National Library of Energy BETA

Sample records for three-junction concentrator cells

  1. Three-junction solar cell

    DOE Patents [OSTI]

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  2. Three-junction solar cells comprised of a thin-film GaInP/GaAs tandem cell mechanically stacked on a Si cell

    SciTech Connect (OSTI)

    Yazawa, Y.; Tamura, K.; Watahiki, S.; Kitatani, T.; Ohtsuka, H.; Warabisako, T.

    1997-12-31

    Three-junction tandem solar cells were fabricated by mechanical stacking of a thin-film GaInP/GaAs monolithic tandem cell and a Si cell. The epitaxial lift-off (ELO) technique was used for the thinning of GaInP/GaAs tandem cells. Both spectral responses of the GaInP top cell and the GaAs middle cell in the thin-film GaInP/GaAs monolithic tandem cell were conserved. The Si cell performance has been improved by reducing the absorption loss in the GaAs substrate.

  3. Manufacturing of ultra-high efficiency thin-film concentrator cells

    SciTech Connect (OSTI)

    Gale, R. )

    1992-02-01

    This report describes a research project to study developments required to expedite commercializing the GaAs solar cell concentrator technology. We baseline the GaAs concentrator cell and 1000X module design into pilot operation at Kopin Corporation. To attain these improvements, we will use Kopin's existing pilot line to produce cleavage of lateral epitaxial film for transfer (CLEFT) GaAs solar cells; these cells already exhibit efficiencies of about 24% at air mass 1.5. We will modify the CLEFT cell to form concentrators that perform well at 500--1000 suns. We will derive the know-how for this modification from an integration of Kopin and VS Corporation technologies. The pilot line will be broadened to include cell receiver and module assembly, using VS Corporation technology obtained from Varian as a baseline. A second-generation design will be formulated to address improvements in the module, and these will be incorporated into the pilot line along with the CLEFT concentrator cell. In parallel, we integrate Kopin's CLEFT GaAs cell technology with the advanced AlGaAs and InGaAs material technology obtained by VS Corporation from Varian to develop a near-term, two-junction mechanical stack with an efficiency of 35%. The receiver thus developed will be compatible with a three-junction approach that has been proposed elsewhere by Kopin. Using a three-junction stack can yield an efficiency of over 40%, and when such cells become available, the pilot line process will have been designed to use them. 11 refs.

  4. Development of concentrator solar cells

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    A limited pilot production run on PESC silicon solar cells for use at high concentrations (200 to 400 suns) is summarized. The front contact design of the cells was modified for operation without prismatic covers. The original objective of the contract was to systematically complete a process consolidation phase, in which all the, process improvements developed during the contract would be combined in a pilot production run. This pilot run was going to provide, a basis for estimating cell costs when produced at high throughput. Because of DOE funding limitations, the Photovoltaic Concentrator Initiative is on hold, and Applied Solar`s contract was operated at a low level of effort for most of 1993. The results obtained from the reduced scope pilot run showed the effects of discontinuous process optimization and characterization. However, the run provided valuable insight into the technical areas that can be optimized to achieve the original goals of the contract.

  5. Gas concentration cells for utilizing energy

    DOE Patents [OSTI]

    Salomon, R.E.

    1987-06-30

    An apparatus and method are disclosed for utilizing energy, in which the apparatus may be used for generating electricity or as a heat pump. When used as an electrical generator, two gas concentration cells are connected in a closed gas circuit. The first gas concentration cell is heated and generates electricity. The second gas concentration cell repressurizes the gas which travels between the cells. The electrical energy which is generated by the first cell drives the second cell as well as an electrical load. When used as a heat pump, two gas concentration cells are connected in a closed gas circuit. The first cell is supplied with electrical energy from a direct current source and releases heat. The second cell absorbs heat. The apparatus has no moving parts and thus approximates a heat engine. 4 figs.

  6. Gas concentration cells for utilizing energy

    DOE Patents [OSTI]

    Salomon, Robert E.

    1987-01-01

    An apparatus and method for utilizing energy, in which the apparatus may be used for generating electricity or as a heat pump. When used as an electrical generator, two gas concentration cells are connected in a closed gas circuit. The first gas concentration cell is heated and generates electricity. The second gas concentration cell repressurizes the gas which travels between the cells. The electrical energy which is generated by the first cell drives the second cell as well as an electrical load. When used as a heat pump, two gas concentration cells are connected in a closed gas circuit. The first cell is supplied with electrical energy from a direct current source and releases heat. The second cell absorbs heat. The apparatus has no moving parts and thus approximates a heat engine.

  7. TOPCAT Solar Cell Alignment & Energy Concentration Technology...

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

    Thermal Solar Thermal Find More Like This Return to Search TOPCAT Solar Cell Alignment & Energy Concentration Technology Sandia National Laboratories Contact SNL About This ...

  8. Silicon concentrator cell-assembly development

    SciTech Connect (OSTI)

    Not Available

    1982-08-01

    The purpose of this program is to develop an improved cell assembly design for photovoltaic concentrator receivers. Efforts were concentrated on a study of adhesive/separator systems that might be applied between cell and substrate, because this area holds the key to improved heat transfer, electrical isolation and adhesion. It is also the area in which simpler construction methods offer the greatest benefits for economy and reliability in the manufacturing process. Of the ten most promising designs subjected to rigorous environmental testing, eight designs featuring acrylic and silicon adhesives and fiberglass and polyester separators performed very well.

  9. Thermal regeneration of an electrochemical concentration cell

    DOE Patents [OSTI]

    Krumpelt, Michael; Bates, John K.

    1981-01-01

    A system and method for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 Kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  10. Thermal regeneration of an electrochemical concentration cell

    DOE Patents [OSTI]

    Krumpelt, M.; Bates, J.K.

    1980-05-09

    A system and method are described for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  11. Procedures at NREL for Evaluating Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    Moriarty, T.; Emery, K.

    2000-01-01

    The procedures for evaluating the performance of multijunctiion-concentrator cells at the National Renewable Energy Laboratory are described. The accurate measurement of the performance of multijunction cells requires accurate relative-quantum-efficiency-measurements, "matched" reference cells, and a spectrally adjustable solar simulator.

  12. Effects of angular confinement and concentration to realistic solar cells

    SciTech Connect (OSTI)

    Höhn, O. Kraus, T.; Bläsi, B.; Schwarz, U. T.

    2015-01-21

    In standard solar cells, light impinges under a very small angular range, whereas the solar cell emits light into the whole half space. Due to this expansion of etendué, entropy is generated, which limits the maximal efficiency of solar cells. This limit can be overcome by either increasing the angle of incidence by concentration or by decreasing the angle of emission by an angularly confining element or by a combination of both. In an ideal solar cell with radiative recombination as the only loss mechanism, angular confinement and concentration are thermodynamically equivalent. It is shown that concentration in a device, where non-radiative losses such as Shockley-Read-Hall and Auger recombination are considered, is not equivalent to angular confinement. As soon as non-radiative losses are considered, the gain in efficiency due to angular confinement drops significantly in contrast to the gain caused by concentration. With the help of detailed balance calculations, it is furthermore shown that angular confinement can help to increase the efficiency of solar cells under concentrated sunlight even if no measurable gain is expected for the solar cell under 1-sun-illumination. Our analysis predicts a relative gain of 3.14% relative in efficiency for a realistic solar cell with a concentration factor of 500.

  13. 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.

    2005-11-01

    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.

  14. Analysis of the GaInP/GaAs/1-eV/Ge Cell and Related Structures for Terrestrial Concentrator Application: Preprint

    SciTech Connect (OSTI)

    Friedman, D. J.; Kurtz, S. R.; Geisz, J. F.

    2002-05-01

    This conference paper describes the analysis of the potential of GaInP/GaAs/1-eV/Ge four-junction solar cell to improve on the efficiency of the state-of-the-art GaInP/GaAs/Ge benchmark. We emphasize three factors: (1) The newly proposed terrestrial concentrator spectrum has a lower ratio of red to blue light than does the old AM1.5 direct standard spectrum. (2) Standard two-layer antireflection coatings do not provide near-zero reflectance over the full spectral range of interest for these devices. (3) GaInNAs junctions used to date for the 1-eV junction have quantum efficiencies less than {approx}75%. These factors all limit the device current, adversely affecting the four-junction efficiency. We discuss strategies for ameliorating this problem, including going to alternate structures such as a GaInP/GaAs/0.9-eV three-junction device.

  15. Intra-Fuel Cell Stack Measurements of Transient Concentration Distributions

    SciTech Connect (OSTI)

    Partridge Jr, William P; Toops, Todd J; Green Jr, Johney Boyd; Armstrong, Timothy R.

    2006-01-01

    Intra-fuel-cell measurements are required to understand detailed fuel-cell chemistry and physics, validate models, optimize system design and control, and realize enhanced efficiency regimes; in comparison, conventional integrated fuel-cell supply and effluent measurements are fundamentally limited in value. Intra-reactor measurements are needed for all fuel cell types. This paper demonstrates the ability of a capillary-inlet mass spectrometer to resolve transient species distributions within operating polymer-electrolyte-membrane (PEM) fuel cells and at temperatures typical of solid-oxide fuel cells (SOFC). This is the first such demonstration of a diagnostic that is sufficiently minimally invasive as to allow measurements throughout an operating fuel cell stack. Measurements of transient water, hydrogen, oxygen and diluent concentration dynamics associated with fuel-cell load switching suggest oxygen-limited chemistry. Intra-PEM fuel cell measurements of oxygen distribution at various fuel-cell loads are used to demonstrate concentration gradients, non-uniformities, and anomalous fuel cell operation.

  16. Potentiometric studies at ORNL with hydrogen electrode concentration cells

    SciTech Connect (OSTI)

    Mesmer, R.E.; Palmer, D.A.; Wesolowski, D.J.

    1994-12-31

    The absence of suitably stable reference electrodes for and to 300 C led ORNL to develop hydrogen electrode concentration cells for studies of equilibria of interest in reactor and steam generator systems to about 300 C during the late 1960`s and seventies. During the intervening two dozen years over twenty scientists have participated in potentiometric studies at Oak Ridge and much of that work will be summarized in this paper. A description of hydrogen electrode concentration cells developed in the late sixties and currently in use at Oak Ridge is given. The method of measurement, data interpretation, and published results are reviewed for studies of acid-base ionization, metal ion hydrolysis, and metal complexation reactions using principally such cells in titration or flow modes. 41 refs.

  17. PV Cell and Module Calibrations at NREL

    SciTech Connect (OSTI)

    Emery, Keith

    2012-10-22

    NREL has equipment to measure any conceivable cell or module technology. The lack of standards for low concentration modules complicates matters. Spectrally adjustable simulators are critical for more than three junctions. NREL's 10-channel fiber optic simulator has shown that the light can be set for each junction within 1% of what it would be under the reference spectrum for up to a five-junction cell. Uncertainty in module simulators dominated by spatial nonuniformity for calibration labs. Manufacturers can mitigate this error by using matched reference modules instead of cells.

  18. GaAs quantum dot solar cell under concentrated radiation

    SciTech Connect (OSTI)

    Sablon, K.; Little, J. W.; Hier, H.; Li, Y.; Mitin, V.; Vagidov, N.; Sergeev, A.

    2015-08-17

    Effects of concentrated solar radiation on photovoltaic performance are investigated in well-developed GaAs quantum dot (QD) solar cells with 1-Sun efficiencies of 18%–19%. In these devices, the conversion processes are enhanced by nanoscale potential barriers and/or AlGaAs atomically thin barriers around QDs, which prevent photoelectron capture to QDs. Under concentrated radiation, the short circuit current increases proportionally to the concentration and the open circuit voltage shows the logarithmic increase. In the range up to hundred Suns, the contributions of QDs to the photocurrent are proportional to the light concentration. The ideality factors of 1.1–1.3 found from the V{sub OC}-Sun characteristics demonstrate effective suppression of recombination processes in barrier-separated QDs. The conversion efficiency shows the wide maximum in the range of 40–90 Suns and reaches 21.6%. Detailed analysis of I-V-Sun characteristics shows that at low intensities, the series resistance decreases inversely proportional to the concentration and, at ∼40 Suns, reaches the plateau determined mainly by the front contact resistance. Improvement of contact resistance would increase efficiency to above 24% at thousand Suns.

  19. Electrorefining cell with parallel electrode/concentric cylinder cathode

    DOE Patents [OSTI]

    Gay, Eddie C.; Miller, William E.; Laidler, James J.

    1997-01-01

    A cathode-anode arrangement for use in an electrolytic cell is adapted for electrochemically refining spent nuclear fuel from a nuclear reactor and recovering purified uranium for further treatment and possible recycling as a fresh blanket or core fuel in a nuclear reactor. The arrangement includes a plurality of inner anodic dissolution baskets that are each attached to a respective support rod, are submerged in a molten lithium halide salt, and are rotationally displaced. An inner hollow cylindrical-shaped cathode is concentrically disposed about the inner anodic dissolution baskets. Concentrically disposed about the inner cathode in a spaced manner are a plurality of outer anodic dissolution baskets, while an outer hollow cylindrical-shaped is disposed about the outer anodic dissolution baskets. Uranium is transported from the anode baskets and deposited in a uniform cylindrical shape on the inner and outer cathode cylinders by rotating the anode baskets within the molten lithium halide salt. Scrapers located on each anode basket abrade and remove the spent fuel deposits on the surfaces of the inner and outer cathode cylinders, with the spent fuel falling to the bottom of the cell for removal. Cell resistance is reduced and uranium deposition rate enhanced by increasing the electrode area and reducing the anode-cathode spacing. Collection efficiency is enhanced by trapping and recovery of uranium dendrites scrapped off of the cylindrical cathodes which may be greater in number than two.

  20. Electrorefining cell with parallel electrode/concentric cylinder cathode

    DOE Patents [OSTI]

    Gay, E.C.; Miller, W.E.; Laidler, J.J.

    1997-07-22

    A cathode-anode arrangement for use in an electrolytic cell is adapted for electrochemically refining spent nuclear fuel from a nuclear reactor and recovering purified uranium for further treatment and possible recycling as a fresh blanket or core fuel in a nuclear reactor. The arrangement includes a plurality of inner anodic dissolution baskets that are each attached to a respective support rod, are submerged in a molten lithium halide salt, and are rotationally displaced. An inner hollow cylindrical-shaped cathode is concentrically disposed about the inner anodic dissolution baskets. Concentrically disposed about the inner cathode in a spaced manner are a plurality of outer anodic dissolution baskets, while an outer hollow cylindrical-shaped is disposed about the outer anodic dissolution baskets. Uranium is transported from the anode baskets and deposited in a uniform cylindrical shape on the inner and outer cathode cylinders by rotating the anode baskets within the molten lithium halide salt. Scrapers located on each anode basket abrade and remove the spent fuel deposits on the surfaces of the inner and outer cathode cylinders, with the spent fuel falling to the bottom of the cell for removal. Cell resistance is reduced and uranium deposition rate enhanced by increasing the electrode area and reducing the anode-cathode spacing. Collection efficiency is enhanced by trapping and recovery of uranium dendrites scrapped off of the cylindrical cathodes which may be greater in number than two. 12 figs.

  1. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  2. Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell

    Broader source: Energy.gov [DOE]

    EERE supported the development of Solar Junction's concentrated photovoltaic technology that set a world record for conversion efficiency.

  3. Flexible thermal cycle test equipment for concentrator solar cells

    DOE Patents [OSTI]

    Hebert, Peter H.; Brandt, Randolph J.

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  4. Maintaining molten salt electrolyte concentration in aluminum-producing electrolytic cell

    DOE Patents [OSTI]

    Barnett, Robert J.; Mezner, Michael B.; Bradford, Donald R

    2005-01-04

    A method of maintaining molten salt concentration in a low temperature electrolytic cell used for production of aluminum from alumina dissolved in a molten salt electrolyte contained in a cell free of frozen crust wherein volatile material is vented from the cell and contacted and captured on alumina being added to the cell. The captured volatile material is returned with alumina to cell to maintain the concentration of the molten salt.

  5. Accelerated aging of GaAs concentrator solar cells

    SciTech Connect (OSTI)

    Gregory, P.E.

    1982-04-01

    An accelerated aging study of AlGaAs/GaAs solar cells has been completed. The purpose of the study was to identify the possible degradation mechanisms of AlGaAs/GaAs solar cells in terrestrial applications. Thermal storage tests and accelerated AlGaAs corrosion studies were performed to provide an experimental basis for a statistical analysis of the estimated lifetime. Results of this study suggest that a properly designed and fabricated AlGaAs/GaAs solar cell can be mechanically rugged and environmentally stable with projected lifetimes exceeding 100 years.

  6. NREL Demonstrates 45.7% Efficiency for Concentrator Solar Cell - News

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

    Releases | NREL NREL Demonstrates 45.7% Efficiency for Concentrator Solar Cell New design for ultra-efficient III-V multijunction cell pushes the limits of solar conversion December 16, 2014 The Energy Department's National Renewable Energy Laboratory has announced the demonstration of a 45.7 percent conversion efficiency for a four-junction solar cell at 234 suns concentration. This achievement represents one of the highest photovoltaic research cell efficiencies achieved across all types

  7. SIMPLE TRANSIENT CALCULATIONS OF CELL FLAMMABLE GAS CONCENTRATIONS

    SciTech Connect (OSTI)

    , J; David Allison , D; John Mccord, J

    2009-05-06

    The Saltstone Facility at Savannah River Site (SRS) mixes low-level radiological liquid waste with grout for permanent disposal as cement in vault cells. The grout mixture is poured into each cell in approximately 17 batches (8 to 10 hours duration). The grout mixture contains ten flammable gases of concern that are released from the mixture into the cell. Prior to operations, simple parametric transient calculations were performed to develop batch parameters (including schedule of batch pours) to support operational efficiency while ensuring that a flammable gas mixture does not develop in the cell vapor space. The analysis demonstrated that a nonflammable vapor space environment can be achieved, with workable operational constraints, without crediting the ventilation flow as a safety system control. Isopar L was identified as the primary flammable gas of concern. The transient calculations balanced inflows of the flammable gases into the vapor space with credited outflows of diurnal breathing through vent holes and displacement from new grout pours and gases generated. Other important features of the analyses included identifying conditions that inhibited a well-mixed vapor space, the expected frequency and duration of such conditions, and the estimated level of stratification that could develop.

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

    SciTech Connect (OSTI)

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

    1991-01-01

    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.

  9. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, Mark W.

    1994-01-01

    A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

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

    SciTech Connect (OSTI)

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

    2000-01-01

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

  11. Energy Yield Determination of Concentrator Solar Cells using Laboratory Measurements: Preprint

    SciTech Connect (OSTI)

    Geisz, John F.; Garcia, Ivan; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.

    2015-09-14

    The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used to predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted. temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted.

  12. THE EFFECT OF LOW CONCENTRATIONS OF TETRACHLOROETHYLENE ON THE PERFORMANCE OF PEM FUEL CELLS

    SciTech Connect (OSTI)

    COLON-MERCHADO, H.; MARTINEZ-RODRIGUEZ, M.; FOX, E.; RHODES, W.; MCWHORTER, C.; GREENWAY, S.

    2011-04-18

    Polymer electrolyte membrane (PEM) fuel cells use components that are susceptible to contaminants in the fuel stream. To ensure fuel quality, standards are being set to regulate the amount of impurities allowable in fuel. The present study investigates the effect of chlorinated impurities on fuel cell systems using tetrachloroethylene (PCE) as a model compound for cleaning and degreasing agents. Concentrations between 0.05 parts per million (ppm) and 30 ppm were studied. We show how PCE causes rapid drop in cell performances for all concentrations including 0.05 ppm. At concentrations of 1 and 0.05 ppm, PCE poisoned the cell at a rate dependent on the dosage of the contaminant delivered to the cell. PCE appears to affect the cell when the cell potential was over potentials higher than approximately 0.2 V. No effects were observed at voltages around or below 0.2 V and the cells could be recovered from previous poisoning performed at higher potentials. Recoveries at those low voltages could be induced by changing the operating voltage or by purging the system. Poisoning did not appear to affect the membrane conductivity. Measurements with long-path length IR results suggested catalytic decomposition of the PCE by hydrogen over the anode catalyst.

  13. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, M.W.

    1994-12-27

    A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

  14. Non Invasive estimation of aluminum concentration in Hall-Heroult reduction cells

    SciTech Connect (OSTI)

    David Bell

    2004-03-01

    The present best practice for the preparation of primary aluminum is by electrolysis of alumina in the traditional Hall-Heroult reduction cell. The process conditions in the electrolyte of this cell required for the reduction to proceed are sufficiently harsh to have precluded the implementation of in situ sensing of the electrolyte composition, specifically the concentration of the ionized alumina. This report reveals the theoretical basis for a non-invasive method for estimation of the ionized alumina concentration which does not require the use of any sensor in direct contact with the cell electrolyte. The proposed method can in principle be applied with equal efficacy to the so-called drained cathode cell designs and to cells having any anode composition, because only knowledge of the electrolyte conduction behavior is required a priori. For an operating cell, the proposed method requires only readily available electrical measurements and the facilities to process the acquired signals. The proposed method rests on the ability to identify certain characteristics of the transients in the reduction cell terminal voltages caused by the quasiperiodic introduction of alumina. It will be shown that these voltage transients manifest measurable properties, in a statistical sense, that should permit estimation of the ionized alumina concentration with a delay of one alumina feed cycle. The next logical step following the present work, consistent with the Aluminum Technology Roadmap [1], is to experimentally verify the predictions made here; no doubt practical refinements to the proposed approach will evolve during the course of experimentation. Successful verification of the proposed estimation method will permit the design of reduction cell control algorithms based directly on the mass balance of alumina in the electrolyte. This report assumes that the reader understands certain basic concepts important to the operation of electrolytic cells, and the Hall-Heroult cell

  15. Electrolyte Concentration Effect of a Photoelectrochemical Cell Consisting of TiO 2 Nanotube Anode

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ren, Kai; Gan, Yong X.; Nikolaidis, Efstratios; Sofyani, Sharaf Al; Zhang, Lihua

    2013-01-01

    The photoelectrochemical responses of a TiO 2 nanotube anode in ethylene glycol (EG), glycerol, ammonia, ethanol, urea, and Na 2 S electrolytes with different concentrations were investigated. The TiO 2 nanotube anode was highly efficient in photoelectrocatalysis in these solutions under UV light illumination. The photocurrent density is obviously affected by the concentration change. Na 2 S generated the highest photocurrent density at 0, 1, and 2 V bias voltages, but its concentration does not significantly affect the photocurrent density. Urea shows high open circuit voltage at proper concentration and low photocurrent at different concentrations. Externally applied bias voltage ismore » also an important factor that changes the photoelectrochemical reaction process. In view of the open circuit voltage, EG, ammonia, and ethanol fuel cells show the trend that the open circuit voltage (OCV) increases with the increase of the concentration of the solutions. Glycerol has the highest OCV compared with others, and it deceases with the increase in the concentration because of the high viscosity. The OCV of the urea and Na 2 S solutions did not show obvious concentration effect.« less

  16. 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.

    2014-03-01

    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.

  17. Comparison of Theoretical Efficiencies of Multi-junction Concentrator Solar Cells

    SciTech Connect (OSTI)

    Kurtz, S.; Myers, D.; McMahon, W. E.; Geisz, J.; Steiner, M.

    2008-01-01

    Champion concentrator cell efficiencies have surpassed 40% and now many are asking whether the efficiencies will surpass 50%. Theoretical efficiencies of >60% are described for many approaches, but there is often confusion about the theoretical efficiency for a specific structure. The detailed balance approach to calculating theoretical efficiency gives an upper bound that can be independent of material parameters and device design. Other models predict efficiencies that are closer to those that have been achieved. Changing reference spectra and the choice of concentration further complicate comparison of theoretical efficiencies. This paper provides a side-by-side comparison of theoretical efficiencies of multi-junction solar cells calculated with the detailed balance approach and a common one-dimensional-transport model for different spectral and irradiance conditions. Also, historical experimental champion efficiencies are compared with the theoretical efficiencies.

  18. Method of monitoring CO concentrations in hydrogen feed to a PEM fuel cell

    SciTech Connect (OSTI)

    Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk

    2000-01-01

    The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. The PEM-probe is intermittently purged of any CO build-up on the anode catalyst (e.g., by (1) flushing the anode with air, (2) short circuiting the PEM-probe, or (3) reverse biasing the PEM-probe) to keep the PEM-probe at peak performance levels.

  19. Preservation of high glycolytic phenotype by establishing new acute lymphoblastic leukemia cell lines at physiologic oxygen concentration

    SciTech Connect (OSTI)

    Sheard, Michael A.; Ghent, Matthew V.; Cabral, Daniel J.; Lee, Joanne C.; Khankaldyyan, Vazgen; Ji, Lingyun; Wu, Samuel Q.; Kang, Min H.; and others

    2015-05-15

    Cancer cells typically exhibit increased glycolysis and decreased mitochondrial oxidative phosphorylation, and they continue to exhibit some elevation in glycolysis even under aerobic conditions. However, it is unclear whether cancer cell lines employ a high level of glycolysis comparable to that of the original cancers from which they were derived, even if their culture conditions are changed to physiologically relevant oxygen concentrations. From three childhood acute lymphoblastic leukemia (ALL) patients we established three new pairs of cell lines in both atmospheric (20%) and physiologic (bone marrow level, 5%) oxygen concentrations. Cell lines established in 20% oxygen exhibited lower proliferation, survival, expression of glycolysis genes, glucose consumption, and lactate production. Interestingly, the effects of oxygen concentration used during cell line initiation were only partially reversible when established cell cultures were switched from one oxygen concentration to another for eight weeks. These observations indicate that ALL cell lines established at atmospheric oxygen concentration can exhibit relatively low levels of glycolysis and these levels are semi-permanent, suggesting that physiologic oxygen concentrations may be needed from the time of cell line initiation to preserve the high level of glycolysis commonly exhibited by leukemias in vivo. - Highlights: • Establishing new ALL cell lines in 5% oxygen resulted in higher glycolytic expression and function. • Establishing new ALL cell lines in 5% oxygen resulted in higher proliferation and lower cell death. • The divergent metabolic phenotypes selected in 5% and 20% oxygen are semi-permanent.

  20. Concentration-dependent gene expression responses to flusilazole in embryonic stem cell differentiation cultures

    SciTech Connect (OSTI)

    Dartel, Dorien A.M. van; Pennings, Jeroen L.A.; Fonteyne, Liset J.J. de la; Brauers, Karen J.J.; Claessen, Sandra; Delft, Joost H. van; Kleinjans, Jos C.S.; Piersma, Aldert H.

    2011-03-01

    The murine embryonic stem cell test (EST) is designed to evaluate developmental toxicity based on compound-induced inhibition of embryonic stem cell (ESC) differentiation into cardiomyocytes. The addition of transcriptomic evaluation within the EST may result in enhanced predictability and improved characterization of the applicability domain, therefore improving usage of the EST for regulatory testing strategies. Transcriptomic analyses assessing factors critical for risk assessment (i.e. dose) are needed to determine the value of transcriptomic evaluation in the EST. Here, using the developmentally toxic compound, flusilazole, we investigated the effect of compound concentration on gene expression regulation and toxicity prediction in ESC differentiation cultures. Cultures were exposed for 24 h to multiple concentrations of flusilazole (0.54-54 {mu}M) and RNA was isolated. In addition, we sampled control cultures 0, 24, and 48 h to evaluate the transcriptomic status of the cultures across differentiation. Transcriptomic profiling identified a higher sensitivity of development-related processes as compared to cell division-related processes in flusilazole-exposed differentiation cultures. Furthermore, the sterol synthesis-related mode of action of flusilazole toxicity was detected. Principal component analysis using gene sets related to normal ESC differentiation was used to describe the dynamics of ESC differentiation, defined as the 'differentiation track'. The concentration-dependent effects on development were reflected in the significance of deviation of flusilazole-exposed cultures from this transcriptomic-based differentiation track. Thus, the detection of developmental toxicity in EST using transcriptomics was shown to be compound concentration-dependent. This study provides further insight into the possible application of transcriptomics in the EST as an improved alternative model system for developmental toxicity testing.

  1. Effect of molecular weight and concentration of hyaluronan on cell proliferation and osteogenic differentiation in vitro

    SciTech Connect (OSTI)

    Zhao, Ningbo Wang, Xin Qin, Lei Guo, Zhengze Li, Dehua

    2015-09-25

    Hyaluronan (HA), the simplest glycosaminoglycan and a major component of the extracellular matrix, exists in various tissues. It is involved in some critical biological procedures, including cellular signaling, cell adhesion and proliferation, and cell differentiation. The effect of molecular weight (MW) and concentration of HA on cell proliferation and differentiation was controversial. In this study, we investigated the effect of MW and concentration of HA on the proliferation and osteogenic differentiation of rabbit bone marrow-derived stem cells in vitro. Results showed that high MW HA decreased the cell adhesion rate in a concentration-dependant manner. The cell adhesion rate was decreased by increasing MW of HA. Cell proliferation was significantly enhanced by low MW HA (P < 0.05). The factorial analysis indicated that MW and concentration had an interactive effect on the cell adhesion rate and cell proliferation (P < 0.05). High MW HA increased the mRNA expressions of ALP, RUNX-2 and OCN. The higher the MW was, the higher the mRNA expressions were. The factorial analysis indicated that MW and concentration had an interactive effect on ALP mRNA expression (P < 0.05). HA of higher MW and higher concentration promoted bone formation. These findings provide some useful information in understanding the mechanism underlying the effect of MW and concentration of HA on cell proliferation and differentiation. - Highlights: • Effect of hyaluronan on cell proliferation and differentiation is evaluated in vitro. • Hyaluronan of low molecular weight increases cell proliferation. • Hyaluronan of high molecular weight promotes cell osteogenic differentiation. • Molecular weight and concentration of hyaluronan show interactive effect.

  2. Buffer layer between a planar optical concentrator and a solar cell

    SciTech Connect (OSTI)

    Solano, Manuel E.; Barber, Greg D.; Lakhtakia, Akhlesh; Faryad, Muhammad; Monk, Peter B.; Mallouk, Thomas E.

    2015-09-15

    The effect of inserting a buffer layer between a periodically multilayered isotropic dielectric (PMLID) material acting as a planar optical concentrator and a photovoltaic solar cell was theoretically investigated. The substitution of the photovoltaic material by a cheaper dielectric material in a large area of the structure could reduce the fabrication costs without significantly reducing the efficiency of the solar cell. Both crystalline silicon (c-Si) and gallium arsenide (GaAs) were considered as the photovoltaic material. We found that the buffer layer can act as an antireflection coating at the interface of the PMLID and the photovoltaic materials, and the structure increases the spectrally averaged electron-hole pair density by 36% for c-Si and 38% for GaAs compared to the structure without buffer layer. Numerical evidence indicates that the optimal structure is robust with respect to small changes in the grating profile.

  3. Advances on multijunction solar cell characterization aimed at the optimization of real concentrator performance

    SciTech Connect (OSTI)

    Garcia-Linares, Pablo Dominguez, César Voarino, Philippe Besson, Pierre Baudrit, Mathieu

    2014-09-26

    Multijunction solar cells (MJSC) are usually developed to maximize efficiency under test conditions and not under real operation. This is the case of anti-reflective coatings (ARC), which are meant to minimize Fresnel reflection losses for a family of incident rays at room temperature. In order to understand and quantify the discrepancies between test and operation conditions, we have experimentally analyzed the spectral response of MJSC for a variety of incidence angles that are in practice received by a concentrator cell in high-concentration photovoltaic (HCPV) receiver designs. Moreover, we characterize this angular dependence as a function of temperature in order to reproduce real operation conditions. As the refractive index of the silicone is dependent on temperature, an optical mismatch is expected. Regarding other characterization techniques, a method called Relative EL Homogeneity Analysis (RELHA) is applied to processed wafers prior to dicing, allowing to diagnose the wafer crystalline homogeneity for each junction. Finally, current (I)-voltage (V) characterization under strongly unbalanced light spectra has also been carried out for a number of low-level irradiances, providing insight on each junction shunt resistance and corresponding radiative coupling.

  4. Analysis of a four lamp flash system for calibrating multi-junction solar cells under concentrated light

    SciTech Connect (OSTI)

    Schachtner, Michael Prado, Marcelo Loyo; Reichmuth, S. Kasimir; Siefer, Gerald; Bett, Andreas W.

    2015-09-28

    It has been known for a long time that the precise characterization of multi-junction solar cells demands spectrally tunable solar simulators. The calibration of innovative multi-junction solar cells for CPV applications now requires tunable solar simulators which provide high irradiation levels. This paper describes the commissioning and calibration of a flash-based four-lamp simulator to be used for the measurement of multi-junction solar cells with up to four subcells under concentrated light.

  5. InP single-junction concentrator cell. Semi-annual report, October 1, 1980-March 31, 1981

    SciTech Connect (OSTI)

    Gregory, P.E.

    1981-01-01

    The purpose of this work is to develop a glass-sealed back-contacted InP or InGaAsP solar cell for use in concentrator systems. Work to be performed in developing this cell includes growing the InP epitaxial layers needed for cells and test structures, developing a model to be used in optimizing the cell structure, measurement of InP parameters necessary for use in the model, and developing the glass-bonding and back-contacting scheme. Accomplishments in these areas are discussed.

  6. EERE Success Story—Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell

    Broader source: Energy.gov [DOE]

    EERE supported the development of Solar Junction's concentrated photovoltaic technology that set a world record for conversion efficiency.

  7. Evaluation of Background Concentrations of Contaminants in an Unusual Desert Arroyo Near a Uranium Mill Tailings Disposal Cell - 12260

    SciTech Connect (OSTI)

    Bush, Richard P.; Morrison, Stan J.

    2012-07-01

    The U.S. Department of Energy (DOE) Office of Legacy Management (LM) manages 27 sites that have groundwater containing uranium concentrations above background levels. The distal portions of the plumes merge into background groundwater that can have 50 μg/L or more uranium. Distinguishing background from site-related uranium is often problematic, but it is critical to determining if remediation is warranted, establishing appropriate remediation goals, and evaluating disposal cell performance. In particular, groundwater at disposal cells located on the upper Cretaceous Mancos Shale may have relatively high background concentrations of uranium. Elevated concentrations of nitrate, selenium, and sulfate accompany the uranium. LM used geologic analogs and uranium isotopic signatures to distinguish background groundwater from groundwater contaminated by a former uranium processing site. The same suite of contaminants is present in groundwater near former uranium processing sites and in groundwater seeps emanating from the Mancos Shale over a broad area. The concentrations of these contaminants in Many Devils Wash, located near LM's Shiprock disposal cell, are similar to those in samples collected from many Mancos seeps, including two analog sites that are 8 to 11 km from the disposal cell. Samples collected from Many Devils Wash and the analog sites have high AR values (about 2.0)-in contrast, groundwater samples collected near the tailings disposal cell have AR values near 1.0. These chemical signatures raise questions about the origin of the contamination seeping into Many Devils Wash. (authors)

  8. Variation of carrier concentration and interface trap density in 8MeV electron irradiated c-Si solar cells

    SciTech Connect (OSTI)

    Bhat, Sathyanarayana Rao, Asha; Krishnan, Sheeja; Sanjeev, Ganesh; Suresh, E. P.

    2014-04-24

    The capacitance and conductance measurements were carried out for c-Si solar cells, irradiated with 8 MeV electrons with doses ranging from 5kGy 100kGy in order to investigate the anomalous degradation of the cells in the radiation harsh environments. Capacitance Voltage measurements indicate that there is a slight reduction in the carrier concentration upon electron irradiation due to the creation of radiation induced defects. The conductance measurement results reveal that the interface state densities and the trap time constant increases with electron dose due to displacement damages in c-Si solar cells.

  9. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the 'L-arginine paradox'

    SciTech Connect (OSTI)

    Shin, Soyoung; Mohan, Srinidi; Fung, Ho-Leung

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Our findings provide a possible solution to the 'L-arginine paradox'. Black-Right-Pointing-Pointer Extracellular L-arginine concentration is the major determinant of NO production. Black-Right-Pointing-Pointer Cellular L-arginine action is limited by cellular ARG transport, not the K{sub m} of NOS. Black-Right-Pointing-Pointer We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of {sup 15}N{sub 4}-ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, {sup 15}N{sub 4}-ARG, dimethylarginines, and L-citrulline by an LC-MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by{sup 15}N-nitrite or estimated {sup 15}N{sub 3}-citrulline concentrations when {sup 15}N{sub 4}-ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced {sup 15}N{sub 4}-ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by {sup 15}N-nitrite, total nitrite and {sup 15}N{sub 3}-citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside the cell

  10. Estrogen induced concentration dependent differential gene expression in human breast cancer (MCF7) cells: Role of transcription factors

    SciTech Connect (OSTI)

    Chandrasekharan, Sabarinath; Kandasamy, Krishna Kumar; Dayalan, Pavithra; Ramamurthy, Viraragavan

    2013-08-02

    Highlights: Estradiol (E2) at low dose induced cell proliferation in breast cancer cells. E2 at high concentration induced cell stress in breast cancer cells. Estrogen receptor physically interacts only with a few transcription factors. Differential expression of genes with Oct-1 binding sites increased under stress. Transcription factor binding sites showed distinct spatial distribution on genes. -- Abstract: Background: Breast cancer cells respond to estrogen in a concentration dependent fashion, resulting in proliferation or apoptosis. The mechanism of this concentration dependent differential outcome is not well understood yet. Methodology: Meta-analysis of the expression data of MCF7 cells treated with low (1 nM) or high (100 nM) dose of estradiol (E2) was performed. We identified genes differentially expressed at the low or the high dose, and examined the nature of regulatory elements in the vicinity of these genes. Specifically, we looked for the difference in the presence, abundance and spatial distribution of binding sites for estrogen receptor (ER) and selected transcription factors (TFs) in the genomic region up to 25 kb upstream and downstream from the transcription start site (TSS) of these genes. Results: It was observed that at high dose E2 induced the expression of stress responsive genes, while at low dose, genes involved in cell cycle were induced. We found that the occurrence of transcription factor binding regions (TFBRs) for certain factors such as Sp1 and SREBP1 were higher on regulatory regions of genes expressed at low dose. At high concentration of E2, genes with a higher frequency of Oct-1 binding regions were predominantly involved. In addition, there were differences in the spatial distribution pattern of the TFBRs in the genomic regions among the two sets of genes. Discussion: E2 induced predominantly proliferative/metabolic response at low concentrations; but at high concentration, stressrescue responses were induced. At high E2

  11. Optimized III-V Multijunction Concentrator Solar Cells on Patterned Si and Ge Substrates: Final Technical Report, 15 September 2004--30 September 2006

    SciTech Connect (OSTI)

    Ringel, S. A.

    2008-11-01

    Goal is to demo realistic path to III-V multijunction concentrator efficiencies > 40% by substrate-engineering combining compositional grading with patterned epitaxy for small-area cells for high concentration.

  12. Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

    SciTech Connect (OSTI)

    Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

    2012-04-15

    In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

  13. GaInP/GaAs/GaInAs Monolithic Tandem Cells for High-Performance Solar Concentrators

    SciTech Connect (OSTI)

    Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

    2005-08-01

    We present a new approach for ultra-high-performance tandem solar cells that involves inverted epitaxial growth and ultra-thin device processing. The additional degree of freedom afforded by the inverted design allows the monolithic integration of high-, and medium-bandgap, lattice-matched (LM) subcell materials with lower-bandgap, lattice-mismatched (LMM) materials in a tandem structure through the use of transparent compositionally graded layers. The current work concerns an inverted, series-connected, triple-bandgap, GaInP (LM, 1.87 eV)/GaAs (LM, 1.42 eV)/GaInAs (LMM, {approx}1 eV) device structure grown on a GaAs substrate. Ultra-thin tandem devices are fabricated by mounting the epiwafers to pre-metallized Si wafer handles and selectively removing the parent GaAs substrate. The resulting handle-mounted, ultra-thin tandem cells have a number of important advantages, including improved performance and potential reclamation/reuse of the parent substrate for epitaxial growth. Additionally, realistic performance modeling calculations suggest that terrestrial concentrator efficiencies in the range of 40-45% are possible with this new tandem cell approach. A laboratory-scale (0.24 cm2), prototype GaInP/GaAs/GaInAs tandem cell with a terrestrial concentrator efficiency of 37.9% at a low concentration ratio (10.1 suns) is described, which surpasses the previous world efficiency record of 37.3%.

  14. On-sun concentrator performance of GaInP/GaAs tandem cells

    SciTech Connect (OSTI)

    Friedman, D.J.; Kurtz, S.R.; Sinha, K.; McMahon, W.E.; Olson, J.M.

    1996-05-01

    The GaInP/GaAs concentrator device has been adapted for and tested in a prototype {open_quotes}real-world{close_quotes} concentrator power system. The device achieved an on-sun efficiency of 28% {+-} 1% in the range of approximately 200-260 suns with device operating temperatures of 38{degrees}C to 42{degrees}C. The authors discuss ways of further improving this performance for future devices.

  15. Evaluation of the Cell Voltage of Electrolytic HI Concentration for Thermochemical Water-Splitting Iodine-Sulfur Process

    SciTech Connect (OSTI)

    Tanaka, Nobuyuki; Yoshida, Mitsunori; Okuda, Hiroyuki; Sato, Hiroyuki; Kubo, Shinji; Onuki, Kaoru

    2007-07-01

    Breakdown of the cell voltage in the electro-dialysis process for concentrating HIx solution (HI-H{sub 2}O-I{sub 2} mixture) was preliminarily examined in an effort to clarify the optimal operation condition as well as to optimize the cell design for the application to the thermochemical water-splitting IS process for large-scale hydrogen production. Basic data such as electric resistance of HIx solution, overvoltage of the iodine-iodide ion redox reaction at graphite electrode, and the membrane voltage drop, were measured using HIx solution with composition of interest. Also, a methodology for estimating the cell voltage was discussed. The calculated cell voltage agreed well with the experimental one indicating the validity of the procedure adopted. (authors)

  16. Cytotoxicity and inhibitory effects of low-concentration triclosan on adipogenic differentiation of human mesenchymal stem cells

    SciTech Connect (OSTI)

    Guo, Li-Wu; Wu, Qiangen; Green, Bridgett; Nolen, Greg; Shi, Leming; LoSurdo, Jessica; Deng, Helen; Bauer, Steven; Fang, Jia-Long; Ning, Baitang

    2012-07-15

    Humans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCS (? 5.0 ?M TCS), but not with low-concentration treatments (? 2.5 ?M TCS). TCS inhibited adipocyte differentiation of hMSCs in a concentration-dependent manner in the 0.156 to 2.5 ?M range as indicated by morphological changes with Oil Red O staining, which is an index of lipid accumulation. The inhibitory effect was confirmed by a decrease in gene expression of specific adipocyte differentiation biomarkers including adipocyte protein 2, lipoprotein lipase, and adiponectin. Our study demonstrates that TCS inhibits adipocyte differentiation of hMSCs under concentrations that are not cytotoxic and in the range observed in human blood. -- Highlights: ? TCS is cytotoxic to un-induced hMSCs at concentrations ? 5.0 ?M. ? TCS at concentrations ? 2.5 ?M is not cytotoxic to induced hMSCs. ? TCS at non-cytotoxic concentrations inhibits lipid formation in induced hMSCs. ? TCS decreases the expression of specific biomarkers of adipocyte differentiation. ? TCS at concentrations observed in human blood inhibits adipogenesis of hMSCs.

  17. Terrestrial Concentrator PV Modules Based on GaInP/GaAs/Ge TJ Cells and Minilens Panels

    SciTech Connect (OSTI)

    Rumyantsev, V. D.; Sadchikov, N. A.; Chalov, A. E.; Ionova, E. A.; Friedman, D. J.; Glenn, G.

    2006-01-01

    This paper is a description of research activity in the field of cost-effective modules realizing the concept of very high solar concentration with small-aperture area Fresnel lenses and multijunction III-V cells. Structural simplicity and 'all-glass' design are the guiding principles of the corresponding development. The advanced concentrator modules are made with silicone Fresnel lens panels (from 8 up to 144 lenses, each lens is 4 times 4 cm{sup 2} in aperture area) with composite structure. GaInP/GaAs/Ge triple-junction cells with average efficiencies of 31.1 and 34.7% at 1000 suns were used for the modules. Conversion efficiency as high as 26.3% has been measured indoors in a test module using a newly developed large-area solar simulator.

  18. Final Report- Technology Enabling Ultra High Concentration Multi-Junction Cells

    Broader source: Energy.gov [DOE]

    Awardee: North Carolina State UniversityLocation: Raleigh, NCSubprogram: PhotovoltaicsFunding Program: Foundational Program to Advance Cell Efficiency (F-PACE) ​Principal Investigator: S. M. Bedair

  19. Device characterization for design optimization of 4 junction inverted metamorphic concentrator solar cells

    SciTech Connect (OSTI)

    Geisz, John F.; France, Ryan M.; Steiner, Myles A.; Friedman, Daniel J.; Garca, Ivn

    2014-09-26

    Quantitative electroluminescence (EL) and luminescent coupling (LC) analysis, along with more conventional characterization techniques, are combined to completely characterize the subcell JV curves within a fourjunction (4J) inverted metamorphic solar cell (IMM). The 4J performance under arbitrary spectral conditions can be predicted from these subcell JV curves. The internal radiative efficiency (IRE) of each junction has been determined as a function of current density from the external radiative efficiency using optical modeling, but this required the accurate determination of the individual junction current densities during the EL measurement as affected by LC. These measurement and analysis techniques can be applied to any multijunction solar cell. The 4J IMM solar cell used to illustrate these techniques showed excellent junction quality as exhibited by high IRE and a one-sun AM1.5D efficiency of 36.3%. This device operates up to 1000 suns without limitations due to any of the three tunnel junctions.

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

    SciTech Connect (OSTI)

    Wojtczuk , S.

    2011-06-01

    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.

  1. Current flow and efficiencies of concentrator InGaP/GaAs/Ge solar cells at temperatures below 300K

    SciTech Connect (OSTI)

    Kalinovsky, Vitaly S. Kontrosh, Evgeny V. Dmitriev, Pavel A. Pokrovsky, Pavel V. Chekalin, Alexander V. Andreev, Viacheslav M.

    2014-09-26

    The forward dark current density voltage (J-V) characteristic is one of the most important characteristics of multi-junction solar cells. It indicates that the mechanisms of current flow in the space charge region of photoactive p-n junctions. If one is to idealize the optical and electrical (coupling) elements of the solar cells, it is the J-V characteristic that determines the theoretically possible efficiency of the solar cell. In this paper, using the connection between the dark J-V and photovoltaic (?-J{sub g}) efficiency generated current density characteristics, the effect of current transport mechanisms in the space charge on the efficiency of multi-junction solar cells was investigated in the temperature range of 300 80 K. In the experimental J-V and ?-J{sub g} curves of the multi-junction solar cells, segments corresponding to the dominant current transport mechanisms were identified. The developed method, based on the analysis of forward dark J-V characteristics, makes it possible to identify the parameters affecting the efficiency of the multi-junction solar cells in a wide range of temperatures and solar radiation concentration.

  2. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1eV)/GaInAs(0.7eV) Four-Junction Solar Cell

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-01-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga{sub 0.5}In{sub 0.5} P/GaAs/Ga{sub 0.75}In{sub 0.25}As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga{sub 0.75}In{sub 0.25}As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap Ga{sub x}In{sub 1-x}As fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the Ga{sub x}In{sub 1-x}As fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  3. Concentrating Photovoltaics (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2009-01-20

    Solar is growing rapidly, and the concentrating photovoltaics industry-both high- and low-concentration cell approaches-may be ready to ramp production in 2009.

  4. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-05-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga0.5In0.5P/GaAs/Ga0.75In0.25As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga0.75In0.25As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap GaxIn1-xAs fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the GaxIn1-xAs fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  5. Micropower chemical fuel-to-electric conversion : a "regenerative flip" hydrogen concentration cell promising near carnot efficiency.

    SciTech Connect (OSTI)

    Wally, Karl

    2006-05-01

    Although battery technology is relatively mature, power sources continue to impose serious limitations for small, portable, mobile, or remote applications. A potentially attractive alternative to batteries is chemical fuel-to-electric conversion. Chemical fuels have volumetric energy densities 4 to 10 times those of batteries. However, realizing this advantage requires efficient chemical fuel-to-electric conversion. Direct electrochemical conversion would be the ideal, but, for most fuels, is generally not within the state-of-the-science. Next best, chemical-to-thermal-to-electric conversion can be attractive if efficiencies can be kept high. This small investigative project was an exploration into the feasibility of a novel hybrid (i.e., thermal-electrochemical) micropower converter of high theoretical performance whose demonstration was thought to be within near-term reach. The system is comprised of a hydrogen concentration electrochemical cell with physically identical hydrogen electrodes as anode and cathode, with each electrode connected to physically identical hydride beds each containing the same low-enthalpy-of-formation metal hydride. In operation, electrical power is generated by a hydrogen concentration differential across the electrochemical cell. This differential is established via coordinated heating and passive cooling of the corresponding hydride source and sink. Heating is provided by the exothermic combustion (i.e., either flame combustion or catalytic combustion) of a chemical fuel. Upon hydride source depletion, the role of source and sink are reversed, heating and cooling reversed, electrodes commutatively reversed, cell operation reversed, while power delivery continues unchanged. This 'regenerative flip' of source and sink hydride beds can be cycled continuously until all available heating fuel is consumed. Electricity is efficiently generated electrochemically, but hydrogen is not consumed, rather the hydrogen is regeneratively cycled as

  6. Plasmatic concentration of organochlorine lindane acts as metabolic disruptors in HepG2 liver cell line by inducing mitochondrial disorder

    SciTech Connect (OSTI)

    Benarbia, Mohammed el Amine; Macherel, David; Faure, Sbastien; Jacques, Caroline; Andriantsitohaina, Ramaroson; Malthiry, Yves

    2013-10-15

    Lindane (LD) is a persistent environmental pollutant that has been the subject of several toxicological studies. However, concentrations used in most of the reported studies were relatively higher than those found in the blood of the contaminated area residents and effects of low concentrations remain poorly investigated. Moreover, effects on cell metabolism and mitochondrial function of exposure to LD have received little attention. This study was designed to explore the effects of low concentrations of LD on cellular metabolism and mitochondrial function, using the hepatocarcinoma cell line HepG2. Cells were exposed to LD for 24, 48 and 72 h and different parameters linked with mitochondrial regulation and energy metabolism were analyzed. Despite having any impact on cellular viability, exposure to LD at plasmatic concentrations led to an increase of maximal respiratory capacity, complex I activity, intracellular ATP and NO release but decreased uncoupled respiration to ATP synthesis and medium lactate levels. In addition, LD exposure resulted in the upregulation of mitochondrial biogenesis genes. We suggest that, at plasmatic concentrations, LD acts as a metabolic disruptor through impaired mitochondrial function and regulation with an impact on cellular energetic metabolism. In addition, we propose that a cellular assay based on the analysis of mitochondria function, such as described here for LD, may be applicable for larger studies on the effects of low concentrations of xenobiotics, because of the exquisite sensitivity of this organelle. - Highlights: Our data clearly demonstrated in HepG2 cells that exposure at plasmatic low concentrations of LD were able to: Impair mitochondrial function Caused alteration on nucleo-mitochondrial cross-talk Increase nitric oxide release and protein nitration Impair cellular energetic metabolism and lipid accumulation.

  7. GaAs, AlGaAs and InGaP Tunnel Junctions for Multi-Junction Solar Cells Under Concentration: Resistance Study

    SciTech Connect (OSTI)

    Wheeldon, Jeffrey F.; Valdivia, Christopher E.; Walker, Alex; Kolhatkar, Gitanja; Hall, Trevor J.; Hinzer, Karin; Masson, Denis; Riel, Bruno; Fafard, Simon; Jaouad, Abdelatif; Turala, Artur; Ares, Richard; Aimez, Vincent

    2010-10-14

    The following four TJ designs, AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs are studied to determine minimum doping concentration to achieve a resistance of <10{sup -4} {omega}{center_dot}cm{sup 2} and a peak tunneling current suitable for MJ solar cells up to 1500-suns concentration (operating current of 21 A/cm{sup 2}). Experimentally calibrated numerical models are used to determine how the resistance changes as a function of doping concentration. The AlGaAs/GaAs TJ design is determined to require the least doping concentration to achieve the specified resistance and peak tunneling current, followed by the GaAs/GaAs, and AlGaAs/AlGaAs TJ designs. The AlGaAs/InGaP TJ design can only achieve resistances >5x10{sup -4} {omega}cm{sup 2}.

  8. Bisphenol A at a low concentration boosts mouse spermatogonial cell proliferation by inducing the G protein-coupled receptor 30 expression

    SciTech Connect (OSTI)

    Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang; Zhu, Ben-Zhan

    2013-02-15

    Bisphenol A (BPA) is one of the most prevalent chemicals in daily-use materials, therefore, human exposure to BPA is ubiquitous. We found that low concentrations of BPA stimulate the spermatogonial GC-1 cells proliferation by G protein-coupled receptor 30 (GPR30)-mediated epidermal growth factor receptor (EGFR)-extracellular regulated kinase (ERK)-c-Fos pathway. However, through the same pathway GPR30 expression has been shown to be induced by EGF, an EGFR ligand. Thus, we want to know if low concentrations of BPA are able to induce the GPR30 expression and the possible mechanism(s) in GC-1 cells. By transient transfection with expression plasmids, 10{sup ?9} M BPA significantly transactivates the Gpr30-5?-flanking region through activating the GPR30, cGMP-dependent protein kinase (PKG), estrogen receptor-? (ER-?), and EFGR-ERK pathways. Furthermore, an activator protein-1 (AP-1) site located within this region is found to be responsible for the transactivation of BPA. Expectedly, through the same pathways, BPA significantly induces the gene and protein expression of GPR30. c-Fos is further observed to be strongly recruited to the AP-1 site in a chromatin immunoprecipitation assay and its dysfunction on the AP-1 site markedly suppresses the expression of GPR30, p-ERK1/2, p-Ser118-ER-? and cell proliferation by BPA. Our results demonstrate that a low-concentration BPA induces GPR30 expression through the GPR30-EFGR-ERK-c-Fos, ER-?, and PKG pathways, presumably boosting the cells proliferation via a regulatory loop. The present study provides a novel insight into the potential role of GPR30 in the initiation and progression of male germ cell cancer induced by environmentally relevant BPA. - Highlights: ? Low concentrations of BPA activate the PKG and GPR30-EFGR-ERK-ER-? pathways. ? Low concentrations of BPA activate the AP-1 site of Gpr30-5?-flanking region. ? Low concentrations of BPA induce the expression of GPR30 gene and protein. ? Low concentrations of BPA boost

  9. Enhancement of current collection in epitaxial lift-off InAs/GaAs quantum dot thin film solar cell and concentrated photovoltaic study

    SciTech Connect (OSTI)

    Sogabe, Tomah Shoji, Yasushi; Tamayo, Efrain; Okada, Yoshitaka; Mulder, Peter; Schermer, John

    2014-09-15

    We report the fabrication of a thin film InAs/GaAs quantum dot solar cell (QD cell) by applying epitaxial lift-off (ELO) approach to the GaAs substrate. We confirmed significant current collection enhancement (?0.91?mA/cm{sup 2}) in the ELO-InAs QD cell within the wavelength range of 700?nm900?nm when compared to the ELO-GaAs control cell. This is almost six times of the sub-GaAs bandgap current collection (?0.16?mA/cm{sup 2}) from the wavelength range of 900?nm and beyond, we also confirmed the ELO induced resonance cavity effect was able to increase the solar cell efficiency by increasing both the short circuit current and open voltage. The electric field intensity of the resonance cavity formed in the ELO film between the Au back reflector and the GaAs front contact layer was analyzed in detail by finite-differential time-domain (FDTD) simulation. We found that the calculated current collection enhancement within the wavelength range of 700?nm900?nm was strongly influenced by the size and shape of InAs QD. In addition, we performed concentrated light photovoltaic study and analyzed the effect of intermediate states on the open voltage under varied concentrated light intensity for the ELO-InAs QD cell.

  10. Performance of single-junction and dual-junction InGaP/GaAs solar cells under low concentration ratios

    SciTech Connect (OSTI)

    Khan, Aurangzeb; Yamaguchi, Masafumi; Takamoto, Tatsuya

    2004-10-11

    A study of the performance of single-junction InGaP/GaAs and dual-junction InGaP/GaAs tandem cells under low concentration ratios (up to 15 suns), before and after 1 MeV electron irradiation is presented. Analysis of the tunnel junction parameters under different concentrated light illuminations reveals that the peak current (J{sub P}) and valley current (J{sub V}) densities should be greater than the short-circuit current density (J{sub sc}) for better performance. The tunnel junction behavior against light intensity improved after irradiation. This led to the suggestion that the peak current density (J{sub P}) and valley current density (J{sub V}) of the tunnel junction were enhanced after irradiation or the peak current was shifted to higher concentration. The recovery of the radiation damage under concentrated light illumination conditions suggests that the performance of the InGaP/GaAs tandem solar cell can be enhanced even under low concentration ratios.

  11. Photovoltaic solar concentrator

    DOE Patents [OSTI]

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  12. Photovoltaic solar concentrator

    DOE Patents [OSTI]

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  13. Germanium subcells for multijunction GaInP/GaInAs/Ge solar cells

    SciTech Connect (OSTI)

    Kalyuzhnyy, N. A.; Gudovskikh, A. S.; Evstropov, V. V.; Lantratov, V. M.; Mintairov, S. A.; Timoshina, N. Kh.; Shvarts, M. Z.; Andreev, V. M.

    2010-11-15

    Photovoltaic converters based on n-GaInP/n-p-Ge heterostructures grown by the OMVPE under different conditions of formation of the p-n junction are studied. The heterostructures are intended for use as narrow-gap subcells of the GaInP/GaInAs/Ge three-junction solar cells. It is shown that, in Ge p-tn junctions, along with the diffusion mechanism, the tunneling mechanism of the current flow exists; therefore, the two-diode electrical equivalent circuit of the Ge p-n junction is used. The diode parameters are determined for both mechanisms from the analysis of both dark and 'light' current-voltage dependences. It is shown that the elimination of the component of the tunneling current allows one to increase the efficiency of the Ge subcell by {approx}1% with conversion of nonconcentrated solar radiation. The influence of the tunneling current on the efficiency of the Ge-based devices can be in practice reduced to zero at photogenerated current density of {approx}1.5 A/cm{sup 2} due to the use of the concentrated solar radiation.

  14. An inverted AlGaAs/GaAs patterned-Ge tunnel junction cascade concentrator solar cell

    SciTech Connect (OSTI)

    Venkatasubramanian, R. )

    1993-01-01

    This report describes work to develop inverted-grown Al[sub 0.34]Ga[sub 0.66]As/GaAs cascades. Several significant developments are reported on as follows: (1) The AM1.5 1-sun total-area efficiency of the top Al[sub 0.34]Ga[sub 0.66]As cell for the cascade was improved from 11.3% to 13.2% (NREL measurement [total-area]). (2) The cycled'' organometallic vapor phase epitaxy growth (OMVPE) was studied in detail utilizing a combination of characterization techniques including Hall-data, photoluminescence, and secondary ion mass spectroscopy. (3) A technique called eutectic-metal-bonding (EMB) was developed by strain-free mounting of thin GaAs-AlGaAs films (based on lattice-matched growth on Ge substrates and selective plasma etching of Ge substrates) onto Si carrier substrates. Minority-carrier lifetime in an EMB GaAs double-heterostructure was measured as high as 103 nsec, the highest lifetime report for a freestanding GaAs thin film. (4) A thin-film, inverted-grown GaAs cell with a 1-sun AM1.5 active-area efficiency of 20.3% was obtained. This cell was eutectic-metal-bonded onto Si. (5) A thin-film inverted-grown, Al[sub 0.34]Ga[sub 0.66]As/GaAs cascade with AM1.5 efficiency of 19.9% and 21% at 1-sun and 7-suns, respectively, was obtained. This represents an important milestone in the development of an AlGaAs/GaAs cascade by OMVPE utilizing a tunnel interconnect and demonstrates a proof-of-concept for the inverted-growth approach.

  15. Concentrator Photovoltaic System Basics | Department of Energy

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

    Concentrator Photovoltaic System Basics August 20, 2013 - 4:12pm Addthis Concentrator photovoltaic (PV) systems use less solar cell material than other PV systems. PV cells are the ...

  16. Solar Junction Develops World Record Setting Concentrated Photovoltaic...

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

    Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell April 18, 2013 - ...

  17. Photovoltaic concentrator module improvements study

    SciTech Connect (OSTI)

    Levy, S.L.; Kerschen, K.A. ); Hutchison, G. ); Nowlan, M.J. )

    1991-08-01

    This report presents results of a project to design and fabricate an improved photovoltaic concentrator module. Using previous work as a baseline, this study conducted analyses and testing to select major module components and design features. The lens parquet and concentrator solar cell were selected from the highest performing, available components. A single 185X point-focus module was fabricated by the project team and tested at Sandia. Major module characteristics include a 6 by 4 compression-molded acrylic lens parquet (0.737 m{sup 2} area), twenty-four 0.2 ohms-cm, FZ, p-Si solar cells (1.56 cm{sup 2} area) soldered to ceramic substrates and copper heat spreaders, and an aluminized steel housing with corrugated bottom. This project marked the first attempt to use prismatic covers on solar cells in a high-concentration, point-focus application. Cells with 15 percent metallization were obtained, but problems with the fabrication and placement of prismatic covers on these cells lead to the decision not to use covers in the prototype module. Cell assembly fabrication, module fabrication, and module optical design activities are presented here. Test results are also presented for bare cells, cell assemblies, and module. At operating conditions of 981 watts/m{sup 2} DNI and an estimated cell temperature of 65{degrees}C, the module demonstrated an efficiency of 13.9 percent prior to stressed environmental exposure. 12 refs., 56 figs., 7 tabs.

  18. PROJECT PROFILE: Enabling High Concentration Photovoltaics with...

    Energy Savers [EERE]

    The efficiency and concentration of III-V multi-junction solar cells are essential to reduce the cost of high concentration photovoltaic systems (HCPV). This project will push the ...

  19. National solar technology roadmap: Concentrator PV

    SciTech Connect (OSTI)

    Friedman, Dan

    2007-06-01

    This roadmap addresses high-concentration (>10x) photovoltaic (PV) systems, incorporating high-efficiency III-V or silicon cells, trackers, and reflective or refractive optics.

  20. Concentrating Photovoltaics at the Solar Technology Acceleration Center

    Office of Energy Efficiency and Renewable Energy (EERE)

    This photograph shows concentrating photovoltaic (CPV) systems that use Fresnel lenses to concentrate sunlight onto solar cells. Researchers from the National Renewable Energy Laboratory and Japan...

  1. Concentrating Solar Power Forum Concentrating Photovoltaics (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2008-05-06

    This presentation's summaries: a convenient truth, comparison of three concentrator technologies, value of high efficiency, and status of industry.

  2. Planar photovoltaic solar concentrator module

    DOE Patents [OSTI]

    Chiang, C.J.

    1992-12-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor. 5 figs.

  3. Planar photovoltaic solar concentrator module

    DOE Patents [OSTI]

    Chiang, Clement J.

    1992-01-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

  4. The level of menadione redox-cycling in pancreatic β-cells is proportional to the glucose concentration: Role of NADH and consequences for insulin secretion

    SciTech Connect (OSTI)

    Heart, Emma; Palo, Meridith; Womack, Trayce; Smith, Peter J.S.; Gray, Joshua P.

    2012-01-15

    Pancreatic β-cells release insulin in response to elevation of glucose from basal (4–7 mM) to stimulatory (8–16 mM) levels. Metabolism of glucose by the β-cell results in the production of low levels of reactive oxygen intermediates (ROI), such as hydrogen peroxide (H{sub 2}O{sub 2}), a newly recognized coupling factor linking glucose metabolism to insulin secretion. However, high and toxic levels of H{sub 2}O{sub 2} inhibit insulin secretion. Menadione, which produces H{sub 2}O{sub 2} via redox cycling mechanism in a dose-dependent manner, was investigated for its effect on β-cell metabolism and insulin secretion in INS-1 832/13, a rat β-cell insulinoma cell line, and primary rodent islets. Menadione-dependent redox cycling and resulting H{sub 2}O{sub 2} production under stimulatory glucose exceeded several-fold those reached at basal glucose. This was paralleled by a differential effect of menadione (0.1–10 μM) on insulin secretion, which was enhanced at basal, but inhibited at stimulatory glucose. Redox cycling of menadione and H{sub 2}O{sub 2} formation was dependent on glycolytically-derived NADH, as inhibition of glycolysis and application of non-glycogenic insulin secretagogues did not support redox cycling. In addition, activity of plasma membrane electron transport, a system dependent in part on glycolytically-derived NADH, was also inhibited by menadione. Menadione-dependent redox cycling was sensitive to the NQO1 inhibitor dicoumarol and the flavoprotein inhibitor diphenylene iodonium, suggesting a role for NQO1 and other oxidoreductases in this process. These data may explain the apparent dichotomy between the stimulatory and inhibitory effects of H{sub 2}O{sub 2} and menadione on insulin secretion. -- Highlights: ► Menadione stimulation or inhibition of insulin secretion is dependent upon applied glucose levels. ► Menadione-dependent H{sub 2}O{sub 2} production is proportional to applied glucose levels. ► Quinone-mediated redox cycling

  5. High efficiency and high concentration in photovoltaics

    SciTech Connect (OSTI)

    Yamaguchi, Masafumi; Luque, A.

    1999-10-01

    In this paper, the authors present the state-of-the-art of multijunction solar cells and the future prospects of this technology. Their use in terrestrial applications will likely be for concentrators operating at very high concentrations. Some trends are also discussed and the authors present a cost calculation showing that highly efficient cells under very high concentration would be able to produce electricity at costs competitive with electricity generation costs for some utilities.

  6. An inverted AlGaAs/GaAs patterned-Ge tunnel junction cascade concentrator solar cell. Final subcontract report, 1 January 1991--31 August 1992

    SciTech Connect (OSTI)

    Venkatasubramanian, R.

    1993-01-01

    This report describes work to develop inverted-grown Al{sub 0.34}Ga{sub 0.66}As/GaAs cascades. Several significant developments are reported on as follows: (1) The AM1.5 1-sun total-area efficiency of the top Al{sub 0.34}Ga{sub 0.66}As cell for the cascade was improved from 11.3% to 13.2% (NREL measurement [total-area]). (2) The ``cycled`` organometallic vapor phase epitaxy growth (OMVPE) was studied in detail utilizing a combination of characterization techniques including Hall-data, photoluminescence, and secondary ion mass spectroscopy. (3) A technique called eutectic-metal-bonding (EMB) was developed by strain-free mounting of thin GaAs-AlGaAs films (based on lattice-matched growth on Ge substrates and selective plasma etching of Ge substrates) onto Si carrier substrates. Minority-carrier lifetime in an EMB GaAs double-heterostructure was measured as high as 103 nsec, the highest lifetime report for a freestanding GaAs thin film. (4) A thin-film, inverted-grown GaAs cell with a 1-sun AM1.5 active-area efficiency of 20.3% was obtained. This cell was eutectic-metal-bonded onto Si. (5) A thin-film inverted-grown, Al{sub 0.34}Ga{sub 0.66}As/GaAs cascade with AM1.5 efficiency of 19.9% and 21% at 1-sun and 7-suns, respectively, was obtained. This represents an important milestone in the development of an AlGaAs/GaAs cascade by OMVPE utilizing a tunnel interconnect and demonstrates a proof-of-concept for the inverted-growth approach.

  7. NREL: Concentrating Solar Power Research - Southwest Concentrating...

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

    of deployment, combined with research and development to reduce technology component costs, could help reduce concentrating solar power electricity costs to 0.07kilowatt-hour. ...

  8. NREL: Concentrating Solar Power Research - Concentrating Solar...

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

    Concentrating Solar Power Resource Maps These direct-normal solar radiation maps-filtered by solar resource and land availability-identify the most economically suitable lands ...

  9. Concentrating Solar Power Projects | Concentrating Solar Power...

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

    SolarPACES, an international program of the International Energy Agency, furthers collaborative development, testing, and marketing of concentrating solar power plants. Activities ...

  10. PROJECT PROFILE: Enabling High Concentration Photovoltaics with 50%

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

    Efficient Solar Cells | Department of Energy Enabling High Concentration Photovoltaics with 50% Efficient Solar Cells PROJECT PROFILE: Enabling High Concentration Photovoltaics with 50% Efficient Solar Cells Funding Opportunity: SuNLaMP SunShot Subprogram: Photovoltaics Location: National Renewable Energy Laboratory, Golden, CO Amount Awarded: $8,000,000 The efficiency and concentration of III-V multi-junction solar cells are essential to reduce the cost of high concentration photovoltaic

  11. ARM - Measurement - Ozone Concentration

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

    Measurement : Ozone Concentration The atmospheric concentration or volume mixing ratio (mole fraction) of Ozone Categories Atmospheric State Instruments The above measurement is...

  12. Concentrating Solar Power

    SciTech Connect (OSTI)

    Not Available

    2008-09-01

    Summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  13. Photovoltaic solar concentrator

    SciTech Connect (OSTI)

    Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

    2015-09-08

    A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

  14. Concentrating Solar Power: Concentrating Optics for Lower Levelized...

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

    Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs (CSP: COLLECTS) Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs ...

  15. Concentrating Solar Power

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

    Concentrating Solar Power Concentrating solar power (CSP) technologies use mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. A distinguishing feature of CSP is its ability to incorporate simple, efficient, and cost-effective thermal energy storage by virtue of converting sunlight to heat as an intermediate step to generating electricity. In addition to providing dispatchable

  16. Concentrated Thermoelectric Power

    Broader source: Energy.gov [DOE]

    This fact sheet describes a concentrated solar hydroelectric power project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by MIT, is working to demonstrate concentrating solar thermoelectric generators with >10% solar-to-electrical energy conversion efficiency while limiting optical concentration to less than a factor of 10 and potentially less than 4. When combined with thermal storage, CSTEGs have the potential to provide electricity day and night using no moving parts at both the utility and distributed scale.

  17. Scattering Solar Thermal Concentrators

    Office of Environmental Management (EM)

    sunshot DOEGO-102012-3669 * September 2012 MOTIVATION All thermal concentrating solar power (CSP) systems use solar tracking, which involves moving large mirror surfaces...

  18. Concentrating Solar Power

    SciTech Connect (OSTI)

    Solar Energy Technologies Program

    2010-09-28

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  19. Concentrating photovoltaic solar panel

    DOE Patents [OSTI]

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  20. Water Sample Concentrator

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  1. Solar Junction Develops World Record Setting Concentrated Photovoltaic...

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

    the company's concentrated photovoltaic technology that also set a world record for conversion efficiency. The company's cell technology relies on inexpensive lenses to magnify...

  2. Joined concentric tubes

    DOE Patents [OSTI]

    DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven

    2013-01-01

    Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.

  3. ARM - Measurement - Methane concentration

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

    concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Methane concentration The amount of methane, a greenhouse gas, per unit of volume. Categories Atmospheric Carbon Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those

  4. Concentration Averaging | Department of Energy

    Office of Environmental Management (EM)

    Concentration Averaging Concentration Averaging Summary Notes from 3 October 2007 Generic Technical Issue Discussion on Concentration Averaging PDF icon Summary Notes from 3...

  5. Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy

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

    Costs (CSP: COLLECTS) | Department of Energy Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs (CSP: COLLECTS) Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs (CSP: COLLECTS) Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs (CSP: COLLECTS) The Concentrating Solar Power: Concentrating Optics for Lower Levelized Energy Costs (CSP: COLLECTS) funding program aims to further accelerate progress toward

  6. Cost Competitive Electricity from Photovoltaic Concentrators Called

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

    'Imminent' - News Releases | NREL Cost Competitive Electricity from Photovoltaic Concentrators Called 'Imminent' July 13, 2005 Golden, Colo. - Solar concentrators using highly efficient photovoltaic solar cells will reduce the cost of electricity from sunlight to competitive levels soon, attendees were told at a recent international conference on the subject. Herb Hayden of Arizona Public Service (APS) and Robert McConnell and Martha Symko-Davies of the U.S. Department of Energy's National

  7. Airborne agent concentration analysis

    DOE Patents [OSTI]

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  8. Scattering Solar Thermal Concentrators

    SciTech Connect (OSTI)

    Giebink, Noel C.

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  9. Concentrating Solar Power | NREL

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

    SolarReserve's Crescent Dunes CSP Project, near Tonopah, Nevada, has an electricity generating capacity of 110 megawatts. (credit: SolarReserve) Researchers at the National Renewable Energy Laboratory (NREL) provide scientific, engineering, and analytical expertise to help advance innovation in concentrating solar power (CSP) technologies. These technologies capture sunlight to produce heat that drives today's conventional thermoelectric generation systems or future advanced generation systems.

  10. Concentrating Solar Power Projects | Department of Energy

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

    Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects Concentrating Solar Power Projects

  11. Nonimaging light concentrator with uniform irradiance

    DOE Patents [OSTI]

    Winston, Roland; Gee, Randy C.

    2003-04-01

    A nonimaging light concentrator system including a primary collector of light, an optical mixer disposed near the focal zone for collecting light from the primary collector, the optical mixer having a transparent entrance aperture, an internally reflective housing for substantially total internal reflection of light, a transparent exit aperture and an array of photovoltaic cells disposed near the transparent exit aperture.

  12. Concentrating Solar Power (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01

    Concentrating Solar Power (CSP) offers a utility-scale, firm, dispatchable renewable energy option that can help meet the nation's goal of making solar energy cost competitive with other energy sources by the end of the decade. The DOE SunShot Initiative is a collaborative national initiative to make solar energy technologies cost-competitive with other forms of energy by reducing the cost of solar energy systems by about 75% by the end of the decade. Reducing the total installed cost for utility-scale solar electricity to roughly 6 cents per kilowatt hour without subsidies will result in rapid, large-scale adoption of solar electricity across the United States. Reaching this goal will re-establish American technological leadership, improve the nation's energy security, and strengthen U.S. economic competitiveness in the global clean energy race. SunShot will work to bring down the full cost of solar - including the costs of solar cells and installation by focusing on four main pillars: (1) Technologies for solar cells and arrays that convert sunlight to energy; (2) Electronics that optimize the performance of the installation; (3) Improvements in the efficiency of solar manufacturing processes; and (4) Installation, design, and permitting for solar energy systems.

  13. Concentrated Solar Thermoelectric Power

    SciTech Connect (OSTI)

    Chen, Gang; Ren, Zhifeng

    2015-07-09

    The goal of this project is to demonstrate in the lab that solar thermoelectric generators (STEGs) can exceed 10% solar-to-electricity efficiency, and STEGs can be integrated with phase-change materials (PCM) for thermal storage, providing operation beyond daylight hours. This project achieved significant progress in many tasks necessary to achieving the overall project goals. An accurate Themoelectric Generator (TEG) model was developed, which included realistic treatment of contact materials, contact resistances and radiative losses. In terms of fabricating physical TEGs, high performance contact materials for skutterudite TE segments were developed, along with brazing and soldering methods to assemble segmented TEGs. Accurate measurement systems for determining device performance (in addition to just TE material performance) were built for this project and used to characterize our TEGs. From the optical components’ side, a spectrally selective cermet surface was developed with high solar absorptance and low thermal emittance, with thermal stability at high temperature. A measurement technique was also developed to determine absorptance and total hemispherical emittance at high temperature, and was used to characterize the fabricated spectrally selective surfaces. In addition, a novel reflective cavity was designed to reduce radiative absorber losses and achieve high receiver efficiency at low concentration ratios. A prototype cavity demonstrated that large reductions in radiative losses were possible through this technique. For the overall concentrating STEG system, a number of devices were fabricated and tested in a custom built test platform to characterize their efficiency performance. Additionally, testing was performed with integration of PCM thermal storage, and the storage time of the lab scale system was evaluated. Our latest testing results showed a STEG efficiency of 9.6%, indicating promising potential for high performance concentrated STEGs.

  14. Vapor concentration monitor

    DOE Patents [OSTI]

    Bayly, John G.; Booth, Ronald J.

    1977-01-01

    An apparatus for monitoring the concentration of a vapor, such as heavy water, having at least one narrow bandwidth in its absorption spectrum, in a sample gas such as air. The air is drawn into a chamber in which the vapor content is measured by means of its radiation absorption spectrum. High sensitivity is obtained by modulating the wavelength at a relatively high frequency without changing its optical path, while high stability against zero drift is obtained by the low frequency interchange of the sample gas to be monitored and of a reference sample. The variable HDO background due to natural humidity is automatically corrected.

  15. METHOD OF ISOTOPE CONCENTRATION

    DOE Patents [OSTI]

    Taylor, T.I.; Spindel, W.

    1960-02-01

    A method of concentrating N/sup 15/ in a liquid is described. Gaseous nitric oxide and at least one liquid selected from the group consisting of the aqueous oxyacids and oxides of nitrogen, wherein the atomic ratio of oxygen to nitrogen is greater than unity, are brought into intimate contact to cause an enrichment of the liquid and a depletion of the gas in N/sup 15/. The liquid is, thereafter, reacted with sulfur dioxide to produce a gas contuining nitric oxide. The gas contuining nitric oxide is then continuously passed in countercurrent contact with the liquid to cause further enrichment of the liquid.

  16. Optical oxygen concentration monitor

    DOE Patents [OSTI]

    Kebabian, Paul

    1997-01-01

    A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen's A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest.

  17. Optical oxygen concentration monitor

    DOE Patents [OSTI]

    Kebabian, P.

    1997-07-22

    A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen`s A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2,000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest. 4 figs.

  18. Concentrator Optics | Open Energy Information

    Open Energy Info (EERE)

    Concentrator Optics Jump to: navigation, search Name: Concentrator Optics Place: Marburg, Germany Zip: 35037 Product: A Germany-based company engaged in the design and production...

  19. Non-tracking solar concentrator with a high concentration ratio

    DOE Patents [OSTI]

    Hinterberger, Henry

    1977-01-01

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

  20. Concentrating Solar Power Basics | NREL

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

    Concentrating Solar Power Basics Many power plants today use fossil fuels as a heat source to boil water. The steam from the boiling water spins a large turbine, which drives a generator to produce electricity. However, a new generation of power plants with concentrating solar power systems uses the sun as a heat source. The three main types of concentrating solar power systems are: linear concentrator, dish/engine, and power tower systems. Linear concentrator systems collect the sun's energy

  1. Concentric tube support assembly

    DOE Patents [OSTI]

    Rubio, Mark F.; Glessner, John C.

    2012-09-04

    An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

  2. Current Status of Concentrator Photovoltaic (CPV) Technology

    SciTech Connect (OSTI)

    Philipps, S. P.; Bett, A. W.; Horowitz, K.; Kurtz, S.

    2015-01-01

    This report describes the current status of the market and technology for concentrator photovoltaic (CPV) cells and modules. Significant progress in CPV has been achieved, including record efficiencies for modules (36.7%) and cells (46%), as well as growth of large field installations in recent years. CPV technology may also have the potential to be cost-competitive on a levelized cost of energy (LCOE) basis in regions of high direct normal irradiance (DNI). The study includes an overview of all installations larger than 1 MW, information on companies currently active in the CPV field, efficiency data, and estimates of the LCOE in different scenarios.

  3. Photovoltaic concentrator assembly with optically active cover

    DOE Patents [OSTI]

    Plesniak, Adam P

    2014-01-21

    A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

  4. Markets for concentrating solar power

    SciTech Connect (OSTI)

    Not Available

    1998-04-01

    The report describes the markets for concentrating solar power. As concentrating solar power technologies advance into the early stages of commercialization, their economic potential becomes more sharply defined and increasingly tangible.

  5. Multijunction Photovoltaic Technologies for High-Performance Concentrators

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2006-01-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  6. Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2006-05-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  7. Baseload Concentrating Solar Power Generation | Department of...

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

    Concentrating Solar Power Baseload Concentrating Solar Power Generation Baseload Concentrating Solar Power Generation Baseload Concentrating Solar Power Generation In 2010, DOE ...

  8. Device for measuring the total concentration of oxygen in gases

    DOE Patents [OSTI]

    Isaacs, Hugh S.; Romano, Anthony J.

    1977-01-01

    This invention provides a CO equilibrium in a device for measuring the total concentration of oxygen impurities in a fluid stream. To this end, the CO equilibrium is produced in an electrochemical measuring cell by the interaction of a carbon element in the cell with the chemically combined and uncombined oxygen in the fluid stream at an elevated temperature.

  9. ARM - Measurement - Organic Carbon Concentration

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

    govMeasurementsOrganic Carbon Concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Organic Carbon Concentration The concentration of carbon bound in organic compounds. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available

  10. Continuous flow dielectrophoretic particle concentrator

    DOE Patents [OSTI]

    Cummings, Eric B.

    2007-04-17

    A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

  11. Publications | Concentrating Solar Power | NREL

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

    develops publications-including technical reports, journal articles, and conference papers-about its research and development (R&D) activities in concentrating solar power (CSP). ...

  12. Concentrating Solar Power: Power Towers

    Office of Energy Efficiency and Renewable Energy (EERE)

    This video provides an overview of the principles, applications, and benefits of generating electricity using power towers, a concentrating solar power (CSP) technology. A brief animation explains...

  13. Research | Concentrating Solar Power | NREL

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

    Research Research and development (R&D) capabilities in concentrating solar power (CSP) at the National Renewable Energy Laboratory (NREL) span the entire electricity system-from ...

  14. Facilities | Concentrating Solar Power | NREL

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

    The National Renewable Energy Laboratory (NREL) provides industry, government, and university staff who are researching concentrating solar power (CSP) with access to ...

  15. Utility-scale photovoltaic concentrators

    SciTech Connect (OSTI)

    None, None

    2009-01-18

    The photovoltaics concentrators section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  16. DOE High Performance Concentrator PV Project

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2005-08-01

    Much in demand are next-generation photovoltaic (PV) technologies that can be used economically to make a large-scale impact on world electricity production. The U.S. Department of Energy (DOE) initiated the High-Performance Photovoltaic (HiPerf PV) Project to substantially increase the viability of PV for cost-competitive applications so that PV can contribute significantly to both our energy supply and environment. To accomplish such results, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices with the goal of enabling progress of high-efficiency technologies toward commercial-prototype products. We will describe the details of the subcontractor and in-house progress in exploring and accelerating pathways of III-V multijunction concentrator solar cells and systems toward their long-term goals. By 2020, we anticipate that this project will have demonstrated 33% system efficiency and a system price of $1.00/Wp for concentrator PV systems using III-V multijunction solar cells with efficiencies over 41%.

  17. Light shield for solar concentrators

    DOE Patents [OSTI]

    Plesniak, Adam P.; Martins, Guy L.

    2014-08-26

    A solar receiver unit including a housing defining a recess, a cell assembly received in the recess, the cell assembly including a solar cell, and a light shield received in the recess and including a body and at least two tabs, the body defining a window therein, the tabs extending outward from the body and being engaged with the recess, wherein the window is aligned with the solar cell.

  18. Monitoring electrolyte concentrations in redox flow battery systems

    SciTech Connect (OSTI)

    Chang, On Kok; Sopchak, David Andrew; Pham, Ai Quoc; Kinoshita, Kimio

    2015-03-17

    Methods, systems and structures for monitoring, managing electrolyte concentrations in redox flow batteries are provided by introducing a first quantity of a liquid electrolyte into a first chamber of a test cell and introducing a second quantity of the liquid electrolyte into a second chamber of the test cell. The method further provides for measuring a voltage of the test cell, measuring an elapsed time from the test cell reaching a first voltage until the test cell reaches a second voltage; and determining a degree of imbalance of the liquid electrolyte based on the elapsed time.

  19. Spiral concentrators recover fine coal

    SciTech Connect (OSTI)

    Fiscor, S.

    2005-12-15

    Compound spirals offer better performance in a more efficient configuration. Prep plant operators in the US are increasingly opting to use spiral concentrators. They are easy to install, operate and maintain but their downfall is low capacity. The article describes spirals available from PrepTech/Multotec, Krebs Engineers and Roche MT. It reports on research on spiral concentrator technology. 1 ref., 4 figs.

  20. Monolithic microfluidic concentrators and mixers

    DOE Patents [OSTI]

    Frechet, Jean M.; Svec, Frantisek; Yu, Cong; Rohr, Thomas

    2005-05-03

    Microfluidic devices comprising porous monolithic polymer for concentration, extraction or mixing of fluids. A method for in situ preparation of monolithic polymers by in situ initiated polymerization of polymer precursors within microchannels of a microfluidic device and their use for solid phase extraction (SPE), preconcentration, concentration and mixing.

  1. Process for concentrated biomass saccharification

    DOE Patents [OSTI]

    Hennessey, Susan M.; Seapan, Mayis; Elander, Richard T.; Tucker, Melvin P.

    2010-10-05

    Processes for saccharification of pretreated biomass to obtain high concentrations of fermentable sugars are provided. Specifically, a process was developed that uses a fed batch approach with particle size reduction to provide a high dry weight of biomass content enzymatic saccharification reaction, which produces a high sugars concentration hydrolysate, using a low cost reactor system.

  2. 17β-Estradiol regulates cell proliferation, colony formation...

    Office of Scientific and Technical Information (OSTI)

    ... Subject: 60 APPLIED LIFE SCIENCES; APOPTOSIS; CARCINOMAS; CELL PROLIFERATION; COLONY FORMATION; CONCENTRATION RATIO; CONNECTIVE TISSUE CELLS; DOSES; ESTRADIOL; LUNGS; METASTASES; ...

  3. Linear Concentrator System Basics for Concentrating Solar Power...

    Energy Savers [EERE]

    may be integrated with existing or new combined-cycle natural-gas- and coal-fired plants. ... Illustration of a linear concentrator power plant using parabolic trough collectors. ...

  4. Concentrating Solar Power Projects - Power Tower Projects | Concentrating

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

    Solar Power | NREL Power Tower Projects Aerial photo of a power tower system, showing numerous large, reflective mirrors in concentric circular rows. Tracking the sun, each mirror reflects onto the top of the tower at the center of the circle of mirrors. The receiver at the top of the tower is glowing. Stretched-membrane heliostats with silvered polymer reflectors surround the Solar Two power tower in Daggett, California. Credit: Sandia National Laboratories / PIX 00036 Concentrating solar

  5. NREL's PV Incubator: Where Solar Photovoltaic Records Go to be Broken |

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

    Department of Energy NREL's PV Incubator: Where Solar Photovoltaic Records Go to be Broken NREL's PV Incubator: Where Solar Photovoltaic Records Go to be Broken June 28, 2011 - 11:44am Addthis NREL Principal Engineer Keith Emery prepares to load three-junction concentrator cells into NREL's
 High-Intensity Pulse Solar Simulator to test for efficiency. | Department of Energy Photo | Courtesy of National Renewable Energy Laboratory | Photo by Dennis Schroeder | Public Domain | NREL

  6. Tank waste concentration mechanism study

    SciTech Connect (OSTI)

    Pan, L.C.; Johnson, L.J.

    1994-09-01

    This study determines whether the existing 242-A Evaporator should continue to be used to concentrate the Hanford Site radioactive liquid tank wastes or be replaced by an alternative waste concentration process. Using the same philosophy, the study also determines what the waste concentration mechanism should be for the future TWRS program. Excess water from liquid DST waste should be removed to reduce the volume of waste feed for pretreatment, immobilization, and to free up storage capacity in existing tanks to support interim stabilization of SSTS, terminal cleanout of excess facilities, and other site remediation activities.

  7. Alpha Solarco`s Photovoltaic Concentrator Development program

    SciTech Connect (OSTI)

    Anderson, A.; Bailor, B.; Carroll, D.

    1995-10-01

    This report details the work done under Sandia`s Photovoltaic Concentrator Development contract, funded jointly by Alpha Solarco and the US Department of Energy. It discusses improvements made to the cell assembly and module design of Alpha Solarco`s point-focus, high-concentration photovoltaic module. The goals of this effort were to increase the module efficiency, reduce the manufacturing cost of the cell assembly, and increase product reliability. Redesign of the secondary optical element achieved a 4 percent increase in efficiency due to better cell fill factors and offtrack performance. New, lower cost materials were identified for the secondary optical element, the optical couple between the secondary optical element and the cell, and the cell assembly electrical insulator. Manufacturing process improvements and test equipment are also discussed.

  8. Electrochemical cell

    DOE Patents [OSTI]

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1994-01-01

    An electrochemical cell having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a .beta." alumina electrolyte and NaAlCl.sub.4 or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose.

  9. 500-watt commercialized concentrator system

    SciTech Connect (OSTI)

    Ronney, K.; Aerni, E.

    1983-02-01

    A passively cooled, single-axis tracking, polar-axis mounted photovoltaic concentrator system has been designed, fabricated, installed, and tested. System description, design considerations, system performance and a production cost estimate are detailed.

  10. Energy 101: Concentrating Solar Power

    Broader source: Energy.gov [DOE]

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power...

  11. Concentrating Solar Power (Fact Sheet)

    SciTech Connect (OSTI)

    DOE Solar Energy Technologies Program

    2011-10-13

    Concentrating Solar Power (CSP) offers a utility-scale, firm, dispatchable renewable energy option that can help meet the nation's goal of making solar energy cost competitive with other energy sources by the end of the decade.

  12. ARM - Measurement - Particle number concentration

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

    number concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Particle number concentration The number of particles present in any given volume of air. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those

  13. ARM - Measurement - Trace gas concentration

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

    govMeasurementsTrace gas concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Trace gas concentration The amount per unit volume of trace gases other than carbon dioxide, nitrogen oxides, ozone and water vapor, typically measured in conjunction with in situ aerosol measurements, e.g. carbon monoxide, and sulfur dioxide. Categories Atmospheric State, Atmospheric Carbon Instruments The above

  14. Arontis Solar Concentrator AB | Open Energy Information

    Open Energy Info (EERE)

    Arontis Solar Concentrator AB Jump to: navigation, search Name: Arontis Solar Concentrator AB Place: Harnosand, Sweden Zip: SE-871 31 Product: Developer of a medium-concentrating,...

  15. Concentrated Solar Thermoelectric Power | Department of Energy

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

    Concentrated Solar Thermoelectric Power Concentrated Solar Thermoelectric Power This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, ...

  16. Linear Concentrator System Basics for Concentrating Solar Power

    Broader source: Energy.gov [DOE]

    Linear concentrating solar power (CSP) collectors capture the sun's energy with large mirrors that reflect and focus the sunlight onto a linear receiver tube. The receiver contains a fluid that is heated by the sunlight and then used to heat a traditional power cycle that spins a turbine that drives a generator to produce electricity.

  17. Energy 101: Concentrating Solar Power

    ScienceCinema (OSTI)

    None

    2013-05-29

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  18. Funding Opportunity Announcement: Concentrating Solar Power:...

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

    Funding Opportunity Announcement: Concentrating Solar Power: Advanced Projects Offering Low LCOE Opportunities Funding Opportunity Announcement: Concentrating Solar Power: Advanced ...

  19. Correlations in Characteristic Data of Concentrator Photovoltaics (Poster)

    SciTech Connect (OSTI)

    Sweet, C.; Bosco, N.; Kurtz, S.

    2011-02-01

    This study is motivated by a reported 1-2% infant mortality rate in concentrator photovoltaic cell assemblies. Approximately 650 bare III-V multi-junction PV cells were initially characterized via electroluminescence imaging and both light and dark current-voltage responses were recorded. The cells were then packaged into receivers and their IV response again evaluated both before and after an outdoor high concentration exposure of at least four hours above 750 DNI. Correlations exist between the initial dark IV characteristic and artifacts found in the EL image. Initial results also suggest that artifacts observed in the bare cell may serve as an indicator for early on-sun degradation, though may not be able to predict the infant mortality population.

  20. Photovoltaic concentrator with plastic-film reflector. Final report

    SciTech Connect (OSTI)

    Not Available

    1982-06-01

    A 4m diameter reflective film, parabolic dish concentrator proposed for use with a photovoltaic array has been designed, fabricated, and tested. The concentrator is made from aluminized film gores (wedge shaped pieces) that are taped together along their edges to form a dish. The shape of the dish is maintained by a pressure difference between the front and back. The deep dish was designed to illuminate a cylindrical receiver populated by solar cells with a geometric concentration ratio of 145. Three full scale dishes were made in sequence, each using improvements suggested by the previous design. They were tested with a laser to determine surface errors and flux uniformity on the target.

  1. Fluorescence Correlation Spectroscopy at Micromolar Concentrations without Optical Nanoconfinement

    SciTech Connect (OSTI)

    Laurence, Ted A.; Ly, Sonny; Bourguet, Feliza; Fischer, Nicholas O.; Coleman, Matthew A.

    2014-08-14

    Fluorescence correlation spectroscopy (FCS) is an important technique for studying biochemical interactions dynamically that may be used in vitro and in cell-based studies. It is generally claimed that FCS may only be used at nM concentrations. We show that this general consensus is incorrect and that the limitation to nM concentrations is not fundamental but due to detector limits as well as laser fluctuations. With a high count rate detector system and applying laser fluctuation corrections, we demonstrate FCS measurements up to 38 μM with the same signal-to-noise as at lower concentrations. Optical nanoconfinement approaches previously used to increase the concentration range of FCS are not necessary, and further increases above 38 μM may be expected using detectors and detector arrays with higher saturation rates and better laser fluctuation corrections. This approach greatly widens the possibilities of dynamic measurements of biochemical interactions using FCS at physiological concentrations.

  2. Concentrating Solar Power Projects - Nevada Solar One | Concentrating Solar

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

    Power | NREL Nevada Solar One This page provides information on Nevada Solar One, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. Acciona Energy's Nevada Solar One is the third largest CSP plant in the world and the first plant built in the United States since 1999. Located in Boulder City, Nevada, about 40 miles southeast of Las Vegas, this parabolic trough system has been operating since June 2007. The US$260

  3. Concentrating Solar Power Projects by Country | Concentrating Solar Power |

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

    NREL Country In this section, you can select a country from the map or the following list of countries. You can then select a specific concentrating solar power (CSP) project and review a profile covering project basics, participating organizations, and power plant configuration data for the solar field, power block, and thermal energy storage. Javascript must be enabled to view Flash movie Algeria Australia Canada Chile China Egypt France Germany India Israel Italy Kuwait Mexico Morocco

  4. Concentrating Solar Power Projects by Project Name | Concentrating Solar

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

    Power | NREL Project Name In this section, you can select a concentrating solar power (CSP) project from the alphabetical listing of project names below. You can then review a profile covering project basics, participating organizations, and power plant configuration data for the solar field, power block, and thermal energy storage. Abhijeet Solar Project ACME Solar Tower Agua Prieta II Airlight Energy Ait-Baha Pilot Plant Alba Nova 1 Andasol-1 (AS-1) Andasol-2 (AS-2) Andasol-3 (AS-3)

  5. Concentrating Solar Power Projects by Status | Concentrating Solar Power |

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

    NREL Status In this section, you can select concentrating solar power (CSP) projects under one of five categories: operational, under construction, under development, request for offer or currently non-operational. You can then select a specific project and review a profile covering project basics, participating organizations, and power plant configuration data for the solar field, power block, and thermal energy storage. Operational-projects with working power plants that are producing

  6. Concentrating Solar Power Projects by Technology | Concentrating Solar

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

    Power | NREL Technology In this section, you can select a concentrating solar power (CSP) technology from the list below. You can then select a specific project and review a profile covering project basics, participating organizations, and power plant configuration data for the solar field, power block, and thermal energy storage. Parabolic Trough Systems-line-focus systems that use curved mirrors to focus sunlight on a receiver Linear Fresnel Reflector Systems-line-focus systems that use

  7. Electrokinetic concentration of charged molecules

    DOE Patents [OSTI]

    Singh, Anup K.; Neyer, David W.; Schoeniger, Joseph S.; Garguilo, Michael G.

    2002-01-01

    A method for separating and concentrating charged species from uncharged or neutral species regardless of size differential. The method uses reversible electric field induced retention of charged species, that can include molecules and molecular aggregates such as dimers, polymers, multimers, colloids, micelles, and liposomes, in volumes and on surfaces of porous materials. The retained charged species are subsequently quantitatively removed from the porous material by a pressure driven flow that passes through the retention volume and is independent of direction thus, a multi-directional flow field is not required. Uncharged species pass through the system unimpeded thus effecting a complete separation of charged and uncharged species and making possible concentration factors greater than 1000-fold.

  8. Concentrating Solar Power Fact Sheet

    SciTech Connect (OSTI)

    2015-12-01

    This fact sheet is an overview of the Concentrating Solar Power (CSP) subprogram at the U.S. Department of Energy SunShot Initiative. CSP is a dispatchable, renewable energy option that uses mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. CSP systems can store solar energy to be used when the sun is not shining. It will help meet the nation’s goal of making solar energy fully cost-competitive with other energy sources by the end of the decade. Worldwide, CSP activity is rapidly scaling, with approximately 10 gigawatts (GW) in various stages of operation or development. In the United States alone, nearly 2 GW of CSP are in operation.

  9. Cylindrical acoustic levitator/concentrator

    DOE Patents [OSTI]

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  10. Modular off-axis solar concentrator

    DOE Patents [OSTI]

    Plesniak, Adam P; Hall, John C

    2015-01-27

    A solar concentrator including a housing defining a vertical axis and including a receiving wall connected to a reflecting wall to define an internal volume and an opening into the internal volume, wherein the reflecting wall defines at least one primary optical element, and wherein at least a portion of the reflecting wall includes a layer of reflective material, the housing further including a cover connected to the receiving wall and the reflecting wall to seal the opening, and at least one receiver mounted on the receiving wall such that a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, the receiver including at least one photovoltaic cell.

  11. Enclosed, off-axis solar concentrator

    DOE Patents [OSTI]

    Benitez, Pablo; Grip, Robert E; Minano, Juan C; Narayanan, Authi A; Plesniak, Adam; Schwartz, Joel A

    2013-11-26

    A solar concentrator including a housing having receiving wall, a reflecting wall and at least two end walls, the receiving, reflecting and end walls defining a three-dimensional volume having an inlet, wherein a vertical axis of the housing is generally perpendicular to the inlet, a receiver mounted on the receiving wall of the housing, the receiver including at least one photovoltaic cell, wherein a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, at least one clip disposed on the reflecting wall an optical element received within the three-dimensional volume, the optical element including at least one tab, the tab being engaged by the clip to align the optical element with the receiver, and a window received over the inlet to enclose the housing.

  12. Concentrating Solar Power - Fact Sheet

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

    What will the project do? Combined, the projects are estimated to create nearly 1,800 jobs and enough energy to power more than 100,000 homes. Today, Secretary Chu announced conditional commitments for approximately $2 billion in loan guarantees to two California concentrating solar power plants. The projects are estimated to create nearly 1,800 jobs and will utilize advanced technologies which can help drive down the cost of solar power. The two plants, the Mojave Solar Project in San

  13. Low surfactant concentration enhanced waterflooding

    SciTech Connect (OSTI)

    Wellington, S.L.; Richardson, E.A.

    1995-12-31

    A new gradient scaled flooding test procedure indicated that oil is mobilized by the toe of the surfactant dispersion curve where the concentration is low, 1 to 10 ppm. Underoptimum, highly interfacially active blends of anionic and cationic surfactants were synthesized and formulated to take advantage of the displacement mechanism. Essentially all the initial or residual crude oil was removed from shaly sand packs using approximately 0.4 percent surfactant with less than 0.1 pore volume lag.

  14. Concentrating Solar Power (CSP) Overview

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

    Concentrating Solar Power (CSP) Overview Mark S. Mehos CSP Program Manager National Renewable Energy Laboratory Golden, CO NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC Outline * Technology Overview * U.S. and International Market Overview * DOE Research and Development National Renewable Energy Laboratory Innovation for Our Energy Future CSP, aka Solar Thermal Power Linear

  15. Optofluidic solar concentrators using electrowetting tracking: Concept, design, and characterization

    SciTech Connect (OSTI)

    Cheng, JT; Park, S; Chen, CL

    2013-03-01

    We introduce a novel optofluidic solar concentration system based on electrowetting tracking. With two immiscible fluids in a transparent cell, we can actively control the orientation of fluid fluid interface via electrowetting. The naturally-formed meniscus between the two liquids can function as a dynamic optical prism for solar tracking and sunlight steering. An integrated optofluidic solar concentrator can be constructed from the liquid prism tracker in combination with a fixed and static optical condenser (Fresnel lens). Therefore, the liquid prisms can adaptively focus sunlight on a concentrating photovoltaic (CPV) cell sitting on the focus of the Fresnel lens as the sun moves. Because of the unique design, electrowetting tracking allows the concentrator to adaptively track both the daily and seasonal changes of the sun's orbit (dual-axis tracking) without bulky, expensive and inefficient mechanical moving parts. This approach can potentially reduce capital costs for CPV and increases operational efficiency by eliminating the power consumption of mechanical tracking. Importantly, the elimination of bulky tracking hardware and quiet operation will allow extensive residential deployment of concentrated solar power. In comparison with traditional silicon-based photovoltaic (PV) solar cells, the electrowetting-based self-tracking technology will generate,similar to 70% more green energy with a 50% cost reduction. (C) 2013 Elsevier Ltd. All rights reserved.

  16. New High Energy Gradient Concentration Cathode Material | Department of

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

    Energy 6_amine_2011_p.pdf (1.42 MB) More Documents & Publications FY 2011 Annual Progress Report for Energy Storage R&D Design of Safer High-Energy Density Materials for Lithium-Ion Cells Developing new high energy gradient concentration cathode material

  17. Concentrating Solar Power - Fact Sheet

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

    solar power (CSP) is a dispatchable, renewable energy option that uses mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. CSP systems can store solar energy to be used when the sun is not shining. It will help meet the nation's goal of making solar energy fully cost-competitive with other energy sources by the end of the decade. Worldwide, CSP activity is rapidly scaling, with

  18. High concentration low wattage solar arrays and their applications

    SciTech Connect (OSTI)

    Hoffmann, R.; OGallagher, J.; Winston, R.

    1997-02-01

    Midway Labs currently produces a 335x concentrator module that has reached as high as 19{percent} active area efficiency in production. The current production module uses the single crystal silicon back contact SunPower cell. The National Renewable Energy Lab has developed a multi junction cell using GalnP/GaAs technologies. The high efficiency ({gt}30{percent}) and high cell voltage offer an opportunity for Midway Labs to develop a tracking concentrator module that will provide 24 volts in the 140 to 160 watt range. This voltage and wattage range is applicable to a range of small scale water pumping applications that make up the bulk of water pumping solar panel sales. {copyright} {ital 1997 American Institute of Physics.}

  19. Electrochemical cell

    DOE Patents [OSTI]

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-08-23

    An electrochemical cell is described having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a [beta] alumina electrolyte and NaAlCl[sub 4] or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose. 6 figs.

  20. Concentrating Solar Power Basics | Department of Energy

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

    Solar » Concentrating Solar Power Basics Concentrating Solar Power Basics August 20, 2013 - 4:38pm Addthis Text Version This solar concentrator has a fixed-focus faceted dish with a concentration of about 250 suns. This system can be used for large fields connected to the utility grid, hydrogen generation, or water pumping. Credit: Science Applications International Corporation / PIX 13464 Concentrating solar power (CSP) technologies use mirrors to reflect and concentrate sunlight onto a single

  1. Funding Opportunity Announcement: CSP: Concentrating Optics for...

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

    CSP: Concentrating Optics for Lower Levelized Energy Costs (COLLECTS) Funding Opportunity ... transformative projects for the concentrating solar collectors in the CSP plant. ...

  2. NREL: Concentrating Solar Power Research - Staff Biographies

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

    Learn more about the expertise and technical skills of NREL's concentrating solar power ... Victor primarily works with the Concentrated Solar Power group but also works with several ...

  3. NREL: Concentrating Solar Power Research - Laboratory Capabilities

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

    To research, develop, and test a variety of concentrating solar power technologies, NREL features the following laboratory capabilities: Concentrated Solar Radiation Facility Large ...

  4. Concentrating Solar Power Commercial Application Study: Reducing...

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

    Concentrating Solar Power Commercial Application Study: Reducing Water Consumption of Concentrating Solar Power Electricity Generation Report to Congress U.S. Department of Energy ...

  5. Superhydrophobic analyte concentration utilizing colloid-pillar...

    Office of Scientific and Technical Information (OSTI)

    Superhydrophobic analyte concentration utilizing colloid-pillar array SERS substrates Citation Details In-Document Search Title: Superhydrophobic analyte concentration utilizing ...

  6. Sandia Energy - Concentrating Solar Power Technical Management...

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

    Concentrating Solar Power Technical Management Position Home Renewable Energy Energy Facilities News Concentrating Solar Power Solar Job Listing National Solar Thermal Test...

  7. National Laboratory Concentrating Solar Power Research | Department...

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

    National Laboratory Concentrating Solar Power Research DOE supports concentrating solar power (CSP) research and development and core capabilities at its national laboratories ...

  8. Concentrating Technologies LLC | Open Energy Information

    Open Energy Info (EERE)

    LLC Place: Owens Crossroads, Alabama Zip: 35763 Product: Developer of concentrating photovoltaic technology (CPV). References: Concentrating Technologies LLC1 This article is a...

  9. Daily Fill Factor Variation as a Diagnostic Probe of Multijunction Concentrator Systems During Outdoor Operation

    SciTech Connect (OSTI)

    McMahon, W. E.; Emery, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

    2007-01-01

    The work presented here is for GaInP2/GaAs tandem cells, but the conclusions are equally valid for GaInP2/GaAs/Ge triple-junction cells. Optimizing a concentrator system which uses multijunction solar cells is challenging because: (a) the conditions are variable, so the solar cells rarely operate under optimal conditions and (b) the conditions are not controlled, so any design problems are difficult to characterize. Any change in the spectral content of direct-beam sunlight as it passes through the concentrator optics is of particular interest, as it can reduce the performance of multijunction cells and is difficult to characterize.

  10. The Rheology of Concentrated Suspensions

    SciTech Connect (OSTI)

    Andreas Acrivos

    2004-09-07

    Research program on the rheological properties of flowing suspensions. The primary purpose of the research supported by this grant was to study the flow characteristics of concentrated suspensions of non-colloidal solid particles and thereby construct a comprehensive and robust theoretical framework for modeling such systems quantitatively. At first glance, this seemed like a modest goal, not difficult to achieve, given that such suspensions were viewed simply as Newtonian fluids with an effective viscosity equal to the product of the viscosity of the suspending fluid times a function of the particle volume fraction. But thanks to the research findings of the Principal Investigator and of his Associates, made possible by the steady and continuous support which the PI received from the DOE Office of Basic Energy Sciences, the subject is now seen to be more complicated and therefore much more interesting in that concentrated suspensions have been shown to exhibit fascinating and unique rheological properties of their own that have no counterpart in flowing Newtonian or even non-Newtonian (polymeric) fluids. In fact, it is generally acknowledged that, as the result of these investigations for which the PI received the 2001 National Medal of Science, our understanding of how suspensions behave under flow is far more detailed and comprehensive than was the case even as recently as a decade ago. Thus, given that the flow of suspensions plays a crucial role in many diverse physical processes, our work has had a major and lasting impact in a subject having both fundamental as well as practical importance.

  11. Concentrating Solar Power Facilities | Department of Energy

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

    Facilities Concentrating Solar Power Facilities Florida Hawaii Southwest U.S.

  12. Estimation of the potential efficiency of a multijunction solar cell at a limit balance of photogenerated currents

    SciTech Connect (OSTI)

    Mintairov, M. A. Evstropov, V. V.; Mintairov, S. A.; Shvarts, M. Z.; Timoshina, N. Kh.; Kalyuzhnyy, N. A.

    2015-05-15

    A method is proposed for estimating the potential efficiency which can be achieved in an initially unbalanced multijunction solar cell by the mutual convergence of photogenerated currents: to extract this current from a relatively narrow band-gap cell and to add it to a relatively wide-gap cell. It is already known that the properties facilitating relative convergence are inherent to such objects as bound excitons, quantum dots, donor-acceptor pairs, and others located in relatively wide-gap cells. In fact, the proposed method is reduced to the problem of obtaining such a required light current-voltage (I–V) characteristic which corresponds to the equality of all photogenerated short-circuit currents. Two methods for obtaining the required light I–V characteristic are used. The first one is selection of the spectral composition of the radiation incident on the multijunction solar cell from an illuminator. The second method is a double shift of the dark I–V characteristic: a current shift J{sub g} (common set photogenerated current) and a voltage shift (−J{sub g}R{sub s}), where R{sub s} is the series resistance. For the light and dark I–V characteristics, a general analytical expression is derived, which considers the effect of so-called luminescence coupling in multijunction solar cells. The experimental I–V characteristics are compared with the calculated ones for a three-junction InGaP/GaAs/Ge solar cell with R{sub s} = 0.019 Ω cm{sup 2} and a maximum factual efficiency of 36.9%. Its maximum potential efficiency is estimated as 41.2%.

  13. Photovoltaic solar cell

    SciTech Connect (OSTI)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  14. Design and demonstration of a spectrum-splitting photovoltaic concentrator module

    SciTech Connect (OSTI)

    Borden, P.G.; Gregory, P.E.; Moore, O.E.

    1982-11-01

    A spectrum splitting, concentrating photovoltaic module has been designed and fabricated that uses point focus curved facet Fresnel lenses to concentrate incident sunlight. The concentrated sunlight beam spectrum is split into a high and low energy part by a dichroic filter. The high energy part of the spectrum is transmitted to an AlGaAs solar cell and the low energy part is reflected to a Si cell. Spectrum splitting and using cells that respond best to the two parts of the spectrum splitting and using cells that respond best to the two parts of the spectrum gives a higher efficiency than the use of either cell alone. The experimental module has been tested which consists of 10 AlGaAs and 10 Si cells, and a sunlight to electricity conversion efficiency of 20% has been measured.

  15. Production of fullerenes using concentrated solar flux

    DOE Patents [OSTI]

    Fields, Clark L.; Pitts, John Roland; King, David E.; Hale, Mary Jane; Bingham, Carl E.; Lewandowski, Allan A.

    2000-01-01

    A method of producing soot containing high amounts of fullerenes comprising: providing a primary concentrator capable of impingement of a concentrated beam of sunlight onto a carbon source to cause vaporization of carbon and subsequent formation of fullerenes, or providing a solar furnace having a primary concentrator with a focal point that concentrates a solar beam of sunlight; providing a reflective secondary concentrator having an entrance aperture and an exit aperture at the focal point of the solar furnace; providing a carbon source at the exit aperture of the secondary concentrator; supplying an inert gas over the carbon source to keep the secondary concentrator free from vaporized carbon; and impinging a concentrated beam of sunlight from the secondary concentrator on the carbon source to vaporize the carbon source into a soot containing high amounts of fullerenes.

  16. Summary of Dissolved Concentration Limits

    SciTech Connect (OSTI)

    Yueting Chen

    2001-06-11

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  17. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Poster)

    SciTech Connect (OSTI)

    Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-02-01

    Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate material types, field-induced failure mechanisms, and factors of influence (if possible) of polymeric encapsulation. These results will ultimately be weighed against those of future qualification and accelerated life test procedures.

  18. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Presentation)

    SciTech Connect (OSTI)

    Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2012-03-01

    Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple and optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interface(s), while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced failure modes for a variety of popular PV encapsulation materials. An existing CPV module (with no PV cells present) was modified to accommodate encapsulation specimens. The module (where nominal concentration of solar flux is 500x for the domed-Fresnel design) has been mounted on a tracker in Golden, CO (elevation 1.79 km). Initial results are reported here for 18 months cumulative exposure, including the hottest and coldest months of the past year. Characteristics observed at intervals during that time include: visual appearance, direct and hemispherical transmittance, and mass. Degradation may be assessed from subsequent analysis (including yellowness index and cut-on frequency) relative to the ambient conditions present during field exposure. The fluorescence signature observed of all the silicone specimens is examined here, including possible factors of causation -- the platinum catalyst used in the addition cured materials as well as the primer used to promote adhesion to the quartz substrate and superstrate.

  19. POTENTIAL DIMETHYLMERCURY CONCENTRATION IN WATER & ORGANIC CONDENSATE

    SciTech Connect (OSTI)

    MEACHAM, J.E.

    2004-12-28

    This document bounds potential dimethylmercury concentration in water or organic condensate that might form in ventilation systems or cooler tank regions. Dimethylmercury concentrations were extremely low and would be below drinking water standards in the water condensate.

  20. Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis Webinar

    Office of Energy Efficiency and Renewable Energy (EERE)

    Access the recording and download the presentation slides from the Fuel Cell Technologies Office webinar "Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis" held on January 21, 2016.

  1. Fluorescence Correlation Spectroscopy at Micromolar Concentrations without Optical Nanoconfinement

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Laurence, Ted A.; Ly, Sonny; Bourguet, Feliza; Fischer, Nicholas O.; Coleman, Matthew A.

    2014-08-14

    Fluorescence correlation spectroscopy (FCS) is an important technique for studying biochemical interactions dynamically that may be used in vitro and in cell-based studies. It is generally claimed that FCS may only be used at nM concentrations. We show that this general consensus is incorrect and that the limitation to nM concentrations is not fundamental but due to detector limits as well as laser fluctuations. With a high count rate detector system and applying laser fluctuation corrections, we demonstrate FCS measurements up to 38 μM with the same signal-to-noise as at lower concentrations. Optical nanoconfinement approaches previously used to increase themore » concentration range of FCS are not necessary, and further increases above 38 μM may be expected using detectors and detector arrays with higher saturation rates and better laser fluctuation corrections. This approach greatly widens the possibilities of dynamic measurements of biochemical interactions using FCS at physiological concentrations.« less

  2. Joint measurement of current-phase relations and transport properties of hybrid junctions using a three junctions superconducting quantum interference device

    SciTech Connect (OSTI)

    Basset, J.; Delagrange, R.; Weil, R.; Kasumov, A.; Bouchiat, H.; Deblock, R.

    2014-07-14

    We propose a scheme to measure both the current-phase relation and differential conductance dI/dV of a superconducting junction, in the normal and the superconducting states. This is done using a dc Superconducting Quantum Interference Device with two Josephson junctions in parallel with the device under investigation and three contacts. As a demonstration, we measure the current-phase relation and dI/dV of a small Josephson junction and a carbon nanotube junction. In this latter case, in a regime where the nanotube is well conducting, we show that the non-sinusoidal current phase relation we find is consistent with the theory for a weak link, using the transmission extracted from the differential conductance in the normal state. This method holds great promise for future investigations of the current-phase relation of more exotic junctions.

  3. Advancing Concentrating Solar Power Technology, Performance, and

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

    Dispatchability | Department of Energy Advancing Concentrating Solar Power Technology, Performance, and Dispatchability Advancing Concentrating Solar Power Technology, Performance, and Dispatchability Advancing Concentrating Solar Power Technology, Performance, and Dispatchability Energy storage will help enable CSP compete by adding flexibility value to a high-variable-generation (solar plus wind) power system (see Mehos et al. 2016). Compared with PV, CSP systems are more complex to

  4. 2012 News | Concentrating Solar Power | NREL

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

    2 News Below are news stories related to Concentrating Solar Power. RSS Learn about RSS. November 30, 2012 NREL Analysis Calculates Value of Thermal Energy Storage for Concentrating Solar Power A new report by the National Renewable Energy Laboratory provides an analysis of concentrating solar power integrated with thermal energy storage, using simulations created by recognized, commercially available software. The analysis quantifies the incremental operational value of CSP with TES in multiple

  5. 2014 News | Concentrating Solar Power | NREL

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

    4 News Below are news stories related to Concentrating Solar Power. RSS Learn about RSS. September 16, 2014 NREL Forges Foundation for Advanced Concentrating Solar Power Receivers NREL's Thermal Systems Group is performing research and development on components for high-temperature concentrating solar power (CSP) receivers as part of DOE's SunShot effort. DOE supports R&D of CSP technologies in order to achieve SunShot Initiative cost targets with systems that can supply solar power on

  6. Economic, Energy, and Environmental Benefits of Concentrating...

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

    Economic, Energy, and Environmental Benefits of Concentrating Solar Power in California L. ... NRELSR-550-39291 April 2006 Economic, Energy, and Environmental Benefits of ...

  7. Superhydrophobic analyte concentration utilizing colloid-pillar...

    Office of Scientific and Technical Information (OSTI)

    Surface enhanced Raman spectroscopy (SERS) is a technique that can be utilized to detect molecules at very low absolute numbers. However, detection at trace concentration levels in ...

  8. Concentrating Solar Power (Fact Sheet), Electricity, Resources...

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

    optical concentrators. * NREL's High-Flux Solar Furnace consists of a tracking heliostat ... to determine if the materials meet the optical requirements of CSP solar field components. ...

  9. Concentration Solar la Mancha | Open Energy Information

    Open Energy Info (EERE)

    Solar la Mancha Jump to: navigation, search Name: Concentration Solar la Mancha Place: Manzanares (Cuidad Real), Spain Zip: 13200 Product: Maker of CPV systems and systems...

  10. Concentrating solar power | Open Energy Information

    Open Energy Info (EERE)

    Concentrating solar power (CSP) offers a utility-scale, firm, dispatchable renewable energy option that can help meet our nation's demand for electricity. CSP plants produce...

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

    Office of Environmental Management (EM)

    the development of thermochemical energy storage (TCES) systems that can validate a cost ... Summary: This project seeks to design a system that concentrates sunlight onto a ...

  12. Energy Secretary Moniz Dedicates World's Largest Concentrating...

    Energy Savers [EERE]

    Ivanpah Solar Energy Generating System, the world's largest concentrating solar power (CSP) plant. ... to finance the first solar thermal storage project and the first power tower ...

  13. Solar Energy Technologies Program: Concentrating Solar Power

    SciTech Connect (OSTI)

    2009-10-26

    Fact sheet summarizing the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  14. NREL: Concentrating Solar Power Research - Webmaster

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

    Your email address: Your message: Send Message Printable Version Concentrating Solar Power Research Home Projects Research Staff Working with Us Data & Resources Publications...

  15. NREL: Concentrating Solar Power Research - Technology Basics

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

    Technology Basics Concentrating solar power (CSP) technologies can be a major contributor to our nation's future need for new, clean sources of energy, particularly in the Western...

  16. NREL: Concentrating Solar Power Research - Projects

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

    in its CSP deployment efforts in the following areas: Collectors Receivers Power block Thermal energy storage Analysis. NREL received funding from DOE for concentrating solar...

  17. NREL: Concentrating Solar Power Research - Research Expertise

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

    ... Exploration of advanced components and technologies also provide a means for expanding ... Printable Version Concentrating Solar Power Research Home Projects Research Staff Working ...

  18. Data and Tools | Concentrating Solar Power | NREL

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

    Data and Tools The following data and tools with respect to concentrating solar power (CSP) include databases, maps, and tools produced almost exclusively by the National Renewable ...

  19. Research Staff | Concentrating Solar Power | NREL

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

    Research Staff Learn more about the expertise and technical skills of concentrating solar power (CSP) research team and staff at the National Renewable Energy laboratory (NREL) by ...

  20. SolTrace | Concentrating Solar Power | NREL

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

    SolTrace is a software tool developed at the National Renewable Energy Laboratory (NREL) to model concentrating solar power (CSP) systems and analyze their optical performance. ...

  1. Field Characterization | Concentrating Solar Power | NREL

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

    The National Renewable Energy Laboratory (NREL) also uses its high-flux solar furnace to test and evaluate concentrating solar power (CSP) components and investigate advanced ...

  2. NREL: Photovoltaics Research - Concentrator Photovoltaic (CPV...

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

    Concentrator Photovoltaic (CPV) Report - Fraunhofer ISE and NREL Analyze Status of Market and Technology February 4, 2015 The German Fraunhofer Institute for Solar Energy Systems...

  3. Institute of Concentration Photovoltaic Systems ISFOC | Open...

    Open Energy Info (EERE)

    Photovoltaic Systems ISFOC Jump to: navigation, search Name: Institute of Concentration Photovoltaic Systems (ISFOC) Place: Puertallano, Spain Zip: 13500 Product: Part of the R&D...

  4. OpenEI Community - Concentrated Solar Power

    Open Energy Info (EERE)

    groupbig-clean-data" target"blank">read more

    Big Data Concentrated Solar Power DataAnalysis energy efficiency energy storage expert systems machine learning...

  5. Concentrated Solar Power | OpenEI Community

    Open Energy Info (EERE)

    and Energy Efficiency. Links: Big Clean Data group on linkedin Big Data Concentrated Solar Power DataAnalysis energy efficiency energy storage expert systems machine learning...

  6. Concentrating Solar Power (Revised) (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-11-01

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  7. SunShot Summit: Concentrating Solar Power

    Broader source: Energy.gov [DOE]

    This video on concentrating solar power was shown during the DOE SunShot Grand Challenge: Summit and Technology Forum, June 13-14, 2012, in Denver, Colorado.

  8. Alignment method for parabolic trough solar concentrators

    DOE Patents [OSTI]

    Diver, Richard B.

    2010-02-23

    A Theoretical Overlay Photographic (TOP) alignment method uses the overlay of a theoretical projected image of a perfectly aligned concentrator on a photographic image of the concentrator to align the mirror facets of a parabolic trough solar concentrator. The alignment method is practical and straightforward, and inherently aligns the mirror facets to the receiver. When integrated with clinometer measurements for which gravity and mechanical drag effects have been accounted for and which are made in a manner and location consistent with the alignment method, all of the mirrors on a common drive can be aligned and optimized for any concentrator orientation.

  9. Cyclic Concentration Measurements for Characterizing Pulsating Flow

    SciTech Connect (OSTI)

    Bamberger, Judith A.

    2013-07-07

    Slurry mixed in vessels via pulse jet mixers has a periodic, rather than steady, concentration profile. Measurements of local concentration taken at the center of the tank at a range of elevations within the mixed region were analyzed to obtain a greater understanding of how the periodic pulse jet mixing cycle affects the local concentration. Data were obtained at the critical suspension velocity, when all solids are suspended at the end of the pulse. The data at a range of solids loadings are analyzed to observe the effect of solids concentration during the suspension and settling portions of the mixing cycle.

  10. New High Energy Gradient Concentration Cathode Material

    Broader source: Energy.gov [DOE]

    2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  11. Highly concentrated foam formulation for blast mitigation

    DOE Patents [OSTI]

    Tucker, Mark D.; Gao, Huizhen

    2010-12-14

    A highly concentrated foam formulation for blast suppression and dispersion mitigation for use in responding to a terrorism incident involving a radiological dispersion device. The foam formulation is more concentrated and more stable than the current blast suppression foam (AFC-380), which reduces the logistics burden on the user.

  12. Measuring surfactant concentration in plating solutions

    DOE Patents [OSTI]

    Bonivert, William D.; Farmer, Joseph C.; Hachman, John T.

    1989-01-01

    An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

  13. Observations on using inside air concentrations as a predictor of outside air concentrations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hawkley, Gavin; Whicker, Jeffrey; Harris, Jason

    2015-04-01

    Here, excavations of radiological material were performed within confined structures with known operational parameters, such as a filtered exhaust system with known filtration efficiency. Given the known efficiency, the assumption could be made that the air concentrations of radioactivity measured outside the structure would be proportional to the air concentrations measured inside the structure. To investigate this assumption, the inside concentration data was compared with the outside concentration data. The correlation of the data suggested that the inside concentrations were not a good predictor of the outside concentrations. This poor correlation was deemed to be a result of operational unknownsmore » within the structures.« less

  14. Observations on using inside air concentrations as a predictor of outside air concentrations

    SciTech Connect (OSTI)

    Hawkley, Gavin; Whicker, Jeffrey; Harris, Jason

    2015-04-01

    Here, excavations of radiological material were performed within confined structures with known operational parameters, such as a filtered exhaust system with known filtration efficiency. Given the known efficiency, the assumption could be made that the air concentrations of radioactivity measured outside the structure would be proportional to the air concentrations measured inside the structure. To investigate this assumption, the inside concentration data was compared with the outside concentration data. The correlation of the data suggested that the inside concentrations were not a good predictor of the outside concentrations. This poor correlation was deemed to be a result of operational unknowns within the structures.

  15. Optical loss due to diffraction by concentrator Fresnel lenses

    SciTech Connect (OSTI)

    Hornung, Thorsten Nitz, Peter

    2014-09-26

    Fresnel lenses are widely used in concentrating photovoltaic (CPV) systems as a primary optical element. They focus sunlight on small solar cells or on the entrance apertures of secondary optical elements. A Fresnel lens consists of several prism rings and diffraction by these prism rings is unavoidable. Some of the light that would reach a designated target area according to geometric optics will miss it due to diffraction. This diffraction loss may be of relevant magnitude for CPV applications. The results of published analytical calculations are evaluated, discussed, and compared to computer simulations and measurements.

  16. ELECTROCHEMICAL SEPARATION AND CONCENTRATION OF HYDROGEN SULFIDE FROM GAS MIXTURES

    DOE Patents [OSTI]

    Winnick, Jack; Sather, Norman F.; Huang, Hann S.

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  17. Electrochemical separation and concentration of hydrogen sulfide from gas mixtures

    DOE Patents [OSTI]

    Winnick, Jack; Sather, Norman F.; Huang, Hann S.

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  18. DRUG TESING PANEL & CUTOFF CONCENTRATIONS

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

    DRUG TESTING PANEL & CUTOFF CONCENTRATIONS Initial Test Analyte Initial Test Cutoff Concentration Confirmatory Test Analyte Confirmatory Test Cutoff Concentration Marijuana Metabolites 50 ng/mL THCA \1\ 15 ng/mL Cocaine Metabolites 150 ng/mL Benzoylecgonine 100 ng/mL Codeine 2000 ng/mL Opiate Metabolites: Codeine/Morphine \2\ 2000 ng/mL Morphine 2000 ng/mL 6-Acetylmorphine (Heroine) 10 ng/mL 6-Acetylmorphine 10 ng/mL Phencyclidine 25 ng/mL Phencyclidine 25 ng/mL Amphetamine 250 ng/mL 500

  19. Concentric ring flywheel without expansion separators

    DOE Patents [OSTI]

    Kuklo, Thomas C.

    1999-01-01

    A concentric ring flywheel wherein the adjacent rings are configured to eliminate the need for differential expansion separators between the adjacent rings. This is accomplished by forming a circumferential step on an outer surface of an inner concentric ring and forming a matching circumferential step on the inner surface of an adjacent outer concentric ring. During operation the circumferential steps allow the rings to differentially expand due to the difference in the radius of the rings without the formation of gaps therebetween, thereby eliminating the need for expansion separators to take up the gaps formed by differential expansion.

  20. Concentric ring flywheel without expansion separators

    DOE Patents [OSTI]

    Kuklo, T.C.

    1999-08-24

    A concentric ring flywheel wherein the adjacent rings are configured to eliminate the need for differential expansion separators between the adjacent rings. This is accomplished by forming a circumferential step on an outer surface of an inner concentric ring and forming a matching circumferential step on the inner surface of an adjacent outer concentric ring. During operation the circumferential steps allow the rings to differentially expand due to the difference in the radius of the rings without the formation of gaps therebetween, thereby eliminating the need for expansion separators to take up the gaps formed by differential expansion. 3 figs.

  1. NREL: Concentrating Solar Power Research - Particle Receiver...

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

    Particle Receiver Integrated with a Fluidized Bed-Novel Components to Overcome Existing Barriers Advancing concentrating solar power (CSP) systems to the target cost of 0.06 per...

  2. NREL: Concentrating Solar Power Research - Partnerships

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

    in Albuquerque, New Mexico, through SunLab-a partnership developed by the U.S. Department of Energy to administer its concentrating solar power R&D and analysis activities. ...

  3. Biological denitrification of high concentration nitrate waste

    DOE Patents [OSTI]

    Francis, Chester W.; Brinkley, Frank S.

    1977-01-01

    Biological denitrification of nitrate solutions at concentrations of greater than one kilogram nitrate per cubic meter is accomplished anaerobically in an upflow column having as a packing material a support for denitrifying bacteria.

  4. Concentrating Solar Power Parabolic Trough Systems

    Broader source: Energy.gov [DOE]

    In this b-roll, the parabolic solar trough is just one of the several types of concentrating solar power technologies that focus the sun's heat using reflective surfaces to generate electricity.

  5. ARM - Measurement - Carbon dioxide (CO2) concentration

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

    hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Carbon dioxide (CO2) concentration The amount of carbon dioxide, a heavy, colorless...

  6. ARM - Measurement - Cloud particle number concentration

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

    from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle number concentration The total number of cloud particles present in any given volume...

  7. Concentrating Solar Power Competitive Awards | Department of...

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

    The SunShot Initiative supports the development of novel concentrating solar power (CSP) research and development projects that will reduce the levelized cost of energy to 0.06 ...

  8. Advancing Concentrating Solar Power Research (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) provide scientific, engineering, and analytical expertise to help advance innovation in concentrating solar power (CSP). This fact sheet summarizes how NREL is advancing CSP research.

  9. 2010 News | Concentrating Solar Power | NREL

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

    ... First Hybrid CSP-Coal Power Plant is Fired Up in Colorado Concentrating solar power (CSP) is boosting the energy produced by a coal-fired power plant east of Grand Junction, ...

  10. Cell Data Sheet Specification (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2012-03-01

    The presentation shows a brief status report on the development of a specification being considered by IEC TC82 WG7 for a concentrator cell data sheet and solicits suggestions from the community.