelectric converter (TEC) to use thermal energy efficiently and to achieve high efficiency conversion. The TIC emitter must uniformly heat up to 1800 K. The TIC emitter can be heated using thermal radiation from a solar receiver maintained at a high temperature by concentrated solar irradiation. A cylindrical cavity-type solar receiver constructed from graphite was designed and heated in a vacuum by using the solar concentrator at Tohoku University. The maximum temperature of the solar receiver enclosed by a molybdenum cup reached 1965 K, which was sufficiently high to heat a TIC emitter using thermal radiation from the receiver. 4 refs., 6 figs., 1 tab.

  19. Design and global optimization of high-efficiency solar thermal systems

    E-Print Network [OSTI]

    Soljaèiæ, Marin

    Design and global optimization of high-efficiency solar thermal systems with tungsten cermets David, Massachusetts 02139, USA bermel@mit.edu Abstract: Solar thermal, thermoelectric, and thermophotovoltaic (TPV by selective solar absorbers and TPV selective emitters. To improve these critical components, we study a class

  20. Hybrid Carbon Nanotubes-TiO2 Photoanodes for High Efficiency Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Hybrid Carbon Nanotubes-TiO2 Photoanodes for High Efficiency Dye-Sensitized Solar Cells Kadiatou photoanodes for dye- sensitized solar cells (DSCs), based on nanocrystalline TiO2 with limited addition applied (i.e., soaking in TiCl4 to boost open circuit photovoltage). INTRODUCTION Dye-sensitized solar

  1. ORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission

    E-Print Network [OSTI]

    Atwater, Harry

    ORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission angle Emily D Kosten1. This isotropic emission corresponds to a significant entropy increase in the solar cell, with a corresponding drop in efficiency. Here, using a detailed balance model, we show that limiting the emission angle

  2. innovati nNREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells

    E-Print Network [OSTI]

    . Low-bandgap cells can lose 25% of their power output and efficiency ratings as solar cell operating energy output than a low-bandgap cell with the same wattage or power rating. NREL is a nationalinnovati nNREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells Researchers

  3. New approaches for high-efficiency solar cells. Final report

    SciTech Connect (OSTI)

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

    1997-12-01T23:59:59.000Z

    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.

  4. Power efficiency for very high temperature solar thermal cavity receivers

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  5. High Efficiency Thin Film CdTe and a-Si Based Solar Cells Final Technical Report for the Period

    E-Print Network [OSTI]

    Deng, Xunming

    High Efficiency Thin Film CdTe and a-Si Based Solar Cells Final Technical Report for the Period This is the final report covering approximately 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

  6. High Efficiency CdTe Ink-Based Solar Cells Using Nanocrystals (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01T23:59:59.000Z

    This NREL Highlight is being developed for the 2015 February Alliance S&T Board meeting and describes a solution-processable ink to produce high-efficiency solar cells using low temperature and simple processing.

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

    E-Print Network [OSTI]

    Hsu, W. Chuck

    2012-01-01T23:59:59.000Z

    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 ...

  8. Approaches for Ultra-High Efficiency Solar Cells C.B. Honsberg

    E-Print Network [OSTI]

    Honsberg, Christiana

    Approaches for Ultra-High Efficiency Solar Cells C.B. Honsberg School of Electrical and Computer and to identify the critical physical phenomena important for solar energy conversion. 2. Technical Approach The largest loss mechanism in photovoltaic energy conversion arises from the mismatch between the wavelengths

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

    SciTech Connect (OSTI)

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

    2011-04-01T23:59:59.000Z

    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.

  10. Sandia National Laboratories: high-efficiency solar thermochemical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    July 9, 2014, in Center for Infrastructure Research and Innovation (CIRI), Concentrating Solar Power, Energy, Energy Storage, Energy Storage Systems, Facilities, Infrastructure...

  11. High internal and external quantum efficiency InGaN/GaN solar cells

    SciTech Connect (OSTI)

    Matioli, Elison; Neufeld, C. J.; Iza, Michael; Cruz, S. C.; Al-Heji, Ali A.; Chen, Xu; Farrell, Rober M.; Keller, Stacia; DenBaars, Steven; Mishra, U. K.; Nakamura, Shuji; Speck, J. S.; Weisbuch, Claude

    2011-01-01T23:59:59.000Z

    High internal and external quantum efficiency GaN/InGaN solar cells are demonstrated. The internal quantum efficiency was assessed through the combination of absorption and external quantum efficiency measurements. The measured internal quantum efficiency, as high as 97%, revealed an efficient conversion of absorbed photons into electrons and holes and an efficient transport of these carriers outside the device. Improved light incoupling into the solar cells was achieved by texturing the surface. A peak external quantum efficiency of 72%, a fill factor of 79%, a short-circuit current density of 1.06?mA/cm{sup 2} , and an open circuit voltage of 1.89 V were achieved under 1 sun air-mass 1.5 global spectrumillumination conditions.

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

    SciTech Connect (OSTI)

    Antoniadis, H.

    2011-03-01T23:59:59.000Z

    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.

  13. Solion ion source for high-efficiency, high-throughput solar cell manufacturing

    SciTech Connect (OSTI)

    Koo, John, E-mail: john-koo@amat.com; Binns, Brant; Miller, Timothy; Krause, Stephen; Skinner, Wesley; Mullin, James [Applied Materials, Inc., Varian Semiconductor Equipment Business Unit, 35 Dory Road, Gloucester, Massachusetts 01930 (United States)] [Applied Materials, Inc., Varian Semiconductor Equipment Business Unit, 35 Dory Road, Gloucester, Massachusetts 01930 (United States)

    2014-02-15T23:59:59.000Z

    In this paper, we introduce the Solion ion source for high-throughput solar cell doping. As the source power is increased to enable higher throughput, negative effects degrade the lifetime of the plasma chamber and the extraction electrodes. In order to improve efficiency, we have explored a wide range of electron energies and determined the conditions which best suit production. To extend the lifetime of the source we have developed an in situ cleaning method using only existing hardware. With these combinations, source life-times of >200 h for phosphorous and >100 h for boron ion beams have been achieved while maintaining 1100 cell-per-hour production.

  14. Numerical simulation: Toward the design of high-efficiency planar perovskite solar cells

    SciTech Connect (OSTI)

    Liu, Feng; Zhu, Jun, E-mail: zhujzhu@gmail.com, E-mail: sydai@ipp.ac.cn; Wei, Junfeng; Li, Yi; Lv, Mei [Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Yang, Shangfeng [Hefei National Laboratory for Physical Sciences at Microscale, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Zhang, Bing; Yao, Jianxi [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206 (China); Dai, Songyuan, E-mail: zhujzhu@gmail.com, E-mail: sydai@ipp.ac.cn [Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206 (China)

    2014-06-23T23:59:59.000Z

    Organo-metal halide perovskite solar cells based on planar architecture have been reported to achieve remarkably high power conversion efficiency (PCE, >16%), rendering them highly competitive to the conventional silicon based solar cells. A thorough understanding of the role of each component in solar cells and their effects as a whole is still required for further improvement in PCE. In this work, the planar heterojunction-based perovskite solar cells were simulated with the program AMPS (analysis of microelectronic and photonic structures)-1D. Simulation results revealed a great dependence of PCE on the thickness and defect density of the perovskite layer. Meanwhile, parameters including the work function of the back contact as well as the hole mobility and acceptor density in hole transport materials were identified to significantly influence the performance of the device. Strikingly, an efficiency over 20% was obtained under the moderate simulation conditions.

  15. Design for the fabrication of high efficiency solar cells

    DOE Patents [OSTI]

    Simmons, Joseph H. (Gainesville, FL)

    1998-01-01T23:59:59.000Z

    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.

  16. Highly Efficient Solar Thermochemical Reaction Systems | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking of Blythe Solar PowerCommercial Cold Climate HeatEnergy||

  17. ENI Renewable and Non-conventional Energy Prize 2012 High-efficiency solar cells based on nanophotonic design

    E-Print Network [OSTI]

    Polman, Albert

    new solar cell designs that enable both a higher photovoltaic conversion efficiency and reduced) Photonic design principles for ultrahigh-efficiency photovoltaics, A. Polman and H.A. Atwater, Nature MaterENI Renewable and Non-conventional Energy Prize 2012 High-efficiency solar cells based

  18. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    SciTech Connect (OSTI)

    Hubbard, Seth

    2012-09-12T23:59:59.000Z

    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.

  19. Current-matched high-efficiency, multijunction monolithic solar cells

    DOE Patents [OSTI]

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

    1993-01-01T23:59:59.000Z

    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

  20. Amorphous silicon/crystalline silicon heterojunctions: The future of high-efficiency silicon solar cells

    E-Print Network [OSTI]

    Firestone, Jeremy

    ;5 Record efficiencies #12;6 Diffused-junction solar cells Diffused-junction solar cell Chemical passivation to ~650 mV #12;7 Silicon heterojunction solar cells a-Si:H provides excellent passivation of c-Si surface Heterojunction solar cell Chemical passivation Chemical passivation #12;8 Voc and silicon heterojunction solar

  1. Sandia Energy - High-Efficiency Solar Thermochemical Reactor for Hydrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Scienceand RequirementsCoatingsUltra-High-Voltage

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

    SciTech Connect (OSTI)

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

    2012-06-11T23:59:59.000Z

    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.

  3. High efficiency InGaAs solar cells on Si by InP layer transfer James M. Zahler

    E-Print Network [OSTI]

    Atwater, Harry

    to significantly increase performance while reducing the cost and weight of compound semiconductor solar cellsHigh efficiency InGaAs solar cells on Si by InP layer transfer James M. Zahler Aonex Technologies for solar cell applications. © 2007 American Institute of Physics. DOI: 10.1063/1.2753751 Engineered

  4. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-Print Network [OSTI]

    Asadpour, Reza; Khan, M Ryyan; Alam, Muhammad A

    2015-01-01T23:59:59.000Z

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceed...

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

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    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.

  6. HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X. Xiang and X. Deng

    E-Print Network [OSTI]

    Deng, Xunming

    HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X ABSTRACT We report high-efficiency single-junction a-SiGe n-i-p solar cells deposited using rf PECVD-area efficiencies have been improved to 12.5-13.0% and 10.4%, respectively, for 0.25 cm 2 a-SiGe cells

  7. High-Efficiency Solar Cogeneration with TPV & Fiber-Optic Daylighting...

    Broader source: Energy.gov (indexed) [DOE]

    technologies to maximize energy generation & energy efficiency from the building's solar insolation resources. Project presents a novel, low-cost approach to mitigate...

  8. Development of high-efficiency GaAs solar cells on polycrystalline Ge substrates

    SciTech Connect (OSTI)

    Venkatasubramanian, R.; OQuinn, B.; Hills, J.; Malta, D.; Timmons, M.L.; Hutchby, J.A. [Research Triangle Institute, Research Triangle Park, North Carolina 27709 (United States); Ahrenkiel, R.; Keyes, B.M. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    1996-01-01T23:59:59.000Z

    Progress in the development of high-efficiency GaAs solar cells on low-cost, large-area, large-grain, optical-grade polycrystalline Ge substrates is described in this paper. First, we present results on the growth of specular GaAs-AlGaAs layers, across the various crystalline orientations of a polycrystalline Ge substrate, by metallorganic chemical vapor deposition (MOCVD). Second, we present the preliminary optimization of minority-carrier properties of GaAs-AlGaAs structures on poly-Ge substrates towards the improvement of GaAs solar cells. We have demonstrated comparable minority-carrier lifetimes in GaAs double-hetero structures grown on optical-grade poly-Ge substrates and electronic-grade single-crystal Ge substrates. In addition, we describe device-structure optimization that have led us to achieve a open-circuit voltage of {approximately}1 Volt in a GaAs solar cell on poly-Ge and to improve our previous best efficiency from 15.8{percent} for a 1-cm{sup 2}-area GaAs cell to 16.7{percent} for a 4-cm{sup 2}-area GaAs solar cell on poly-Ge. {copyright} {ital 1996 American Institute of Physics.}

  9. High Efficiency Solar-based Catalytic Structure for CO{sub 2} Reforming

    SciTech Connect (OSTI)

    Menkara, Hisham

    2013-09-30T23:59:59.000Z

    Throughout this project, we developed and optimized various photocatalyst structures for CO{sub 2} reforming into hydrocarbon fuels and various commodity chemical products. We also built several closed-loop and continuous fixed-bed photocatalytic reactor system prototypes for a larger-scale demonstration of CO{sub 2} reforming into hydrocarbons, mainly methane and formic acid. The results achieved have indicated that with each type of reactor and structure, high reforming yields can be obtained by refining the structural and operational conditions of the reactor, as well as by using various sacrificial agents (hole scavengers). We have also demonstrated, for the first time, that an aqueous solution containing acid whey (a common bio waste) is a highly effective hole scavenger for a solar-based photocatalytic reactor system and can help reform CO{sub 2} into several products at once. The optimization tasks performed throughout the project have resulted in efficiency increase in our conventional reactors from an initial 0.02% to about 0.25%, which is 10X higher than our original project goal. When acid whey was used as a sacrificial agent, the achieved energy efficiency for formic acid alone was ~0.4%, which is 16X that of our original project goal and higher than anything ever reported for a solar-based photocatalytic reactor. Therefore, by carefully selecting sacrificial agents, it should be possible to reach energy efficiency in the range of the photosynthetic efficiency of typical crop and biofuel plants (1-3%).

  10. NANOSTRUCTURED SOLAR CELLS FOR HIGH EFFICIENCY PHOTOVOLTAICS Christiana B. Honsberg1

    E-Print Network [OSTI]

    Honsberg, Christiana

    mechanisms and device structures and materials to implement nanostructured solar cells, and low cost to lattice matching and; (3) the potential for low cost solar cell structures using self to circumvent both existing efficiency and cost drivers. While nanostructured solar cells have significant

  11. Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations

    E-Print Network [OSTI]

    important evaluation criterion for photovoltaic (PV) technology. Therefore, research on novel structuresTowards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping February 2014; published online 3 March 2014) Thin-film solar cells based on silicon have emerged

  12. Study of a-SiGe:H films and nip devices used in high efficiency triple junction solar cells

    E-Print Network [OSTI]

    Deng, Xunming

    Study of a-SiGe:H films and n­i­p devices used in high efficiency triple junction solar cells and n­i­p solar cells for GeH4=Si2H6 ratio varying from 1.43 to 0. This results in a variation of band measurements on n­i­p solar cells with i-layer having different Ge content show that as Ge content increase

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

    SciTech Connect (OSTI)

    Carmody, M.; Gilmore, A.

    2011-05-01T23:59:59.000Z

    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.

  14. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-Print Network [OSTI]

    Reza Asadpour; Raghu V. K. Chavali; M. Ryyan Khan; Muhammad A. Alam

    2015-05-15T23:59:59.000Z

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceeding the bifacial HIT performance at practical albedo reflections. Unlike the traditional design, this bifacial design is relatively insensitive to Perovskite thickness variations, which may translate to simpler manufacture and higher yield.

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

    E-Print Network [OSTI]

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

    2008-01-01T23:59:59.000Z

    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 ...

  16. High throughput parallel backside contacting and periodic texturing for high-efficiency solar cells

    DOE Patents [OSTI]

    Daniel, Claus; Blue, Craig A.; Ott, Ronald D.

    2014-08-19T23:59:59.000Z

    Disclosed are configurations of long-range ordered features of solar cell materials, and methods for forming same. Some features include electrical access openings through a backing layer to a photovoltaic material in the solar cell. Some features include textured features disposed adjacent a surface of a solar cell material. Typically the long-range ordered features are formed by ablating the solar cell material with a laser interference pattern from at least two laser beams.

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

    SciTech Connect (OSTI)

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

    1991-01-01T23:59:59.000Z

    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.

  18. Graphene oxide hole transport layers for large area, high efficiency organic solar cells

    SciTech Connect (OSTI)

    Smith, Chris T. G.; Rhodes, Rhys W.; Beliatis, Michail J.; Imalka Jayawardena, K. D. G.; Rozanski, Lynn J.; Mills, Christopher A.; Silva, S. Ravi P., E-mail: s.silva@surrey.ac.uk [Advanced Technology Institute, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2014-08-18T23:59:59.000Z

    Graphene oxide (GO) is becoming increasingly popular for organic electronic applications. We present large active area (0.64?cm{sup 2}), solution processable, poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1, 3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]:[6,6]-Phenyl C{sub 71} butyric acid methyl ester (PCDTBT:PC{sub 70}BM) organic photovoltaic (OPV) solar cells, incorporating GO hole transport layers (HTL). The power conversion efficiency (PCE) of ?5% is the highest reported for OPV using this architecture. A comparative study of solution-processable devices has been undertaken to benchmark GO OPV performance with poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) HTL devices, confirming the viability of GO devices, with comparable PCEs, suitable as high chemical and thermal stability replacements for PEDOT:PSS in OPV.

  19. High-efficiency radiation-resistant InGaP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Takamoto, T. [Toyota Technological Inst., Tempaku, Nagoya (Japan); [Japan Energy Corp., Toda, Saitama (Japan); Yamaguchi, M.; Taylor, S.J. [Toyota Technological Inst., Tempaku, Nagoya (Japan); Ikeda, E.; Agui, T.; Kurita, H. [Japan Energy Corp., Toda, Saitama (Japan)

    1997-12-31T23:59:59.000Z

    A world-record efficiency of 26.9% (AM0, 28 C) has been obtained for InGaP/GaAs tandem solar cells fabricated by the MOCVD method. The radiation resistance of the InGaP/GaAs tandem solar cells has also been evaluated following 1 MeV electron irradiation. Degradation in the tandem cell performance has been confirmed to be mainly attributed to large degradation in the GaAs bottom cell, which features a highly doped base layer. Similar radiation-resistance with GaAs-on-Ge cells has been observed for the InGaP/GaAs tandem cell. However, some recovery of the tandem cell performance has been found due to minority-carrier injection under light illumination of forward bias, which causes defect annealing in InGaP cells. The optimal design of the InGaP base layer thickness for current matching at end of life (EOL) (after irradiation with 10{sup 15} electrons cm{sup {minus}2}) has been examined.

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

    SciTech Connect (OSTI)

    Not Available

    2012-09-01T23:59:59.000Z

    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.'

  1. A Highly Efficient Solar Cell Made from a Dye-Modified ZnO-Covered TiO2 Nanoporous Electrode

    E-Print Network [OSTI]

    Huang, Yanyi

    -circuit photovoltage. Introduction Overall power conversion efficiency1,2 reaching 10% for dye sensitized solar cellA Highly Efficient Solar Cell Made from a Dye-Modified ZnO-Covered TiO2 Nanoporous Electrode Zhong A photoelectrochemical solar cell based on porous ZnO-covered TiO2 film has been fabricated with ruthenium bipyridyl

  2. An Unconventional Route to High-Efficiency Dye-Sensitized Solar Cells via Embedding Graphitic Thin Films into TiO2 Nanoparticle

    E-Print Network [OSTI]

    Lin, Zhiqun

    An Unconventional Route to High-Efficiency Dye-Sensitized Solar Cells via Embedding Graphitic Thin into the conventional dye- sensitized solar cells (DSSCs), resulting in a remarkably improved cell efficiency due to its followed by direct carbonization. For dye-sensitized TiO2 based solar cells containing carbon/TiO2 thin

  3. Layer-By-Layer Self-Assembly of CIGS Nanoparticles and Polymers for All-Solution Processable Low-Cost, High-Efficiency Solar Cells

    E-Print Network [OSTI]

    Zhou, Yaoqi

    -Cost, High-Efficiency Solar Cells Tung Ho1 , Robert Vittoe3 , Namratha Kakumanu2 , Sudhir Shrestha2-Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202 Thin film solar cells made from copper indium gallium thereby affecting solar cell efficiency. This research aims to study various polymer materials to replace

  4. HIGH-EFFICIENCY BACK-JUNCTION SILICON SOLAR CELL WITH AN IN-LINE EVAPORATED ALUMINUM FRONT GRID

    E-Print Network [OSTI]

    HIGH-EFFICIENCY BACK-JUNCTION SILICON SOLAR CELL WITH AN IN-LINE EVAPORATED ALUMINUM FRONT GRID M-diffused back-junction emitter. The aluminum front side grid is evaporated in an industrial-type in-thick silicon shadow masks for the in-line evaporation of the aluminum front grid. The masks are fabricated

  5. ATOMIC-LAYER-DEPOSITED ALUMINUM OXIDE FOR THE SURFACE PASSIVATION OF HIGH-EFFICIENCY SILICON SOLAR CELLS

    E-Print Network [OSTI]

    ATOMIC-LAYER-DEPOSITED ALUMINUM OXIDE FOR THE SURFACE PASSIVATION OF HIGH-EFFICIENCY SILICON SOLAR to those measured on reference cells passivated by an aluminum-annealed thermal SiO2, while those of the Al of aluminum ox- ide (Al2O3) grown by atomic layer deposition (ALD) pro- vide an excellent level of sur

  6. DEVELOPMENT OF HIGH EFFICIENCY FLEXIBLE CdTe SOLAR CELLS A.Romeo, M. Arnold, D.L. Btzner, H. Zogg and A.N. Tiwari*

    E-Print Network [OSTI]

    Romeo, Alessandro

    applications that require a very high specific power (ratio of output electrical power to the solar module specific power is an important issue for space solar cells: if satellites are lighter they are easierDEVELOPMENT OF HIGH EFFICIENCY FLEXIBLE CdTe SOLAR CELLS A.Romeo, M. Arnold, D.L. Bätzner, H. Zogg

  7. Concentrating Solar Power: Efficiently Leveraging Equilibrium...

    Office of Environmental Management (EM)

    Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage Concentrating Solar Power: Efficiently Leveraging Equilibrium...

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

    SciTech Connect (OSTI)

    None

    2010-01-01T23:59:59.000Z

    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.

  9. New strategy to promote conversion efficiency using high-index nanostructures in thin-film solar cells

    E-Print Network [OSTI]

    Wang, DongLin

    2014-01-01T23:59:59.000Z

    Nano-scaled metallic or dielectric structures may provide various ways to trap light into thin-film solar cells for improving the conversion efficiency. In most schemes, the textured active layers are involved into light trapping structures that can provide perfect optical benefits but also bring undesirable degradation of electrical performance. Here we propose a novel approach to design high-performance thin-film solar cells. In our strategy, a flat active layer is adopted for avoiding electrical degradation, and an optimization algorithm is applied to seek for an optimized light trapping structure for the best optical benefit. As an example, we show that the efficiency of a flat a-Si:H thin-film solar cell can be promoted close to the certified highest value. It is also pointed out that, by choosing appropriate dielectric materials with high refractive index (>3) and high transmissivity in wavelength region of 350nm-800nm, the conversion efficiency of solar cells can be further enhanced.

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

    SciTech Connect (OSTI)

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

    1997-06-01T23:59:59.000Z

    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.

  11. Evaluation of annual efficiencies of high temperature central receiver concentrated solar power plants with thermal energy storage.

    SciTech Connect (OSTI)

    Ehrhart, Brian David; Gill, David Dennis

    2013-07-01T23:59:59.000Z

    The current study has examined four cases of a central receiver concentrated solar power plant with thermal energy storage using the DELSOL and SOLERGY computer codes. The current state-of-the-art base case was compared with a theoretical high temperature case which was based on the scaling of some input parameters and the estimation of other parameters based on performance targets from the Department of Energy SunShot Initiative. This comparison was done for both current and high temperature cases in two configurations: a surround field with an external cylindrical receiver and a north field with a single cavity receiver. There is a fairly dramatic difference between the design point and annual average performance, especially in the solar field and receiver subsystems, and also in energy losses due to the thermal energy storage being full to capacity. Additionally, there are relatively small differences (<2%) in annual average efficiencies between the Base and High Temperature cases, despite an increase in thermal to electric conversion efficiency of over 8%. This is due the increased thermal losses at higher temperature and operational losses due to subsystem start-up and shut-down. Thermal energy storage can mitigate some of these losses by utilizing larger thermal energy storage to ensure that the electric power production system does not need to stop and re-start as often, but solar energy is inherently transient. Economic and cost considerations were not considered here, but will have a significant impact on solar thermal electric power production strategy and sizing.

  12. Improving Solar-Cell Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Improving Solar Cell Efficiency October 7, 2014 Bookmark and Share The two-dimensional grazing...

  13. High efficiency resonant dc/dc converter for solar power applications

    E-Print Network [OSTI]

    Inam, Wardah

    2013-01-01T23:59:59.000Z

    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 ...

  14. Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    1 Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells, Setagaya-ku, Tokyo 157-8572, Japan (Received ) KEYWORDS: ZnS buffer, Cu(In,Ga)Se2, thin-film solar cells alternative to CdS in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency

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

    DOE Patents [OSTI]

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

    1982-04-14T23:59:59.000Z

    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.

  16. Where solar thermal meets photovoltaic for high-efficiency power conversion

    E-Print Network [OSTI]

    Bierman, David M. (David Matthew)

    2014-01-01T23:59:59.000Z

    To develop disruptive techniques which generate power from the Sun, one must understand the aspects of existing technologies that limit performance. Solar thermal and solar photovoltaic schemes dominate today's solar market ...

  17. High-efficiency indium tin oxide/indium phosphide solar cells

    SciTech Connect (OSTI)

    Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

    1989-06-26T23:59:59.000Z

    Improvements in the performance of indium tin oxide/indium phosphide (ITO/InP) solar cells have been achieved by using dc magnetron sputter deposited /ital n/-ITO onto an epitaxial /ital p///ital p//sup +/ structure grown on good quality commercial /ital p//sup +/ bulk substrates. The composition of the sputtering gas has been investigated and the highest efficiency cells resulted when the surface of the epilayer was exposed to an Ar/H/sub 2/ plasma before depositing the bulk of the ITO in a more typical Ar/O/sub 2/ plasma. With H/sub 2/ processing, record efficiencies of 18.9% global, 1000 W m/sup /minus/2/, 25 /degree/C (17.0% air mass zero) were achieved. Without H/sub 2/ processing, the devices exhibited lower efficiencies and were unstable. Type conversion of the InP was shown to occur and was established as being associated with the ITO (possibly due to Sn donors) rather than sputter damage. These improvements in performance have resulted from the optimization of the doping, thickness, transport, and surface properties of the /ital p/-type base, as well as from better control over the ITO deposition procedure.

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

    SciTech Connect (OSTI)

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

    1993-04-01T23:59:59.000Z

    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.

  19. Hierarchically Structured Microspheres for High-Efficiency Rutile TiO2Based Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Lin, Zhiqun

    and the Ostwald ripening process. Dye-sensitized solar cells (DSSCs) assembled by employing these complex rutile method, dye-sensitized solar cells, post-treatments, light-to-electricity conversion efficiency candidate for use in water splitting, photo- catalysis, sensors, and dye-sensitized solar cells (DSSCs) over

  20. Los Alamos develops new technique for growing high-efficiency...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Growing high-efficiency perovskite solar cells Los Alamos develops new technique for growing high-efficiency perovskite solar cells Researchers reveal a new solution-based...

  1. High-efficient solar power systems based on thermionic converter with small gap

    SciTech Connect (OSTI)

    Nikolaev, Y.V.; Eryomin, S.A.; Kalmykov, S.S.; Karpechenko, Y.D.; Kucherov, R.Y.; Lapochkin, N.V. [Research Institute of Scientific Industrial Association ``Lutch``, 142100, Podolsk, Moscow Region (Russian Federation)

    1996-03-01T23:59:59.000Z

    Various configurations of power systems based on thermionic converter with small interelectrode gap have been considered. The results of studies of systems energy characteristics are presented. The high efficiency and perspectivety of such systems for different applications have been shown. {copyright} {ital 1996 American Institute of Physics.}

  2. HIGH EFFICIENCY Cu(ln,Ga)SepBASED SOLAR CELLS: PROCESSING OF NOVEL ABSORBER STRUCTURES

    E-Print Network [OSTI]

    Scofield, John H.

    be more optimally solved by either lowering substrate temperature or finding other suitable and low-cost ABSTRACT Our effort towards the attainment of high performance devices has yielded several devices, and 15.3% for a 4.85-cm* single cell. Achievement of a 17.2% device efficiency fabricated for operation

  3. Final Report: Tunable Narrow Band Gap Absorbers For Ultra High Efficiency Solar Cells

    SciTech Connect (OSTI)

    Bedair, Salah M. [NCSU; Hauser, John R. [NCSU; Elmasry, Nadia [NCSU; Colter, Peter C. [NCSU; Bradshaw, G. [NCSU; Carlin, C. Z. [NCSU; Samberg, J. [NCSU; Edmonson, Kenneth [Spectrolab

    2012-07-31T23:59:59.000Z

    We report on a joint research program between NCSU and Spectrolab to develop an upright multijunction solar cell structure with a potential efficiency exceeding the current record of 41.6% reported by Spectrolab. The record efficiency Ge/GaAs/InGaP triple junction cell structure is handicapped by the fact that the current generated by the Ge cell is much higher than that of both the middle and top cells. We carried out a modification of the record cell structure that will keep the lattice matched condition and allow better matching of the current generated by each cell. We used the concept of strain balanced strained layer superlattices (SLS), inserted in the i-layer, to reduce the bandgap of the middle cell without violating the desirable lattice matched condition. For the middle GaAs cell, we have demonstrated an n-GaAs/i-(InGaAs/GaAsP)/p-GaAs structure, where the InxGa1-xAs/GaAs1-yPy SLS is grown lattice matched to GaAs and with reduced bandgap from 1.43 eV to 1.2 eV, depending upon the values of x and y.

  4. 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

    SciTech Connect (OSTI)

    Ravi, T. S.

    2013-05-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Deng, X.

    2006-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  7. Design and Analysis of a High-Efficiency, Cost-Effective Solar Concentrator John H. Reif

    E-Print Network [OSTI]

    Reif, John H.

    , wind and sand loading, and abrasion. Many arid and desert areas, best suited for solar energy on a given surface area over a given time; in particular, it is the amount of solar radiation energy radiation scattered by the atmosphere. There are many areas of the world ideally suited for solar energy

  8. Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells

    E-Print Network [OSTI]

    Cao, Guozhong

    ) as a derivative of dye-sensitized solar cells (DSCs) have attracted considerable attention and been regardedMesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells Ru Zhou for a CdS/CdSe quantum dot (QD) co-sensitized solar cell, which was constructed with the mesoporous TiO2

  9. Wafer Bonding and Layer Transfer Processes for High Efficiency Solar Cells

    SciTech Connect (OSTI)

    Zahler, J. M.; Fontcuberta i Morral, A.; Ahn, C. G.; Atwater, H. A.; Wanlass, M. W.; Chu, C.; Iles, P. A.

    2003-05-01T23:59:59.000Z

    A wafer-bonded four-junction cell design consisting of InGaAs, InGaAsP, GaAs, and Ga0.5In0.5P subcells that could reach one-sun AM0 efficiencies of 35.4% is described. The design relies on wafer-bonding and layer transfer for integration of non-lattice-matched subcells. Wafer bonding and layer transfer processes have shown promise in the fabrication of InP/Si epitaxial templates for growth of the bottom InGaAs and InGaAsP subcells on a Si support substrate. Subsequent wafer bonding and layer transfer of a thin Ge layer onto the lower subcell stack can serve as an epitaxial template for GaAs and Ga0.5In0.5P subcells. Additionally, wafer bonded Ge/Si substrates offer the possibility to improve the mechanical performance of existing triple-junction solar cell designs, while simultaneously reducing their cost. Present results indicate that optically active III/V compound semiconductors can be grown on both Ge/Si and InP/Si heterostructures. Current-voltage electrical characterization of the interfaces of these structures indicates that both InP/Si and Ge/Si interfaces have specific resistances lower than 0.1 W?cm2 for heavily doped wafer bonded interfaces, enabling back surface power extraction from the finished cell structure.

  10. High efficiency InGaP solar cells for InGaP/GaAs tandem cell application

    SciTech Connect (OSTI)

    Takamoto, T.; Ikeda, E.; Kurita, H.; Ohmori, M. [Japan Energy Corp., Toda, Saitama (Japan). Central Research Lab.

    1994-12-31T23:59:59.000Z

    In this paper, high conversion efficiency single junction InGaP solar cells with n-p-p{sup +} structure are presented and their application to InGaP/GaAs monolithic tandem cells is discussed. In the InGaP cells, a best conversion efficiency of 18.48% was achieved by introducing the p{sup +} peak back surface field (BSF) layer with a high carrier concentration of 2 {times} 10{sup 18} cm{sup {minus}3}, which improved both short circuit current (Isc) and open circuit voltage (Voc). However, in the case of InGaP/GaAs tandem cells, a decrease in carrier concentration of the InGaP BSF layer, which was caused by the diffusion of Zn, was found to reduce the Isc and Voc of the tandem cell. The reduction in the carrier concentration was suppressed by using a thicker BSF layer of 0.5 {micro}m, which reduced the current density in the GaAs bottom cell. An InGaP/GaAs tandem cell with 27.3% efficiency and a high Voc of 2.418 V was obtained.

  11. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    film photovoltaics [1]. This roughly doubling of efficiencyMJ photovoltaics. MJ solar cells achieve higher efficiencies

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

    E-Print Network [OSTI]

    Judkins, Zachara Steele

    2007-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    Not Available

    2011-08-01T23:59:59.000Z

    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.

  14. Earth abundant materials for high efficiency heterojunction thin film solar cells

    E-Print Network [OSTI]

    Buonassisi, Tonio

    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 ...

  15. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    III! V Multijunction Solar Cells,” (2003). J. F. Geisz, etEfficiency Multi-Junction Solar Cells A thesis submitted inEfficiency Multi-Junction Solar Cells By David Michael Fong

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

    SciTech Connect (OSTI)

    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

    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).

  17. MILESTONES TOWARD 50% EFFICIENT SOLAR CELL MODULES Allen Barnett1

    E-Print Network [OSTI]

    Honsberg, Christiana

    and a new silicon solar cell for the mid-energy photons, all while circumventing existing cost driversMILESTONES TOWARD 50% EFFICIENT SOLAR CELL MODULES Allen Barnett1 , Douglas Kirkpatrick2 LightSpin Technologies ABSTRACT: The Very High Efficiency Solar Cell (VHESC) program is developing

  18. Energy Efficiency First, Zero Energy Ready Homes, and Solar PV...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the National Renewable Energy Laboratory on the latest developments in energy efficiency, net zero housing, solar, and wind. Find out how they are facilitating high renewable...

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

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.

    2005-10-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1999-07-01T23:59:59.000Z

    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.

  1. Forming high efficiency silicon solar cells using density-graded anti-reflection surfaces

    DOE Patents [OSTI]

    Yuan, Hao-Chih; Branz, Howard M.; Page, Matthew R.

    2014-09-09T23:59:59.000Z

    A method (50) is provided for processing a graded-density AR silicon surface (14) to provide effective surface passivation. The method (50) includes positioning a substrate or wafer (12) with a silicon surface (14) in a reaction or processing chamber (42). The silicon surface (14) has been processed (52) to be an AR surface with a density gradient or region of black silicon. The method (50) continues with heating (54) the chamber (42) to a high temperature for both doping and surface passivation. The method (50) includes forming (58), with a dopant-containing precursor in contact with the silicon surface (14) of the substrate (12), an emitter junction (16) proximate to the silicon surface (14) by doping the substrate (12). The method (50) further includes, while the chamber is maintained at the high or raised temperature, forming (62) a passivation layer (19) on the graded-density silicon anti-reflection surface (14).

  2. Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5LetLooking5investsLouisPrepared:

  3. High-Efficiency Solar Cogeneration with Thermophotovoltaic & Fiber-Optic

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov.Energy02.pdf7 OPAM Flash2011-37 OPAMResourceEmploymentHealth,HelpHighDaylighting

  4. High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently Asked Questions for DOE FYAffairs,Assessment Hazle Spindle,Here toHigh

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

    SciTech Connect (OSTI)

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

    1999-09-16T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    1999-01-01T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Sopori, B.L.

    1999-04-27T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    2001-01-01T23:59:59.000Z

    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.

  9. Green synthesis of highly efficient CdSe quantum dots for quantum-dots-sensitized solar cells

    SciTech Connect (OSTI)

    Gao, Bing; Shen, Chao; Zhang, Mengya; Yuan, Shuanglong; Yang, Yunxia, E-mail: yangyunxia@ecust.edu.cn, E-mail: grchen@ecust.edu.cn; Chen, Guorong, E-mail: yangyunxia@ecust.edu.cn, E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Bo [Department of Physics, East China University of Science and Technology, Shanghai 200237 (China)

    2014-05-21T23:59:59.000Z

    Green synthesis of CdSe quantum dots for application in the quantum-dots-sensitized solar cells (QDSCs) is investigated in this work. The CdSe QDs were prepared with glycerol as the solvent, with sharp emission peak, full width at half maximum around 30?nm, and absorption peak from 475?nm to 510?nm. The reaction is environmental friendly and energy saving. What's more, the green synthesized CdSe QDs are coherence to the maximum remittance region of the solar spectrum and suitable as sensitizers to assemble onto TiO{sub 2} electrodes for cell devices application. What's more, the dynamic procedure of the carriers' excitation, transportation, and recombination in the QDSCs are discussed. Because the recombination of the electrons from the conduction band of TiO{sub 2}'s to the electrolyte affects the efficiency of the solar cells greatly, 3-Mercaptopropionic acid capped water-dispersible QDs were used to cover the surface of TiO{sub 2}. The resulting green synthesized CdSe QDSCs with Cu{sub 2}S as the electrode show a photovoltaic performance with a conversion efficiency of 3.39%.

  10. High Efficiency Thin Film CdTe and a-Si Based Solar Cells: Annual Technical Report, 4 March 1999 - 3 March 2000

    SciTech Connect (OSTI)

    Compaan, A. D.; Deng, X.; Bohn, R. G. (The University of Toledo)

    2001-08-29T23:59:59.000Z

    This report describes the research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Implemented a diode-array spectrograph system and used optical emission spectroscopy to help optimize the reactive sputtering of N-doped ZnTe for CdTe back-contact structures. Identified the photoluminescence signatures of various defect states in CdTe related to Cd vacancies, CuCd acceptors, Cu-VCd complexes, and donor-acceptor pairs, and related these states to instabilities in the hole concentration at room temperature. Showed that Cu is an important non-radiative center in CdS, reducing the PL efficiency. Studied band tailing in CdS weakly alloyed with CdTe and CdTe weakly alloyed with CdS. Fabricated superstrate ITO/CdS/CdTe cells on Mo substrates with efficiencies above 7.5%. Collaborated in studies of EXAFS of Cu in CdTe which indicate a Cu-Te bond length of 2.62 {angstrom} or 6.7% shorter than the CdTe, bond in agreement with calculations of Wei et al. Provided assistance to two groups on laser scribing. Comparatively studied the performance of a-SiGe solar cells and properties of a-SiGe single-layer films deposited using a wide range of H dilution, observed transition from a-SiGe to {mu}c-SiGe at high H dilution and the impact on cell performances. Comparatively studied the performance of a-SiGe solar cells and properties of a-SiGe single-layer films with different Ge contents, suitable for use as component cells of triple-junction devices. Fabricated a-Si-based solar cells on ultra-thin stainless-steel substrate (7.5 micron) and obtained equivalent performance and yield as on the regular SS substrates (127 microns). Comparatively studied the performance of a-Si-based solar cells on SS substrates and on SnO2-coated glass substrates. Studied the performance of p-layers deposited under various deposition conditions for n-i-p type solar cells. Performed an analysis for the component cell current-matching within a triple-junction solar cell.

  11. An easy-to-fabricate low-temperature TiO{sub 2} electron collection layer for high efficiency planar heterojunction perovskite solar cells

    SciTech Connect (OSTI)

    Conings, B.; Baeten, L.; Jacobs, T.; Dera, R.; D’Haen, J.; Manca, J.; Boyen, H.-G. [Instituut voor Materiaalonderzoek, Universiteit Hasselt, Wetenschapspark 1, 3590 Diepenbeek (Belgium)

    2014-08-01T23:59:59.000Z

    Organometal trihalide perovskite solar cells arguably represent the most auspicious new photovoltaic technology so far, as they possess an astonishing combination of properties. The impressive and brisk advances achieved so far bring forth highly efficient and solution processable solar cells, holding great promise to grow into a mature technology that is ready to be embedded on a large scale. However, the vast majority of state-of-the-art perovskite solar cells contains a dense TiO{sub 2} electron collection layer that requires a high temperature treatment (>450?°C), which obstructs the road towards roll-to-roll processing on flexible foils that can withstand no more than ?150?°C. Furthermore, this high temperature treatment leads to an overall increased energy payback time and cumulative energy demand for this emerging photovoltaic technology. Here we present the implementation of an alternative TiO{sub 2} layer formed from an easily prepared nanoparticle dispersion, with annealing needs well within reach of roll-to-roll processing, making this technology also appealing from the energy payback aspect. Chemical and morphological analysis allows to understand and optimize the processing conditions of the TiO{sub 2} layer, finally resulting in a maximum obtained efficiency of 13.6% for a planar heterojunction solar cell within an ITO/TiO{sub 2}/CH{sub 3}NH{sub 3}PbI{sub 3-x}Cl{sub x}poly(3-hexylthiophene)/Ag architecture.

  12. Ames Lab 101: Improving Solar Cell Efficiency

    ScienceCinema (OSTI)

    Biswas, Rana

    2012-08-29T23:59:59.000Z

    Rana Biswas, a scientist with the Ames Laboratory, discusses his team's research in creating more efficient solar cells and working with Iowa Thin Film to produce these cells.

  13. "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...

  14. High Efficiency CdTe/CdS Thin Film solar Cells by a Process Suitable for Large Scale Production. N. Romeo, A. Bosio, A. Romeo, M. Bianucci, L. Bonci, C. Lenti

    E-Print Network [OSTI]

    Romeo, Alessandro

    High Efficiency CdTe/CdS Thin Film solar Cells by a Process Suitable for Large Scale Production. N-mail:Nicola.Romeo@fis.unipr.it ABSTRACT: It has been demonstrated that CdTe/CdS thin film solar cells can exhibit an efficiency around 16 diffusor in CdTe and at a long run it can segregates at the grain boundaries damaging the solar cell

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

    E-Print Network [OSTI]

    Lenert, Andrej

    2010-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    Dhere, N. G.

    2009-04-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  18. Optical design and efficiency improvement for organic luminescent solar concentrators

    E-Print Network [OSTI]

    Hirst, Linda

    and hybrid photovoltaic/thermal solar conversation systems1 . Generally, an organic LSC is a piece of highly solar energy. We designed, fabricated organic LSCs at different sizes and characterized their optical and electrical properties. The output efficiency enhancement methods for LSCs photovoltaics (PVs) are explored

  19. Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

    E-Print Network [OSTI]

    Lawrence Berkeley National Laboratory

    2007-01-01T23:59:59.000Z

    light on improving solar cell efficiency Ernest Orlandomanufacturing methods produce solar cells with an efficiencythe impaired performance of solar cells manufactured from

  20. Investigation of the basic physics of high efficiency semiconductor hot carrier solar cell. Annual status report, 31 May 1994-30 May 1995

    SciTech Connect (OSTI)

    Alfano, R.R.; Wang, W.B.; Mohaidat, J.M.; Cavicchia, M.A.; Raisky, O.Y.

    1995-05-01T23:59:59.000Z

    The main purpose of this research program is to investigate potential semiconductor materials and their multi-band-gap MQW (multiple quantum wells) structures for high efficiency solar cells for aerospace and commercial applications. The absorption and PL (photoluminescence) spectra, the carrier dynamics, and band structures have been investigated for semiconductors of InP, GaP, GaInP, and InGaAsP/InP MQW structures, and for semiconductors of GaAs and AlGaAs by previous measurements. The barrier potential design criteria for achieving maximum energy conversion efficiency, and the resonant tunneling time as a function of barrier width in high efficiency MQW solar cell structures have also been investigated in the first two years. Based on previous carrier dynamics measurements and the time-dependent short circuit current density calculations, an InAs/InGaAs - InGaAs/GaAs - GaAs/AlGaAs MQW solar cell structure with 15 bandgaps has been designed. The absorption and PL spectra in InGaAsP/InP bulk and MQW structures were measured at room temperature and 77 K with different pump wavelength and intensity, to search for resonant states that may affect the solar cell activities. Time-resolved IR absorption for InGaAsP/InP bulk and MQW structures has been measured by femtosecond visible-pump and IR-probe absorption spectroscopy. This, with the absorption and PL measurements, will be helpful to understand the basic physics and device performance in multi-bandgap InAs/InGaAs - InGaAs/InP - InP/InGaP MQW solar cells. In particular, the lifetime of the photoexcited hot electrons is an important parameter for the device operation of InGaAsP/InP MQW solar cells working in the resonant tunneling conditions. Lastly, time evolution of the hot electron relaxation in GaAs has been measured in the temperature range of 4 K through 288 K using femtosecond pump-IR-probe absorption technique.

  1. Theoretical efficiency of solar thermoelectric energy generators

    E-Print Network [OSTI]

    Chen, Gang

    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 ...

  2. NANO REVIEW Enhancing Solar Cell Efficiencies through 1-D Nanostructures

    E-Print Network [OSTI]

    Chen, Junhong

    include dye-sensitized solar cells, quantum- dot-sensitized solar cells, and p-n junction solar cells their efficiencies more practical. Now the third-generation solar cells, such as dye-sensitized solar cells (DSSCsNANO REVIEW Enhancing Solar Cell Efficiencies through 1-D Nanostructures Kehan Yu Ã? Junhong Chen

  3. High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  4. Remnant PbI{sub 2}, an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?

    SciTech Connect (OSTI)

    Cao, Duyen H.; Stoumpos, Constantinos C.; Malliakas, Christos D.; Katz, Michael J.; Hupp, Joseph T., E-mail: j-hupp@northwestern.edu, E-mail: m-kanatzidis@northwestern.edu; Kanatzidis, Mercouri G., E-mail: j-hupp@northwestern.edu, E-mail: m-kanatzidis@northwestern.edu [Department of Chemistry, and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States); Farha, Omar K. [Department of Chemistry, and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States); Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia)

    2014-09-01T23:59:59.000Z

    Perovskite-containing solar cells were fabricated in a two-step procedure in which PbI{sub 2} is deposited via spin-coating and subsequently converted to the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite by dipping in a solution of CH{sub 3}NH{sub 3}I. By varying the dipping time from 5 s to 2 h, we observe that the device performance shows an unexpectedly remarkable trend. At dipping times below 15 min the current density and voltage of the device are enhanced from 10.1 mA/cm{sup 2} and 933 mV (5 s) to 15.1 mA/cm{sup 2} and 1036 mV (15 min). However, upon further conversion, the current density decreases to 9.7 mA/cm{sup 2} and 846 mV after 2 h. Based on X-ray diffraction data, we determined that remnant PbI{sub 2} is always present in these devices. Work function and dark current measurements showed that the remnant PbI{sub 2} has a beneficial effect and acts as a blocking layer between the TiO{sub 2} semiconductor and the perovskite itself reducing the probability of back electron transfer (charge recombination). Furthermore, we find that increased dipping time leads to an increase in the size of perovskite crystals at the perovskite-hole-transporting material interface. Overall, approximately 15 min dipping time (?2% unconverted PbI{sub 2}) is necessary for achieving optimal device efficiency.

  5. Material and device characterization toward high-efficiency GaAs solar cells on optical-grade polycrystalline Ge substrates

    SciTech Connect (OSTI)

    Venkatasubramanian, R.; Malta, D.P.; Timmons, M.L.; Posthill, J.B.; Hutchby, J.A. [Research Triangle Inst., Research Triangle Park, NC (United States); Ahrenkiel, R.; Keyes, B.; Wangensteen, T. [National Renewable Energy Lab., Golden, CO (United States)

    1994-12-31T23:59:59.000Z

    In this work, the authors present a detailed characterization of the material and device properties of GaAs materials grown on optical-grade poly-Ge substrates. Although the minority-carrier lifetime of the starting optical-grade polycrystalline Ge substrate is about a factor of 8 less than that measured in single-crystal electronic-grade Ge, the minority carrier lifetime in GaAs-AlGaAs double-hetero (DH) structures grown on these two substrates were about comparable. C-V measurements on poly-GaAs p{sup +}n junctions indicate negligible role of grain-boundaries in majority-carrier trapping and also that no compensating deep levels were introduced into the n-GaAs active layers from the optical-grade substrates. The polycrystalline GaAs p{sup +}-n junctions were evaluated by dark In I-V measurements and the authors observed that there is a considerable variation of the saturation dark current density (within a factor of ten) of diodes located in various grains. The performance of the poly p{sup +}n GaAs cells is improved by the introduction of an undoped spacer in the p{sup +}-n junction. Diode I-V data of p{sup +}-n GaAs junctions, grown with this spacer, show a factor of near 100 reduction in diode saturation dark-current density. The reduction in dark current is believed to be associated with the reduction of tunneling currents in the depletion-layer of the p{sup +}-n junction in polycrystalline materials. Since the series resistance of the lightly-doped substrate is presently limiting the efficiency of large-area cells, efforts are underway to develop GaAs solar cells on more heavily-doped poly-Ge substrates.

  6. Sandia National Laboratories: very high solar energy conversion...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    very high solar energy conversion efficiency ECIS-Princeton Power Systems, Inc.: Demand Response Inverter On March 19, 2013, in DETL, Distribution Grid Integration, Energy, Energy...

  7. Increasing Solar Efficiency through Luminescent Solar Concentrators -

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News Community Connections:HAZARD ANALYSES

  8. 2 Highly efficient inverted rapid-drying blade-coated organic solar cells 3 Jung-Hao Chang a

    E-Print Network [OSTI]

    -coated were demonstrated. Optimized self-organization interpenetration networks 26and donor/acceptor domain organic solar cells (OSCs) based 39 on mixture of conjugated polymers and fullerene deriva- 40 tives have

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

    DOE Patents [OSTI]

    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

    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.

  10. Project Profile: Development and Productization of High-Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells Project Profile: Development and Productization of High-Efficiency, Low-Cost...

  11. DESIGN APPROACHES AND MATERIALS PROCESSES FOR ULTRAHIGH EFFICIENCY LATTICE MISMATCHED MULTI-JUNCTION SOLAR CELLS

    E-Print Network [OSTI]

    Atwater, Harry

    -JUNCTION SOLAR CELLS Melissa J. Griggs 1 , Daniel C. Law 2 , Richard R. King 2 , Arthur C. Ackerman 3 , James M heterostructures grown in a multi-junction solar cell-like structure by MOCVD. Initial solar cell data are also of the minority carrier lifetime. INTRODUCTION High efficiency triple junction solar cells have recently been

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

    SciTech Connect (OSTI)

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

    1994-10-01T23:59:59.000Z

    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.

  13. High Penetration Solar Deployment Funding Opportunity

    Broader source: Energy.gov [DOE]

    Through the High Penetration Solar Deployment program, DOE is funding solar projects that are accelerating the placement of solar photovoltaic (PV) systems into existing and newly designed...

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

    SciTech Connect (OSTI)

    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

    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.

  15. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    At Silicon Solar Cell Performance. Energ. Conv. 11, 63 (efficiency of solar cells. Sol. Energ. Mat. Sol. C. 139. E.Solar Cells: Comparison between Carrier Multiplication and Down- Conversion, Sol. Energ.

  16. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    91, 43. T. Markvart, Solar cell as a heat engine: energy–Tiedje, Physical Limits to Solar Cell Efficiency, in EnergyThe Carnot Factor in Solar-Cell Theory. Solid State

  17. High efficiency incandescent lighting

    DOE Patents [OSTI]

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02T23:59:59.000Z

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  18. High Efficiency, Clean Combustion

    SciTech Connect (OSTI)

    Donald Stanton

    2010-03-31T23:59:59.000Z

    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

  19. Module greenhouse with high efficiency of transformation of solar energy, utilizing active and passive glass optical rasters

    SciTech Connect (OSTI)

    Korecko, J.; Jirka, V. [ENKI, o.p.s., Dukelska 145, 379 01 Trebon (Czech Republic); Sourek, B. [ENKI, o.p.s., Dukelska 145, 379 01 Trebon (Czech Republic); Czech Technical University of Prague, Technicka 4, 166 07 Prague (Czech Republic); Cerveny, J. [ENKI, o.p.s., Dukelska 145, 379 01 Trebon (Czech Republic); Institute of Physical Biology, Zamek 136, 373 33 Nove Hrady (Czech Republic)

    2010-10-15T23:59:59.000Z

    Since the eighties of the 20th century, various types of linear glass rasters for architectural usage have been developed in the Czech Republic made by the continuous melting technology. The development was focused on two main groups of rasters - active rasters with linear Fresnel lenses in fixed installation and with movable photo-thermal and/or photo-thermal/photo-voltaic absorbers. The second group are passive rasters based on total reflection of rays on an optical prism. During the last years we have been working on their standardization, exact measuring of their optical and thermal-technical characteristics and on creation of a final product that could be applied in solar architecture. With the project supported by the Ministry of Environment of the Czech Republic we were able to build an experimental greenhouse using these active and passive optical glass rasters. The project followed the growing number of technical objectives. The concept of the greenhouse consisted of interdependence construction - structural design of the greenhouse with its technological equipment securing the required temperature and humidity conditions in the interior of the greenhouse. This article aims to show the merits of the proposed scheme and presents the results of the mathematical model in the TRNSYS environment through which we could predict the future energy balance carried out similar works, thus optimizing the investment and operating costs. In this article description of various technology applications for passive and active utilization of solar radiation is presented, as well as some results of short-term and long-term experiments, including evaluation of 1-year operation of the greenhouse from the energy and interior temperature viewpoints. A comparison of the calculated energy flows in the greenhouse to real measured values, for verification of the installed model is also involved. (author)

  20. Minding the Gap Makes for More Efficient Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Minding the Gap Makes for More Efficient Solar Cells Minding the Gap Makes for More Efficient Solar Cells Print Thursday, 19 December 2013 11:01 Using novel materials to develop...

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

    E-Print Network [OSTI]

    Dowling, Jonathan P.

    Solar Energy Materials & Solar Cells 91 (2007) 1599­1610 Improving solar cell efficiency using) solar energy conversion systems (or solar cells) are the most widely used power systems. However and reliable solar-cell devices is presented. We show that due their ability to modify the spectral and angular

  2. Thermal efficiency of single-pass solar air collector

    SciTech Connect (OSTI)

    Ibrahim, Zamry; Ibarahim, Zahari; Yatim, Baharudin [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ruslan, Mohd Hafidz [Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27T23:59:59.000Z

    Efficiency of a finned single-pass solar air collector was studied. This paper presents the experimental study to investigate the effect of solar radiation and mass flow rate on efficiency. The fins attached at the back of absorbing plate to improve the thermal efficiency of the system. The results show that the efficiency is increased proportional to solar radiation and mass flow rate. Efficiency of the collector archived steady state when reach to certain value or can be said the maximum performance.

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

    SciTech Connect (OSTI)

    Wojtczuk , S.

    2011-06-01T23:59:59.000Z

    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.

  4. Computationally Efficient Modeling of High-Efficiency Clean Combustion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    & Publications Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines...

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

    SciTech Connect (OSTI)

    Wanlass, M.

    2012-07-01T23:59:59.000Z

    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.

  6. High efficiency photoionization detector

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  7. European Photovoltaic Solar Energy Conference, Frankfurt, Germany, 24-28 September 2012, 2AO.2.4 HIGH EFFICIENCY BACK-CONTACT BACK-JUNCTION SILICON SOLAR CELLS WITH CELL

    E-Print Network [OSTI]

    27th European Photovoltaic Solar Energy Conference, Frankfurt, Germany, 24-28 September 2012, 2AO.2 cost of energy in photovoltaics can be achieved by increasing the conversion efficiency as well into the surface of a thick silicon wafer. After sintering at 1100 °C in hydrogen atmosphere silicon is grown

  8. High flux solar energy transformation

    DOE Patents [OSTI]

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

    1991-04-09T23:59:59.000Z

    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.

  9. High flux solar energy transformation

    DOE Patents [OSTI]

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

    1991-04-09T23:59:59.000Z

    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.

  10. High efficiency diamond solar cells

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL)

    2008-05-06T23:59:59.000Z

    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.

  11. High-efficiency photovoltaic cells

    DOE Patents [OSTI]

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

    1982-06-21T23:59:59.000Z

    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.

  12. Solar cell efficiency enhancement via light trapping in printable resonant

    E-Print Network [OSTI]

    Atwater, Harry

    Solar cell efficiency enhancement via light trapping in printable resonant dielectric nanosphere´de´rale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics, photovoltaics, resonant dielectric structures, solar cells * Corresponding author: e-mail jgrandid

  13. Efficiency of silicon solar cells containing chromium

    DOE Patents [OSTI]

    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

    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.

  14. High Efficiency CdTe/CdS Thin Film Solar Cells Prepared by Treating CdTe Films with a Freon Gas in Substitution of CdCl2

    E-Print Network [OSTI]

    Romeo, Alessandro

    High Efficiency CdTe/CdS Thin Film Solar Cells Prepared by Treating CdTe Films with a Freon Gas process. A further simplification has been done by substituting the CdCl2 step by treating CdTe films to treat CdTe. In this case CdCl2 vapor is obtained by a source facing the CdTe film or conveyed from

  15. High Efficiency Integrated Package

    SciTech Connect (OSTI)

    Ibbetson, James

    2013-09-15T23:59:59.000Z

    Solid-state lighting based on LEDs has emerged as a superior alternative to inefficient conventional lighting, particularly incandescent. LED lighting can lead to 80 percent energy savings; can last 50,000 hours – 2-50 times longer than most bulbs; and contains no toxic lead or mercury. However, to enable mass adoption, particularly at the consumer level, the cost of LED luminaires must be reduced by an order of magnitude while achieving superior efficiency, light quality and lifetime. To become viable, energy-efficient replacement solutions must deliver system efficacies of ? 100 lumens per watt (LPW) with excellent color rendering (CRI > 85) at a cost that enables payback cycles of two years or less for commercial applications. This development will enable significant site energy savings as it targets commercial and retail lighting applications that are most sensitive to the lifetime operating costs with their extended operating hours per day. If costs are reduced substantially, dramatic energy savings can be realized by replacing incandescent lighting in the residential market as well. In light of these challenges, Cree proposed to develop a multi-chip integrated LED package with an output of > 1000 lumens of warm white light operating at an efficacy of at least 128 LPW with a CRI > 85. This product will serve as the light engine for replacement lamps and luminaires. At the end of the proposed program, this integrated package was to be used in a proof-of-concept lamp prototype to demonstrate the component’s viability in a common form factor. During this project Cree SBTC developed an efficient, compact warm-white LED package with an integrated remote color down-converter. Via a combination of intensive optical, electrical, and thermal optimization, a package design was obtained that met nearly all project goals. This package emitted 1295 lm under instant-on, room-temperature testing conditions, with an efficacy of 128.4 lm/W at a color temperature of ~2873K and 83 CRI. As such, the package’s performance exceeds DOE’s warm-white phosphor LED efficacy target for 2013. At the end of the program, we assembled an A19 sized demonstration bulb housing the integrated package which met Energy Star intensity variation requirements. With further development to reduce overall component cost, we anticipate that an integrated remote converter package such as developed during this program will find application in compact, high-efficacy LED-based lamps, particularly those requiring omnidirectional emission.

  16. Solar thermophotovoltaic efficiency potentials : surpassing photovoltaic device efficiencies

    E-Print Network [OSTI]

    Barnes, Kathryn M

    2012-01-01T23:59:59.000Z

    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 ...

  17. Sandia National Laboratories: Concentrating Solar Power: Efficiently...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Funding Award On June 4, 2014, in Advanced Materials Laboratory, Concentrating Solar Power, Energy, Energy Storage, Facilities, National Solar Thermal Test Facility,...

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

    E-Print Network [OSTI]

    Atwater, Harry

    INCREASED CELL EFFICIENCY IN InGaAs THIN FILM SOLAR CELLS WITH DIELECTRIC AND METAL BACK REFLECTORS solar cells enable very high photovoltaic efficiencies by virtue of employing different band gap materials in series- connected tandem cells to access the full solar spectrum. Researchers focused

  19. Oncor Energy Efficiency Programs Solar Photovoltaic and Demand Response 

    E-Print Network [OSTI]

    Tyra, K.; Hanel, J.

    2012-01-01T23:59:59.000Z

    Oncor Energy Efficiency Programs Solar Photovoltaic and Demand Response October 10, 2012 ENERGY EFFICIENCY PROGRAMS OVERVIEW ?Program rules and guidelines established by Public Utility Commission of Texas (PUCT) ?All Texas investor...

  20. Oncor Energy Efficiency Programs Solar Photovoltaic and Demand Response

    E-Print Network [OSTI]

    Tyra, K.; Hanel, J.

    2012-01-01T23:59:59.000Z

    Oncor Energy Efficiency Programs Solar Photovoltaic and Demand Response October 10, 2012 ENERGY EFFICIENCY PROGRAMS OVERVIEW ?Program rules and guidelines established by Public Utility Commission of Texas (PUCT) ?All Texas investor... to be administered by transmission-distribution utilities ?Programs are implemented by Energy Efficiency Services Providers and Retail Electric Providers 1 WHY DOES ONCOR DO SOLAR PV? ?Helps meet our energy efficiency goals ?Helps customers reduce...

  1. 50% EFFICIENT SOLAR CELL ARCHITECTURES AND DESIGNS Allen Barnett1

    E-Print Network [OSTI]

    Honsberg, Christiana

    paths to low cost. Our central innovation is to co-design the optical, interconnect and solar cell cost drivers through novel solar cell architectures and optical elements. LOW CONCENTRATION50% EFFICIENT SOLAR CELL ARCHITECTURES AND DESIGNS Allen Barnett1 , Christiana Honsberg1 , Douglas

  2. NREL showcase solar systems and energy efficient design

    SciTech Connect (OSTI)

    NONE

    1995-12-31T23:59:59.000Z

    THe Thermal Test Facility at NREL, which should be completed in the summer of 1996, will incorporate natural lighting from clerestories and may other solar and energy-efficiency features; roof-mounted solar collectors, which will be monitored as part of NREL`s work on active solar systems, will help to heat water and interior spaces in the building.

  3. Plasmonic Nanostructure Design for Efficient Light Coupling into Solar Cells

    E-Print Network [OSTI]

    Atwater, Harry

    Plasmonic Nanostructure Design for Efficient Light Coupling into Solar Cells Vivian E. Ferry, Luke sunlight into guided modes in thin film Si and GaAs plasmonic solar cells whose back interface is coated. These findings show promise for the design of ultrathin solar cells that exhibit enhanced absorption

  4. Investigating the efficiency of Silicon Solar cells at

    E-Print Network [OSTI]

    Attari, Shahzeen Z.

    Investigating the efficiency of Silicon Solar cells at different temperatures and wavelengths to study the characteristics of silicon photovoltaic cells (solar cells). We vary the wavelength of light as well as the temperature of the solar cell to investigate how the open voltage across the cell varies

  5. High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    high-efficiency solar receiver that is compatible with s-CO2 cycles and modern thermal storage subsystems. Supercritical CO2 Brayton-cycle engines have the potential to...

  6. Upconversion as a Viable Route to Increased Efficiency Solar Energy

    E-Print Network [OSTI]

    Firestone, Jeremy

    Upconversion as a Viable Route to Increased Efficiency Solar Energy Conversion Joshua Zide, Matt University of Delaware Energy Institute #12;Efficiency drives reduced $/W.... http://www.nrel.gov/ncpv/! Shockley-Queisser Limit! *adopted from http://www.lbl.gov/Science-Articles/Archive/MSD-full-spectrum-solar

  7. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS

    E-Print Network [OSTI]

    ) · Solar (Solar thermal, Photovoltaic) · Renewables (Hydropower, Geothermal, Wind, Biomass) Nuclear power power generation ­ Electrolysis · Overall efficiency approximately 25-30% (efficiency of electric power · Splits water at moderate temperatures (~700-900°C vs ~5,000°C for thermolysis) · Plant efficiencies

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

    SciTech Connect (OSTI)

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

    1993-04-01T23:59:59.000Z

    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.

  9. Cu(In,Ga)Se2 alloys are the leading choice for absorber layers in high-efficiency thin film solar cells due to their direct gap, high absorption

    E-Print Network [OSTI]

    Rockett, Angus

    film solar cells due to their direct gap, high absorption coefficient and excellent thermal stability Cu(In,Ga)Se2 are used to interpret PL results. ·No evidence of band-to-band transitions (rare in CIGS

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

    SciTech Connect (OSTI)

    Not Available

    2010-12-01T23:59:59.000Z

    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.

  11. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    Generation Photovoltaics: Ultra-High Conversion EfficiencyPhotovoltaics, as a Function of Cost and Efficiency. The ‘EFFICIENCY OF A LATERALLY ENGINEERED ARCHITECTURE FOR PHOTOVOLTAICS,

  12. High Efficiency Recoil

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartmentInnovation Portal 130221326|Efficiency

  13. Ultrahigh Efficiency Multiband Solar Cells Final Report for Director's Innovation Initiative Project DII-2005-1221

    E-Print Network [OSTI]

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-01-01T23:59:59.000Z

    of Multijunction Solar Cell Performance in RadiationIgari, and W. Warta, “Solar Cell Efficiency Tables (Versionof Multijunction Solar Cell Performance in Radiation

  14. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01T23:59:59.000Z

    photovoltaic devices with a world record efficiency ofhigh efficiencies as compared to traditional photovoltaic

  15. New solar cell technology captures high-energy photons more efficientl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (click to enlarge) Argonne's Center for Nanoscale Materials (click to enlarge) New solar cell technology captures high-energy photons more efficiently By Jared Sagoff *...

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

    E-Print Network [OSTI]

    Summers, Edward K

    2010-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    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

    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.

  18. Recent progress in enhancing solar-to-hydrogen efficiency

    SciTech Connect (OSTI)

    Chen, Jianqing [Hohai University, China; Yang, Donghui [Hohai University, China; Song, Dan [Hohai University, China; Jiang, Jinghua [Hohai University, China; Ma, Aibin [Hohai University, China; Hu, Michael Z. [ORNL; Ni, Chaoying [University of Delaware

    2015-01-01T23:59:59.000Z

    Solar water splitting is a promising and ideal route for renewable production of hydrogen by using the most abundant resources of solar light and water. Focusing on the working principal of solar water splitting, including photon absorption and exciton generation in semiconductor, exciton separation and transfer to the surface of semiconductor, and respective electron and hole reactions with absorbed surface species to generate hydrogen and oxygen, this review covers the comprehensive efforts and findings made in recent years on the improvement for the solar-to-hydrogen efficiency (STH) determined by a combination of light absorption process, charge separation and migration, and catalytic reduction and oxidation reactions. Critical evaluation is attempted on the strategies for improving solar light harvesting efficiency, enhancing charge separation and migration, and improving surface reactions. Towards the end, new and emerging technologies for boosting the STH efficiency are discussed on multiple exciton generation, up-conversion, multi-strategy modifications and the potentials of organometal hybrid perovskite materials.

  19. Impact of surface roughness on the electrical parameters of industrial high efficiency NaOH-NaOCl textured multicrystalline silicon solar cell

    SciTech Connect (OSTI)

    Basu, P.K. [Department of Physics, Echelon Institute of Technology, Faridabad 121002, Haryana (India); Pujahari, R.M. [Department of Physics, Echelon Institute of Technology, Faridabad 121002, Haryana (India); Department of Physics, Manav Rachna International University, Faridabad 121001, Haryana (India); Kaur, Harpreet [Department of Physics, Manav Rachna International University, Faridabad 121001, Haryana (India); Department of Physics, Advanced Institute of Technology and Management, Palwal 121105, Haryana (India); Singh, Devi [Department of Physics, Manav Rachna International University, Faridabad 121001, Haryana (India); Varandani, D.; Mehta, B.R. [Department of Physics, Indian Institute of Technology, New Delhi 110016 (India)

    2010-09-15T23:59:59.000Z

    Sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) solution (1:1 ratio by volume) based texturization process at 80-82 C is an easy, low cost and comparatively new and convenient option for fabrication of any multicrystalline silicon (mC-Si) solar cell. In the present study atomic force microscope is used to observe the intragrain surface in a miniscule area (3 {mu}m x 3 {mu}m) of NaOH-NaOCl textured surface by two and three dimensional analysis, roughness analysis and section analysis. The r.m.s value of the surface parameter of 7.0 nm ascertains the smoothness of the textured surface and further the surface reflectivity is minimized to 4-6% in the 500-1000 nm wavelength range by a proper silicon nitride anti-reflection coating. Comparing with the standard HF-HNO{sub 3}-CH{sub 3}COOH acid textured cell, the NaOH-NaOCl textured cell shows a comparatively lower value of series resistance of 7.17 m{omega}, higher value of shunt resistance of 18.4 {omega} to yield a fill factor of 0.766 leading to more than 15% cell efficiency in the industrial cell processing line. This AFM study yields different surface roughness parameters for the NaOH-NaOCl textured wafers which can be used as a reference standard for optimized texturing. (author)

  20. Parabolic trough solar collectors : design for increasing efficiency

    E-Print Network [OSTI]

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

    2011-01-01T23:59:59.000Z

    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 ...

  1. SUPPORTING INFORMATION Si Microwire Solar Cells: Improved Efficiency with a

    E-Print Network [OSTI]

    S1 SUPPORTING INFORMATION Si Microwire Solar Cells: Improved Efficiency with a Conformal SiO2 Layer Technologies, 174 Haverhill Road, Topsfield, MA 01983 School of Engineering and Applied Sciences, Harvard improvements (%) of Si microwire solar cells (6 µµµµm height) after conformal SiO2 coating SiO2 thickness Jsc

  2. Is efficiency the only important aspect to solar energy?

    E-Print Network [OSTI]

    Franssen, Michael

    1 Is efficiency the only important aspect to solar energy? Michael G. Debije Chemical Engineering Dag #12;2 Meeting the solar challenge Buildings residential 21% Buildings commercial 18%Industry 33 use 40% of our energy Our inability to control sunlight costs ~16% of worldwide energy consumption

  3. Comparative efficiencies of solar energy collectors Laboratoire de Technologie Optique

    E-Print Network [OSTI]

    Boyer, Edmond

    57 Comparative efficiencies of solar energy collectors M. Duban Laboratoire de Technologie Optique the solar energy during a day or a year, independant of their dimensions, the amount of energy collected seuils K = 0 et K = 0,5 (K étant le rapport entre 1'energie minimum nécessaire pour un fonctionnement

  4. High-Flux Microchannel Solar Receiver

    Broader source: Energy.gov [DOE]

    This fact sheet describes a high-flux, microchannel solar receiver project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by Oregon State University, is working to demonstrate a microchannel-based solar receiver capable of absorbing high solar flux, while using a variety of liquid and gaseous working fluids. High-flux microchannel receivers have the potential to dramatically reduce the size and cost of a solar receiver by minimizing re-radiation and convective losses.

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    efficient and affordable solar cells so highly coveted? Volume. The amount of solar energy lighting up Earth's land mass every year is nearly 3,000 times current usage. But to...

  6. DEVELOPMENT OF A NOVEL PRECURSOR FOR THE PREPARATION BY SELENIZATION OF HIGH EFFICIENCY CuInGaSe2/CdS THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Romeo, Alessandro

    /CdS THIN FILM SOLAR CELLS N. Romeo1 , A. Bosio1 , V. Canevari2 , R. Tedeschi1 , S. Sivelli1 , A. Solar cells prepared by depositing in sequence on top of the CuInGaSe2 film 60 nm of CdS, 100 nm of pure(InGa)Se2, Thin Films, Selenization 1 INTRODUCTION CuInGaSe2 based solar cells exhibit the highest

  7. Detecting Extra-Solar Planets via Microlensing at High Magnification

    E-Print Network [OSTI]

    Nicholas J. Rattenbury; Ian A. Bond; Jovan Skuljan; Phil Yock

    2002-09-09T23:59:59.000Z

    Extra-solar planets can be efficiently detected in gravitational microlensing events of high magnification. High accuracy photometry is required over a short, well-defined time interval only, of order 10-30 hours. Most planets orbiting the lens star are evidenced by perturbations of the microlensing light curve in this time.

  8. NCTCOG Solar Ready II Project: Clean Air Through Energy Efficiency 

    E-Print Network [OSTI]

    Clark,L.

    2014-01-01T23:59:59.000Z

    for connecting solar power to the electric grid, and increasing access to financing, teams will clear a path for rapid expansion of solar energy and serve as models for other communities across the nation. 4 ESL-KT-14-11-12 CATEE 2014: Clean Air Through...Clean Air Through Energy Efficiency November 20, 2014 NCTCOG Solar Ready II Project Lori Clark Principal Air Quality Planner ESL-KT-14-11-12 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 U.S. Department of Energy Sun...

  9. Mode Splitting for Efficient Plasmoinc Thin-film Solar Cell

    E-Print Network [OSTI]

    Li, Tong; Jiang, Chun

    2010-01-01T23:59:59.000Z

    We propose an efficient plasmonic structure consisting of metal strips and thin-film silicon for solar energy absorption. We numerically demonstrate the absorption enhancement in symmetrical structure based on the mode coupling between the localized plasmonic mode in Ag strip pair and the excited waveguide mode in silicon slab. Then we explore the method of symmetry-breaking to excite the dark modes that can further enhance the absorption ability. We compare our structure with bare thin-film Si solar cell, and results show that the integrated quantum efficiency is improved by nearly 90% in such thin geometry. It is a promising way for the solar cell.

  10. Sunshot Initiative High Penetration Solar Portal

    DOE Data Explorer [Office of Scientific and Technical Information (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. [from https://solarhighpen.energy.gov/about_the_high_penetration_solar_portal

  11. NCTCOG Solar Ready II Project: Clean Air Through Energy Efficiency

    E-Print Network [OSTI]

    Clark,L.

    2014-01-01T23:59:59.000Z

    Clean Air Through Energy Efficiency November 20, 2014 NCTCOG Solar Ready II Project Lori Clark Principal Air Quality Planner ESL-KT-14-11-12 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 U.S. Department of Energy Sun...Shot Initiative Rooftop Solar Challenge 2 ESL-KT-14-11-12 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 U.S. Department of Energy (DOE) SunShot Initiative The U.S. Department of Energy SunShot Initiative is a collaborative national...

  12. Project Profile: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells

    Broader source: Energy.gov [DOE]

    The Solexel-OC team is developing a BIPV roofing shingle product that includes low-profile solar modules and a unique attachment system that will be fastened directly to the roof and incorporates...

  13. High Efficiency Engine Technologies Program

    SciTech Connect (OSTI)

    Rich Kruiswyk

    2010-07-13T23:59:59.000Z

    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.

  14. Highly Efficient Electric Motor Systems

    E-Print Network [OSTI]

    over wider operating range with same size motor Uses up to 40% less electricity NREL Energy Forum;Annual Serviceable Addressable Market (SAM) for >1hp non-hermetic motors NREL Energy Forum November 2009Highly Efficient Electric Motor Systems NREL Energy Forum November 2009 www.novatorque.com Emily

  15. Solar Tracing Sensors for Maximum Solar Concentrator Efficiency - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary Moniz9MorganYouof Energy Projects toSolar

  16. Highly Mismatched Alloys for Intermediate Band Solar Cells

    E-Print Network [OSTI]

    2005-01-01T23:59:59.000Z

    for Intermediate Band Solar Cells W. Walukiewicz 1 , K. M.single-junction intermediate band solar cells. Figure 5:conversion efficiency for a solar cell fabricated from a Zn

  17. Toward High-Performance Organic-Inorganic Hybrid Solar Cells: Bringing Conjugated Polymers and Inorganic Nanocrystals in Close

    E-Print Network [OSTI]

    Lin, Zhiqun

    , China ABSTRACT: Organic-inorganic hybrid solar cells composed of conjugated polymers (CPs) and inorganicToward High-Performance Organic-Inorganic Hybrid Solar Cells: Bringing Conjugated Polymers to traditional silicon solar cells due to the capacity of producing high- efficiency solar energy in a cost

  18. High frequency and high wavenumber solar oscillations

    E-Print Network [OSTI]

    H. M. Antia; Sarbani Basu

    1999-02-10T23:59:59.000Z

    We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\

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

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.

    2008-05-01T23:59:59.000Z

    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.

  20. Intermediate Mirrors to Reach Theoretical Efficiency Limits of Multi-Bandgap Solar Cells

    E-Print Network [OSTI]

    Ganapati, Vidya; Yablonovitch, Eli

    2014-01-01T23:59:59.000Z

    Creating a single bandgap solar cell that approaches the Shockley-Queisser limit requires a highly reflective rear mirror. This mirror enhances the voltage of the solar cell by providing photons with multiple opportunities for escaping out the front surface. Efficient external luminescence is a pre-requisite for high voltage. Intermediate mirrors in a multijunction solar cell can enhance the voltage for each cell in the stack. These intermediate mirrors need to have the added function of transmitting the below bandgap photons to the next cell in the stack. In this work, we quantitatively establish the efficiency increase possible with the use of intermediate selective reflectors between cells in a tandem stack. The absolute efficiency increase can be up to ~6% in dual bandgap cells with optimal intermediate and rear mirrors. A practical implementation of an intermediate selective mirror is an air gap sandwiched by antireflection coatings. The air gap provides perfect reflection for angles outside the escape c...

  1. Efficiency limits of quantum well solar cells

    E-Print Network [OSTI]

    Connolly, J P; Barnham, K W J; Bushnell, D B; Tibbits, T N D; Roberts, J S

    2010-01-01T23:59:59.000Z

    The quantum well solar cell (QWSC) has been proposed as a flexible means to ensuring current matching for tandem cells. This paper explores the further advantage afforded by the indication that QWSCs operate in the radiative limit because radiative contribution to the dark current is seen to dominate in experimental data at biases corresponding to operation under concentration. The dark currents of QWSCs are analysed in terms of a light and dark current model. The model calculates the spectral response (QE) from field bearing regions and charge neutral layers and from the quantum wells by calculating the confined densities of states and absorption coefficient, and solving transport equations analytically. The total dark current is expressed as the sum of depletion layer and charge neutral radiative and non radiative currents consistent with parameter values extracted from QE fits to data. The depletion layer dark current is a sum of Shockley-Read-Hall non radiative, and radiative contributions. The charge neu...

  2. Tunable Localized Surface Plasmon-Enabled Broadband Light-Harvesting Enhancement for High-Efficiency Panchromatic Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Dang, Xiangnan

    In photovoltaic devices, light harvesting (LH) and carrier collection have opposite relations with the thickness of the photoactive layer, which imposes a fundamental compromise for the power conversion efficiency (PCE). ...

  3. High Efficiency Germanium Immersion Gratings

    SciTech Connect (OSTI)

    Kuzmenko, P J; Davis, P J; Little, S L; Little, L M; Bixler, J V

    2006-05-01T23:59:59.000Z

    We have fabricated several germanium immersion gratings by single crystal, single point diamond flycutting on an ultra-precision lathe. Use of a dead sharp tool produces groove corners less than 0.1 micron in radius and consequently high diffraction efficiency. We measured first order efficiencies in immersion of over 80% at 10.6 micron wavelength. Wavefront error was low averaging 0.06 wave rms (at 633 nm) across the full aperture. The grating spectral response was free of ghosts down to our detection limit of 1 part in 10{sup 4}. Scatter should be low based upon the surface roughness. Measurement of the spectral line profile of a CO{sub 2} laser sets an upper bound on total integrated scatter of 0.5%.

  4. High-Temperatuer Solar Selective Coating Development for Power...

    Broader source: Energy.gov (indexed) [DOE]

    High-Temperatuer Solar Selective Coating Development for Power Tower Receivers High-Temperatuer Solar Selective Coating Development for Power Tower Receivers This presentation was...

  5. High Temperature Thermal Array for Next Generation Solar Thermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Temperature Thermal Array for Next Generation Solar Thermal Power Production High Temperature Thermal Array for Next Generation Solar Thermal Power Production This...

  6. Computationally Efficient Modeling of High-Efficiency Clean Combustion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Meeting, June 7-11, 2010 -- Washington D.C. ace012aceves2010o.pdf More Documents & Publications Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines...

  7. A low cost high flux solar simulator

    E-Print Network [OSTI]

    Codd, Daniel S.

    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 ...

  8. Techniques for Maximizing Efficiency of Solar Energy Harvesting Systems (Invited Paper)

    E-Print Network [OSTI]

    Shinozuka, Masanobu

    Techniques for Maximizing Efficiency of Solar Energy Harvesting Systems (Invited Paper) Pai H requiring battery replacement. This paper ex- amines technical issues with solar energy harvesting. First power point tracking, energy harvest- ing, solar panel, photovoltaic cell, supercapacitor, ultracapac

  9. Enabling High Efficiency Ethanol Engines

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:RevisedAdvisoryStandard | Department ofEmily KnouseEnSys EnergyHigh Efficiency

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

    SciTech Connect (OSTI)

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

    2010-09-01T23:59:59.000Z

    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.

  11. Improved Solar Power Plant Efficiency: Low Cost Solar Irradiance Sensor -

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School footballHydrogenIT |HotImpactControlInnovation PortalEnergy

  12. High temperature solar selective coatings

    DOE Patents [OSTI]

    Kennedy, Cheryl E

    2014-11-25T23:59:59.000Z

    Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.

  13. High efficiency cadmium telluride and zinc telluride based thin-film solar cells. Annual subcontract report, 1 March 1990--28 February 1992

    SciTech Connect (OSTI)

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

    1992-10-01T23:59:59.000Z

    This report describes work to improve the basic understanding of CdTe and ZnTe alloys by growing and characterizing these films along with cell fabrication. The major objective was to develop wide-band-gap (1.6--1.8 eV) material for the top cell, along with compatible window material and transparent ohmic contacts, so that a cascade cell design can be optimized. Front-wall solar cells were fabricated with a glass/SnO{sub 2}/CdS window, where the CdS film is thin to maximize transmission and current. Wide-band-gap absorber films (E{sub g} = 1.75 eV) were grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) techniques, which provided excellent control for tailoring the film composition and properties. CdZnTe films were grown by both MBE and MOCVD. All the as-grown films were characterized by several techniques (surface photovoltage spectroscopy, Auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS)) for composition, bulk uniformity, thickness, and film and interface quality. Front-wall-type solar cells were fabricated in collaboration with Ametek Materials Research Laboratory using CdTe and CdZnTe polycrystalline absorber films. The effects of processing on ternary film were studied by AES and XPS coupled with capacitance voltage and current voltage measurements as a function of temperature. Bias-dependent spectral response and electrical measurements were used to test some models in order to identify and quantify dominant loss mechanisms.

  14. Efficient Solar Concentrators: Affordable Energy from Water and Sunlight

    SciTech Connect (OSTI)

    None

    2010-01-01T23:59:59.000Z

    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.

  15. Geek-Up[4.29.2011]: Boosting the Efficiency of Wind and Solar...

    Broader source: Energy.gov (indexed) [DOE]

    4.29.2011: Boosting the Efficiency of Wind and Solar Power Geek-Up4.29.2011: Boosting the Efficiency of Wind and Solar Power April 29, 2011 - 5:14pm Addthis Niketa Kumar Niketa...

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (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...

  17. Geothermal, Energy Efficiency, and Solar PV Opportunities at Nissan USE

    E-Print Network [OSTI]

    Ford, R.; Ong, J.; Reeder, J.; Sridar, V.; Zhang, R.

    2014-01-01T23:59:59.000Z

    Geothermal, Energy Efficiency, and Solar PV Opportunities at Nissan USA May 21st, 2014 Robinson Ford Justin Ong Jake Reeder Vikram Sridar Rica Zhang ESL-IE-14-05-04 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New... Orleans, LA. May 20-23, 2014 Carbon Goal is Driving Innovation ESL-IE-14-05-04 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20-23, 2014 Research Areas Geothermal Solar Photovoltaics EE Verification ESL...

  18. DISSERTATION Investigation of Spatial Variations in Collection Efficiency of Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION Investigation of Spatial Variations in Collection Efficiency of Solar Cells Submitted BY JASON F. HILTNER ENTITLED INVESTIGATION OF SPATIAL VARIATIONS IN COLLECTION EFFICIENCY OF SOLAR CELLS OF SOLAR CELLS In an effort to investigate spatial variations in solar cells, an apparatus which is capable

  19. Computationally Efficient Modeling of High-Efficiency Clean Combustion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Peer Evaluation ace012aceves2011o.pdf More Documents & Publications Simulation of High Efficiency Clean Combustion Engines and Detailed Chemical Kinetic Mechanisms Development...

  20. High Efficiency Fans and High Efficiency Electrical Motors

    E-Print Network [OSTI]

    Breedlove, C. W.

    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...

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

    E-Print Network [OSTI]

    Fan, Shanhui

    Absorber and emitter for solar thermo- photovoltaic systems to achieve efficiency exceeding-junction solar cell can attain efficiency that exceeds the Shockley-Queisser limit. ©2009 Optical Society and links 1. W. Shockley, and H. J. Queisser, "Detailed Balance Limit of Efficiency of p-n Junction Solar

  2. High Energy Particles in the Solar Corona

    E-Print Network [OSTI]

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

    2008-04-16T23:59:59.000Z

    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.

  3. The mission of the UC Davis Solar Collaborative is simple: to find ways to make solar cells more efficient. Even in theory, the efficiency of conventional solar cells is limited to a disappointing 31%. However, this limit is based

    E-Print Network [OSTI]

    Mission The mission of the UC Davis Solar Collaborative is simple: to find ways to make solar cells more efficient. Even in theory, the efficiency of conventional solar cells is limited to a disappointing 31%. However, this limit is based on the traditional operation of solar cells, where an incoming

  4. 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

    SciTech Connect (OSTI)

    Fatemi, H.

    2012-07-01T23:59:59.000Z

    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.

  5. The Design of Organic Polymers and Small Molecules to Improve the Efficiency of Excitonic Solar Cells

    E-Print Network [OSTI]

    Armstrong, Paul Barber

    2010-01-01T23:59:59.000Z

    of High Efficiency Polymer Photovoltaics…………………7 Futureof High Efficiency Polymer Photovoltaics Although the Tangthe Efficiency of Organic Photovoltaics……………..7 Development

  6. Internal quantum efficiency analysis of solar cell by genetic algorithm

    SciTech Connect (OSTI)

    Xiong, Kanglin; Yang, Hui [Institute of Semiconductors, CAS, No. A35, Qing Hua East Road, Beijing 100083 (China); Suzhou Institute of Nano-tech and Nano-bionics, CAS, Ruoshui Road 398, Suzhou 215125 (China); Lu, Shulong; Zhou, Taofei; Wang, Rongxin; Qiu, Kai; Dong, Jianrong [Suzhou Institute of Nano-tech and Nano-bionics, CAS, Ruoshui Road 398, Suzhou 215125 (China); Jiang, Desheng [Institute of Semiconductors, CAS, No. A35, Qing Hua East Road, Beijing 100083 (China)

    2010-11-15T23:59:59.000Z

    To investigate factors limiting the performance of a GaAs solar cell, genetic algorithm is employed to fit the experimentally measured internal quantum efficiency (IQE) in the full spectra range. The device parameters such as diffusion lengths and surface recombination velocities are extracted. Electron beam induced current (EBIC) is performed in the base region of the cell with obtained diffusion length agreeing with the fit result. The advantage of genetic algorithm is illustrated. (author)

  7. Lithographic antennas for enhancement of solar cell efficiency

    SciTech Connect (OSTI)

    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

    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.

  8. Basic studies of 3-5 high efficiency cell components

    SciTech Connect (OSTI)

    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

    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.

  9. Chemical beam epitaxy for high efficiency photovoltaic devices

    SciTech Connect (OSTI)

    Bensaoula, A.; Freundlich, A.; Vilela, M. F.; Medelci, N.; Renaud, P.

    1994-09-01T23:59:59.000Z

    InP-based multijunction tandem solar cells show great promise for the conversion efficiency (eta) and high radiation resistance. InP and its related ternary and quanternary compound semiconductors such as InGaAs and InGaAsP offer desirable combinations for energy bandgap values which are very suitable for multijunction tandem solar cell applications. The monolithically integrated InP/In(0.53)Ga(0.47)As tandem solar cells are expected to reach efficiencies above 30 percent. Wanlass, et.al., have reported AMO efficiencies as high as 20.1% for two terminal cells fabricated using atmospheric-pressure metalorganic vapor phase epitaxy (APMOVPE). The main limitations in their technique are first related to the degradation of the intercell ohmic contact (IOC), in this case the In(0.53)Ga(0.47)As tunnel junction during the growth of the top InP subcell structure, and second to the current matching, often limited by the In(0.53)Ga(0.47)As bottom subcell. Chemical beam epitaxy (CBE) has been shown to allow the growth of high quality materials with reproducible complex compositional and doping profiles. The main advantage of CBE compared to metalorganic chemical vapor deposition (MOCVD), the most popular technique for InP-based photovoltaic device fabrication, is the ability to grow high purity epilayers at much lower temperatures (450 C - 530 C). In a recent report it was shown that cost-wise CBE is a breakthrough technology for photovoltaic (PV) solar energy progress in the energy conversion efficiency of InP-based solar cells fabricated using chemical beam epitaxy. This communication summarizes recent results on PV devices and demonstrates the strength of this new technology.

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

    SciTech Connect (OSTI)

    Simon, J.

    2012-01-01T23:59:59.000Z

    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.

  11. Enabling High Efficiency Clean Combustion

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Efficiency Clean Combustion 2008 Semi-Mega Merit Review Donald Stanton Research & Technology February 26 th , 2008 This presentation does not contain any proprietary or...

  12. Enabling High Efficiency Clean Combustion

    Broader source: Energy.gov (indexed) [DOE]

    penalty associated with aftertreatment 3% improvement in open cycle efficiency (turbo, EGR system, etc.) 8 This presentation does not contain any proprietary or...

  13. First-principle calculation of solar cell efficiency under incoherent illumination

    E-Print Network [OSTI]

    Sarrazin, Michael; Deparis, Olivier

    2013-01-01T23:59:59.000Z

    Because of the temporal incoherence of sunlight, solar cells efficiency should depend on the degree of coherence of the incident light. However, numerical computation methods, which are used to optimize these devices, fundamentally consider fully coherent light. Hereafter, we show that the incoherent efficiency of solar cells can be easily analytically calculated. The incoherent efficiency is simply derived from the coherent one thanks to a convolution product with a function characterizing the incoherent light. Our approach is neither heuristic nor empiric but is deduced from first-principle, i.e. Maxwell's equations. Usually, in order to reproduce the incoherent behavior, statistical methods requiring a high number of numerical simulations are used. With our method, such approaches are not required. Our results are compared with those from previous works and good agreement is found.

  14. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    of analytical expressions for solar cell fill factors.Solar Cells 7, 31. A. Luque and V. Andreev, Concentratorenergy gap terrestrial solar cells. J. Appl. Phys. 51,

  15. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    Based Performance Analysis of a Solar Absorption Cooling andExperimental Investigation of a Solar Adsorption ChillerKreith, Jan F. Kreider. "Solar Cooling." Principles of Solar

  16. Multijunction solar cell efficiencies: effect of spectral window, optical environment and radiative

    E-Print Network [OSTI]

    Atwater, Harry

    Multijunction solar cell efficiencies: effect of spectral window, optical environment and radiative,9 The optical environment of a solar cell controls where the radiated photons from a subcell are directed*a Solar cell efficiency is maximized through multijunction architectures that minimize carrier

  17. Solar power conversion efficiency in modulated silicon nanowire photonic Alexei Deinega and Sajeev John

    E-Print Network [OSTI]

    John, Sajeev

    Solar power conversion efficiency in modulated silicon nanowire photonic crystals Alexei Deinega://jap.aip.org/about/rights_and_permissions #12;Solar power conversion efficiency in modulated silicon nanowire photonic crystals Alexei Deinegaa that using only 1 lm of silicon, sculpted in the form of a modulated nanowire photonic crystal, solar power

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

    E-Print Network [OSTI]

    Kammen, Daniel M.

    Toward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power By Merrian C. Fuller, such as improving energy efficiency and add- ing solar photovoltaics (PV) and solar thermal systems to buildings, and the aver- age cost of natural gas has risen more than 10 percent a year for residential customers

  19. The role of three-dimensional morphology on the efficiency of hybrid polymer solar cells

    E-Print Network [OSTI]

    Schmidt, Volker

    1 The role of three-dimensional morphology on the efficiency of hybrid polymer solar cells Stefan D.a.j.janssen@tue.nl #12;2 Abstract: The efficiency of polymer solar cells critically depends on the intimacy of mixing and quantitative correlation between solar cell performance, photophysical data and the three

  20. METAL BLACKS AS SCATTERING CENTERS TO INCREASE THE EFFICIENCY OF THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Peale, Robert E.

    METAL BLACKS AS SCATTERING CENTERS TO INCREASE THE EFFICIENCY OF THIN FILM SOLAR CELLS by DEEP R surface of thin-film solar cells to improve efficiency. The principle is that scattering, which film solar cell. The particular types of particles investigated here are known as "metal-black", well

  1. High efficiency turbine blade coatings.

    SciTech Connect (OSTI)

    Youchison, Dennis L.; Gallis, Michail A.

    2014-06-01T23:59:59.000Z

    The development of advanced thermal barrier coatings (TBCs) of yttria stabilized zirconia (YSZ) that exhibit lower thermal conductivity through better control of electron beam - physical vapor deposition (EB-PVD) processing is of prime interest to both the aerospace and power industries. This report summarizes the work performed under a two-year Lab-Directed Research and Development (LDRD) project (38664) to produce lower thermal conductivity, graded-layer thermal barrier coatings for turbine blades in an effort to increase the efficiency of high temperature gas turbines. This project was sponsored by the Nuclear Fuel Cycle Investment Area. Therefore, particular importance was given to the processing of the large blades required for industrial gas turbines proposed for use in the Brayton cycle of nuclear plants powered by high temperature gas-cooled reactors (HTGRs). During this modest (~1 full-time equivalent (FTE)) project, the processing technology was developed to create graded TBCs by coupling ion beam-assisted deposition (IBAD) with substrate pivoting in the alumina-YSZ system. The Electron Beam - 1200 kW (EB-1200) PVD system was used to deposit a variety of TBC coatings with micron layered microstructures and reduced thermal conductivity below 1.5 W/m.K. The use of IBAD produced fully stoichiometric coatings at a reduced substrate temperature of 600 oC and a reduced oxygen background pressure of 0.1 Pa. IBAD was also used to successfully demonstrate the transitioning of amorphous PVD-deposited alumina to the -phase alumina required as an oxygen diffusion barrier and for good adhesion to the substrate Ni2Al3 bondcoat. This process replaces the time consuming thermally grown oxide formation required before the YSZ deposition. In addition to the process technology, Direct Simulation Monte Carlo plume modeling and spectroscopic characterization of the PVD plumes were performed. The project consisted of five tasks. These included the production of layered periodic microstructures in the coating, the Direct Simulation Monte Carlo (DSMC) modeling of particle transport in the PVD plume, functional graded layer development, the deposition of all layers to form a complete coating, and materials characterization including thermal testing. Ion beam-assisted deposition, beam sharing through advanced digital rastering, substrate pivoting, hearth calorimetry, infrared imaging, fiber optic-enabled optical emission spectroscopy and careful thermal management were used to achieve all the milestones outlined in the FY02 LDRD proposal.

  2. Highly Efficient Coherent Raman Generation 

    E-Print Network [OSTI]

    Hua, Xia

    2014-08-04T23:59:59.000Z

    explore detection and sensing applications, and achieve further improvement of efficiency by using field enhancement due to surface plasmon resonances in aggregates of gold nanoparticles. By scanning the time delay of the probe pulse, we demonstrate a new...

  3. Highly Efficient Solar Thermochemical Reaction Systems

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEND D e e p p a a rDepartment|Energy Part

  4. High Efficiency, High Performance Clothes Dryer

    SciTech Connect (OSTI)

    Peter Pescatore; Phil Carbone

    2005-03-31T23:59:59.000Z

    This program covered the development of two separate products; an electric heat pump clothes dryer and a modulating gas dryer. These development efforts were independent of one another and are presented in this report in two separate volumes. Volume 1 details the Heat Pump Dryer Development while Volume 2 details the Modulating Gas Dryer Development. In both product development efforts, the intent was to develop high efficiency, high performance designs that would be attractive to US consumers. Working with Whirlpool Corporation as our commercial partner, TIAX applied this approach of satisfying consumer needs throughout the Product Development Process for both dryer designs. Heat pump clothes dryers have been in existence for years, especially in Europe, but have not been able to penetrate the market. This has been especially true in the US market where no volume production heat pump dryers are available. The issue has typically been around two key areas: cost and performance. Cost is a given in that a heat pump clothes dryer has numerous additional components associated with it. While heat pump dryers have been able to achieve significant energy savings compared to standard electric resistance dryers (over 50% in some cases), designs to date have been hampered by excessively long dry times, a major market driver in the US. The development work done on the heat pump dryer over the course of this program led to a demonstration dryer that delivered the following performance characteristics: (1) 40-50% energy savings on large loads with 35 F lower fabric temperatures and similar dry times; (2) 10-30 F reduction in fabric temperature for delicate loads with up to 50% energy savings and 30-40% time savings; (3) Improved fabric temperature uniformity; and (4) Robust performance across a range of vent restrictions. For the gas dryer development, the concept developed was one of modulating the gas flow to the dryer throughout the dry cycle. Through heat modulation in a gas dryer, significant time and energy savings, combined with dramatically reduced fabric temperatures, was achieved in a cost-effective manner. The key design factor lay in developing a system that matches the heat input to the dryer with the fabrics ability to absorb it. The development work done on the modulating gas dryer over the course of this program led to a demonstration dryer that delivered the following performance characteristics: (1) Up to 25% reduction in energy consumption for small and medium loads; (2) Up to 35% time savings for large loads with 10-15% energy reduction and no adverse effect on cloth temperatures; (3) Reduced fabric temperatures, dry times and 18% energy reduction for delicate loads; and, (4) Robust performance across a range of vent restrictions.

  5. High Energy Efficiency Air Conditioning

    SciTech Connect (OSTI)

    Edward McCullough; Patrick Dhooge; Jonathan Nimitz

    2003-12-31T23:59:59.000Z

    This project determined the performance of a new high efficiency refrigerant, Ikon B, in a residential air conditioner designed to use R-22. The refrigerant R-22, used in residential and small commercial air conditioners, is being phased out of production in developed countries beginning this year because of concerns regarding its ozone depletion potential. Although a replacement refrigerant, R-410A, is available, it operates at much higher pressure than R-22 and requires new equipment. R-22 air conditioners will continue to be in use for many years to come. Air conditioning is a large part of expensive summer peak power use in many parts of the U.S. Previous testing and computer simulations of Ikon B indicated that it would have 20 - 25% higher coefficient of performance (COP, the amount of cooling obtained per energy used) than R-22 in an air-cooled air conditioner. In this project, a typical new R-22 residential air conditioner was obtained, installed in a large environmental chamber, instrumented, and run both with its original charge of R-22 and then with Ikon B. In the environmental chamber, controlled temperature and humidity could be maintained to obtain repeatable and comparable energy use results. Tests with Ikon B included runs with and without a power controller, and an extended run for several months with subsequent analyses to check compatibility of Ikon B with the air conditioner materials and lubricant. Baseline energy use of the air conditioner with its original R-22 charge was measured at 90 deg F and 100 deg F. After changeover to Ikon B and a larger expansion orifice, energy use was measured at 90 deg F and 100 deg F. Ikon B proved to have about 19% higher COP at 90 deg F and about 26% higher COP at 100 deg F versus R-22. Ikon B had about 20% lower cooling capacity at 90 deg F and about 17% lower cooling capacity at 100 deg F versus R-22 in this system. All results over multiple runs were within 1% relative standard deviation (RSD). All of these values agree well with previous results and computer simulations of Ikon B performance versus R-22. The lower cooling capacity of Ikon B is not a concern unless a particular air conditioner is near its maximum cooling capacity in application. Typically, oversized A/C systems are installed by contractors to cover contingencies. In the extended run with Ikon B, which lasted about 4.5 months at 100 deg F ambient temperature and 68% compressor on time, the air conditioner performed well with no significant loss of energy efficiency. Post-run analysis of the refrigerant, compressor lubricant oil, compressor, compressor outlet tubing, and the filter/dryer showed minor effects but nothing that was considered significant. The project was very successful. All objectives were achieved, and the performance of Ikon B indicates that it can easily be retrofitted into R-22 air conditioners to give 15 - 20% energy savings and a 1 - 3 year payback of retrofit costs depending on location and use. Ikon B has the potential to be a successful commercial product.

  6. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01T23:59:59.000Z

    materials (PCM) in solar thermal concentrating technologyeffective and efficient solar thermal electricity generatorbeen considered for solar thermal energy storages. These are

  7. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01T23:59:59.000Z

    parts of the solar spectrum, the power output of the LSC PVson our lab. The power output of the solar simulator is aboutinput solar radiation, the higher the power output. Solar

  8. High-efficiency solar cells fabricated from direct-current magnetron sputtered n-indium tin oxide onto p-InP grown by atmospheric pressure metalorganic vapor phase epitaxy

    SciTech Connect (OSTI)

    Li, X.; Wanlass, M.W.; Gessert, T.A.; Emery, K.A.; Coutts, T.J.

    1989-05-01T23:59:59.000Z

    Solar cells based on dc magnetron sputtered indium tin oxide onto epitaxially grown films of p-InP have been fabricated and analyzed. The best cells had a global efficiency of 18.4% and an air mass zero (AMO) efficiency of 16.0%. The principal fabrication variable considered was the constituency of the sputtering gas and both argon/hydrogen and argon/oxygen mixtures have been used. The former cells have the higher efficiencies, are apparently stable, and exhibit almost ideal junction characteristics. The latter cells are relatively unstable and exhibit much higher ideality factors and reverse saturation current densities. The temperature dependence of the reverse saturation current indicates totally different charge transfer mechanisms in the two cases.

  9. Modeling of High Efficiency Clean Combustion Engines

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Lawrence Livermore National Laboratory Modeling of high efficiency clean combustion engines Daniel Flowers Salvador Aceves Tom Piggott Daniel Flowers, Salvador Aceves, Tom Piggott,...

  10. Nanostructured Thermoelectric Materials and High Efficiency Power...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nanostructured Thermoelectric Materials and High Efficiency Power Generation Modules Home Author: T. Hogan, A. Downey, J. Short, S. D. Mahanti, H. Schock, E. Case Year: 2007...

  11. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure of All-Polymer Solar Cells Impedes Efficiency Print Organic

  12. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure of All-Polymer Solar Cells Impedes Efficiency Print

  13. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure of All-Polymer Solar Cells Impedes Efficiency PrintStructure

  14. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure of All-Polymer Solar Cells Impedes Efficiency

  15. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure of All-Polymer Solar Cells Impedes EfficiencyStructure of

  16. High Efficiency Broadband Envelope-Tracking Power Amplifiers

    E-Print Network [OSTI]

    Yan, Jonmei Johana

    17] Bumman, K. , et.al; "Efficiently Amplified," MicrowaveM. ,   “   Wideband High Efficiency Envelope Tracking PowerPeter  M. ,  “High-Efficiency Envelope Tracking High Power

  17. Advanced CFD Models for High Efficiency Compression Ignition...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    CFD Models for High Efficiency Compression Ignition Engines Advanced CFD Models for High Efficiency Compression Ignition Engines Advanced CFD models for high efficiency...

  18. High Efficiency Broadband Envelope-Tracking Power Amplifiers

    E-Print Network [OSTI]

    Yan, Jonmei Johana

    M. ,   “   Wideband High Efficiency Envelope Tracking PowerPeter  M. ,  “High-Efficiency Envelope Tracking High PowerMemory! DPD! Drain! Efficiency! (%)! Gain! (dB)! Output!

  19. Maximizing Efficiency of Solar-Powered Systems by Load Matching

    E-Print Network [OSTI]

    Shinozuka, Masanobu

    energy. However, solar powered sys- tems must also consider the output level of the solar panel for power be counterproductive. Another problem that is of particular importance to solar pan- els is load matching. Solar panels is around 0.7­1.2, solar panels have a much larger Ri value as a function of the solar output and current

  20. High Rate Laser Pitting Technique for Solar Cell Texturing

    SciTech Connect (OSTI)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10T23:59:59.000Z

    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.

  1. Improved Energy Conversion Efficiency in Wide Bandgap Cu(In,Ga)Se2 Solar Cells

    SciTech Connect (OSTI)

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

    2011-01-01T23:59:59.000Z

    This report outlines improvements to the energy conversion efficiency in wide bandgap (E{sub g} > ;1.2 eV) solar cells based on CuIn{sub 1-x}Ga{sub x}Se{sub 2}. 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 1.2 < E{sub g} < 1.45 eV. Initial results of this work have led to efficiencies >18% for absorber bandgaps {approx}1.30 eV and efficiencies {approx}16% for bandgaps up to {approx}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.

  2. Evaluating High Efficiency Motor Retrofit 

    E-Print Network [OSTI]

    Evans, T. A.

    1984-01-01T23:59:59.000Z

    OPERATING COST Although It would seem that most peoPlel un derstand the re I atlonsh I p beneen the fIrst cost and operating cost for motors, that's not the case. The purchase price of a standard efficIency 50 HP enclosed motor I s about $2000. Operatl...Ife, the energy efficIent motor will save about $7100 - assum f ng power costs grow as forecasted. That's why the co nom J cs of Energy $aver motors are so attractIve. The savIngs, assuming continuous operatIon at a 5i/kWh power cost, range from $300 per year...

  3. Material and Device Analysis for Efficiency Improvement in Epitaxial Crystalline Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-11-433

    SciTech Connect (OSTI)

    Sopori, B.

    2014-01-01T23:59:59.000Z

    Crystal Solar has a novel approach for producing low-cost, monocrystalline silicon wafers that are capable of yielding high-efficiency solar cells. The approach involves epitaxial growth of the substrate and a proprietary lift-off technology. Crystal Solar will send selected wafers and cells to NREL for characterization and analyses. NREL will apply a variety of techniques to help identify mechanism(s) that limit the cell efficiency and suggest suitable approaches for mitigation.

  4. 36Super-fast solar flares ! NASA's Ramaty High Energy Solar

    E-Print Network [OSTI]

    36Super-fast solar flares ! NASA's Ramaty High Energy Solar Spectroscopic Imager (RHESSI) satellite has been studying solar flares since 2002. The sequence of figures to the left shows a flaring region hr/3600 sec = 0.98 kilometers/sec. The solar flare blob was traveling at 207 kilometers per second

  5. New Funding Boosts Carbon Capture, Solar Energy and High Gas...

    Office of Environmental Management (EM)

    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 -...

  6. High-Temperature Solar Selective Coating Development for Power...

    Broader source: Energy.gov (indexed) [DOE]

    High-Temperature Solar Selective Coating Development for Power Tower Receivers - FY13 Q1 High-Temperature Solar Selective Coating Development for Power Tower Receivers - FY13 Q1...

  7. High-Temperature Solar Selective Coating Development for Power...

    Broader source: Energy.gov (indexed) [DOE]

    High-Temperature Solar Selective Coating Development for Power Tower Receivers - FY13 Q2 High-Temperature Solar Selective Coating Development for Power Tower Receivers - FY13 Q2...

  8. "Tuning" microalgae for high photosynthesis efficiency

    E-Print Network [OSTI]

    biomass. Optimizing the size of the light harvesting antennae for microalgae reduces light energy waste- 1 - "Tuning" microalgae for high photosynthesis efficiency March 25, 2013 Los Alamos scientist more efficient microalgae. Microalgae have large rates of biomass accumulation due to their high

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

    SciTech Connect (OSTI)

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

    2008-09-02T23:59:59.000Z

    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.

  10. Effects of Spectral Error in Efficiency Measurements of GaInAs-Based Concentrator Solar Cells

    SciTech Connect (OSTI)

    Osterwald, C. R.; Wanlass, M. W.; Moriarty, T.; Steiner, M. A.; Emery, K. A.

    2014-03-01T23:59:59.000Z

    This technical report documents a particular error in efficiency measurements of triple-absorber concentrator solar cells caused by incorrect spectral irradiance -- specifically, one that occurs when the irradiance from unfiltered, pulsed xenon solar simulators into the GaInAs bottom subcell is too high. For cells designed so that the light-generated photocurrents in the three subcells are nearly equal, this condition can cause a large increase in the measured fill factor, which, in turn, causes a significant artificial increase in the efficiency. The error is readily apparent when the data under concentration are compared to measurements with correctly balanced photocurrents, and manifests itself as discontinuities in plots of fill factor and efficiency versus concentration ratio. In this work, we simulate the magnitudes and effects of this error with a device-level model of two concentrator cell designs, and demonstrate how a new Spectrolab, Inc., Model 460 Tunable-High Intensity Pulsed Solar Simulator (T-HIPSS) can mitigate the error.

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

    SciTech Connect (OSTI)

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

    2008-08-01T23:59:59.000Z

    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.

  12. Thermal Strategies for High Efficiency Thermoelectric Power Generation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Strategies for High Efficiency Thermoelectric Power Generation Thermal Strategies for High Efficiency Thermoelectric Power Generation Developing integrated TE system configurations...

  13. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    2004) “Advances in solar thermal electricity technology”.1: Comparison of the pros and cons for various solar thermalof Three Concentrating Solar Thermal Units Designed with

  14. Proposal of high efficiency solar cells with closely stacked InAs/In{sub 0.48}Ga{sub 0.52}P quantum dot superlattices: Analysis of polarized absorption characteristics via intermediate–band

    SciTech Connect (OSTI)

    Yoshikawa, H., E-mail: yoshikawa-hirofumi@sharp.co.jp; Kotani, T.; Kuzumoto, Y.; Izumi, M.; Tomomura, Y.; Hamaguchi, C. [Advanced Technology Research Laboratories, Sharp Corporation Tenri, Nara 632-8567 (Japan)

    2014-07-07T23:59:59.000Z

    We present a theoretical study of the electronic structures and polarized absorption properties of quantum dot superlattices (QDSLs) using wide–gap matrix material, InAs/In{sub 0.48}Ga{sub 0.52}P QDSLs, for realizing intermediate–band solar cells (IBSCs) with two–step photon–absorption. The plane–wave expanded Burt–Foreman operator ordered 8–band k·p theory is used for this calculation, where strain effect and piezoelectric effect are taken into account. We find that the absorption spectra of the second transitions of two–step photon–absorption can be shifted to higher energy region by using In{sub 0.48}Ga{sub 0.52}P, which is lattice–matched material to GaAs substrate, as a matrix material instead of GaAs. We also find that the transverse magnetic polarized absorption spectra in InAs/In{sub 0.48}Ga{sub 0.52}P QDSL with a separate IB from the rest of the conduction minibands can be shifted to higher energy region by decreasing the QD height. As a result, the second transitions of two–step photon–absorption by the sunlight occur efficiently. These results indicate that InAs/In{sub 0.48}Ga{sub 0.52}P QDSLs are suitable material combination of IBSCs toward the realization of ultrahigh efficiency solar cells.

  15. Technology Development for Light Duty High Efficient Diesel Engines...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Light Duty High Efficient Diesel Engines Technology Development for Light Duty High Efficient Diesel Engines Improve the efficiency of diesel engines for light duty applications...

  16. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01T23:59:59.000Z

    to increase the power density of solar radiation, the costat a power density of 1000W/m 2 [GKK00]. Solar technologies

  17. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01T23:59:59.000Z

    LSCs in concentration solar radiation without tracking. TheLSCs in concentration solar radiation without tracking. Thesolar concentrators based on lens and mirrors with tracking

  18. HIGH-POWER, HIGH-EFFICIENCY FELS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01T23:59:59.000Z

    M. Kumada, "Scaling of the FEL-ID Equations", ELF Note 128,Instability in a High-power, Short- Wavelength FEL", Proc.of the Ninth FEL" Conference, Williamsburg (1988), and

  19. Efficient high density train operations

    DOE Patents [OSTI]

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

    2001-01-01T23:59:59.000Z

    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.

  20. Optimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell

    E-Print Network [OSTI]

    to bring down the cost of photovoltaic (PV) solar cells has gained huge momentum, and many strategiesOptimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell-wave approach was used to compute the plane-wave absorptance of a thin-film tandem solar cell with a metallic

  1. Nanodome Solar Cells with Efficient Light Management and Self-Cleaning

    E-Print Network [OSTI]

    Cui, Yi

    Nanodome Solar Cells with Efficient Light Management and Self-Cleaning Jia Zhu, Ching-Mei Hsu 94305 ABSTRACT Here for the first time, we demonstrate novel nanodome solar cells, which have periodic and enhance absorption over a broad spectral range. Nanodome solar cells with only a 280 nm thick hydrogenated

  2. FRONTIERS ARTICLE Efficiency enhancement of copper contaminated radial pn junction solar cells

    E-Print Network [OSTI]

    Yang, Peidong

    energy represents one of the most important sustainable and renewable energy sources. The most common power from solar cells [1]. The reason is that crystalline silicon solar cell manufacturingFRONTIERS ARTICLE Efficiency enhancement of copper contaminated radial p­n junction solar cells

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

    E-Print Network [OSTI]

    California at Berkeley, University of

    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

  4. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    conversion efficiency of photovoltaic and photoelectrolysisLimiting efficiencies for photovoltaic energy conversion inlimiting efficiencies for photovoltaic energy conversion.

  5. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01T23:59:59.000Z

    to standardize the performance of photovoltaic devices,Performance of organic luminescent solar concentrator photovoltaic

  6. Efficient, air-stable colloidal quantum dot solar cells encapsulated using atomic layer deposition of a nanolaminate barrier

    SciTech Connect (OSTI)

    Ip, Alexander H.; Labelle, André J.; Sargent, Edward H., E-mail: ted.sargent@utoronto.ca [Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario M5S 3G4 (Canada)

    2013-12-23T23:59:59.000Z

    Atomic layer deposition was used to encapsulate colloidal quantum dot solar cells. A nanolaminate layer consisting of alternating alumina and zirconia films provided a robust gas permeation barrier which prevented device performance degradation over a period of multiple weeks. Unencapsulated cells stored in ambient and nitrogen environments demonstrated significant performance losses over the same period. The encapsulated cell also exhibited stable performance under constant simulated solar illumination without filtration of harsh ultraviolet photons. This monolithically integrated thin film encapsulation method is promising for roll-to-roll processed high efficiency nanocrystal solar cells.

  7. IMPROVING THE EFFICIENCY OF THERMOELECTRIC GENERATORS BY USING SOLAR HEAT CONCENTRATORS

    E-Print Network [OSTI]

    IMPROVING THE EFFICIENCY OF THERMOELECTRIC GENERATORS BY USING SOLAR HEAT CONCENTRATORS M. T. de of thermoelectric genera- tors (TEGs) by using a lens to concentrate heat on the heat source of a TEG. Initial : Thermoelectric generator, Solar heat concentrator, Carnot efficiency I - Introduction The global energy crisis

  8. The action mechanism of TiO{sub 2}:NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} cathode buffer layer in highly efficient inverted organic solar cells

    SciTech Connect (OSTI)

    Liu, Chunyu; Chen, Huan; Zhao, Dan; Shen, Liang; He, Yeyuan; Guo, Wenbin, E-mail: guowb@jlu.edu.cn, E-mail: chenwy@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Chen, Weiyou, E-mail: guowb@jlu.edu.cn, E-mail: chenwy@jlu.edu.cn [College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2014-08-04T23:59:59.000Z

    We report the fabrication and characteristics of organic solar cells with 6.86% power conversion efficiency (PCE) by doping NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} into TiO{sub 2} cathode buffer layer. The dependence of devices performance on doping concentration of NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} is investigated. Results indicate that short-circuit current density (J{sub sc}) has an apparent improvement, leading to an enhancement of 22.7% in PCE for the optimized doping concentration of 0.05?mmol ml{sup ?1} compared to the control devices. NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} nanoparticles (NPs) can play threefold roles, one is that the incident light in visible region can be scattered by NaYF{sub 4} NPs, the second is that solar irradiation in infrared region can be better utilized by Up-conversion effect of Yb{sup 3+} and Tm{sup 3+} ions, the third is that electron transport property in TiO{sub 2} thin film can be greatly improved.

  9. Multicolor, High Efficiency, Nanotextured LEDs

    SciTech Connect (OSTI)

    Jung Han; Arto Nurmikko

    2011-09-30T23:59:59.000Z

    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.

  10. 14%-efficient flexible CdTe solar cells on ultra-thin glass substrates

    SciTech Connect (OSTI)

    Rance, W. L.; Burst, J. M.; Reese, M. O.; Gessert, T. A.; Metzger, W. K.; Barnes, T. M. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Meysing, D. M.; Wolden, C. A. [Colorado School of Mines, Golden, Colorado 80401 (United States); Garner, S.; Cimo, P. [Corning Incorporated, Corning, New York 14831 (United States)

    2014-04-07T23:59:59.000Z

    Flexible glass enables high-temperature, roll-to-roll processing of superstrate devices with higher photocurrents than flexible polymer foils because of its higher optical transmission. Using flexible glass in our high-temperature CdTe process, we achieved a certified record conversion efficiency of 14.05% for a flexible CdTe solar cell. Little has been reported on the flexibility of CdTe devices, so we investigated the effects of three different static bending conditions on device performance. We observed a consistent trend of increased short-circuit current and fill factor, whereas the open-circuit voltage consistently dropped. The quantum efficiency under the same static bend condition showed no change in the response. After storage in a flexed state for 24 h, there was very little change in device efficiency relative to its unflexed state. This indicates that flexible glass is a suitable replacement for rigid glass substrates, and that CdTe solar cells can tolerate bending without a decrease in device performance.

  11. California: TetraCell Silicon Solar Cell Improves Efficiency...

    Energy Savers [EERE]

    at the SunShot Grand Challenge Summit in Denver, Colorado. | Photo by John De La Rosa. Solar Companies Go for the Gold with SunShot Incubator The Story of a Cutting-Edge Solar...

  12. Efficiency enhancement of InGaN/GaN solar cells with nanostructures

    SciTech Connect (OSTI)

    Bai, J.; Yang, C. C.; Athanasiou, M.; Wang, T. [Department of Electronics and Electrical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2014-02-03T23:59:59.000Z

    We demonstrate InGaN/GaN multi-quantum-well solar cells with nanostructures operating at a wavelength of 520?nm. Nanostructures with a periodic nanorod or nanohole array are fabricated by means of modified nanosphere lithography. Under 1 sun air-mass 1.5 global spectrum illumination, a fill factor of 50 and an open circuit voltage of 1.9?V are achieved in spite of very high indium content in InGaN alloys usually causing degradation of crystal quality. Both the nanorod array and the nanohole array significantly improve the performance of solar cells, while a larger enhancement is observed for the nanohole array, where the conversion efficiency is enhanced by 51%.

  13. Efficient small-scale dynamo in solar convection zone

    E-Print Network [OSTI]

    Hotta, H; Yokoyama, T

    2015-01-01T23:59:59.000Z

    We investigate small-scale dynamo action in the solar convection zone through a series of high resolution MHD simulations in a local Cartesian domain with 1$R_\\odot$ (solar radius) of horizontal extent and a radial extent from 0.715 to 0.96$R_\\odot$. The dependence of the solution on resolution and diffusivity is studied. For a grid spacing of less than 350 km, the root mean square magnetic field strength near the base of the convection zone reaches 95% of the equipartition field strength (i.e. magnetic and kinetic energy are comparable). For these solutions the Lorentz force feedback on the convection velocity is found to be significant. The velocity near the base of the convection zone is reduced to 50% of the hydrodynamic one. In spite of a significant decrease of the convection velocity, the reduction in the enthalpy flux is relatively small, since the magnetic field also suppresses the horizontal mixing of the entropy between up- and downflow regions. This effect increases the amplitude of the entropy pe...

  14. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    of Solar Energy Conversion (Oxford University Press, Newsolar energy back into the forefront of technological research in universities

  15. Impact of High Solar Penetration in the Western Interconnection

    SciTech Connect (OSTI)

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

    2010-12-01T23:59:59.000Z

    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.

  16. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    Cooling: First Ever Non-tracking solar collectors powering aCooling: First Ever Non-tracking solar collectors powering athe first ever non-tracking solar powered double effect

  17. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    Ari Rabl, “Active Solar Collectors and Their Applications,”A. and Winston, R. (1980) “Solar collectors for low anda standard flat plate solar collector, and to the right is a

  18. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    natural gas and using solar thermal energy. There is a solarnatural gas or on solar thermal energy before it will switcha solar thermal system, strictly in terms of energy only.

  19. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    to buffer the incoming solar power to the glycol loop so asarea the available power to the solar thermal collector was

  20. High-Temperatuer Solar Selective Coating Development for Power...

    Broader source: Energy.gov (indexed) [DOE]

    must maintain high absorptance in the solar spectrum but lower emittance in the infrared spectrum. It must also be stable in air, easily applied at large scales, cost...

  1. Impact of High Solar Penetration in the Western Interconnection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    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...

  2. High-Performance Home Technologies: Solar Thermal & Photovoltaic...

    Broader source: Energy.gov (indexed) [DOE]

    in each of the volumes. High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems More Documents & Publications Building America Whole-House Solutions for...

  3. Measure Guideline: High Efficiency Natural Gas Furnaces

    SciTech Connect (OSTI)

    Brand, L.; Rose, W.

    2012-10-01T23:59:59.000Z

    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.

  4. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01T23:59:59.000Z

    trend towards high-efficiency photovoltaics involves multi-efficiency tables (version 35), "Progress in Photovoltaics:efficiency solar cell modules," Progress in Photovoltaics:

  5. High efficiency switching-mode amplifiers for wireless communication systems

    E-Print Network [OSTI]

    Hung, Tsai-Pi

    2008-01-01T23:59:59.000Z

    M. Asbeck, “Design of high-efficiency current-mode class-Dand G. Rabjohn, “A high efficiency Chireix Out- phasingE-A new class of high efficiency tuned single-ended power

  6. Efficient methylammonium lead iodide perovskite solar cells with active layers from 300 to 900 nm

    SciTech Connect (OSTI)

    Momblona, C.; Malinkiewicz, O.; Soriano, A.; Gil-Escrig, L.; Bandiello, E.; Scheepers, M.; Bolink, H. J., E-mail: henk.bolink@uv.es [Instituto de Ciencia Molecular, Universidad de Valencia, C/Catedrático J. Beltrán 2, 46980 Paterna, Valencia (Spain); Roldán-Carmona, C. [Instituto de Ciencia Molecular, Universidad de Valencia, C/Catedrático J. Beltrán 2, 46980 Paterna, Valencia (Spain); Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Rabanales, Ed. C3, 14014, Córdoba (Spain); Edri, E. [Department of Materials and Interfaces, Weizmann Institute of Science, Herzl St. 34, Rehovot 76100 (Israel)

    2014-08-01T23:59:59.000Z

    Efficient methylammonium lead iodide perovskite-based solar cells have been prepared in which the perovskite layer is sandwiched in between two organic charge transporting layers that block holes and electrons, respectively. This configuration leads to stable and reproducible devices that do not suffer from strong hysteresis effects and when optimized lead to efficiencies close to 15%. The perovskite layer is formed by using a dual-source thermal evaporation method, whereas the organic layers are processed from solution. The dual-source thermal evaporation method leads to smooth films and allows for high precision thickness variations. Devices were prepared with perovskite layer thicknesses ranging from 160 to 900 nm. The short-circuit current observed for these devices increased with increasing perovskite layer thickness. The main parameter that decreases with increasing perovskite layer thickness is the fill factor and as a result optimum device performance is obtained for perovskite layer thickness around 300 nm. However, here we demonstrate that with a slightly oxidized electron blocking layer the fill factor for the solar cells with a perovskite layer thickness of 900 nm increases to the same values as for the devices with thin perovskite layers. As a result the power conversion efficiencies for the cells with 300 and 900 nm are very similar, 12.7% and 12%, respectively.

  7. Towards the efficiency limits of silicon solar cells: how thin is too thin?

    E-Print Network [OSTI]

    Kowalczewski, Piotr

    2015-01-01T23:59:59.000Z

    It is currently possible to fabricate crystalline silicon solar cells with the absorber thickness ranging from a few hundreds of micrometers (conventional wafer-based cells) to devices as thin as $1\\,\\mu\\mathrm{m}$. In this work, we use a model single-junction solar cell to calculate the limits of energy conversion efficiency and estimate the optimal absorber thickness. The limiting efficiency for cells in the thickness range between 40 and $500\\,\\mu\\mathrm{m}$ is very similar and close to 29%. In this regard, we argue that decreasing the thickness below around $40\\,\\mu\\mathrm{m}$ is counter-productive, as it significantly reduces the maximum achievable efficiency, even when optimal light trapping is implemented. We analyse the roles of incomplete light trapping and extrinsic (bulk and surface) recombination mechanisms. For a reasonably high material quality, consistent with present-day fabrication techniques, the optimal thickness is always higher than a few tens of micrometers. We identify incomplete light ...

  8. 19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 QUANTUM EFFICIENCY OF CdTe SOLAR CELLS IN FORWARD BIAS

    E-Print Network [OSTI]

    Sites, James R.

    19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 QUANTUM EFFICIENCY OF CdTe SOLAR CELLS IN FORWARD BIAS M. Gloeckler and J. R. Sites Department of Physics, Colorado State@lamar.colostate.edu ABSTRACT: When the quantum efficiency of a CdS/CdTe solar cell is measured under forward voltage

  9. Enhanced efficiency of graphene-silicon Schottky junction solar cells by doping with Au nanoparticles

    SciTech Connect (OSTI)

    Liu, X.; Zhang, X. W., E-mail: xwzhang@semi.ac.cn; Yin, Z. G.; Meng, J. H.; Gao, H. L.; Zhang, L. Q.; Zhao, Y. J.; Wang, H. L. [Key Lab of Semiconductor Materials Science, Institute of Semiconductors, CAS, Beijing 100083 (China)

    2014-11-03T23:59:59.000Z

    We have reported a method to enhance the performance of graphene-Si (Gr/Si) Schottky junction solar cells by introducing Au nanoparticles (NPs) onto the monolayer graphene and few-layer graphene. The electron transfer between Au NPs and graphene leads to the increased work function and enhanced electrical conductivity of graphene, resulting in a remarkable improvement of device efficiency. By optimizing the initial thickness of Au layers, the power conversion efficiency of Gr/Si solar cells can be increased by more than three times, with a maximum value of 7.34%. These results show a route for fabricating efficient and stable Gr/Si solar cells.

  10. Glass-like thermal conductivity in high efficiency thermoelectric...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Glass-like thermal conductivity in high efficiency thermoelectric materials Glass-like thermal conductivity in high efficiency thermoelectric materials Discusses strategies to...

  11. Energy-Efficient Melting and Direct Delivery of High Quality...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy-Efficient Melting and Direct Delivery of High Quality Molten Aluminum Energy-Efficient Melting and Direct Delivery of High Quality Molten Aluminum itmdelivery.pdf More...

  12. Highly Energy Efficient Directed Green Liquor Utilization (D...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Highly Energy Efficient Directed Green Liquor Utilization (D-GLU) Pulping Highly Energy Efficient Directed Green Liquor Utilization (D-GLU) Pulping This factsheet describes a...

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

    Office of Environmental Management (EM)

    High-Efficiency Combustion Engines Vehicle Technologies Office: Materials for High-Efficiency Combustion Engines The Vehicle Technologies Office (VTO) is supporting work to improve...

  14. Low Temperature Combustion Demonstrator for High Efficiency Clean...

    Energy Savers [EERE]

    Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Presentation from the U.S....

  15. High-Efficiency Clean Combustion Engine Designs for Compression...

    Energy Savers [EERE]

    High-Efficiency Clean Combustion Engine Designs for Compression Ignition Engines High-Efficiency Clean Combustion Engine Designs for Compression Ignition Engines Presentation from...

  16. Heavy-Duty Engine Combustion Optimization for High Thermal Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Combustion Optimization for High Thermal Efficiency Targeting EPA 2010 Emissions Heavy-Duty Engine Combustion Optimization for High Thermal Efficiency Targeting EPA 2010 Emissions...

  17. Low Temperature Combustion Demonstrator for High Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Applied low temperature combustion to the Navistar...

  18. Low-Temperature Combustion Demonstrator for High-Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low-Temperature Combustion Demonstrator for High-Efficiency Clean Combustion Low-Temperature Combustion Demonstrator for High-Efficiency Clean Combustion 2010 DOE Vehicle...

  19. High-Efficiency Clean Combustion Design for Compression Ignition...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Efficiency Clean Combustion Design for Compression Ignition Engines High-Efficiency Clean Combustion Design for Compression Ignition Engines Presentation given at DEER 2006,...

  20. Low Temperature Combustion Demonstrator for High Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion 2009 DOE Hydrogen Program...

  1. Advanced Combustion Technology to Enable High Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Technology to Enable High Efficiency Clean Combustion Advanced Combustion Technology to Enable High Efficiency Clean Combustion Summary of advanced combustion research at Cummins...

  2. High Efficiency GDI Engine Research, with Emphasis on Ignition...

    Broader source: Energy.gov (indexed) [DOE]

    High Efficiency GDI Engine Research, with Emphasis on Ignition Systems High Efficiency GDI Engine Research, with Emphasis on Ignition Systems 2013 DOE Hydrogen and Fuel Cells...

  3. High Efficiency Engine Systems Development and Evaluation | Department...

    Broader source: Energy.gov (indexed) [DOE]

    High Efficiency Engine Systems Development and Evaluation High Efficiency Engine Systems Development and Evaluation 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle...

  4. Tailored Materials for High Efficiency CIDI Engines (Caterpillar...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency CIDI Engines (Caterpillar CRADA) Tailored Materials for High Efficiency CIDI Engines (Caterpillar CRADA) 2009 DOE Hydrogen Program and Vehicle Technologies Program...

  5. Novel Materials for High Efficiency Direct Methanol Fuel Cells...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Materials for High Efficiency Direct Methanol Fuel Cells Novel Materials for High Efficiency Direct Methanol Fuel Cells Presented at the Department of Energy Fuel Cell Projects...

  6. Energy Efficiency Opportunities in Federal High Performance Computing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

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

  7. High-Efficiency Window Air Conditioners - Building America Top...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Efficiency Window Air Conditioners - Building America Top Innovation High-Efficiency Window Air Conditioners - Building America Top Innovation This photo shows a window air...

  8. Unregulated Emissions from High-Efficiency Clean Combustion Modes...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Poster presentation at...

  9. Syngas Enhanced High Efficiency Low Temperature Combustion for...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines Syngas Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines A significant...

  10. High Efficiency Microturbine with Integral Heat Recovery - Presentatio...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency Microturbine with Integral Heat Recovery - Presentation by Capstone Turbine Corporation, June 2011 High Efficiency Microturbine with Integral Heat Recovery -...

  11. Electrical and Thermal Transport Optimization of High Efficient...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Electrical and Thermal Transport Optimization of High Efficient n-type Skutterudites Electrical and Thermal Transport Optimization of High Efficient n-type Skutterudites Work on...

  12. Technology and System Level Demonstration of Highly Efficient...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered Class 8 Trucks Technology and System Level Demonstration of Highly Efficient and Clean,...

  13. Development of a High-Efficiency Zonal Thermoelectric HVAC System...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    a High-Efficiency Zonal Thermoelectric HVAC System for Automotive Applications Development of a High-Efficiency Zonal Thermoelectric HVAC System for Automotive Applications...

  14. Progress toward Development of a High-Efficiency Zonal Thermoelectric...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    toward Development of a High-Efficiency Zonal Thermoelectric HVAC System for Automotive Applications Progress toward Development of a High-Efficiency Zonal Thermoelectric HVAC...

  15. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    Australia, the political and economic crises of the early 21 st century have once again brought the concept of solar energy

  16. Geothermal, Energy Efficiency, and Solar PV Opportunities at Nissan USE 

    E-Print Network [OSTI]

    Ford, R.; Ong, J.; Reeder, J.; Sridar, V.; Zhang, R.

    2014-01-01T23:59:59.000Z

    Orleans, LA. May 20-23, 2014 Carbon Goal is Driving Innovation ESL-IE-14-05-04 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20-23, 2014 Research Areas Geothermal Solar Photovoltaics EE Verification ESL...-IE-14-05-04 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20-23, 2014 Solar PV Research Question Given forecasted solar prices, will an on-site solar project meet Nissan’s investment criteria? ESL-IE-14...

  17. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

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

  18. Sandia National Laboratories: drive affordable efficient so-lar...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DOE SunShot Program On November 27, 2013, in Energy, News, News & Events, Partnership, Photovoltaic, Renewable Energy, Solar, Systems Analysis, Systems Engineering On October...

  19. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01T23:59:59.000Z

    and V.U. Ho?mann. Photovoltaic Solar Energy Gen- eration.Concentrations for Photovoltaic Technologies A dissertationThirteenth IEEE Photovoltaic Specialists Conference- 1978—

  20. 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]

    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

    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.

  1. Design and global optimization of high-efficiency thermophotovoltaic

    E-Print Network [OSTI]

    increase in their efficiency and power output; solar thermal TPV systems see an even greater 45-fold. References and links 1. H. H. Kolm, "Solar-battery power source," Tech. Rep., MIT Lincoln Laboratory (1956 experimental thermopho- tovoltaic (TPV) systems at 1000 K generally exhibit extremely low power conversion

  2. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    CIGS, so the addition of the dc layer would not alter the material choice for a solar cell.solar cell, the use of GaAs has recently become feasible due to scalable manufacturing techniques, and compound materials such as CIGS (

  3. High-Temperature Solar Thermoelectric Generators (STEG)

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  4. President Obama Announces Commitments and Executive Actions to Advance Solar Deployment and Energy Efficiency

    Broader source: Energy.gov [DOE]

    On May 9, 2014, President Obama announced more than 300 private and public sector commitments to create jobs and cut carbon pollution by advancing solar deployment and energy efficiency.

  5. Improving the efficiency of water splitting in dye-sensitized solar cells by using a biomimetic

    E-Print Network [OSTI]

    Improving the efficiency of water splitting in dye-sensitized solar cells by using a biomimetic studied this problem in dye-sensitized solar cells where a molecular dye and a porous TiO2 electrode act been demonstrated using dye-sensitized electrodes. The quantum yield for water splitting in these dye

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

    E-Print Network [OSTI]

    Pilon, Laurent

    to thermochemical or electrolytic hydrogen production technologies [1­3]. However, solar to hydrogen energyAuthor'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

  7. 15.7% Efficient 10-?m-Thick Crystalline Silicon Solar Cells Using Periodic Nanostructures

    E-Print Network [OSTI]

    Branham, Matthew Sanders

    Only ten micrometer thick crystalline silicon solar cells deliver a short-circuit current of 34.5 mA cm[superscript ?2] and power conversion efficiency of 15.7%. The record performance for a crystalline silicon solar cell ...

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

    SciTech Connect (OSTI)

    Not Available

    2011-08-01T23:59:59.000Z

    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.

  9. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    collector, and to the right is a standard evacuated solar tube system.. 12 Figure 3: Left is a linear Fresnel

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

    E-Print Network [OSTI]

    Viswanathan, R.

    2011-01-01T23:59:59.000Z

    of Various Coatings, Substrate Materials and Solar Collectorl'Optimiz ctive Coatings for Solar Collectors", N77-11529,on High Efficiency Solar Collector Coatings", N77 -30286,

  11. Electron Transfer Dynamics in Efficient Molecular Solar Cells

    SciTech Connect (OSTI)

    Meyer, Gerald John

    2014-10-01T23:59:59.000Z

    This research provided new mechanistic insights into surface mediated photochemical processes relevant to solar energy conversion. In this past three years our research has focused on oxidation photo-redox chemistry and on the role surface electric fields play on basic spectroscopic properties of molecular-semiconductor interfaces. Although this research as purely fundamental science, the results and their interpretation have relevance to applications in dye sensitized and photogalvanic solar cells as well as in the storage of solar energy in the form of chemical bonds.

  12. Design guidelines for efficient plasmonic solar cells exploiting the trade-off between scattering and metallic absorption

    E-Print Network [OSTI]

    Li, Xiaofeng; Giannini, Vincenzo; Ekins-Daukes, Ned J; Maier, Stefan A

    2014-01-01T23:59:59.000Z

    We report on the role of plasmonic resonances in determining the delicate balance between scattering and absorption of light in nanometric particle arrays applied to the front surface of solar cells. Strong parasitic absorption is shown to be dependent upon the excitation of localized surface plasmon resonances and prohibits efficient scattering into the underlying semiconductor. Via detailed analytical and numerical investigations we obtain the dependence of scattering and absorption in nanoparticles upon their complex refractive index. These results provide an insight into the optimum material properties required to minimize parasitic optical absorption, while maintaining high scattering cross-section efficiency, thus providing a general design guideline for efficient light trapping with scattering nanoparticles. The work is extended to include comprehensive optoelectronic simulations of plasmonic solar cells in which the scattering metals are made from either Au, Ag or Al. We show that Al particles provide...

  13. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01T23:59:59.000Z

    and V.U. Ho?mann. Photovoltaic Solar Energy Gen- eration.stacked LSC plates for photovoltaics with the green LSC onsolar concentra- tors for photovoltaics. Science, 321(5886):

  14. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    IR Infra-Red I sc Short-circuit current I-V Current vs.contributes to the short-circuit current of the solar cell.term. Since the short-circuit current is directly

  15. Efficient light trapping structure in thin film silicon solar cells

    E-Print Network [OSTI]

    Sheng, Xing

    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, ...

  16. New Metallization Technique Suitable for 6-MW Pilot Production of Efficient Multicrystalline Solar Cells Using Upgraded Metallurgical Silicon: Final Technical Progress Report, December 17, 2007-- June 16, 2009

    Broader source: Energy.gov [DOE]

    This report describes CaliSolar's work as a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's Solar Energy Technologies Program. The term of this subcontract with the National Renewable Energy Laboratory was two years. During this time, CaliSolar evolved from a handful of employees to over 100 scientists, engineers, technicians, and operators. On the technical side, the company transitioned from a proof-of-concept through pilot-scale to large-scale industrial production. A fully automated 60-megawatt manufacturing line was commissioned in Sunnyvale, California. The facility converts upgraded metallurgical-grade silicon feedstock to ingots, wafers, and high-efficiency multicrystalline solar cells.

  17. Optimization of a high efficiency FEL amplifier

    E-Print Network [OSTI]

    Schneidmiller, E A

    2014-01-01T23:59:59.000Z

    The problem of an efficiency increase of an FEL amplifier is now of great practical importance. Technique of undulator tapering in the post-saturation regime is used at the existing x-ray FELs LCLS and SACLA, and is planned for use at the European XFEL, Swiss FEL, and PAL XFEL. There are also discussions on the future of high peak and average power FELs for scientific and industrial applications. In this paper we perform detailed analysis of the tapering strategies for high power seeded FEL amplifiers. Application of similarity techniques allows us to derive universal law of the undulator tapering.

  18. Improving the Power Conversion Efficiency of Ultrathin Organic Solar Cells by Incorporating Plasmonic Effects of Spheroidal Metallic Nanoparticles

    E-Print Network [OSTI]

    Park, Namkyoo

    Improving the Power Conversion Efficiency of Ultrathin Organic Solar Cells by Incorporating be exploited to achieve efficient harvesting of solar energy. Notably, the incorporation of plasmonic effects can allow the light harvesting capability of a solar cell to be maintained even as the thickness

  19. High Efficiency Colloidal Quantum Dot Phosphors

    SciTech Connect (OSTI)

    Kahen, Keith

    2013-12-31T23:59:59.000Z

    The project showed that non-Cd containing, InP-based nanocrystals (semiconductor materials with dimensions of ~6 nm) have high potential for enabling next-generation, nanocrystal-based, on chip phosphors for solid state lighting. Typical nanocrystals fall short of the requirements for on chip phosphors due to their loss of quantum efficiency under the operating conditions of LEDs, such as, high temperature (up to 150 °C) and high optical flux (up to 200 W/cm2). The InP-based nanocrystals invented during this project maintain high quantum efficiency (>80%) in polymer-based films under these operating conditions for emission wavelengths ranging from ~530 to 620 nm. These nanocrystals also show other desirable attributes, such as, lack of blinking (a common problem with nanocrystals which limits their performance) and no increase in the emission spectral width from room to 150 °C (emitters with narrower spectral widths enable higher efficiency LEDs). Prior to these nanocrystals, no nanocrystal system (regardless of nanocrystal type) showed this collection of properties; in fact, other nanocrystal systems are typically limited to showing only one desirable trait (such as high temperature stability) but being deficient in other properties (such as high flux stability). The project showed that one can reproducibly obtain these properties by generating a novel compositional structure inside of the nanomaterials; in addition, the project formulated an initial theoretical framework linking the compositional structure to the list of high performance optical properties. Over the course of the project, the synthetic methodology for producing the novel composition was evolved to enable the synthesis of these nanomaterials at a cost approximately equal to that required for forming typical conventional nanocrystals. Given the above results, the last major remaining step prior to scale up of the nanomaterials is to limit the oxidation of these materials during the tens of thousands of hours of LED operation. Once the LED phosphor lifetime specifications are met, these nanocrystals will enable white LEDs for solid state lighting to simultaneously have increased efficiency and improved light quality, in addition to enabling the creation of custom light spectrums. These improvements to white LEDs will help accelerate the adoption of SSL, leading to large savings in US and worldwide energy costs.

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

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    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.

  1. Approaches To Integrating A HIgh Penertration Of Solar PV and CPV Onto The Electrical Grid

    E-Print Network [OSTI]

    Hill, Steven Craig

    2013-01-01T23:59:59.000Z

    A CONCENTRATION PHOTOVOLTAIC APPLICATIONS A.1 AND EFFICIENCYA   Concentration and Efficiency in Solar PhotovoltaicPhotovoltaic Applications  . 121  A.4  Concentrator Cell Efficiency . 

  2. Photodegradation effects in materials exposed to high flux solar and solar simulated radiation

    SciTech Connect (OSTI)

    Ignatiev, A. [Houston Univ., TX (United States)

    1992-04-01T23:59:59.000Z

    This report contains study results about photodegradation effects in materials exposed to high flux solar and solar simulated radiation. The studies show that high flux photoirradiation of materials can result in significant changes in the stability of materials. Photodesorption and photo-enhanced oxidation were determined to be the major mechanisms. These mechanisms were shown to affect, in extremely adverse ways, the expected thermal stability of solar relevant materials, especially stainless steels, (It is expected that related high temperature alloy steels will be similarly affected.) An analytical expression was generated to predict the flux behavior of the steels using {number_sign}304 as a prototypical stainless steel system.

  3. Photodegradation effects in materials exposed to high flux solar and solar simulated radiation

    SciTech Connect (OSTI)

    Ignatiev, A [Houston Univ., TX (United States)

    1992-04-01T23:59:59.000Z

    This report contains study results about photodegradation effects in materials exposed to high flux solar and solar simulated radiation. The studies show that high flux photoirradiation of materials can result in significant changes in the stability of materials. Photodesorption and photo-enhanced oxidation were determined to be the major mechanisms. These mechanisms were shown to affect, in extremely adverse ways, the expected thermal stability of solar relevant materials, especially stainless steels, (It is expected that related high temperature alloy steels will be similarly affected.) An analytical expression was generated to predict the flux behavior of the steels using {number sign}304 as a prototypical stainless steel system.

  4. Highly efficient blue organic light emitting devices with indium...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    efficient blue organic light emitting devices with indium-free transparent anode on flexible substrates. Highly efficient blue organic light emitting devices with indium-free...

  5. High-efficiency turquoise-blue electrophosphorescence from a...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    efficiency turquoise-blue electrophosphorescence from a Pt(II)-pyridyltriazolate complex in phosphine oxide host. High-efficiency turquoise-blue electrophosphorescence from a...

  6. High efficiency and low roll-off blue phosphorescent organic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    efficiency and low roll-off blue phosphorescent organic light-emitting devices using mixed host architecture. High efficiency and low roll-off blue phosphorescent organic...

  7. Development of Enabling Technologies for High Efficiency, Low...

    Broader source: Energy.gov (indexed) [DOE]

    Advanced Combustion in Improving Thermal Efficiency Development of Enabling Technologies for High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines...

  8. High Efficiency Microturbine with Integral Heat Recovery - Fact...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    efficiency. The microturbine technology will maximize usable exhaust energy and achieve ultra-low emissions levels. High Efficiency Microturbine with Integral Heat Recovery More...

  9. Charge Trapping in High Efficiency Alternating Copolymers: Implication...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency Home > Research > ANSER Research Highlights > Charge Trapping in...

  10. Project Profile: High-Efficiency Receivers for Supercritical...

    Energy Savers [EERE]

    Efficiency Receivers for Supercritical Carbon Dioxide Cycles Project Profile: High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles Brayton logo Brayton Energy, under...

  11. High Efficiency Full Expansion (FEx) Engine for Automotive Application...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Full Expansion (FEx) Engine for Automotive Applications High Efficiency Full Expansion (FEx) Engine for Automotive Applications Large increases in engine thermal efficiency result...

  12. Highly Efficient Silicon Light Emitting Diode

    E-Print Network [OSTI]

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

    2000-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Kurtin, J.

    2011-05-01T23:59:59.000Z

    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.

  14. High Gain, High Efficiency Vertical-Cavity Semiconductor Optical Amplifiers

    E-Print Network [OSTI]

    Bowers, John

    -cavity semiconductor optical amplifiers (VCSOAs) are interesting devices for applications such as wavelength selective coupling efficiency to optical fiber (yielding a low noise figure), small form factor, and the potential of fabricating high-density 2D arrays on wafer. Furthermore, the vertical-cavity design is compatible with low

  15. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    R. (1980) “Solar collectors for low and intermediateSystem Using Double- glazed Collectors." Applied Thermal40: Heat loss in thermal watts from the collectors to the

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

    SciTech Connect (OSTI)

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

    2011-07-01T23:59:59.000Z

    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.

  17. High Quantum Efficiency OLED Lighting Systems

    SciTech Connect (OSTI)

    Shiang, Joseph

    2011-09-30T23:59:59.000Z

    The overall goal of the program was to apply improvements in light outcoupling technology to a practical large area plastic luminaire, and thus enable the product vision of an extremely thin form factor high efficiency large area light source. The target substrate was plastic and the baseline device was operating at 35 LPW at the start of the program. The target LPW of the program was a >2x improvement in the LPW efficacy and the overall amount of light to be delivered was relatively high 900 lumens. Despite the extremely difficult challenges associated with scaling up a wet solution process on plastic substrates, the program was able to make substantial progress. A small molecule wet solution process was successfully implemented on plastic substrates with almost no loss in efficiency in transitioning from the laboratory scale glass to large area plastic substrates. By transitioning to a small molecule based process, the LPW entitlement increased from 35 LPW to 60 LPW. A further 10% improvement in outcoupling efficiency was demonstrated via the use of a highly reflecting cathode, which reduced absorptive loss in the OLED device. The calculated potential improvement in some cases is even larger, ~30%, and thus there is considerable room for optimism in improving the net light coupling efficacy, provided absorptive loss mechanisms are eliminated. Further improvements are possible if scattering schemes such as the silver nanowire based hard coat structure are fully developed. The wet coating processes were successfully scaled to large area plastic substrate and resulted in the construction of a 900 lumens luminaire device.

  18. A High Efficiency PSOFC/ATS-Gas Turbine Power System

    SciTech Connect (OSTI)

    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

    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.

  19. High temperature solar thermal technology: The North Africa Market

    SciTech Connect (OSTI)

    Not Available

    1990-12-01T23:59:59.000Z

    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.

  20. High Efficiency Modular Chemical Processes (HEMCP)

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEN TOTechnologyHigh Efficiency Low - ADVANCED

  1. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

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

  2. Knoxville, Tennessee: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Knoxville, TN, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  3. Sacramento, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Sacramento, CA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  4. Santa Rosa, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Santa Rosa, CA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  5. Philadelphia, Pennsylvania: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Philadelphia, PA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  6. Pittsburgh, Pennsylvania: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Pittsburgh, PA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  7. Salt Lake City, Utah: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Salt Lake City, UT, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  8. Berkeley, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Berkeley, CA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  9. San Diego, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of San Diego, CA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  10. Austin, Texas: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Austin, Texas, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  11. Tucson, Arizona: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Tucson, AZ, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  12. Seattle, Washington: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Seattle, WA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  13. Boston Massachusetts: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Boston, MA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  14. Denver, Colorado: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Denver, Colorado, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  15. Madison, Wisconsin: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Madison, WI, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  16. Ann Arbor, Michigan: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Ann Arbor, Michigan, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  17. Houston, Texas: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Houston, TX, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  18. Orlando, Florida: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Orlando, FL, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  19. Milwaukee, Wisconsin: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Milwaukee, WI, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  20. Indium oxide/n-silicon heterojunction solar cells

    DOE Patents [OSTI]

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

    1982-12-28T23:59:59.000Z

    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%.

  1. Technology Development for High Efficiency Clean Diesel Engines...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and a Pathway to 50% Thermal Efficiency Technology Development for High Efficiency Clean Diesel Engines and a Pathway to 50% Thermal Efficiency Cost reduction is a key area of...

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

    SciTech Connect (OSTI)

    None

    2012-02-13T23:59:59.000Z

    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.

  3. High Efficiency, Illumination Quality OLEDs for Lighting

    SciTech Connect (OSTI)

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

    2008-03-31T23:59:59.000Z

    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

  4. High throughput solar cell ablation system

    DOE Patents [OSTI]

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

    2012-09-11T23:59:59.000Z

    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.

  5. High throughput solar cell ablation system

    DOE Patents [OSTI]

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

    2014-10-14T23:59:59.000Z

    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.

  6. High-Temperature Thermal Array for Next Generation Solar Thermal...

    Broader source: Energy.gov (indexed) [DOE]

    3 Q1 High-Temperature Thermal Array for Next Generation Solar Thermal Power Production - FY13 Q1 This document summarizes the progress of this Los Alamos National Laboratory...

  7. High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems

    SciTech Connect (OSTI)

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

    2007-06-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2012-06-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    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.

  10. Commercialization of High-Temperature Solar Selective Coating: Cooperative Research and Development Final Report, CRADA Number CRD-08-300

    SciTech Connect (OSTI)

    Gray, M. H.

    2014-01-01T23:59:59.000Z

    The goal for Concentrating Solar Power (CSP) technologies is to produce electricity at 15 cents/kilowatt-hour (kWh) with six hours of thermal storage in 2015 (intermediate power) and close to 10 cents/kWh with 12-17 hours of thermal storage in 2020 (baseload power). Cost reductions of up to 50% to the solar concentrator are targeted through technology advances. The overall solar-to-electric efficiency of parabolic-trough solar power plants can be improved and the cost of solar electricity can be reduced by improving the properties of the selective coating on the receiver and increasing the solar-field operating temperature to >450 degrees C. New, more-efficient selective coatings will be needed that have both high solar absorptance and low thermal emittance at elevated temperatures. Conduction and convection losses from the hot absorber surface are usually negligible for parabolic trough receivers. The objective is to develop new, more-efficient selective coatings with both high solar absorptance (..alpha.. > 0.95) and low thermal emittance (..epsilon.. < 0.08 @ 450 degrees C) that are thermally stable above 450 degrees C, ideally in air, with improved durability and manufacturability, and reduced cost.

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

    E-Print Network [OSTI]

    Miller, Owen D; Kurtz, Sarah R

    2012-01-01T23:59:59.000Z

    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%.

  12. Solar wind-magnetosphere coupling leading to relativistic electron energization during high-speed streams

    E-Print Network [OSTI]

    Lyons, Larry

    Solar wind-magnetosphere coupling leading to relativistic electron energization during high. Smith (2005), Solar wind-magnetosphere coupling leading to relativistic electron energization during. Using observations during a period of persistent high-speed, corotating, solar wind streams, we

  13. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01T23:59:59.000Z

    research focused on solar powered cooling which has amounted to systemscooling system in 2009, the year I graduated with my B.S. and I chose to continue this research

  14. Solar Foundational Program to Advance Cell Efficiency Round 1

    Broader source: Energy.gov [DOE]

    The first round of the Foundational Program to Advance Cell Efficiency (F-PACE) program supported 18 projects working to create the technical foundation for significant increases in photovoltaic ...

  15. Development of High-Efficiency Clean Combustion Engines Designs...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Efficiency Clean Combustion Engines Designs for SI and CI Engines Development of High-Efficiency Clean Combustion Engines Designs for SI and CI Engines 2010 DOE Vehicle...

  16. Development of a New Generation, High Efficiency PEM Fuel Cell...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    a New Generation, High Efficiency PEM Fuel Cell Based, CHP System Development of a New Generation, High Efficiency PEM Fuel Cell Based, CHP System Part of a 100 million fuel cell...

  17. High Efficiency Organic Light Emitting Devices for Lighting

    SciTech Connect (OSTI)

    So, Franky; Tansu, Nelson; Gilchrist, James

    2013-06-30T23:59:59.000Z

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

  18. Solar System Tops Off Efficient NREL Building - News Feature | NREL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary Moniz9MorganYouof Energy Projects toSolar Swimming

  19. Glass Coating Makes Solar Panels More Efficient | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdf Flash2006-52.pdf0.pdfDepartmentCounselGlass Coating Makes Solar Panels More

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

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn April 23, 2014,Zaleski - PolicyWorkSunShot SolarDownloadTerry Sandstrom's home inWhatof

  1. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ... Strengthening aStructure of All-Polymer Solar Cells

  2. High efficiency Brayton cycles using LNG

    DOE Patents [OSTI]

    Morrow, Charles W. (Albuquerque, NM)

    2006-04-18T23:59:59.000Z

    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.

  3. Process Development for High Voc CdTe Solar Cells

    SciTech Connect (OSTI)

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

    2011-05-01T23:59:59.000Z

    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.

  4. Graphene-Polypyrrole Nanocomposite as a Highly Efficient and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graphene-Polypyrrole Nanocomposite as a Highly Efficient and Low Cost Electrically Switched Ion Exchanger for Removing ClO4- Graphene-Polypyrrole Nanocomposite as a Highly...

  5. 19.4% -EFFICIENT LARGE AREA REAR-PASSIVATED SCREEN-PRINTED SILICON SOLAR CELLS T. Dullweber*1

    E-Print Network [OSTI]

    be reduced by applying the PERC (passivated emitter and rear cell) solar cell design [8]. The following19.4% -EFFICIENT LARGE AREA REAR-PASSIVATED SCREEN-PRINTED SILICON SOLAR CELLS T. Dullweber*1 , S% in the near future. Keywords: Silicon Solar Cell, Screen Printing, Rear Passivation 1 Introduction About 80

  6. Enhanced light-conversion efficiency of titanium-dioxide dye-sensitized solar cells with the addition of

    E-Print Network [OSTI]

    Cao, Guozhong

    Enhanced light-conversion efficiency of titanium- dioxide dye-sensitized solar cells-doped tin oxide (FTO) nanoparticles and the application of such electrodes on dye-sensitized solar cell to the presence of ITO or FTO nanoparticles. Keywords: dye-sensitized solar cell, nanoparticle, electrode film

  7. Tailored Materials for High Efficiency CIDI Engines

    SciTech Connect (OSTI)

    Grant, G.J.; Jana, S.

    2012-03-30T23:59:59.000Z

    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.

  8. 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]

    2009-01-01T23:59:59.000Z

    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

  9. White LED with High Package Extraction Efficiency

    SciTech Connect (OSTI)

    Yi Zheng; Matthew Stough

    2008-09-30T23:59:59.000Z

    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.

  10. High SO2 Removal Efficiency Testing

    SciTech Connect (OSTI)

    Gary Blythe

    1997-02-12T23:59:59.000Z

    This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, "High Efficiency SO Removal Testing," for 2 the time period 1 October through 31 December 1996. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO removal efficiency. The upgrades being 2 evaluated mostly involve using performance additives in the FGD systems. The "base" project involved testing at the Tampa Electric Company?s Big Bend Station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy?s Merom Station (Option I), Southwestern Electric Power Company?s Pirkey Station (Option II), PSI Energy?s Gibson Station (Option III), Duquesne Light?s Elrama Station (Option IV), and New York State Electric and Gas Corporation?s Kintigh Station (Option V). The originally planned testing has been completed for all six sites. However, additional testing has been planned at the Big Bend Station, and that testing commenced during the current quarter. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the first quarter of calendar year 1996. Section 5 contains a brief acknowledgment.

  11. High SO2 Removal Efficiency Testing

    SciTech Connect (OSTI)

    Gary Blythe

    1997-04-23T23:59:59.000Z

    This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, "High Efficiency SO2 Removal Testing", for the time period 1 January through 31 March 1997. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO2 removal efficiency. The upgrades being evaluated mostly involve using performance additives in the FGD systems. The "base" project involved testing at the Tampa Electric Company?s Big Bend Station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy?s Merom Station (Option I), Southwestern Electric Power Company?s Pirkey Station (Option II), PSI Energy?s Gibson Station (Option III), Duquesne Light?s Elrama Station (Option IV), and New York State Electric and Gas Corporation?s (NYSEG) Kintigh Station (Option V). The originally planned testing has been completed for all six sites. However, additional testing is planned at the Big Bend Station. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the second quarter of calendar year 1997. Section 5 contains a brief acknowledgement.

  12. High SO2 Removal Efficiency Testing

    SciTech Connect (OSTI)

    Gary Blythe

    1997-07-29T23:59:59.000Z

    This document provides a discussion of the technical progress on DOE/PETC project number DE-AC22-92PC91338, "High Efficiency SO2 Removal Testing", for the time period 1 April through 30 June 1997. The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO2 removal efficiency. The upgrades being evaluated mostly involve using performance additives in the FGD systems. The "base" project involved testing at the Tampa Electric Company?s Big Bend Station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy?s Merom Station (Option I), Southwestern Electric Power Company?s Pirkey Station (Option II), PSI Energy?s Gibson Station (Option III), Duquesne Light?s Elrama Station (Option IV), and New York State Electric and Gas Corporation?s Kintigh Station (Option V). The originally planned testing has been completed for all six sites. However, additional testing is being conducted at the Big Bend Station. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the third quarter of calendar year 1997. Section 5 contains a brief acknowledgment.

  13. High efficiency thin-film multiple-gap photovoltaic device

    DOE Patents [OSTI]

    Dalal, Vikram L. (Newark, DE)

    1983-01-01T23:59:59.000Z

    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.

  14. Over 30{percent} efficient InGaP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Takamoto, T.; Ikeda, E.; Kurita, H. [Central Research Laboratory, Japan Energy Corporation, 3-17-35 Niizo-Minami, Toda, Saitama 335 (Japan)] [Central Research Laboratory, Japan Energy Corporation, 3-17-35 Niizo-Minami, Toda, Saitama 335 (Japan); Ohmori, M. [Japan Energy Research Center Company, Ltd., 1-11-9 Azabudai, Minato-ku, Tokyo 106 (Japan)] [Japan Energy Research Center Company, Ltd., 1-11-9 Azabudai, Minato-ku, Tokyo 106 (Japan)

    1997-01-01T23:59:59.000Z

    A two-terminal monolithic InGaP/GaAs tandem solar cell with a new efficiency record of 30.28{percent} is realized with a practical large area of 4 cm{sup 2} under one-sun air-mass 1.5 global illumination. We report improvements of the tandem cell performance by introducing a double-hetero (hereafter DH) structure InGaP tunnel junction, in which the InGaP layers are surrounded by high band gap AlInP barriers. The DH structure by AlInP barriers increase the peak current of InGaP tunnel junction. The AlInP barrier directly below the InGaP top cell, which takes the part of a back surface field (hereafter BSF) layer, is found to be considerably effective in reflecting minority carriers in the top cell. The AlInP BSF layer does not only form a high potential barrier but also prevents the diffusion of zinc from a high doped tunnel junction toward the top cell during epitaxial growth. Furthermore, an InGaP tunnel junction reduces the absorption loss, which exists in a GaAs tunnel junction, and increases the photogenerated current in the GaAs bottom cell. {copyright} {ital 1997 American Institute of Physics.}

  15. Computationally Efficient Modeling of High-Efficiency Clean Combustion...

    Broader source: Energy.gov (indexed) [DOE]

    Volvo; multi-zone cycle simulation, OpenFOAM model development Bosch; High Performance Computing of HCCISI transition Delphi; direct injection GE Research; new...

  16. Support for Cost Analyses on Solar-Driven High Temperature Thermochemi...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    near-term (2015) and longer-term (2025) cost projections for eight solar thermochemical hydrogen production reaction cycles. Support for Cost Analyses on Solar-Driven High...

  17. Approaches To Integrating A HIgh Penertration Of Solar PV and CPV Onto The Electrical Grid

    E-Print Network [OSTI]

    Hill, Steven Craig

    2013-01-01T23:59:59.000Z

    solar PV and distributed generation. UTILITY RATE DESIGN ANDutility concerns that a high penetration of inverter-based solar energy systems along with other distributed generation

  18. Philadelphia, Pennsylvania: Solar in Action (Brochure), Solar...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Philadelphia, Pennsylvania: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE) Philadelphia, Pennsylvania: Solar in Action (Brochure),...

  19. Design and Performance of Solar Decathlon 2011 High-Penetration Microgrid: Preprint

    SciTech Connect (OSTI)

    Stafford, B.; Coddington, M.; Butt, R.; Solomon, S.; Wiegand, G.; Wagner, C.; Gonzalez, B.

    2012-04-01T23:59:59.000Z

    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.

  20. High Efficiency Organic Multilayer Photodetectors based on Singlet Fission ....................................................................................................................................................................................

    E-Print Network [OSTI]

    Reif, Rafael

    .........................................................................................................................PH.14 High-efficiency, Low-cost Photovoltaics using III-V on Silicon Tandem CellsPhotonics High Efficiency Organic Multilayer Photodetectors based on Singlet Fission.........................................................................................................................PH.2 Efficiently Coupling Light to Superconducting Nanowire Single-photon Detectors

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

    SciTech Connect (OSTI)

    Nalwa, Kanwar

    2012-11-03T23:59:59.000Z

    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.

  2. Counterfactual quantum key distribution with high efficiency

    SciTech Connect (OSTI)

    Sun Ying [State Key Laboratory of Networking and SwitchingTechnology, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Beijing Electronic Science and Technology Institute, Beijing 100070 (China); Wen Qiaoyan [State Key Laboratory of Networking and SwitchingTechnology, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2010-11-15T23:59:59.000Z

    In a counterfactual quantum key distribution scheme, a secret key can be generated merely by transmitting the split vacuum pulses of single particles. We improve the efficiency of the first quantum key distribution scheme based on the counterfactual phenomenon. This scheme not only achieves the same security level as the original one but also has higher efficiency. We also analyze how to achieve the optimal efficiency under various conditions.

  3. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01T23:59:59.000Z

    V. Andreev, Concentrator Photovoltaics (Springer, Berlin,Green, Third Generation Photovoltaics: Ultra-High Conversionexciton generation improve photovoltaics? Sol. Energy Mater.

  4. Vehicle Technologies Office Merit Review 2015: High-Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Efficiency High-Density GaN-Based 6.6kW Bidirectional On-Board Charger for PEVs Vehicle Technologies Office Merit Review 2015: High-Efficiency High-Density GaN-Based 6.6kW...

  5. Solar and Energy Efficiency Justice | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmart Metersofand Energy Efficiency Justice

  6. Solar Foundational Program to Advance Cell Efficiency Round 2 | Department

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn April 23, 2014,Zaleski - PolicyWork ForceSectorProcessDepartmentEfficient Energyof

  7. High-efficiency photovoltaics based on semiconductor nanostructures

    SciTech Connect (OSTI)

    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

    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.

  8. Broadband Quantum Efficiency Enhancement in High Index Nanowires Resonators

    E-Print Network [OSTI]

    Yang, Yiming; Hyatt, Steven; Yu, Dong

    2015-01-01T23:59:59.000Z

    Light trapping in sub-wavelength semiconductor nanowires (NWs) offers a promising approach to simultaneously reducing material consumption and enhancing photovoltaic performance. Nevertheless, the absorption efficiency of a NW, defined by the ratio of optical absorption cross section to the NW diameter, lingers around 1 in existing NW photonic devices, and the absorption enhancement suffers from a narrow spectral width. Here, we show that the absorption efficiency can be significantly improved in NWs with higher refractive indices, by an experimental observation of up to 350% external quantum efficiency (EQE) in lead sulfide (PbS) NW resonators, a 3-fold increase compared to Si NWs. Furthermore, broadband absorption enhancement is achieved in single tapered NWs, where light of various wavelengths is absorbed at segments with different diameters analogous to a tandem solar cell. Overall, the single NW Schottky junction solar cells benefit from optical resonance, near bandgap open circuit voltage, and long mino...

  9. Desalination of seawater using a high-efficiency jet ejector

    E-Print Network [OSTI]

    Vishwanathappa, Manohar D.

    2005-08-29T23:59:59.000Z

    . These methods cost more than potable water produced from natural resources; hence an attempt is made in this research project to produce potable water using a modified high-efficiency jet ejector in vapor-compression distillation. The greater efficiency...

  10. Techniques for high-efficiency outphasing power amplifiers

    E-Print Network [OSTI]

    Godoy, Philip (Philip Andrew)

    2011-01-01T23:59:59.000Z

    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 ...

  11. High efficiency pulse motor drive for robotic propulsion

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    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 ...

  12. High-Efficiency Nitride-Base Photonic Crystal Light Sources

    SciTech Connect (OSTI)

    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

    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.

  13. Solar High Temperature Water-Splitting Cycle with Quantum Boost

    SciTech Connect (OSTI)

    Taylor, Robin [SAIC] [SAIC; Davenport, Roger [SAIC] [SAIC; Talbot, Jan [UCSD] [UCSD; Herz, Richard [UCSD] [UCSD; Genders, David [Electrosynthesis Co.] [Electrosynthesis Co.; Symons, Peter [Electrosynthesis Co.] [Electrosynthesis Co.; Brown, Lloyd [TChemE] [TChemE

    2014-04-25T23:59:59.000Z

    A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are proposed for future activities. Electrolysis membranes that permit higher temperatures and lower voltages are attainable. The oxygen half cycle will need further development and improvement.

  14. Nanostructured Thermoelectric Materials and High Efficiency Power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy: GridTruckNanostructued Glass-CeramicInnovationSolar

  15. HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

    SciTech Connect (OSTI)

    Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

    2013-08-01T23:59:59.000Z

    Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. 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 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

  16. High efficiency quasi-monochromatic infrared emitter

    SciTech Connect (OSTI)

    Brucoli, Giovanni; Besbes, Mondher; Benisty, Henri, E-mail: henri.benisty@institutoptique.fr; Greffet, Jean-Jacques [Laboratoire Charles Fabry, UMR 8501, Institut d’Optique, CNRS, Université Paris-Sud 11, 2, Avenue Augustin Fresnel, 91127 Palaiseau Cedex (France); Bouchon, Patrick; Haïdar, Riad [Office National d’Études et de Recherches Aérospatiales, Chemin de la Hunière, 91761 Palaiseau (France)

    2014-02-24T23:59:59.000Z

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  17. Evaluation of a High-Performance Solar Home in Loveland, Colorado

    SciTech Connect (OSTI)

    Hendron, R.; Eastment, M.; Hancock, E.; Barker, G.; Reeves, P.

    2006-01-01T23:59:59.000Z

    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.

  18. Evaluation of a High-Performance Solar Home in Loveland, Colorado: Preprint

    SciTech Connect (OSTI)

    Hendron, R.; Eastment, M.; Hancock, E.; Barker, G.; Reeves, P.

    2006-08-01T23:59:59.000Z

    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.

  19. Novel High Efficiency Photovoltaic Devices Based on the III-N Material System: Final Technical Report, 7 December 2005 - 29 August 2008

    SciTech Connect (OSTI)

    Hornsberg, C.; Doolittle, W. A.; Ferguson, I.

    2008-10-01T23:59:59.000Z

    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.

  20. Development of efficient photoreactors for solar hydrogen production

    SciTech Connect (OSTI)

    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

    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)

  1. High speed linear induction motor efficiency optimization

    E-Print Network [OSTI]

    Johnson, Andrew P. (Andrew Peter)

    2005-01-01T23:59:59.000Z

    One of the reasons linear motors, a technology nearly a century old, have not been adopted for a large number of linear motion applications is that they have historically had poor efficiencies. This has restricted the ...

  2. Method for forming indium oxide/n-silicon heterojunction solar cells

    DOE Patents [OSTI]

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

    1984-03-13T23:59:59.000Z

    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%.

  3. Technology and System Level Demonstration of Highly Efficient...

    Broader source: Energy.gov (indexed) [DOE]

    DoE SuperTruck Program Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered Class 8 Trucks Principal Investigator: Donald Stanton (Cummins)...

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    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Russ Durrett For Public Release GM R&D - Diesel Engine Systems High-Efficiency Clean Combustion Engine Designs for Compression Ignition Engines Russ Durrett, Xin He - General...

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    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

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  6. High Efficiency Clean Combustion Engine Designs for Gasoline...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Engine Designs for Gasoline and Diesel Engines High Efficiency Clean Combustion Engine Designs for Gasoline and Diesel Engines 2009 DOE Hydrogen Program and Vehicle Technologies...

  7. Simulation of High Efficiency Clean Combustion Engines and Detailed...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    analysis of and improving simulation methodologies for high efficiency clean combustion regimes, and computational performance deer11flowers.pdf More Documents &...

  8. Building Algorithm-Based Energy Efficient High Performance Computing...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Building Algorithm-Based Energy Efficient High Performance Computing Systems with Resilience Event Sponsor: Mathematics and Computing Science Seminar Start Date: May 12 2015 -...

  9. IBM Research Report Efficient High-precision Dense Matrix Algebra ...

    E-Print Network [OSTI]

    2008-10-28T23:59:59.000Z

    Oct 29, 2008 ... staple of high performance computing to efficiently solve discrete optimization problems on modern computational platforms. Matrix-based ...

  10. High Efficiency GDI Engine Research, with Emphasis on Ignition...

    Broader source: Energy.gov (indexed) [DOE]

    confidential, or otherwise restricted information Overview High Efficiency GDI Engine Research with Emphasis on Ignition Systems 2 Timeline Project start: Sept. 2012...

  11. Technology and System Level Demonstration of Highly Efficient...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and Peer Evaluation arravt081vssnewhouse2011o.pdf More Documents & Publications Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered Class 8...

  12. Materials-Enabled High-Efficiency Diesel Engines (CRADA with...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Engines (CRADA with Caterpillar) Materials-Enabled High-Efficiency Diesel Engines (CRADA with Caterpillar) 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit...

  13. Energy Savings Potential and Opportunities for High-Efficiency...

    Broader source: Energy.gov (indexed) [DOE]

    sponsored this assignment and provided comments on draft versions of the report. iii Energy Savings Potential and Opportunities for High-Efficiency Electric Motors in Residential...

  14. Enabling High Efficiency Low Temperature Combustion by Adaptive...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low Temperature Combustion by Adaptive In-Situ Jet Cooling Enabling High Efficiency Low Temperature Combustion by Adaptive In-Situ Jet Cooling A new approach, called...

  15. Optimization Online - Efficient high-precision dense matrix algebra ...

    E-Print Network [OSTI]

    John Gunnels

    2008-11-10T23:59:59.000Z

    Nov 10, 2008 ... Efficient high-precision dense matrix algebra on parallel architectures for nonlinear discrete optimization. John Gunnels(gunnels ***at*** ...

  16. Recent Progress in the Development of High Efficiency Thermoelectrics...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    More Documents & Publications High-Efficiency Quantum-Well Thermoelectrics for Waste Heat Power Generation Quantum Well Thermoelectrics and Waste Heat Recovery Scale Up...

  17. Advanced High Efficiency Clean Diesel Combustion with Low Cost...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Clean Combustion with Micro-Variable Circular-Orifice (MVCO) Fuel Injector and Adaptive PCCI Syngas Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines...

  18. Evaluation of High Efficiency Clean Combustion (HECC) Strategies...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Clean Combustion (HECC) Strategies for Meeting Future Emissions Regulations in Light-Duty Engines Evaluation of High Efficiency Clean Combustion (HECC) Strategies for Meeting...

  19. Technology and System Level Demonstration of Highly Efficient...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Publications Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered Class 8 Trucks Vehicle Technologies Office Merit Review 2014: Technology and...

  20. advanced high efficiency: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to 100 devices, including memory and logic. Josephson junctions are widely used in superconduct- ing quantum Nadgorny, Boris 65 Design of Efficient Java Communications for High...