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Sample records for photovoltaic domestic field

  1. 48 CFR 225.7017 - Utilization of domestic photovoltaic devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Utilization of domestic photovoltaic devices. 225.7017 Section 225.7017 Federal Acquisition Regulations System DEFENSE ACQUISITION... photovoltaic devices....

  2. 48 CFR 225.7017 - Utilization of domestic photovoltaic devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Utilization of domestic photovoltaic devices. 225.7017 Section 225.7017 Federal Acquisition Regulations System DEFENSE ACQUISITION... photovoltaic devices....

  3. 48 CFR 225.7017 - Utilization of domestic photovoltaic devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Utilization of domestic photovoltaic devices. 225.7017 Section 225.7017 Federal Acquisition Regulations System DEFENSE ACQUISITION... photovoltaic devices....

  4. 76 FR 78858 - Defense Federal Acquisition Regulation Supplement; Utilization of Domestic Photovoltaic Devices...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-20

    ... Acquisition Regulation Supplement; Utilization of Domestic Photovoltaic Devices (DFARS Case 2011-D046) AGENCY... 2011. The section provides that photovoltaic devices to be utilized in performance of any covered... subpart 225.70 by adding a new section 225.7017, Utilization of domestic photovoltaic devices, as well...

  5. 77 FR 30368 - Defense Federal Acquisition Regulation Supplement; Utilization of Domestic Photovoltaic Devices...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-22

    ... Acquisition Regulation Supplement; Utilization of Domestic Photovoltaic Devices (DFARS Case 2011-D046) AGENCY... section provides that photovoltaic devices to be utilized in performance of any covered contract shall... domestic photovoltaic devices under certain covered contracts. The objective of the rule is to...

  6. AC photovoltaic module magnetic fields

    SciTech Connect

    Jennings, C.; Chang, G.J.; Reyes, A.B.; Whitaker, C.M.

    1997-12-31

    Implementation of alternating current (AC) photovoltaic (PV) modules, particularly for distributed applications such as PV rooftops and facades, may be slowed by public concern about electric and magnetic fields (EMF). This paper documents magnetic field measurements on an AC PV module, complementing EMF research on direct-current PV modules conducted by PG and E in 1993. Although not comprehensive, the PV EMF data indicate that 60 Hz magnetic fields (the EMF type of greatest public concern) from PV modules are comparable to, or significantly less than, those from household appliances. Given the present EMF research knowledge, AC PV module EMF may not merit considerable concern.

  7. Field failure mechanisms for photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Dumas, L. N.; Shumka, A.

    1981-01-01

    Beginning in 1976, Department of Energy field centers have installed and monitored a number of field tests and application experiments using current state-of-the-art photovoltaic modules. On-site observations of module physical and electrical degradation, together with in-depth laboratory analysis of failed modules, permits an overall assessment of the nature and causes of early field failures. Data on failure rates are presented, and key failure mechanisms are analyzed with respect to origin, effect, and prospects for correction. It is concluded that all failure modes identified to date are avoidable or controllable through sound design and production practices.

  8. Reliability of photovoltaic systems: A field report

    NASA Astrophysics Data System (ADS)

    Thomas, M. G.; Fuentes, M. K.; Lashway, C.; Black, B. D.

    Performance studies and field measurements of photovoltaic systems indicate a 1 to 2% per year degradation in array energy production. The cause for much of the degradation has been identified as soiling, failed modules, and failures in interconnections. System performance evaluation continues to be complicated by the poor reliability of some power conditioning hardware that has greatly diminished the system availability and by inconsistent field ratings. Nevertheless, the current system reliability is consistent with degradation of less than 10% in 5 years and with estimates of less than 10% per year of the energy value for O and M.

  9. Reliability of photovoltaic systems - A field report

    NASA Astrophysics Data System (ADS)

    Thomas, M. G.; Fuentes, M. K.; Lashway, C.; Black, B. D.

    Performance studies and field measurements of photovoltaic systems indicate a 1-2-percent/yr degradation in array energy production. The cause for much of the degradation has been identified as soiling, failed modules, and failures in interconnections. System performance evaluation continues to be complicated by the poor reliability of some power conditioning hardware (which greatly diminished system availability) and by inconsistent field ratings. Nevertheless, the current system reliability is consistent with degradation of less than 10 percent in 5 years and with estimates of less than 10 percent/yr of the energy value for O&M.

  10. An investigation of photovoltaic powered pumps in direct solar domestic hot water systems

    SciTech Connect

    Al-Ibrahim, A.M.; Klein, S.A.; Mitchell, J.W.; Beckman, W.A.

    1996-09-01

    The performance of photovoltaic powered pumps in direct solar domestic hot water (PV-SDHW) systems has been studied. The direct PV- SDHW system employs a photovoltaic array, a separately excited DC- motor, a centrifugal pump, a thermal collector, and a storage tank. A search methodology for an optimum PV-SDHW system configuration has been proposed. A comparison is made between the long-term performance of a PV-SDHW system and a conventional SDHW system operating under three control schemes. The three schemes are: an ON-OFF flow controlled SDHW system operating at the manufacturer-recommended constant flow rate, and a linear proportional flow controlled SDHW system with the flow proportional to the solar radiation operating under an optimum proportionality. 13 refs., 6 figs.

  11. A novel application for concentrator photovoltaic in the field of agriculture photovoltaics

    NASA Astrophysics Data System (ADS)

    Liu, Luqing; Guan, Chenggang; Zhang, Fangxin; Li, Ming; Lv, Hui; Liu, Yang; Yao, Peijun; Ingenhoff, Jan; Liu, Wen

    2017-09-01

    Agriculture photovoltaics is a trend setting area which has already led to a new industrial revolution. Shortage of land in some countries and desertification of land where regular solar panels are deployed are some of the major problems in the photovoltaic industry. Concentrator photovoltaics experienced a decline in applicability after the cost erosion of regular solar panels at the end of the last decade. We demonstrate a novel and unique application for concentrator photovoltaics tackling at a same time the issue of conventional photovoltaics preventing the land being used for agricultural purpose where ever solar panels are installed. We leverage the principle of diffractive and interference technology to split the sun light into transmitted wavelengths necessary for plant growth and reflected wavelengths useful for solar energy generation. The technology has been successfully implemented in field trials and sophisticated scientific studies have been undertaken to evaluate the suitability of this technology for competitive solar power generation and simultaneous high-quality plant growth. The average efficiency of the agriculture photovoltaic system has reached more than 8% and the average efficiency of the CPV system is 6.80%.

  12. Conjugated ionomers for photovoltaic applications: electric field driven charge separation in organic photovoltaics. Final Technical report

    SciTech Connect

    Lonergan, Mark

    2015-05-29

    Final technical report for Conjugated ionomers for photovoltaic applications, electric field driven charge separation in organic photovoltaics. The central goal of the work we completed was been to understand the photochemical and photovoltaic properties of ionically functionalized conjugated polymers (conjugated ionomers or polyelectrolytes) and energy conversion systems based on them. We primarily studied two classes of conjugated polymer interfaces that we developed based either upon undoped conjugated polymers with an asymmetry in ionic composition (the ionic junction) or doped conjugated polymers with an asymmetry in doping type (the p-n junction). The materials used for these studies have primarily been the polyacetylene ionomers. We completed a detailed study of p-n junctions with systematically varying dopant density, photochemical creation of doped junctions, and experimental and theoretical work on charge transport and injection in polyacetylene ionomers. We have also completed related work on the use of conjugated ionomers as interlayers that improve the efficiency or organic photovoltaic systems and studied several important aspects of the chemistry of ionically functionalized semiconductors, including mechanisms of so-called "anion-doping", the formation of charge transfer complexes with oxygen, and the synthesis of new polyfluorene polyelectrolytes. We also worked worked with the Haley group at the University of Oregon on new indenofluorene-based organic acceptors.

  13. Field trial of rural solar photovoltaic system

    NASA Astrophysics Data System (ADS)

    Basu, P.; Mukhopadhyay, K.; Banerjee, T.; Das, S.; Saha, H.

    Experience, costs, and performance of photovoltaic (PV) systems set up in a remote Indian village to power an adult literacy center and an irrigation pump are described. The center was furnished with a 14-module, 200 W array to power a television and three fluorescent lamps. The pumping installation has 20 modules for a 300 W output directly coupled to a 300-W dc pump motor. Data were gathered on the open circuit voltage, short circuit current, specific gravity of the battery fluid, degradation of the cells, nominal operating temperature of the cells, load currents, Amp-hours, water flow rate (pump), and the static head and draw down rate (pump). Monitoring of the array performances in the dusty environment showed that once/week cleaning is necessary. Al-substrates cracked at the center installation and sealant evaporation caused condensation which degraded the light transmissivity and thereby the short-circuit current of the modules. The combination of low-efficiency (5 pct) cells and cheap labor demonstrated economic operation without high-efficiency cells.

  14. Analysis techniques used on field degraded photovoltaic modules

    SciTech Connect

    Hund, T.D.; King, D.L.

    1995-09-01

    Sandia National Laboratory`s PV System Components Department performs comprehensive failure analysis of photovoltaic modules after extended field exposure at various sites around the world. A full spectrum of analytical techniques are used to help identify the causes of degradation. The techniques are used to make solder fatigue life predictions for PV concentrator modules, identify cell damage or current mismatch, and measure the adhesive strength of the module encapsulant.

  15. Propagation of Magnetic Fields from Electrical Domestic Appliances

    NASA Astrophysics Data System (ADS)

    Orlova, K. N.; Gaidamak, M. A.; Borovikov, I. F.

    2016-08-01

    The article presents a research into propagation of magnetic fields from electrical domestic devices. A safe distance at which magnetic induction does not exceed the background level is determined for each type of devices. It is proved that there are two stages of increasing magnetic induction as the distance from the source increases. At the first stage magnetic induction rises and electromagnetic field is formed. At the second stage exponential decrease of magnetic field induction takes place. Mathematical regularities of propagation of magnetic field from electrical domestic devices are experimentally educed.

  16. Photovoltaic-Powered Vaccine Refrigerator: Freezer Systems Field Test Results

    NASA Technical Reports Server (NTRS)

    Ratajczak, A. F.

    1985-01-01

    A project to develop and field test photovoltaic-powered refrigerator/freezers suitable for vaccine storage was undertaken. Three refrigerator/freezers were qualified; one by Solar Power Corp. and two by Solvolt. Follow-on contracts were awarded for 19 field test systems and for 10 field test systems. A total of 29 systems were installed in 24 countries between October 1981 and October 1984. The project, systems descriptions, installation experiences, performance data for the 22 systems for which field test data was reported, an operational reliability summary, and recommendations relative to system designs and future use of such systems are explained. Performance data indicate that the systems are highly reliable and are capable of maintaining proper vaccine storage temperatures in a wide range of climatological and user environments.

  17. Field experience with voltage breakdown in photovoltaic (PV) arrays

    NASA Astrophysics Data System (ADS)

    Harrison, T. D.; Fernandez, J. P.

    Information about voltage breakdown of photovoltaic arrays in the field was obtained array sites. The arrays were located at Beverly High School, Lovington Square Shopping Center, Newman Power Station, and the Oklahoma Center for Sciences and Arts. No breakdowns are reported for these sites. Breakdowns at other sites which are attributed to burrs on washers piercing insulation in one instance and delamination of a metal frame causing a short circuit in another are discussed. Other problems not attributable to voltage breakdown are also discussed.

  18. Magnetic field enhancement of organic photovoltaic cells performance.

    PubMed

    Oviedo-Casado, S; Urbina, A; Prior, J

    2017-06-27

    Charge separation is a critical process for achieving high efficiencies in organic photovoltaic cells. The initial tightly bound excitonic electron-hole pair has to dissociate fast enough in order to avoid photocurrent generation and thus power conversion efficiency loss via geminate recombination. Such process takes place assisted by transitional states that lie between the initial exciton and the free charge state. Due to spin conservation rules these intermediate charge transfer states typically have singlet character. Here we propose a donor-acceptor model for a generic organic photovoltaic cell in which the process of charge separation is modulated by a magnetic field which tunes the energy levels. The impact of a magnetic field is to intensify the generation of charge transfer states with triplet character via inter-system crossing. As the ground state of the system has singlet character, triplet states are recombination-protected, thus leading to a higher probability of successful charge separation. Using the open quantum systems formalism we demonstrate that the population of triplet charge transfer states grows in the presence of a magnetic field, and discuss the impact on carrier population and hence photocurrent, highlighting its potential as a tool for research on charge transfer kinetics in this complex systems.

  19. Field Performance of Photovoltaic Systems in the Tucson Desert

    NASA Astrophysics Data System (ADS)

    Orsburn, Sean; Brooks, Adria; Cormode, Daniel; Greenberg, James; Hardesty, Garrett; Lonij, Vincent; Salhab, Anas; St. Germaine, Tyler; Torres, Gabe; Cronin, Alexander

    2011-10-01

    At the Tucson Electric Power (TEP) solar test yard, over 20 different grid-connected photovoltaic (PV) systems are being tested. The goal at the TEP solar test yard is to measure and model real-world performance of PV systems and to benchmark new technologies such as holographic concentrators. By studying voltage and current produced by the PV systems as a function of incident irradiance, and module temperature, we can compare our measurements of field-performance (in a harsh desert environment) to manufacturer specifications (determined under laboratory conditions). In order to measure high-voltage and high-current signals, we designed and built reliable, accurate sensors that can handle extreme desert temperatures. We will present several benchmarks of sensors in a controlled environment, including shunt resistors and Hall-effect current sensors, to determine temperature drift and accuracy. Finally we will present preliminary field measurements of PV performance for several different PV technologies.

  20. On the photovoltaic effect in local field potential recordings.

    PubMed

    Mikulovic, Sanja; Pupe, Stefano; Peixoto, Helton Maia; Do Nascimento, George C; Kullander, Klas; Tort, Adriano B L; Leão, Richardson N

    2016-01-01

    Optogenetics allows light activation of genetically defined cell populations and the study of their link to specific brain functions. While it is a powerful method that has revolutionized neuroscience in the last decade, the shortcomings of directly stimulating electrodes and living tissue with light have been poorly characterized. Here, we assessed the photovoltaic effects in local field potential (LFP) recordings of the mouse hippocampus. We found that light leads to several artifacts that resemble genuine LFP features in animals with no opsin expression, such as stereotyped peaks at the power spectrum, phase shifts across different recording channels, coupling between low and high oscillation frequencies, and sharp signal deflections that are detected as spikes. Further, we tested how light stimulation affected hippocampal LFP recordings in mice expressing channelrhodopsin 2 in parvalbumin neurons (PV/ChR2 mice). Genuine oscillatory activity at the frequency of light stimulation could not be separated from light-induced artifacts. In addition, light stimulation in PV/ChR2 mice led to an overall decrease in LFP power. Thus, genuine LFP changes caused by the stimulation of specific cell populations may be intermingled with spurious changes caused by photovoltaic effects. Our data suggest that care should be taken in the interpretation of electrophysiology experiments involving light stimulation.

  1. On the photovoltaic effect in local field potential recordings

    PubMed Central

    Mikulovic, Sanja; Pupe, Stefano; Peixoto, Helton Maia; Do Nascimento, George C.; Kullander, Klas; Tort, Adriano B. L.; Leão, Richardson N.

    2016-01-01

    Abstract. Optogenetics allows light activation of genetically defined cell populations and the study of their link to specific brain functions. While it is a powerful method that has revolutionized neuroscience in the last decade, the shortcomings of directly stimulating electrodes and living tissue with light have been poorly characterized. Here, we assessed the photovoltaic effects in local field potential (LFP) recordings of the mouse hippocampus. We found that light leads to several artifacts that resemble genuine LFP features in animals with no opsin expression, such as stereotyped peaks at the power spectrum, phase shifts across different recording channels, coupling between low and high oscillation frequencies, and sharp signal deflections that are detected as spikes. Further, we tested how light stimulation affected hippocampal LFP recordings in mice expressing channelrhodopsin 2 in parvalbumin neurons (PV/ChR2 mice). Genuine oscillatory activity at the frequency of light stimulation could not be separated from light-induced artifacts. In addition, light stimulation in PV/ChR2 mice led to an overall decrease in LFP power. Thus, genuine LFP changes caused by the stimulation of specific cell populations may be intermingled with spurious changes caused by photovoltaic effects. Our data suggest that care should be taken in the interpretation of electrophysiology experiments involving light stimulation. PMID:26835485

  2. Method for calculating multidimensional electric fields in photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Kallis, J. M.; Trucker, D. C.; Cuddihy, E. F.; Garcia, A., III

    1984-05-01

    A finite element method for evaluating the electrical isolation characteristics of photovoltaic modules was developed; its accuracy was verified by comparison with an exact solution for a geometry similar to that of solar cells. Tests on a square test coupon, employed in electrical isolation tests, and a group of disc-shaped solar cells illustrated the finite element method's usefulness in evaluating module encapsulation designs. Finite element models had to avoid adjacent large and small elements and elements with large aspect ratios, and the NASTRAN output had to be curve fitted to calculate the maximum field. Geometric limits were indicated: cells with very sharp edges, and cells much thinner or thicker than the dielectric pottant layer.

  3. Method for calculating multidimensional electric fields in photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Kallis, J. M.; Trucker, D. C.; Cuddihy, E. F.; Garcia, A., III

    1984-01-01

    A finite element method for evaluating the electrical isolation characteristics of photovoltaic modules was developed; its accuracy was verified by comparison with an exact solution for a geometry similar to that of solar cells. Tests on a square test coupon, employed in electrical isolation tests, and a group of disc-shaped solar cells illustrated the finite element method's usefulness in evaluating module encapsulation designs. Finite element models had to avoid adjacent large and small elements and elements with large aspect ratios, and the NASTRAN output had to be curve fitted to calculate the maximum field. Geometric limits were indicated: cells with very sharp edges, and cells much thinner or thicker than the dielectric pottant layer.

  4. Photovoltaic performance models: an evaluation with actual field data

    NASA Astrophysics Data System (ADS)

    TamizhMani, Govindasamy; Ishioye, John-Paul; Voropayev, Arseniy; Kang, Yi

    2008-08-01

    Prediction of energy production is crucial to the design and installation of the building integrated photovoltaic systems. This prediction should be attainable based on the commonly available parameters such as system size, orientation and tilt angle. Several commercially available as well as free downloadable software tools exist to predict energy production. Six software models have been evaluated in this study and they are: PV Watts, PVsyst, MAUI, Clean Power Estimator, Solar Advisor Model (SAM) and RETScreen. This evaluation has been done by comparing the monthly, seasonaly and annually predicted data with the actual, field data obtained over a year period on a large number of residential PV systems ranging between 2 and 3 kWdc. All the systems are located in Arizona, within the Phoenix metropolitan area which lies at latitude 33° North, and longitude 112 West, and are all connected to the electrical grid.

  5. Near-field transport imaging applied to photovoltaic materials

    DOE PAGES

    Xiao, Chuanxiao; Jiang, Chun -Sheng; Moseley, John; ...

    2017-05-26

    We developed and applied a new analytical technique - near-field transport imaging (NF-TI or simply TI) - to photovoltaic materials. Charge-carrier transport is an important factor in solar cell performance, and TI is an innovative approach that integrates a scanning electron microscope with a near-field scanning optical microscope, providing the possibility to study luminescence associated with recombination and transport with high spatial resolution. In this paper, we describe in detail the technical barriers we had to overcome to develop the technique for routine application and the data-fitting procedure used to calculate minority-carrier diffusion length values. The diffusion length measured bymore » TI agrees well with the results calculated by time-resolved photoluminescence on well-controlled gallium arsenide (GaAs) thin-film samples. We report for the first time on measurements on thin-film cadmium telluride using this technique, including the determination of effective carrier diffusion length, as well as the first near-field imaging of the effect of a single localized defect on carrier transport and recombination in a GaAs heterostructure. Furthermore, by changing the scanning setup, we were able to demonstrate near-field cathodoluminescence (CL), and correlated the results with standard CL measurements. In conclusion, the TI technique shows great potential for mapping transport properties in solar cell materials with high spatial resolution.« less

  6. Wind loads on flat plate photovoltaic array fields

    NASA Technical Reports Server (NTRS)

    Miller, R. D.; Zimmerman, D. K.

    1981-01-01

    The results of an experimental analysis (boundary layer wind tunnel test) of the aerodynamic forces resulting from winds acting on flat plate photovoltaic arrays are presented. Local pressure coefficient distributions and normal force coefficients on the arrays are shown and compared to theoretical results. Parameters that were varied when determining the aerodynamic forces included tilt angle, array separation, ground clearance, protective wind barriers, and the effect of the wind velocity profile. Recommended design wind forces and pressures are presented, which envelop the test results for winds perpendicular to the array's longitudinal axis. This wind direction produces the maximum wind loads on the arrays except at the array edge where oblique winds produce larger edge pressure loads. The arrays located at the outer boundary of an array field have a protective influence on the interior arrays of the field. A significant decrease of the array wind loads were recorded in the wind tunnel test on array panels located behind a fence and/or interior to the array field compared to the arrays on the boundary and unprotected from the wind. The magnitude of this decrease was the same whether caused by a fence or upwind arrays.

  7. Field performance of lead-acid batteries in photovoltaic rural electrification kits

    SciTech Connect

    Huacuz, J.M.; Flores, R.; Agredano, J.; Munguia, G.

    1995-12-31

    A field survey was carried out in 83 rural communities within seven different states in Mexico, to assess the performance of photovoltaic (PV) rural electrification systems previously installed and to sense the degree of user satisfaction with PV technology. The present work reports on the performance of lead-acid batteries associated with domestic PV lighting kits. A sample of 555 batteries, from a total of 2512 PV kits installed in the region of study at the time of the survey, was randomly taken for analysis. Batteries were rated using a semiquantitative methodology developed at the Electrical Research Institute of Mexico (IIE). Results obtained from the survey are on the positive side, meaning that car-type batteries (representing 87% of the sample) perform reasonably well as part of PV lighting kits. However, there may be reasons for concern. A number of factors of technical, environmental and socio cultural nature, can negatively influence the performance of batteries in the field. Results from the survey show that undersized storage capacity is one of the main technical factors contributing to a rapid decrease in battery performance. However, improper operation and maintenance practices, derived from socio cultural factors and a lack of proper user training, are important recurring elements that may result in battery lifes shorter than anticipated. 18 refs., 8 figs., 3 tabs.

  8. Photovoltaic dependence of photorefractive grating on the externally applied dc electric field

    NASA Astrophysics Data System (ADS)

    Maurya, M. K.; Yadav, R. A.

    2013-04-01

    Photovoltaic dependence of photorefractive grating (i.e., space-charge field and phase-shift of the index grating) on the externally applied dc electric field in photovoltaic-photorefractive materials has been investigated. The influence of photovoltaic field (EPhN), diffusion field and carrier concentration ratio r (donor/acceptor impurity concentration ratio) on the space-charge field (SCF) and phase-shift of the index grating in the presence and absence of the externally applied dc electric field have also been studied in details. Our results show that, for a given value of EPhN and r, the magnitude of the SCF and phase-shift of the index grating can be enhanced significantly by employing the lower dc electric field (EON<10) across the photovoltaic-photorefractive crystal and higher value of diffusion field (EDN>40). Such an enhancement in the magnitude of the SCF and phase-shift of the index grating are responsible for the strongest beam coupling in photovoltaic-photorefractive materials. This sufficiently strong beam coupling increases the two-beam coupling gain that may be exceed the absorption and reflection losses of the photovoltaic-photorefractive sample, and optical amplification can occur. The higher value of optical amplification in photovoltaic-photorefractive sample is required for the every applications of photorefractive effect so that technology based on the photorefractive effect such as holographic storage devices, optical information processing, acousto-optic tunable filters, gyro-sensors, optical modulators, optical switches, photorefractive-photovoltaic solitons, biomedical applications, and frequency converters could be improved.

  9. Magnetic field effects in a polymer/fullerene blend photovoltaic cell

    NASA Astrophysics Data System (ADS)

    Jang, Hyuk-Jae; Basham, James I.; Gundlach, David J.; Richter, Curt A.

    Organic photovoltaic (OPV) systems based on blends of conjugated polymers and fullerene derivatives have shown great promise for low-cost and efficient photovoltaic applications. Recent findings suggest that a weak external magnetic field can disturb the spin configuration of excited states and subsequently change properties of OPV cells such as photocurrent. These changes are referred to as magnetic field effects (MFEs). In order to have a better understanding of the underlying mechanisms responsible for the MFEs in polymer/fullerene blend photovoltaic systems, we fabricated poly-3-hexylthiophene (P3HT):phenyl-C61-butyric acid methyl ester (PC61BM) cells and carried out photovoltaic device performance and impedance spectroscopy measurements with and without an externally applied magnetic field. A significant reduction in short circuit current (JSC) as well as open circuit voltage (VOC) was observed with an applied magnetic field of a 0.1 tesla compared to those measured without a magnetic field under the same intensity of illumination. Impedance spectroscopy data gives insights into the influence of an external magnetic field on charge generation and recombination near normal photovoltaic operating conditions.

  10. Design and field performance of the KENETECH photovoltaic inverter system

    SciTech Connect

    Behnke, M.R.

    1995-11-01

    KENETECH Windpower has recently adapted the power conversion technology developed for the company`s variable speed wind turbine to grid-connected photovoltaic applications. KENETECH PV inverter systems are now in successful operation at the Sacramento Municipal Utility District`s (SMUD) Hedge Substation and the PVUSA-Davis site, with additional systems scheduled to be placed into service by the end of 1995 at SMUD, the New York Power Authority, Xerox Corporation`s Clean Air Now project, and the Georgia Tech Aquatic Center. The features of the inverter are described.

  11. Magnetic fields from domestic appliances in the UK

    NASA Astrophysics Data System (ADS)

    Preece, A. W.; Kaune, W.; Grainger, P.; Preece, S.; Golding, J.

    1997-01-01

    In a survey of 50 UK homes the 50 Hz fundamental and harmonic magnetic fields generated by 806 domestic appliances found in the homes, and used regularly by mothers, were measured. Measurements were made in the direction of most likely access, and from the surface of the appliances. Mothers completed a questionnaire on the use of appliances and were monitored for 24 h so that acquired exposure could be compared with the measured ambient fields in the home. Appliances were measured at standard distances and an algorithm was used to calculate fields at 100 and 50 cm to remove room background contributions. A few appliances generated fields in excess of at 1 m: microwave cookers ; washing machines ; dishwashers ; some electric showers and can openers . Of continuously operating devices, only central heating pumps (), central heating boilers () and fish-tank air pumps () produced significant fields at 0.5 m. There were no obvious ways to group different types of appliances as high- or low-strength sources. Mothers spent on average about 4.5 h per day in the kitchen, where the strongest sources of magnetic field were located.

  12. Photovoltaic field test performance assessment. Technology status report No. 3

    SciTech Connect

    Inglis, D.J.

    1984-11-01

    Descriptions of 1983 performance are provided for five flat plate and two concentrator photovoltaic systems. They range in size from 18 kW to 1000 kW. All of the systems have extensive instrumentation; performance readings are generally available every 10 minutes. Array nameplate ratings are optimistic, and observed power outputs equal them only under rare combinations of high insolation and low ambient temperatures. Module efficiencies ranged from 5.5 to 10%. The older flat plate systems were the lowest; the concentrator systems were the highest. The newer flat plate modules fell in the middle. Tracking flat plate systems demonstrated high insolation capture and energy densities. Power conditioner failures were the largest contributors to decreased system availabilities.

  13. Wind loads on flat plate photovoltaic array fields (nonsteady winds)

    NASA Technical Reports Server (NTRS)

    Miller, R. D.; Zimmerman, D. K.

    1981-01-01

    Techniques to predict the dynamic response and the structural dynamic loads of flat plate photovoltaic arrays due to wind turbulence were analyzed. Guidelines for use in predicting the turbulent portion of the wind loading on future similar arrays are presented. The dynamic response and the loads dynamic magnification factor of the two array configurations are similar. The magnification factors at a mid chord and outer chord location on the array illustrated and at four points on the chord are shown. The wind tunnel test experimental rms pressure coefficient on which magnification factors are based is shown. It is found that the largest response and dynamic magnification factor occur at a mid chord location on an array and near the trailing edge. A technique employing these magnification factors and the wind tunnel test rms fluctuating pressure coefficients to calculate design pressure loads due to wind turbulence is presented.

  14. Wind Loads on Flat Plate Photovoltaic Array Fields

    NASA Technical Reports Server (NTRS)

    Miller, R.; Zimmerman, D.

    1979-01-01

    The aerodynamic forces resulting from winds acting on flat plate photovoltaic arrays were investigated. Local pressure distributions and total aerodynamic forces on the arrays are shown. Design loads are presented to cover the conditions of array angles relative to the ground from 20 deg to 60 deg, variable array spacings, a ground clearance gap up to 1.2 m (4 ft) and array slant heights of 2.4 m (8 ft) and 4.8 m (16 ft). Several means of alleviating the wind loads on the arrays are detailed. The expected reduction of the steady state wind velocity with the use of fences as a load alleviation device are indicated to be in excess of a factor of three for some conditions. This yields steady state wind load reductions as much as a factor of ten compared to the load incurred if no fence is used to protect the arrays. This steady state wind load reduction is offset by the increase in turbulence due to the fence but still an overall load reduction of 2.5 can be realized. Other load alleviation devices suggested are the installation of air gaps in the arrays, blocking the flow under the arrays and rounding the edges of the array. A wind tunnel test plan to supplement the theoretical study and to evaluate the load alleviation devices is outlined.

  15. Domestic violence against 116 Turkish housewives: a field study.

    PubMed

    Mayda, Atilla S; Akkuş, Dilek

    2004-01-01

    In order to clarify the factors associated with domestic violence against married women and to learn the attitude of women toward violence and toward the inquiry of health personnel about domestic violence, a cross-sectional survey was conducted on 116 married Turkish women. The prevalence of domestic physical violence was found to be 41.4%, emotional violence 25.9%, sexual violence 8.6%, and controlling behavior 77.6%. Physical violence experienced at any time in their life was 50.9%. Rate of physical violence was found related with lower formal education of both women and husbands and their place of birth. The opinion of "husbands must not beat their wives" was more common among women with formal education. Eighty-two percent of women indicated that they would be willing to answer questions regarding domestic violence by health personnel. In conclusion, cultural background and formal education of either woman or man influence the likelihood of imposing or tolerating violent behavior at home. Inquiry about violence may be a routine in women's health care practice, and it is welcome by most women.

  16. Field experience with a new performance characterization procedure for photovoltaic arrays

    SciTech Connect

    King, D.L.; Kratochvil, J.A.; Boyson, W.E.

    1997-12-31

    As photovoltaic systems become larger and more numerous, improved methods are needed for testing and modeling their performance. Test methods that successfully separate the interacting, time-of-day dependent influences of solar irradiance, operating temperature, solar spectrum, and solar angle-of-incidence have now been developed. These test methods have resulted in a new array performance model that is reasonably simple, yet accurately predicts performance for all operating conditions. This paper describes the new model, outdoor tests required to implement it, results of field tests for five arrays of different technologies, and the evolution of the model into a numerical tool for designing and sizing photovoltaic arrays based on annual energy production.

  17. Photovoltaic module performance and durability following long-term field exposure

    SciTech Connect

    Ellibee, D.E.; Hansen, B.R.; King, D.L.; Kratochvil, J.A.; Quintana, M.A.

    1998-09-08

    Our investigations of both new and field-aged photovoltaic modules have indicated that, in general, today's commercially available modules area highly reliable product. However, by using new test procedures, subtle failure mechanisms have also been identified that must be addressed in order to achieve 30-year module lifetimes. This paper summarizes diagnostic test procedures, results, and implications of in-depth investigations of the performance and durability characteristics of commercial modules after long-term field exposure. A collaborative effort with U.S. module manufacturers aimed at achieving 30-year module lifetimes is also described.

  18. Photovoltaic concentrator optical system design: Solar energy engineering from physics to field

    NASA Astrophysics Data System (ADS)

    Coughenour, Blake Michael

    This dissertation describes the design, development, and field validation of a concentrator photovoltaic (CPV) solar energy system. The challenges of creating a highly efficient yet low-cost system architecture come from many sources. The solid-state physics of photovoltaic devices present fundamental limits to photoelectron conversion efficiency, while the electrical and thermal characteristics of widely available materials limit the design arena. Furthermore, the need for high solar spectral throughput, evenly concentrated sunlight, and tolerance to off-axis pointing places strict illumination requirements on the optical design. To be commercially viable, the cost associated with all components must be minimized so that when taken together, the absolute installed cost of the system in kWh is lower than any other solar energy method, and competitive with fossil fuel power generation. The work detailed herein focuses specifically on unique optical design and illumination concepts discovered when developing a viable commercial CPV system. By designing from the ground up with the fundamental physics of photovoltaic devices and the required system tolerances in mind, a select range of optical designs are determined and modeled. Component cost analysis, assembly effort, and development time frame further influence design choices to arrive at a final optical system design. When coupled with the collecting mirror, the final optical hardware unit placed at the focus generates more than 800W, yet is small and lightweight enough to hold in your hand. After fabrication and installation, the completed system's illumination, spectral, and thermal performance is validated with on-sun operational testing.

  19. Photovoltaics industry profile

    SciTech Connect

    1980-10-01

    A description of the status of the US photovoltaics industry is given. Principal end-user industries are identified, domestic and foreign market trends are discussed, and industry-organized and US government-organized trade promotion events are listed. Trade associations and trade journals are listed, and a photovoltaic product manufacturers list is included. (WHK)

  20. Development of a building block design of modular photovoltaic concentrator array fields

    SciTech Connect

    Carmichael, D.C.; Alexander, G.; Noel, G.T.; Scurlock, L.D.; Huss, W.R.; Stickford, G.H.

    1983-08-01

    To reduce the balance-of-system (BOS) costs and site-specific design costs for photovoltaic concentrator array fields, a modular Building Block design has been developed for installing array fields of each of two available concentrator collectors. The array-field subsystems and requirements incorporated in the design analyses include site preparation, foundations, electrical wiring, grounding, lightning protection, electromagnetic interference provisions, and tracking and controls. The Building Block designs developed minimize these array-field BOS costs and serve as standardized units to be used in multiples to construct array fields of various sizes. The detailed drawings and construction specifications prepared for the designs require only minimal design modification and cost for adaption to a specific site and application. The two concentrator collectors for which the modular array-field designs were developed are the linear-focus Fresnel-lens array manufactured by E-Systems, Inc., and the point-focus Fresnel-lens array manufactured by Martin Marietta Aerospace Corporation. Both designs are two-axis tracking and passively cooled. The developed Building Block designs are immediately applicable and reduce the array-field BOS costs and site-specific design costs to a fraction of those experienced in previous installations. The estimated array-field BOS costs (in 1982 dollars) using these modular designs are $0.78/W for the modular field based on the E-Systems array and $1.18/W for the modular field based on the Martin-Marietta array.

  1. Optimization of Electric Power Systems for Off-Grid Domestic Applications: An Argument for Wind/Photovoltaic Hybrids

    SciTech Connect

    Jennings, W.; Green, J.

    2001-01-01

    The purpose of this research was to determine the optimal configuration of home power systems relevant to different regions in the United States. The hypothesis was that, regardless of region, the optimal system would be a hybrid incorporating wind technology, versus a photovoltaic hybrid system without the use of wind technology. The method used in this research was HOMER, the Hybrid Optimization Model for Electric Renewables. HOMER is a computer program that optimizes electrical configurations under user-defined circumstances. According to HOMER, the optimal system for the four regions studied (Kansas, Massachusetts, Oregon, and Arizona) was a hybrid incorporating wind technology. The cost differences between these regions, however, were dependent upon regional renewable resources. Future studies will be necessary, as it is difficult to estimate meteorological impacts for other regions.

  2. Introducing a computer program devoted to renewable integration assessment of multi-field solar photovoltaic power plants

    SciTech Connect

    Gil, M.A.C.; Arroba, J.P.; Ibanez, J.C.; Criado, J.A.R.

    1996-11-01

    The objectives of this paper are to present a computer program devoted to the simulation of solar photovoltaic power plants, namely the assessment of their power generation technical potential. The most general configuration of a former program devoted to single-field photovoltaic generators has been extended and updated to multi-field systems. This program is also intended to provide capabilities in order to assess the integration of renewable energy resources. Mainly solar and wind energy systems will be considered, as well as pumped-storage stations, of which an example is included.

  3. Graphene-based photovoltaic cells for near-field thermal energy conversion.

    PubMed

    Messina, Riccardo; Ben-Abdallah, Philippe

    2013-01-01

    Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. While their efficiency is limited in far field by the Schockley-Queisser limit, in near field the heat flux transferred to a photovoltaic cell can be largely enhanced because of the contribution of evanescent photons, in particular for a source supporting a surface mode. Unfortunately, in the infrared where these systems operate, the mismatch between the surface-mode frequency and the semiconductor gap reduces drastically the potential of this technology. In this paper we propose a modified thermophotovoltaic device in which the cell is covered by a graphene sheet. By discussing the transmission coefficient and the spectral properties of the flux, we show that both the cell efficiency and the produced current can be enhanced, paving the way to promising developments for the production of electricity from waste heat.

  4. Low-cost modular array-field designs for flat-panel and concentrator photovoltaic systems

    SciTech Connect

    Post, H.N.; Alexander, G.; Carmichael, D.C.; Castle, J.A.

    1982-09-01

    This paper describes the design and development of low-cost, modular array fields for flatpanel and concentrator photovoltaic (PV) systems. The objective of the work was to reduce substantially the cost of the array-field balance-of-system (BOS) subsystems and site-specific design costs as compared to previous PV installations. These subsystems include site preparation, foundations, support structures, electrical wiring, grounding, lightning protection, electromagnetic interference considerations, and controls. To reduce these BOS and design costs, standardized modular (building-block) designs for flat-panel and concentrator array fields have been developed that are fully integrated and optimized for lowest life-cycle costs. Using drawings and specifications now available, these building-block designs can be used in multiples to install various size array fields. The developed designs are immediately applicable and reduce the array-field BOS costs to a small fraction of previous costs. Prototype array fields are currently being installed using each of the two alternative building-block designs developed for flat-panel PV array fields.

  5. Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials

    DOE PAGES

    Kempe, Michael D.; Miller, David C.; Wohlgemuth, John H.; ...

    2016-01-08

    As creep of polymeric materials is potentially a safety concern for photovoltaic modules, the potential for module creep has become a significant topic of discussion in the development of IEC 61730 and IEC 61215. To investigate the possibility of creep, modules were constructed, using several thermoplastic encapsulant materials, into thin-film mock modules and deployed in Mesa, Arizona. The materials examined included poly(ethylene)-co-vinyl acetate (EVA, including formulations both cross-linked and with no curing agent), polyethylene/polyoctene copolymer (PO), poly(dimethylsiloxane) (PDMS), polyvinyl butyral (PVB), and thermoplastic polyurethane (TPU). The absence of creep in this experiment is attributable to several factors of which themore » most notable one was the unexpected cross-linking of an EVA formulation without a cross-linking agent. It was also found that some materials experienced both chain scission and cross-linking reactions, sometimes with a significant dependence on location within a module. The TPU and EVA samples were found to degrade with cross-linking reactions dominating over chain scission. In contrast, the PO materials degraded with chain scission dominating over cross-linking reactions. Furthermore, we found no significant indications that viscous creep is likely to occur in fielded modules capable of passing the qualification tests, we note that one should consider how a polymer degrades, chain scission or cross-linking, in assessing the suitability of a thermoplastic polymer in terrestrial photovoltaic applications.« less

  6. Electromagnetic Fields Associated with Commercial Solar Photovoltaic Electric Power Generating Facilities.

    PubMed

    Tell, R A; Hooper, H C; Sias, G G; Mezei, G; Hung, P; Kavet, R

    2015-01-01

    The southwest region of the United States is expected to experience an expansion of commercial solar photovoltaic generation facilities over the next 25 years. A solar facility converts direct current generated by the solar panels to three-phase 60-Hz power that is fed to the grid. This conversion involves sequential processing of the direct current through an inverter that produces low-voltage three-phase power, which is stepped up to distribution voltage (∼12 kV) through a transformer. This study characterized magnetic and electric fields between the frequencies of 0 Hz and 3 GHz at two facilities operated by the Southern California Edison Company in Porterville, CA and San Bernardino, CA. Static magnetic fields were very small compared to exposure limits established by IEEE and ICNIRP. The highest 60-Hz magnetic fields were measured adjacent to transformers and inverters, and radiofrequency fields from 5-100 kHz were associated with the inverters. The fields measured complied in every case with IEEE controlled and ICNIRP occupational exposure limits. In all cases, electric fields were negligible compared to IEEE and ICNIRP limits across the spectrum measured and when compared to the FCC limits (≥0.3 MHz).

  7. Field Guide for Testing Existing Photovoltaic Systems for Ground Faults and Installing Equipment to Mitigate Fire Hazards

    SciTech Connect

    Brooks, William; Basso, Thomas; Coddington, Michael

    2015-10-01

    Ground faults and arc faults are the two most common reasons for fires in photovoltaic (PV) arrays and methods exist that can mitigate the hazards. This report provides field procedures for testing PV arrays for ground faults, and for implementing high resolution ground fault and arc fault detectors in existing and new PV system designs.

  8. Research in the Field of Organic Photovoltaics at the Institute for Problems of Chemical Physics of Russian Academy of Sciences

    NASA Astrophysics Data System (ADS)

    Troshin, Pavel A.

    2015-08-01

    In the present review we highlight the main research activities in the field of organic photonics and photovoltaics at the Institute for Problems of Chemical Physics of Russian Academy of Sciences (IPCP RAS). Extensive investigation of optical and electrical properties of π-conjugated organic compounds performed at IPCP RAS since 1960's resulted in design of many exciting materials representing organic semiconductors, metals and superconductors. Organic Schottky barrier and p/n junction photovoltaic devices constructed at IPCP RAS in 1960's and 1970's were among the first examples of reasonably efficient organic solar cells at that time. These early discoveries inspired younger generations of the researchers to continue the work of their mentors and explore the world of organic materials and photonic devices such as molecular photonic switches, organic light emitting diodes, solar cells, photodetectors, photoswitchable organic field-effect transistors and memory elements.

  9. Photovoltaics: The endless spring

    NASA Technical Reports Server (NTRS)

    Brandhorst, H. W., Jr.

    1984-01-01

    An overview of the developments in the photovoltaic field over the past decade or two is presented. Accomplishments in the terrestrial field are reviewed along with projections and challenges toward meeting cost goals. The contrasts and commonality of space and terrestrial photovoltaics are presented. Finally, a strategic philosophy of photovoltaics research highlighting critical factors, appropriate directions, emerging opportunities, and challenges of the future is given.

  10. At home in the postcolony: Ecology, empire and domesticity at the Lamto field station, Ivory Coast.

    PubMed

    Lachenal, Guillaume

    2016-12-01

    This article is a history of the field station Lamto, in Ivory Coast, which was created by French ecologists in 1962, after independence. It retraces the origins, the logics and the contradictions of an extraordinarily ambitious scientific project, which aimed at the systematic, holistic, quantitative and multi-disciplinary description of a unit of African nature - the savannah ecosystem. It explores how knowledge-making was articulated with work hierarchies and postcolonial politics, lifestyles, values and affects. It reconstitutes the political ecology of a research station in ecology, following in its residences, laboratories and open-air experiments the co-production of domesticity, nature, science and (post-)colonial situations.

  11. The Application of GeoRSC Based on Domestic Satellite in Field Remote Sensing Anomaly Verification

    NASA Astrophysics Data System (ADS)

    Gao, Ting; Yang, Min; Han, Haihui; Li, Jianqiang; Yi, Huan

    2016-11-01

    The Geo REC is the digital remote sensing survey system which based on domestic satellites, and by means of it, the thesis carriedy out a remote sensing anomaly verification field application test in Nachitai area of Qinghai. Field test checks the system installation, the stability of the system operation, the efficiency of reading and show the romoate image or vector data, the security of the data management system and the accuracy of BeiDou navigation; through the test data, the author indicated that the hardware and software system could satisfy the remote sensing anomaly verification work in field, which could also could make it convenient forconvenient the workflow of remote sense survey and, improve the work efficiency,. Aat the same time, in the course of the experiment, we also found some shortcomings of the system, and give some suggestions for improvement combineding with the practical work for the system.

  12. Optical, electrical, and magnetic field studies of organic materials for light emitting diodes and photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Basel, Tek Prasad

    We studied optical, electrical, and magnetic field responses of films and devices based on organic semiconductors that are used for organic light emitting diodes (OLEDs) and photovoltaic (OPV) solar cell applications. Our studies show that the hyperfine interaction (HFI)-mediated spin mixing is the key process underlying various magnetic field effects (MFE) and spin transport in aluminum tris(8-hydroxyquinoline)[Alq3]-based OLEDs and organic spin-valve (OSV). Conductivity-detected magnetic resonance in OLEDs and magneto-resistance (MR) in OSVs show substantial isotope dependence. In contrast, isotope-insensitive behavior in the magneto-conductance (MC) of same devices is explained by the collision of spin ½ carriers with triplet polaron pairs. We used steady state optical spectroscopy for studying the energy transfer dynamics in films and OLEDs based on host-guest blends of the fluorescent polymer and phosphorescent molecule. We have also studied the magnetic-field controlled color manipulation in these devices, which provide a strong proof for the `polaron-pair' mechanism underlying the MFE in organic devices. The critical issue that hampers organic spintronics device applications is significant magneto-electroluminescence (MEL) at room temperature (RT). Whereas inorganic spin valves (ISVs) show RT magneto-resistance, MR>80%, however, the devices do not exhibit electroluminescence (EL). In contrast, OLEDs show substantive EL emission, and are particularly attractive because of their flexibility, low cost, and potential for multicolor display. We report a conceptual novel hybrid organic/inorganic spintronics device (h-OLED), where we employ both ISV with large MR at RT, and OLED that has efficient EL emission. We investigated the charge transfer process in an OPV solar cell through optical, electrical, and magnetic field measurements of thin films and devices based on a low bandgap polymer, PTB7 (fluorinated poly-thienothiophene-benzodithiophene). We found that

  13. Design of a Glenn Research Center Solar Field Grid-Tied Photovoltaic Power System

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2009-01-01

    The NASA Glenn Research Center (GRC) designed, developed, and installed, a 37.5 kW DC photovoltaic (PV) Solar Field in the GRC West Area in the 1970s for the purpose of testing PV panels for various space and terrestrial applications. The PV panels are arranged to provide a nominal 120 VDC. The GRC Solar Field has been extremely successful in meeting its mission. The PV panels and the supporting electrical systems are all near their end of life. GRC has designed a 72 kW DC grid-tied PV power system to replace the existing GRC West Area Solar Field. The 72 kW DC grid-tied PV power system will provide DC solar power for GRC PV testing applications, and provide AC facility power for all times that research power is not required. A grid-tied system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility for use by all. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provide valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. The report concludes that the GRC West Area grid-tied PV power system design is viable for a reliable

  14. Development of a second-generation linear Fresnel lens photovoltaic and thermal (PVT) concentrator array, including fabrication and installation of a 200 square meter collector field

    SciTech Connect

    O'Neill, M.J.

    1985-02-01

    This report summarizes work performed in two areas: development of a second-generation linear Fresnel lens photovoltaic concentrator array, and development and fabrication of a 22 kilowatt photovoltaic and thermal concentrator array. Under these programs, ENTECH, Inc. developed a new second-generation linear Fresnel lens PVT concentrator system, and deployed a 200 square meter collector field of the new design at Sandia-Albuquerque. The new system combines excellent performance and low mass-production cost.

  15. Photovoltaics (Fact Sheet)

    SciTech Connect

    DOE Solar Energy Technologies Program

    2011-10-13

    DOE works with national labs, academia, and industry to support the domestic photovoltaics (PV) industry and research enterprise. SunShot aims to achieve widespread, unsubsidized cost-competitiveness through an applied research and development (R&D) portfolio spanning PV materials, devices, and manufacturing technologies.

  16. Photovoltaics (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    DOE works with national labs, academia, and industry to support the domestic photovoltaics (PV) industry and research enterprise. SunShot aims to achieve widespread, unsubsidized cost-competitiveness through an applied research and development (R&D) portfolio spanning PV materials, devices, and manufacturing technologies.

  17. Photovoltaics (Fact Sheet)

    SciTech Connect

    Not Available

    2012-11-01

    The U.S. Department of Energy (DOE) works with industry, academia, national laboratories, and other government agencies to advance solar photovoltaics (PV) domestically. The SunShot Initiative aims to achieve widespread, unsubsidized cost-competitiveness through an applied research and development (R&D) portfolio spanning PV materials, devices, and manufacturing technologies.

  18. Effect of magnetic field on the photovoltaic properties of YBa2Cu3O6.96/Ag heterojunction

    NASA Astrophysics Data System (ADS)

    Yang, Feng; Han, Mengyuan; Chu, Zhuang; Ma, Zhipan; Chang, Fanggao

    2017-02-01

    The obvious photovoltaic effect (Voc ˜ 30 μV) induced by purple-laser illumination at high Tc superconductor YBa2Cu3O6.96/Ag (YBCO/Ag) heterojunction has been observed, revealing that there exists an electrical field across the YBCO/Ag interface. It has been found that magnetic field can dramatically change the photo-induced voltage in the vicinity of superconducting transition. With increasing magnetic fields up to 3 T, the photovoltage at 74 K and 30 mW/mm2 is reduced from 15 μV to zero and then reaches -15 μV. The polarity of the voltage can be switched by applying an external magnetic field, as well as by varying the laser intensity. Our results can be understood in terms of the magnetic vortex penetrating in high Tc superconductors and provide strong evidence for the existence of an interface electrical field in the superconductor/metal heterojunction.

  19. Acenes, Heteroacenes and Analogous Molecules for Organic Photovoltaic and Field Effect Transistor Applications

    NASA Astrophysics Data System (ADS)

    Granger, Devin Benjamin

    donor molecules for bulk heterojunction organic photovoltaics based on anthrathiophene and benzo[1,2-b:4,5-b']dithiophene central units like literature molecules containing fluorene and dithieno[2,3-b:2',3'-d]silole cores. The synthetic strategies of developing reduced symmetry benzo[1,2-b:4,5-b']dithiophene to study the effect of substitution around the central unit is also described. The optical and electronic properties of the donors and acceptors are described along with the performance and characteristics of devices employing these molecules. The final two data chapters focus on new nitrogen containing polycyclic hydrocarbons containing indolizine and (2.2.2) cyclazine units. The optical, electronic and other physical properties of these molecules are explored, in addition to the synthetic strategies for incorporating the indolizine and cyclazine units. By use of alkylsilylethynyl groups, crystal engineering was investigated for the benzo[2,3-b:5,6-b']diindolizine chromophore described in chapter 4 to target the 2-D "brick-work" packing motif for application in field effect transistor devices. Optical and electronic properties of the cyclazine end-capped acene molecules described in chapter 5 were investigated and described in relation to the base acene molecules. In both cases, density functional theory calculations were conducted to better understand unexpected optical properties of these molecules, which are like the linear acene series despite the non-linear attachment.

  20. In-field measurements of PCDD/F emissions from domestic heating appliances for solid fuels.

    PubMed

    Hübner, C; Boos, R; Prey, T

    2005-01-01

    Within this project the emissions into the atmosphere of polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) of 30 domestic heating appliances in Austrian households were tested. The appliances were single stoves (kitchen stove, continuous burning stove and tiled stove) and central heating boilers for solid fuels up to a nominal heat input of 50 kW. A main objective of this survey was to determine the PCDD/F emissions of domestic heating units under routine conditions. Therefore, the habitual combustion conditions used by the operators were not influenced. The original fuels and lightning supports were used and the operation of the units was carried out by the householders according to their usual practice. The data obtained were used to calculate in-field PCDD/F-emission factors. Most of the appliances have shown PCDD/F emissions within a concentration range of 0.01-0.3 ng TEQ/MJ. Modern fan-assisted wood heating boilers with afterburning and units for continuously burning of wood chips and wood pellets had the lowest emissions. High emissions were caused by unsuitable heating habits such as combustion of wastes and inappropriate operation of the appliances. There were only small differences between single stoves and central heating boilers or between wood and coal-fired appliances. The emission factors calculated are higher than those cited in literature, which are mainly derived from trials on test stands under laboratory conditions.

  1. Costs and indices for domestic oil and gas field equipment and production operations, 1992--1995

    SciTech Connect

    1996-08-01

    This report presents estimated costs and cost indices for domestic oil and natural gas field equipment and production operations for 1992, 1993, 1994, and 1995. The costs of all equipment and services are those in effect during June of each year. The sum (aggregates) of the costs for representative leases by region, depth, and production rate were averaged and indexed. This provides a general measure of the increased or decreased costs from year to year for lease equipment and operations. These general measured do not capture changes in industry-wide costs exactly because of annual variations in the ratio of the total number of oil wells to the total number of gas wells. The detail provided in this report is unavailable elsewhere. The body of this report contains summary tables, and the appendices contain detailed tables.

  2. Characterization of Photovoltaic Generators

    ERIC Educational Resources Information Center

    Boitier, V.; Cressault, Y.

    2011-01-01

    This paper discusses photovoltaic panel systems and reviews their electrical properties and use in several industrial fields. We explain how different photovoltaic panels may be characterized by undergraduate students at university using simple methods to retrieve their electrical properties (power, current and voltage) and compare these values…

  3. Characterization of Photovoltaic Generators

    ERIC Educational Resources Information Center

    Boitier, V.; Cressault, Y.

    2011-01-01

    This paper discusses photovoltaic panel systems and reviews their electrical properties and use in several industrial fields. We explain how different photovoltaic panels may be characterized by undergraduate students at university using simple methods to retrieve their electrical properties (power, current and voltage) and compare these values…

  4. Evaluation of Ageratum conyzoides in field scale constructed wetlands (CWs) for domestic wastewater treatment.

    PubMed

    Tilak, A S; Wani, Suhas P; Datta, A; Patil, M D; Kaushal, M; Reddy, K R

    2017-05-01

    Ageratum conyzoides were evaluated in field scale subsurface flow constructed wetlands (CWs) to quantify its nitrogen (N) and phosphorus (P) uptake and compare with wetland plants (Pistia stratiotes, Typha latifolia and Canna indica). The two-field scale subsurface flow CWs, located in the International Crops Research Institute for Semi-Arid Tropics, received wastewater from an urban colony. The CW1 and CW2 had the same dimensions (length:10 m, width:3 m, total depth:1.5 m and sand and gravel:1 m), similar flow rates (3 m(3)/d), hydraulic loading rates (HLRs-10 cm/d) and hydraulic retention time (HRT-5 days) from July 2014-August 2015. The vegetation in both CWs consisted of Pistia stratiotes, Typha latifolia, Canna indica, and Ageratum conyzoides, respectively. The CW1 (% reduction with respect to concentrations) reduced total suspended solids (TSS) (68%), NH4-N (26%), NO3-N (30%), soluble reactive P (SRP) (20%), chemical oxygen demand (COD) (45%) and fecal coliforms (71%), while the CW2 (%-reduction with respect to concentrations) reduced TSS (63%), NH4-N (32%), NO3-N (26%), SRP (35%), COD (39%) and fecal coliforms (70%). Ageratum conyzoides can be used in combination with Pistia stratiotes, Typha latifolia and Canna indica to enhance removal of excessive N, P and fecal coliforms from domestic wastewater.

  5. The worldwide market for photovoltaics in the rural sector

    NASA Astrophysics Data System (ADS)

    Brainard, W. A.

    1982-09-01

    The worldwide market for stand-alone photovoltaic power systems in three specific segments of the rural sector were determined. The worldwide market for photovoltaic power systems for village power, cottage industry, and agricultural applications were addressed. The objectives of these studies were to: The market potential for small stand-alone photovoltaic power system in specific application areas was assessed. Technical, social and institutional barriers to PV utilization were identified. Funding sources available to potential users was also identified and marketing strategies appropriate for each sector were recommended to PV product manufacturers. The studies were prepared on the basis of data gathered from domestic sources and from field trips to representative countries. Both country-specific and sector-specific results are discussed, and broadly applicable barriers pertinent to international marketing of PV products are presented.

  6. The worldwide market for photovoltaics in the rural sector

    NASA Technical Reports Server (NTRS)

    Brainard, W. A.

    1982-01-01

    The worldwide market for stand-alone photovoltaic power systems in three specific segments of the rural sector were determined. The worldwide market for photovoltaic power systems for village power, cottage industry, and agricultural applications were addressed. The objectives of these studies were to: The market potential for small stand-alone photovoltaic power system in specific application areas was assessed. Technical, social and institutional barriers to PV utilization were identified. Funding sources available to potential users was also identified and marketing strategies appropriate for each sector were recommended to PV product manufacturers. The studies were prepared on the basis of data gathered from domestic sources and from field trips to representative countries. Both country-specific and sector-specific results are discussed, and broadly applicable barriers pertinent to international marketing of PV products are presented.

  7. Domestic Violence during Pregnancy in an Eastern City of Turkey: A Field Study

    ERIC Educational Resources Information Center

    Arslantas, Hulya; Adana, Filiz; Ergin, Filiz; Gey, Neriman; Bicer, Nejla; Kiransal, Nilufer

    2012-01-01

    Violence is an increasing and important community health problem that can be seen in any area of human life. Limited studies were found about domestic violence among pregnant women and its relation with social status of women. The aim of this study was to determine the prevalence and types of domestic violence during pregnancy, factors affecting…

  8. Domestic Violence during Pregnancy in an Eastern City of Turkey: A Field Study

    ERIC Educational Resources Information Center

    Arslantas, Hulya; Adana, Filiz; Ergin, Filiz; Gey, Neriman; Bicer, Nejla; Kiransal, Nilufer

    2012-01-01

    Violence is an increasing and important community health problem that can be seen in any area of human life. Limited studies were found about domestic violence among pregnant women and its relation with social status of women. The aim of this study was to determine the prevalence and types of domestic violence during pregnancy, factors affecting…

  9. Potential for Photovoltaic Solar Installation in Non-Irrigated Corners of Center Pivot Irrigation Fields in the State of Colorado

    SciTech Connect

    Roberts, B.

    2011-07-01

    The State of Colorado expressed an interest in assessing the potential for photovoltaic (PV) solar installations on non-irrigated corners of center-pivot irrigation (CPI) fields throughout the state. Using aerial imagery and irrigated land data available from the Colorado Water Conservation Board, an assessment of potentially suitable sites was produced. Productivity estimates were calculated from that assessment. The total area of non-irrigated corners of CPI fields in Colorado was estimated to be 314,674 acres, which could yield 223,418 acres of installed PV panels assuming 71% coverage in triangular plots. The total potential annual electricity production for the state was estimated to be 56,821 gigawatt hours (GWH), with an average of 1.3 GWH per available plot.

  10. Costs and indices for domestic oil and gas field equipment and production operations 1994 through 1997

    SciTech Connect

    1998-03-01

    This report presents estimated costs and cost indices for domestic oil and natural gas field equipment and production operations for 1994, 1995, 1996, and 1997. The costs of all equipment and services are those in effect during June of each year. The sums (aggregates) of the costs for representative leases by region, depth, and production rate were averaged and indexed. This provides a general measure of the increased or decreased costs from year to year for lease equipment and operations. These general measures do not capture changes in industry-wide costs exactly because of annual variations in the ratio of the total number of oil wells to the total number of gas wells. The detail provided in this report is unavailable elsewhere. The body of this report contains summary tables, and the appendices contain detailed tables. Price changes for oil and gas, changes in taxes on oil and gas revenues, and environmental factors (compliance costs and lease availability) have a significant impact on the number and cost of oil and gas wells drilled. These changes also impact the cost of oil and gas equipment and production operations.

  11. Costs and indices for domestic oil and gas field equipment and production operations 1990 through 1993

    SciTech Connect

    Not Available

    1994-07-08

    This report presents estimated costs and indice for domestic oil and gas field equipment and production operations for 1990, 1991, 1992, and 1993. The costs of all equipment and serives were those in effect during June of each year. The sums (aggregates) of the costs for representative leases by region, depth, and production rate were averaged and indexed. This provides a general measure of the increased or decreased costs from year to year for lease equipment and operations. These general measures do not capture changes in industry-wide costs exactly because of annual variations in the ratio of oil wells to gas wells. The body of the report contains summary tables, and the appendices contain detailed tables. Price changes for oil and gas, changes in taxes on oil and gas revenues, and environmental factors (costs and lease availability) have significant impact on the number and cost of oil and gas wells drilled. These changes also impact the cost of oil and gas production equipment and operations.

  12. Early experience and domestication affect auditory discrimination learning, open field behaviour and brain size in wild Mongolian gerbils and domesticated laboratory gerbils (Meriones unguiculatus forma domestica).

    PubMed

    Stuermer, Ingo W; Wetzel, Wolfram

    2006-10-02

    The influence of early experience and strain differences on auditory discrimination learning, open field behaviour and brain size was investigated in wild-type Mongolian gerbils (strain Ugoe:MU95) raised in the wild (wild F-0) or in the laboratory (wild F-1) and in domesticated Laboratory Gerbils (LAB). Adult males were conditioned for 10 days in a shuttle box go/no-go paradigm to discriminate two frequency-modulated tones. Significant learning was established within 5 days in wild F-0 and within 3 days in wild F-1 and LAB. Spontaneous jumps in the shuttle box (inter-trial crossings) were frequently seen in wild F-0 and F-1, but rarely in LAB. All groups exhibited nearly the same ability to remember after 2 weeks without training. In the open field test applied on 5 consecutive days, no differences in locomotion patterns and inner field preferences were found. Rearing frequency decreased over 5 days in wild gerbils. Running distances (4-6m/min) were similar in wild F-0 and LAB, but higher in wild F-1. The ratio of brain size to body weight did not differ between wild F-0 and F-1, but was 17.1% lower in LAB. Correspondingly high brain weights in wild F-1 and F-0 support our domestication hypothesis and negate any serious effect of early experience or captivity on brain size in Mongolian gerbils. In contrast, wild F-1 raised in the laboratory show a rapid improvement in learning performance, indicating that early experience rather that genetic differences between strains affect shuttle box discrimination learning in gerbils.

  13. Field Guide for Testing Existing Photovoltaic Systems for Ground Faults and Installing Equipment to Mitigate Fire Hazards: November 2012 - October 2013

    SciTech Connect

    Brooks, William

    2015-02-01

    Ground faults and arc faults are the two most common reasons for fires in photovoltaic (PV) arrays and methods exist that can mitigate the hazards. This report provides field procedures for testing PV arrays for ground faults, and for implementing high resolution ground fault and arc fault detectors in existing and new PV system designs.

  14. Wind loads on flat plate photovoltaic array fields. Phase III, final report

    SciTech Connect

    Miller, R.D.; Zimmerman, D.K.

    1981-04-01

    The results of an experimental analysis (boundary layer wind tunnel test) of the aerodynamic forces resulting from winds acting on flat plate photovoltaic arrays are presented. Local pressure coefficient distributions and normal force coefficients on the arrays are shown and compared to theoretical results. Parameters that were varied when determining the aerodynamic forces included tilt angle, array separation, ground clearance, protective wind barriers, and the effect of the wind velocity profile. Recommended design wind forces and pressures are presented, which envelop the test results for winds perpendicular to the array's longitudinal axis. This wind direction produces the maximum wind loads on the arrays except at the array edge where oblique winds produce larger edge pressure loads.

  15. Status of DOE and AID stand-alone photovoltaic system field tests

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Delombard, R.; Ratajczak, A. F.; Scudder, L. R.

    1984-01-01

    The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system projects sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, and PV-powered vaccine refrigerator systems in six countries. The AID project includes a large village power system, a farmhouse system and two water pumping-irrigation systems in Tunisia, a water pumping/grain grinding system in Upper Volta, five medical clinic systems in four countries, PV-powered vaccine refrigerator systems in 18 countries and a PV-powered remote earth station in Indonesia. This paper reviews these PV projects and summarizes significant findings to date.

  16. Field test analysis of concentrator photovoltaic system focusing on average photon energy and temperature

    NASA Astrophysics Data System (ADS)

    Husna, Husyira Al; Ota, Yasuyuki; Minemoto, Takashi; Nishioka, Kensuke

    2015-08-01

    The concentrator photovoltaic (CPV) system is unique and different from the common flat-plate PV system. It uses a multi-junction solar cell and a Fresnel lens to concentrate direct solar radiation onto the cell while tracking the sun throughout the day. The cell efficiency could reach over 40% under high concentration ratio. In this study, we analyzed a one year set of environmental condition data of the University of Miyazaki, Japan, where the CPV system was installed. Performance ratio (PR) was discussed to describe the system’s performance. Meanwhile, the average photon energy (APE) was used to describe the spectrum distribution at the site where the CPV system was installed. A circuit simulator network was used to simulate the CPV system electrical characteristics under various environmental conditions. As for the result, we found that the PR of the CPV systems depends on the APE level rather than the cell temperature.

  17. Status of DOE and AID stand-alone photovoltaic system field tests

    NASA Astrophysics Data System (ADS)

    Bifano, W. J.; Delombard, R.; Ratajczak, A. F.; Scudder, L. R.

    The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system projects sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, and PV-powered vaccine refrigerator systems in six countries. The AID project includes a large village power system, a farmhouse system and two water pumping-irrigation systems in Tunisia, a water pumping/grain grinding system in Upper Volta, five medical clinic systems in four countries, PV-powered vaccine refrigerator systems in 18 countries and a PV-powered remote earth station in Indonesia. This paper reviews these PV projects and summarizes significant findings to date.

  18. Status of DOE and AID stand-alone photovoltaic system field tests

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Delombard, R.; Ratajczak, A. F.; Scudder, L. R.

    1984-01-01

    The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system projects sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, and PV-powered vaccine refrigerator systems in six countries. The AID project includes a large village power system, a farmhouse system and two water pumping-irrigation systems in Tunisia, a water pumping/grain grinding system in Upper Volta, five medical clinic systems in four countries, PV-powered vaccine refrigerator systems in 18 countries and a PV-powered remote earth station in Indonesia. This paper reviews these PV projects and summarizes significant findings to date.

  19. Nanostructured photovoltaics

    NASA Astrophysics Data System (ADS)

    Fu, Lan; Tan, H. Hoe; Jagadish, Chennupati

    2013-01-01

    Energy and the environment are two of the most important global issues that we currently face. The development of clean and sustainable energy resources is essential to reduce greenhouse gas emission and meet our ever-increasing demand for energy. Over the last decade photovoltaics, as one of the leading technologies to meet these challenges, has seen a continuous increase in research, development and investment. Meanwhile, nanotechnology, which is considered to be the technology of the future, is gradually revolutionizing our everyday life through adaptation and incorporation into many traditional technologies, particularly energy-related technologies, such as photovoltaics. While the record for the highest efficiency is firmly held by multijunction III-V solar cells, there has never been a shortage of new research effort put into improving the efficiencies of all types of solar cells and making them more cost effective. In particular, there have been extensive and exciting developments in employing nanostructures; features with different low dimensionalities, such as quantum wells, nanowires, nanotubes, nanoparticles and quantum dots, have been incorporated into existing photovoltaic technologies to enhance their performance and/or reduce their cost. Investigations into light trapping using plasmonic nanostructures to effectively increase light absorption in various solar cells are also being rigorously pursued. In addition, nanotechnology provides researchers with great opportunities to explore the new ideas and physics offered by nanostructures to implement advanced solar cell concepts such as hot carrier, multi-exciton and intermediate band solar cells. This special issue of Journal of Physics D: Applied Physics contains selected papers on nanostructured photovoltaics written by researchers in their respective fields of expertise. These papers capture the current excitement, as well as addressing some open questions in the field, covering topics including the

  20. Organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Leo, Karl

    2016-08-01

    Organic photovoltaics are on the verge of revolutionizing building-integrated photovoltaics. For other applications, however, several basic open scientific questions need answering to, in particular, further improve energy-conversion efficiency and lifetime.

  1. Photovoltaic device

    DOEpatents

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  2. Photovoltaic device

    DOEpatents

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  3. Photovoltaic device

    DOEpatents

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  4. Plasmonic photovoltaics: near-field of a metal nanowire array on the interface for solar cell efficiency enhancement

    NASA Astrophysics Data System (ADS)

    Dmitruk, N. L.; Korovin, A. V.

    2013-05-01

    The analysis of the main principles of plasmonic photovoltaics relative to the enhancement of the efficiency of solar cells (SCs) by means of light trapping in a thin film SC is considered in this paper. Theoretical analysis and corresponding numerical calculations of the transmittance into a semiconductor base enhancement due to light trapping via the excitation of local (surface) plasmons and surface plasmon polaritons in a periodic metal nanowire array have been performed. The calculations have been performed for rectangular cross-section metal nanowires by the differential formalism method using the covariant form of Maxwell’s equations in a curvilinear coordinate system. Local distributions of the electric field in plasmonic nanostructures are calculated for metal nanowires in both s- and p-polarization of incident light. Then both the light transmittance in the near- and far-field (wave) zones and the local generation rate of electron-hole pairs have been calculated using the spatial distribution of the Poynting vector. Angular/spectral distributions of transmittance and position/spectral distributions of the generation rate in the near-field zone have complicated the non-homogeneous character due to the excitation of surface plasmons and surface plasmon polaritons. It has been shown that the main highly enhanced near-field generation is localized in the so-called hot points on the nanoparticles/nanowires surface. The planar-averaged generation rate for the p-polarization of light has a near-field component, which is always more for a Si base (indirect bandgap semiconductor) than for GaAs (direct bandgap one). This plasmonic effect can be used for the base thicknesses down up to 100-150 nm due to light scattering and the surface plasmon enhancement of near-fields. These plasmon-carrying metal nanowires can be used as a current grid in an SC too.

  5. Photovoltaic field test performance assessment. Technology status report No. 4. Final report

    SciTech Connect

    Mayorga, H.; Hostetler, R.

    1986-03-01

    Descriptions of 1984 performance are provided for five fixed-tilt flat plate, one tracking flat plate, and two concentrator photovoltaic systems. They range in size from 18 kW to 1000 kW. All of the systems have extensive instrumentation; performance readings are generally available every 10 minutes. Installations vary in energy efficiency. The older, fixed-tilt, flat plate sites have the lowest efficiency (5%). Next are the newer flat plate sites of both fixed-tilt and tracking types (6 to 7%). The Fresnel lens concentrator sites have the highest efficiency (6 to 9%). Installations vary widely in availability. Power conditioning unit failure is the largest contributor to decreased availability. In general, nameplate ratings are optimistic. Observed power output equals these ratings only under rare combinations of high insolation and low ambient temperature. Degradation in energy efficiency may be occurring at Oklahoma City. The tracking flat plate site demonstrates high energy capture and capacity factor. The Fresnel lens concentrators are especially sensitive to tracking error and cloudiness. At flat plate sites that have monocrystalline silicon cells, energy efficiency is fairly constant with insolation. At flat plate sites using polycrystalline cells, energy efficiency increases with insolation. At the Fresnel lens concentrator sites (both using monocrystalline cells), energy efficiency increases with insolation. Problems, mostly of the hardware type, with the on-site data acquisition system continue to hinder data collection.

  6. Degradation of Photovoltaic Modules Under High Voltage Stress in the Field: Preprint

    SciTech Connect

    del Cueto, J. A.; Rummel, S. R.

    2010-08-01

    The degradation in performance for eight photovoltaic (PV) modules stressed at high voltage (HV) is presented. Four types of modules--tandem-junction and triple-junction amorphous thin-film silicon, plus crystalline and polycrystalline silicon modules--were tested, with a pair of each biased at opposite polarities. They were deployed outdoors between 2001 and 2009 with their respective HV leakage currents through the module encapsulation continuously monitored with a data acquisition system, along with air temperature and relative humidity. For the first 5 years, all modules were biased continuously at fixed 600 VDC, day and night. In the last 2 years, the modules were step-bias stressed cyclically up and down in voltage between 10 and 600 VDC, in steps of tens to hundreds of volts. This allowed characterization of leakage current versus voltage under a large range of temperature and moisture conditions, facilitating determination of leakage paths. An analysis of the degradation is presented, along with integrated leakage charge. In HV operation: the bulk silicon modules degraded either insignificantly or at rates of 0.1%/yr higher than modules not biased at HV; for the thin-film silicon modules, the added loss rates are insignificant for one type, or 0.2%/yr-0.6%/yr larger for the other type.

  7. Screening-engineered Field-effect Photovoltaics and Synthesis, Characterization, and Applications of Carbon-based and Related Nanomaterials

    NASA Astrophysics Data System (ADS)

    Regan, William Raymond

    Carbon nanomaterials, and especially graphene (a 2D carbon allotrope), possess unique electronic, optical, and mechanical properties and allow access to both new physical phenomena and reinventions of familiar technologies. In the first part of this thesis (chapter 2), the low carrier density and high conductivity of graphene are used to repurpose the electric field effect (used for many decades in transistors) into a universally-applicable doping method for electrically-contacted semiconductors. This method, referred to as "screening-engineered field-effect photovoltaics" as the electric field doping is enabled by a carefully-designed poorly-screening electrode (e.g. graphene), is shown to open up many new low-cost and abundant semiconductors for use in high efficiency solar cells. We extend this method beyond ultrathin materials such as graphene and show that 1D nanowire electrodes made of any material also allow penetration of applied electric fields. The next part of this thesis (chapter 3) focuses on the fundamental properties of graphene -- its structure, synthesis, characterization, and manipulation -- and on using graphene as a building block for other nanostructures: grafold, graphene sandwiches and veils, and graphritos. In chapter 4, various graphene electronics are constructed and tested. Graphene field-effect transistors (FETs) and p-n junctions are fabricated to study the influence of the substrate on graphene carrier mobility and doping. Graphene nanoribbons and grafold FETs are made to investigate the effects of additional confinement on electronic transport. Chapter 5 summarizes synthesis methods and additional experiments with other nanomaterials, including dichalcogenides and chalcogenides (magnesium diboride, gallium selenide, and tin sulfide), carbon nanomaterials (carbon nanotubes and graphene), and copper oxide. Additional measurement and fabrication methods are discussed in appendix A.

  8. Tuning the photovoltaic effect of multiferroic CoFe2O4/Pb(Zr, Ti)O3 composite films by magnetic fields

    NASA Astrophysics Data System (ADS)

    Pan, Dan-Feng; Chen, Guang-Yi; Bi, Gui-Feng; Zhang, Hao; Liu, Jun-Ming; Wang, Guang-Hou; Wan, Jian-Guo

    2016-05-01

    The 0-3 type CoFe2O4-Pb(Zr,Ti)O3 (CFO-PZT) multiferroic composite films have been prepared by a sol-gel process and spin-coating technique. A confirmable photovoltaic effect is observed under ultraviolet light irradiation. Moreover, this photovoltaic effect can be tuned by external magnetic fields. The maximum magnetic modulation ratios of short-circuit current density and open-circuit voltage can reach as high as 13.7% and 12.8% upon the application of 6 kOe DC magnetic field. Through remnant polarization measurements under various magnetic fields and detailed analysis of the energy band structures, we elucidate the mechanism of tuning photovoltaic effect by magnetic fields and attribute it to the combination of two factors. One is the decreased ferroelectric-polarization-induced depolarization electric field and another is the band structure reconstruction at CFO-PZT interfaces, both of which are dominated by the magnetoelectric coupling via interfacial stress transferring at nanoscale. This work makes some attempts of coupling photo-induced effects with magnetoelectric effect in multiferroic materials and will widen the practical ranges of multiferroic-based applications.

  9. Tuning the photovoltaic effect of multiferroic CoFe{sub 2}O{sub 4}/Pb(Zr, Ti)O{sub 3} composite films by magnetic fields

    SciTech Connect

    Pan, Dan-Feng; Chen, Guang-Yi; Bi, Gui-Feng; Zhang, Hao; Liu, Jun-Ming; Wang, Guang-Hou; Wan, Jian-Guo

    2016-05-30

    The 0–3 type CoFe{sub 2}O{sub 4}-Pb(Zr,Ti)O{sub 3} (CFO-PZT) multiferroic composite films have been prepared by a sol-gel process and spin-coating technique. A confirmable photovoltaic effect is observed under ultraviolet light irradiation. Moreover, this photovoltaic effect can be tuned by external magnetic fields. The maximum magnetic modulation ratios of short-circuit current density and open-circuit voltage can reach as high as 13.7% and 12.8% upon the application of 6 kOe DC magnetic field. Through remnant polarization measurements under various magnetic fields and detailed analysis of the energy band structures, we elucidate the mechanism of tuning photovoltaic effect by magnetic fields and attribute it to the combination of two factors. One is the decreased ferroelectric-polarization-induced depolarization electric field and another is the band structure reconstruction at CFO-PZT interfaces, both of which are dominated by the magnetoelectric coupling via interfacial stress transferring at nanoscale. This work makes some attempts of coupling photo-induced effects with magnetoelectric effect in multiferroic materials and will widen the practical ranges of multiferroic-based applications.

  10. Combined effects of space charge and energetic disorder on photocurrent efficiency loss of field-dependent organic photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Yoon, Sangcheol; Park, Byoungchoo; Hwang, Inchan

    2015-11-01

    The loss of photocurrent efficiency by space-charge effects in organic solar cells with energetic disorder was investigated to account for how energetic disorder incorporates space-charge effects, utilizing a drift-diffusion model with field-dependent charge-pair dissociation and suppressed bimolecular recombination. Energetic disorder, which induces the Poole-Frenkel behavior of charge carrier mobility, is known to decrease the mobility of charge carriers and thus reduces photovoltaic performance. We found that even if the mobilities are the same in the absence of space-charge effects, the degree of energetic disorder can be an additional parameter affecting photocurrent efficiency when space-charge effects occur. Introducing the field-dependence parameter that reflects the energetic disorder, the behavior of efficiency loss with energetic disorder can differ depending on which charge carrier is subject to energetic disorder. While the energetic disorder that is applied to higher-mobility charge carriers decreases photocurrent efficiency further, the efficiency loss can be suppressed when energetic disorder is applied to lower-mobility charge carriers.

  11. International photovoltaic program. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Costello, D.; Koontz, R.; Posner, D.; Heiferling, P.; Carpenter, P.; Forman, S.; Perelman, L.

    1979-01-01

    The results of analyses conducted in preparation of an international photovoltaic marketing plan are summarized. Included are compilations of relevant statutes and existing Federal programs; strategies designed to expand the use of photovoltaics abroad; information on the domestic photovoltaic plan and its impact on the proposed international plan; perspectives on foreign competition; industry views on the international photovoltaic market and ideas about the how US government actions could affect this market;international financing issues; and information on issues affecting foreign policy and developing countries.

  12. Domestic Violence

    MedlinePlus

    ... Press Room Careers OVW FOIA Contact the Office Domestic Violence Get Help | What is Domestic Violence? Get Help ... 7233) 1-800-787-3224 (TTY) What is Domestic Violence? We define domestic violence as a pattern of ...

  13. Plasmonics for improved photovoltaic devices.

    PubMed

    Atwater, Harry A; Polman, Albert

    2010-03-01

    The emerging field of plasmonics has yielded methods for guiding and localizing light at the nanoscale, well below the scale of the wavelength of light in free space. Now plasmonics researchers are turning their attention to photovoltaics, where design approaches based on plasmonics can be used to improve absorption in photovoltaic devices, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers, and yielding new options for solar-cell design. In this review, we survey recent advances at the intersection of plasmonics and photovoltaics and offer an outlook on the future of solar cells based on these principles.

  14. Solar photovoltaic residential project

    NASA Astrophysics Data System (ADS)

    1981-10-01

    Progress with technology transfer and the performance of photovoltaic power supplies in Northeastern and Southwestern residences are reported. Also, systems operation in Florida and Hawaii are discussed briefly. Technology development in the field of power conditioning and flywheel storage is described. Work on some non-residential field tests is also described. Project management data are summarized.

  15. Experimental Infection of Domestic Pigs with African Swine Fever Virus Lithuania 2014 Genotype II Field Isolate.

    PubMed

    Gallardo, C; Soler, A; Nieto, R; Cano, C; Pelayo, V; Sánchez, M A; Pridotkas, G; Fernandez-Pinero, J; Briones, V; Arias, M

    2017-02-01

    An experimental infection was conducted to evaluate horizontal transmission, clinical, virological and humoral response induced in domestic pigs infected with African swine fever (ASF) genotype II virus circulating in 2014 into the European Union (EU). Ten naive pigs were placed in contact with eight pigs experimentally inoculated with the Lithuanian LT14/1490 ASF virus (ASFV) responsible for the first ASF case detected in wild boar in Lithuania in January 2014. Clinical examination and rectal temperature were recorded each day. Blood sampling from every animal was carried out twice weekly. Blood samples were examined for presence of ASF virus-specific antibodies and for determining the ASFV viral load. From the obtained results, it was concluded that the Lithuanian ASFV induced an acute disease which resulted in 94, 5% mortality. The disease was easily detected by real-time PCR prior to the onset of clinical signs and 33% of the animals seroconverted. All findings were in accordance with observations previously made in domestic pigs and wild boar when infected with ASF genotype II viruses characterized by a high virulence. One in-contact pig remained asymptomatic and survived the infection. The role of such animals in virus transmission would need further investigation. © 2015 Blackwell Verlag GmbH.

  16. Photovoltaic systems overview

    NASA Technical Reports Server (NTRS)

    Hesse, J. L.

    1981-01-01

    Selected photovoltaic systems currently under user-environment field test by the U.S. Department of Energy Photovoltaics Program are discussed, and operational results are summarized. There are many systems in the stand-alone sector that are cost effective now. As proven products become available, distributed residential, commercial, institutional and industrial on-site systems should be able to displace significant amounts of centrally-generated electricity throughout most of the United States. Finally, utilities should ultimately be able to augment their generating capacity with larger-scale systems. Field experience and industry interface has led to excellent overall product performance.

  17. Photovoltaic cell

    DOEpatents

    Gordon, Roy G.; Kurtz, Sarah

    1984-11-27

    In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

  18. Evaluation and Field Assessment of Bifacial Photovoltaic Module Power Rating Methodologies

    SciTech Connect

    Deline, Chris; MacAlpine, Sara; Marion, Bill; Toor, Fatima; Asgharzadeh, Amir; Stein, Joshua S.

    2016-11-21

    1-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 Wm-2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing 1-sun irradiance standards leads to a bifacial reference condition of 1000 Wm-2 Gfront and 130-140 Wm-2 Grear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity will be affected by self-shade from adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this work. Here, we compare outdoor field measurements of bifacial modules with irradiance on both sides with proposed indoor test methods where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that the indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module types.

  19. Evaluation and Field Assessment of Bifacial Photovoltaic Module Power Rating Methodologies: Preprint

    SciTech Connect

    Deline, Chris; MacAlpine, Sara; Marion, Bill; Toor, Fatima; Asgharzadeh, Amir; Stein, Joshua S.

    2016-06-16

    1-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 Wm-2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing 1-sun irradiance standards leads to a bifacial reference condition of 1000 Wm-2 Gfront and 130-140 Wm-2 Grear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity will be affected by self-shade from adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this work. Here, we compare outdoor field measurements of bifacial modules with irradiance on both sides with proposed indoor test methods where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that the indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module types.

  20. Photovoltaic product directory and buyers guide

    SciTech Connect

    Watts, R.L.; Smith, S.A.; Mazzucchi, R.P.

    1981-06-01

    Basic information on photovoltaic conversion technology is provided for those unfamiliar with the field. Various types of photovoltaic products and systems currently available off-the-shelf are described. These include products without batteries, battery chargers, power packages, home electric systems, and partial systems. Procedures are given for designing a photovoltaic system from scratch. A few custom photovoltaic systems are described, and a list is compiled of photovoltaic firms which can provide custom systems. Guidance is offered for deciding whether or not to use photovoltaic products. A variety of installations are described and their performance is appraised by the owners. Information is given on various financial incentives available from state and federal governments. Sources of additional information on photovoltaics are listed. A matrix is provided indicating the sources of various types of photovoltaic products. The addresses of suppliers are listed. (LEW)

  1. Photovoltaic materials.

    PubMed

    Perez-Albuerne, E A; Tyan, Y S

    1980-05-23

    Solid-state photovoltaic cells are feasible devices for converting solar energy directly to electricity. Recent cost reductions have spurred an incipient industry, but further advances in materials science and technology are needed before photovoltaic cells can compete with other sources for the supply of large amounts of energy. In this article energy loss mechanisms in solid-state photovoltaic cells are examined and related to materials properties. Various systems under development are reviewed which illustrate some key concepts, opportunities, and problems of this most promising emerging technology. Areas where contributions from innovative materials research would have a significant effect are also indicated.

  2. Graphene quantum dot (GQD)-induced photovoltaic and photoelectric memory elements in a pentacene/GQD field effect transistor as a probe of functional interface

    NASA Astrophysics Data System (ADS)

    Kim, Youngjun; Cho, Seongeun; Kim, Hyeran; Seo, Soonjoo; Lee, Hyun Uk; Lee, Jouhahn; Ko, Hyungduk; Chang, Mincheol; Park, Byoungnam

    2017-09-01

    Electric field-induced charge trapping and exciton dissociation were demonstrated at a penatcene/grapheme quantum dot (GQD) interface using a bottom contact bi-layer field effect transistor (FET) as an electrical nano-probe. Large threshold voltage shift in a pentacene/GQD FET in the dark arises from field-induced carrier trapping in the GQD layer or GQD-induced trap states at the pentacene/GQD interface. As the gate electric field increases, hysteresis characterized by the threshold voltage shift depending on the direction of the gate voltage scan becomes stronger due to carrier trapping associated with the presence of a GQD layer. Upon illumination, exciton dissociation and gate electric field-induced charge trapping simultaneously contribute to increase the threshold voltage window, which can potentially be exploited for photoelectric memory and/or photovoltaic devices through interface engineering.

  3. From field to fermentation: the origins of Lactococcus lactis and its domestication to the dairy environment.

    PubMed

    Cavanagh, Daniel; Fitzgerald, Gerald F; McAuliffe, Olivia

    2015-05-01

    Lactococcus lactis is an organism of substantial economic importance, used extensively in the production of fermented foods and widely held to have evolved from plant strains. The domestication of this organism to the milk environment is associated with genome reduction and gene decay, and the acquisition of specific genes involved in protein and lactose utilisation by horizontal gene transfer. In recent years, numerous studies have focused on uncovering the physiology and molecular biology of lactococcal strains from the wider environment for exploitation in the dairy industry. This in turn has facilitated comparative genome analysis of lactococci from different environments and provided insight into the natural phenotypic and genetic diversity of L. lactis. This diversity may be exploited in dairy fermentations to develop products with improved quality and sensory attributes. In this review, we discuss the classification of L. lactis and the problems that arise with phenotype/genotype designation. We also discuss the adaptation of non-dairy lactococci to milk, the traits associated with this adaptation and the potential application of non-dairy lactococci to dairy fermentations.

  4. Vacuum lamination of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1982-01-01

    Vacuum lamination of terrestrial photovoltaic modules is a new high volume process requiring new equipment and newly develop materials. Equipment development, materials research, and some research in related fields and testing methods are discussed.

  5. Photovoltaic module reliability workshop

    NASA Astrophysics Data System (ADS)

    Mrig, L.

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986 to 1990. The reliability photovoltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warrantees available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the U.S., PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  6. Photovoltaic roofing tile systems

    NASA Astrophysics Data System (ADS)

    Melchior, B.

    The integration of photovoltaic (PV) systems in architecture is discussed. A PV-solar roofing tile system with polymer concrete base; PV-roofing tile with elastomer frame profiles and aluminum profile frames; contact technique; and solar cell modules measuring technique are described. Field tests at several places were conducted on the solar generator, electric current behavior, battery station, electric installation, power conditioner, solar measuring system with magnetic bubble memory technique, data transmission via telephone modems, and data processing system. The very favorable response to the PV-compact system proves the commercial possibilities of photovoltaic integration in architecture.

  7. Photovoltaic array performance model.

    SciTech Connect

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  8. Current topics in photovoltaics

    SciTech Connect

    Coutts, T.J. ); Meakin, J.O. . Inst. of Energy Conversion)

    1988-01-01

    Steady growth in the commercial application of solar cell systems has been achieved since the last volume of this series was published. In many parts of the world photovoltaics are being used in essential life sustaining or enhancing applications such as communications, water pumping, and vaccine refrigeration. Even in the more industrialized nations a growing number of uses are being found for photovoltaics, some of them far from essential, in areas which are surrounded by grid distribution systems. This book covers the latest advances in research and development, many of them in the amorphous field although progress continues with crystalline silicon and the II-VI and IIIV compounds.

  9. Current topics in photovoltaics

    SciTech Connect

    Coutts, J.J. ); Meakin, J.O. . Inst. of Energy Conversion)

    1988-01-01

    The authors discuss the steady growth in the commercial application of solar cell systems. In many parts of the world photovoltaics are being used in essential life sustaining or enhancing applications such as communications, water pumping, and vaccine refrigeration. Even in the more industrialized nations a growing number of uses are being found for photovoltaics, in areas which are surrounded by grid distribution systems. This volume covers advances in research and development, many of them in the amorphous field, although progress continues with crystalline silicon and the II-VI and III-V compounds.

  10. From Crop Domestication to Super-domestication

    PubMed Central

    Vaughan, D. A.; Balázs, E.; Heslop-Harrison, J. S.

    2007-01-01

    Research related to crop domestication has been transformed by technologies and discoveries in the genome sciences as well as information-related sciences that are providing new tools for bioinformatics and systems' biology. Rapid progress in archaeobotany and ethnobotany are also contributing new knowledge to understanding crop domestication. This sense of rapid progress is encapsulated in this Special Issue, which contains 18 papers by scientists in botanical, crop sciences and related disciplines on the topic of crop domestication. One paper focuses on current themes in the genetics of crop domestication across crops, whereas other papers have a crop or geographic focus. One feature of progress in the sciences related to crop domestication is the availability of well-characterized germplasm resources in the global network of genetic resources centres (genebanks). Germplasm in genebanks is providing research materials for understanding domestication as well as for plant breeding. In this review, we highlight current genetic themes related to crop domestication. Impressive progress in this field in recent years is transforming plant breeding into crop engineering to meet the human need for increased crop yield with the minimum environmental impact – we consider this to be ‘super-domestication’. While the time scale of domestication of 10 000 years or less is a very short evolutionary time span, the details emerging of what has happened and what is happening provide a window to see where domestication might – and can – advance in the future. PMID:17940074

  11. Domestic violence

    MedlinePlus

    ... Spousal abuse; Elder abuse; Child abuse; Sexual abuse - domestic violence ... Domestic violence can include any of these behaviors: Physical abuse, including hitting, kicking, biting, slapping, choking, or attacking ...

  12. Domestic Violence

    MedlinePlus

    ... f AQ FREQUENTLY ASKED QUESTIONS FAQ083 WOMEN’S HEALTH Domestic Violence • What is domestic violence? • What are the types of abuse? • How ... are available to help abused women? What is domestic violence? Domestic violence is a pattern of threatening ...

  13. Domestic Violence

    MedlinePlus

    f AQ FREQUENTLY ASKED QUESTIONS FAQ083 WOMEN’S HEALTH Domestic Violence • What is domestic violence? • What are the types of abuse? • How can ... are available to help abused women? What is domestic violence? Domestic violence is a pattern of threatening or ...

  14. Ligand field density functional theory for the prediction of future domestic lighting.

    PubMed

    Ramanantoanina, Harry; Urland, Werner; García-Fuente, Amador; Cimpoesu, Fanica; Daul, Claude

    2014-07-28

    We deal with the computational determination of the electronic structure and properties of lanthanide ions in complexes and extended structures having open-shell f and d configurations. Particularly, we present conceptual and methodological issues based on Density Functional Theory (DFT) enabling the reliable calculation and description of the f → d transitions in lanthanide doped phosphors. We consider here the optical properties of the Pr(3+) ion embedded into various solid state fluoride host lattices, for the prospection and understanding of the so-called quantum cutting process, being important in the further quest of warm-white light source in light emitting diodes (LED). We use the conceptual formulation of the revisited ligand field (LF) theory, fully compatibilized with the quantum chemistry tools: LFDFT. We present methodological advances for the calculations of the Slater-Condon parameters, the ligand field interaction and the spin-orbit coupling constants, important in the non-empirical parameterization of the effective Hamiltonian adjusted from the ligand field theory. The model shows simple procedure using less sophisticated computational tools, which is intended to contribute to the design of modern phosphors and to help to complement the understanding of the 4f(n) → 4f(n-1)5d(1) transitions in any lanthanide system.

  15. Photovoltaic Engineering

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The Ohio Aerospace Institute through David Scheiman and Phillip Jenkins provided the Photovoltaics Branch at the NASA Glenn Research Center (GRC) with expertise in photovoltaic (PV) research, flight experiments and solar cell calibration. NASA GRC maintains the only world-class solar cell calibration and measurement facility within NASA. GRC also has a leadership role within the solar cell calibration community, and is leading the effort to develop ISO standards for solar cell calibration. OAI scientists working under this grant provided much of the expertise and leadership in this area.

  16. The Experiential Learning Impact of International and Domestic Study Tours: Class Excursions That Are More than Field Trips

    ERIC Educational Resources Information Center

    Gomez-Lanier, Lilia

    2017-01-01

    Experiential education programs, such as international and domestic study tours, bridge the limitations of formal learning classroom by allowing students to experience reality in a new learning dimension. This mixed-methods study explores experiential learning during a domestic interior design study tour to New York City and an international…

  17. A draft genome of field pennycress (Thlaspi arvense) provides tools for the domestication of a new winter biofuel crop

    PubMed Central

    Dorn, Kevin M.; Fankhauser, Johnathon D.; Wyse, Donald L.; Marks, M. David

    2015-01-01

    Field pennycress (Thlaspi arvense L.) is being domesticated as a new winter cover crop and biofuel species for the Midwestern United States that can be double-cropped between corn and soybeans. A genome sequence will enable the use of new technologies to make improvements in pennycress. To generate a draft genome, a hybrid sequencing approach was used to generate 47 Gb of DNA sequencing reads from both the Illumina and PacBio platforms. These reads were used to assemble 6,768 genomic scaffolds. The draft genome was annotated using the MAKER pipeline, which identified 27,390 predicted protein-coding genes, with almost all of these predicted peptides having significant sequence similarity to Arabidopsis proteins. A comprehensive analysis of pennycress gene homologues involved in glucosinolate biosynthesis, metabolism, and transport pathways revealed high sequence conservation compared with other Brassicaceae species, and helps validate the assembly of the pennycress gene space in this draft genome. Additional comparative genomic analyses indicate that the knowledge gained from years of basic Brassicaceae research will serve as a powerful tool for identifying gene targets whose manipulation can be predicted to result in improvements for pennycress. PMID:25632110

  18. Fate of synthetic musks in a domestic wastewater treatment plant and in an agricultural field amended with biosolids.

    PubMed

    Yang, Jian-Jun; Metcalfe, Chris D

    2006-06-15

    Synthetic musks are widely used as fragrance ingredients in personal care products, and they enter domestic wastewater treatment plants (WWTPs) through discharges into municipal sewage systems. Samples of aqueous sewage and biosolids collected from the Peterborough Wastewater Treatment Plant (WWTP), Ontario, Canada were analyzed for 11 synthetic musk compounds using GC/MS. The results showed that 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta[g]-2-benzopyrane (HHCB, 173.1+/-43.4 ng/L) and 7-acetyl-1,1,3,4,4,6-hexamethyl-tetrahydronaphthalene (AHTN, 41.6+/-15.8 ng/L) were the dominant fragrances in sewage, but other polycyclic musks and nitro musks were present at lower concentrations. The concentrations of HHCB and AHTN in the aqueous phase of the sewage were highly correlated with both BOD5 and TOC. The overall removal efficiency of synthetic musks from the aqueous sewage in the WWTP ranged from 43.3% to 56.9%, but removal occurred mainly by partitioning into the biosolids. Based on a mass balance model, the daily input and output of HHCB and AHTN in the Peterborough WWTP were 47 g and 46 g, respectively. In an agricultural field amended with biosolids from the Peterborough WWTP, HHCB and AHTN were detected in soil immediately after application at mean concentrations of 1.0 and 1.3 mug/kg, respectively, but concentrations declined relatively rapidly over the next 6 weeks, post-application.

  19. Photovoltaic energy

    NASA Astrophysics Data System (ADS)

    1990-01-01

    In 1989, the U.S. photovoltaic industry enjoyed a growth rate of 30 percent in sales for the second year in a row. This sends a message that the way we think about electricity is changing. Instead of big energy projects that perpetuate environmental and economic damage, there is a growing trend toward small renewable technologies that are well matched to end-user needs and operating conditions. As demand grows and markets expand, investment capital will be drawn to the industry and new growth trends will emerge. The photovoltaic industry around the world achieved record shipments also. Worldwide shipments of photovoltaic (PV) modules for 1989 totaled more than 40 megawatts (MW), nearly a 20 percent increase over last year's shipments. The previous two years showed increases in worldwide shipments of 23 and 25 percent, respectively. If this growth rate continues through the 1990s, as industry back orders would indicate, 300 to 1000 MW of PV-supplied power could be on line by 2000. Photovoltaic systems have low environmental impact and they are inexpensive to operate and maintain. Using solid-state technology, PV systems directly convert sunlight to electricity without high-temperature fluids or moving parts that could cause mechanical failure. This makes the technology very reliable.

  20. Photovoltaic concentrators

    NASA Astrophysics Data System (ADS)

    Boes, E. C.

    1980-01-01

    A status report on photovoltaic (PV) concentrators technology is presented. The major topics covered are as follows: (1) current PV concentrator arrays; designs, performances, and costs; (2) current PV concentrator array components; cells and cell assemblies, optical concentrators, support structures, tracking, and drive; (3) design of PV concentrator arrays; and (4) array manufacturing technology.

  1. Photovoltaic module reliability workshop

    SciTech Connect

    Mrig, L.

    1990-01-01

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986--1990. The reliability Photo Voltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warranties available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the US, PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  2. Environmental aging in polycrystalline-Si photovoltaic modules: comparison of chamber-based accelerated degradation studies with field-test data

    NASA Astrophysics Data System (ADS)

    Lai, T.; Biggie, R.; Brooks, A.; Potter, B. G.; Simmons-Potter, K.

    2015-09-01

    Lifecycle degradation testing of photovoltaic (PV) modules in accelerated-degradation chambers can enable the prediction both of PV performance lifetimes and of return-on-investment for installations of PV systems. With degradation results strongly dependent on chamber test parameters, the validity of such studies relative to fielded, installed PV systems must be determined. In the present work, accelerated aging of a 250 W polycrystalline silicon module is compared to real-time performance degradation in a similar polycrystalline-silicon, fielded, PV technology that has been operating since October 2013. Investigation of environmental aging effects are performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability providing illumination uniformity of 98% over a 2 x 1.6 m area. Time-dependent, photovoltaic performance (J-V) is evaluated over a recurring, compressed night-day cycle providing representative local daily solar insolation for the southwestern United States, followed by dark (night) cycling. This cycle is synchronized with thermal and humidity environmental variations that are designed to mimic, as closely as possible, test-yard conditions specific to a 12 month weather profile for a fielded system in Tucson, AZ. Results confirm the impact of environmental conditions on the module long-term performance. While the effects of temperature de-rating can be clearly seen in the data, removal of these effects enables the clear interpretation of module efficiency degradation with time and environmental exposure. With the temperature-dependent effect removed, the normalized efficiency is computed and compared to performance results from another panel of similar technology that has previously experienced identical climate changes in the test yard. Analysis of relative PV module efficiency degradation for the chamber-tested system shows good comparison to the field-tested system with ~2.5% degradation following

  3. Domestic Violence

    MedlinePlus

    Domestic violence is a type of abuse. It usually involves a spouse or partner, but it can also ... a child, elderly relative, or other family member. Domestic violence may include Physical violence that can lead to ...

  4. Photovoltaic fibers

    NASA Astrophysics Data System (ADS)

    Gaudiana, Russell; Eckert, Robert; Cardone, John; Ryan, James; Montello, Alan

    2006-08-01

    It was realized early in the history of Konarka that the ability to produce fibers that generate power from solar energy could be applied to a wide variety of applications where fabrics are utilized currently. These applications include personal items such as jackets, shirts and hats, to architectural uses such as awnings, tents, large covers for cars, trucks and even doomed stadiums, to indoor furnishings such as window blinds, shades and drapes. They may also be used as small fabric patches or fiber bundles for powering or recharging batteries in small sensors. Power generating fabrics for clothing is of particular interest to the military where they would be used in uniforms and body armor where portable power is vital to field operations. In strong sunlight these power generating fabrics could be used as a primary source of energy, or they can be used in either direct sunlight or low light conditions to recharge batteries. Early in 2002, Konarka performed a series of proof-of-concept experiments to demonstrate the feasibility of building a photovoltaic cell using dye-sensitized titania and electrolyte on a metal wire core. The approach taken was based on the sequential coating processes used in making fiber optics, namely, a fiber core, e.g., a metal wire serving as the primary electrode, is passed through a series of vertically aligned coating cups. Each of the cups contains a coating fluid that has a specific function in the photocell. A second wire, used as the counter electrode, is brought into the process prior to entering the final coating cup. The latter contains a photopolymerizable, transparent cladding which hardens when passed through a UV chamber. Upon exiting the UV chamber, the finished PV fiber is spooled. Two hundred of foot lengths of PV fiber have been made using this process. When the fiber is exposed to visible radiation, it generates electrical power. The best efficiency exhibited by these fibers is 6% with an average value in the 4

  5. Vaccination of domestic animals against tuberculosis: review of progress and contributions to the field of the TBSTEP project.

    PubMed

    Vordermeier, H Martin; Pérez de Val, Bernat; Buddle, Bryce M; Villarreal-Ramos, Bernardo; Jones, Gareth J; Hewinson, R Glyn; Domingo, Mariano

    2014-10-01

    Tuberculosis either caused by Mycobacterium bovis or M. caprae is a significant burden to agricultural industries worldwide. Vaccination of domestic ruminant species such as cattle and goats constitutes a potential tool to support disease control. This review will discuss recent progress made to develop tuberculosis vaccines against domestic ruminants as well as approaches to differentiate vaccinated and infected animals (DIVA) and biomarker discovery studies.

  6. Photovoltaic Materials

    SciTech Connect

    Duty, C.; Angelini, J.; Armstrong, B.; Bennett, C.; Evans, B.; Jellison, G. E.; Joshi, P.; List, F.; Paranthaman, P.; Parish, C.; Wereszczak, A.

    2012-10-15

    modules in the field for 25 years. Under this project, Ferro leveraged world leading analytical capabilities at ORNL to characterize the paste-to-silicon interface microstructure and develop high efficiency next generation contact pastes. Ampulse Corporation is developing a revolutionary crystalline-silicon (c-Si) thin-film solar photovoltaic (PV) technology. Utilizing uniquely-textured substrates and buffer materials from the Oak Ridge National Laboratory (ORNL), and breakthroughs in Hot-Wire Chemical Vapor Deposition (HW-CVD) techniques in epitaxial silicon developed at the National Renewable Energy Laboratory (NREL), Ampulse is creating a solar technology that is tunable in silicon thickness, and hence in efficiency and economics, to meet the specific requirements of multiple solar PV applications. This project focused on the development of a high rate deposition process to deposit Si, Ge, and Si1-xGex films as an alternate to hot-wire CVD. Mossey Creek Solar is a start-up company with great expertise in the solar field. The primary interest is to create and preserve jobs in the solar sector by developing high-yield, low-cost, high-efficiency solar cells using MSC-patented and -proprietary technologies. The specific goal of this project was to produce large grain formation in thin, net-shape-thickness mc-Si wafers processed with high-purity silicon powder and ORNL's plasma arc lamp melting without introducing impurities that compromise absorption coefficient and carrier lifetime. As part of this project, ORNL also added specific pieces of equipment to enhance our ability to provide unique insight for the solar industry. These capabilities include a moisture barrier measurement system, a combined physical vapor deposition and sputtering system dedicated to cadmium-containing deposits, adeep level transient spectroscopy system useful for identifying defects, an integrating sphere photoluminescence system, and a high-speed ink jet printing system. These tools were

  7. Photovoltaic Roofs

    NASA Technical Reports Server (NTRS)

    Drummond, R. W., Jr.; Shepard, N. F., Jr.

    1984-01-01

    Solar cells perform two functions: waterproofing roof and generating electricity. Sections through horizontal and slanting joints show overlapping modules sealed by L-section rubber strips and side-by-side modules sealed by P-section strips. Water seeping through seals of slanting joints drains along channels. Rooftop photovoltaic array used watertight south facing roof, replacing shingles, tar, and gravel. Concept reduces cost of residential solar-cell array.

  8. Photovoltaic fabrics

    DTIC Science & Technology

    2015-04-22

    during wire fabrication. Weaving was demonstrated for both military-type nylon -cotton blend (NYCO) warp fibers and cotton-polyester warp fibers. A...Lowell, MA 01852 14. ABSTRACT This report describes a project to improve photovoltaic fabrics. It had four objectives: 1) Efficiency – make PV wires on...a continuous basis that exhibit 7% efficiency; 2) Automated Welding – demonstrate an automated means of interconnecting the electrodes of one wire

  9. Effect of industrial and domestic ash from biomass combustion, and spent coffee grounds, on soil fertility and plant growth: experiments at field conditions.

    PubMed

    Ribeiro, João Peres; Vicente, Estela Domingos; Gomes, Ana Paula; Nunes, Maria Isabel; Alves, Célia; Tarelho, Luís A C

    2017-06-01

    An experimental study was conducted at field conditions in order to evaluate the effect of application of ash from biomass combustion on some soil fertility characteristics and plant growth. Application of 7.5 Mg ha(-1) industrial fly ash (IA), domestic ash (DA), and a 50:50 mix of domestic ash (DA) and spent coffee grounds (SCG) was made in different soil parcels. Lolium perenne seeds were sown and the grown biomass was harvested and quantified after 60 days. Soil samples from each parcel were also collected after that period and characterized. Both soil and grown biomass samples were analyzed for Ca, Mg, Na, K, P, Fe, Mn, Zn, and Al contents. Soil pH was determined before and after amendment. All applications rose significantly soil pH. Domestic ash, whether combined with coffee grounds or not, proved to be efficient at supplying available macronutrients Ca, Mg, K, and P to the soil and also reducing availability of Al (more than industrial ash). However, it inhibited plant growth, even more when combined with spent coffee grounds. As regards to elemental abundance in plant tissue, both domestic ash treatments reduced Ca and enhanced Al contents, unlike industrial ash, which proved less harmful for the load applied in the soil. Hence, it was possible to conclude that application load should be a limiting factor for this management option for the studied materials.

  10. Molecular Epidemiology of Salmonella enterica Serovar Typhimurium Isolates Determined by Pulsed-Field Gel Electrophoresis: Comparison of Isolates from Avian Wildlife, Domestic Animals, and the Environment in Norway

    PubMed Central

    Refsum, Thorbjørn; Heir, Even; Kapperud, Georg; Vardund, Traute; Holstad, Gudmund

    2002-01-01

    The molecular epidemiology of 142 isolates of Salmonella enterica serovar Typhimurium from avian wildlife, domestic animals, and the environment in Norway was investigated using pulsed-field gel electrophoresis (PFGE) and computerized numerical analysis of the data. The bacterial isolates comprised 79 isolates from wild-living birds, including 46 small passerines and 26 gulls, and 63 isolates of nonavian origin, including 50 domestic animals and 13 environmental samples. Thirteen main clusters were discernible at the 90% similarity level. Most of the isolates (83%) were grouped into three main clusters. These were further divided into 20 subclusters at the 95% similarity level. Isolates from passerines, gulls, and pigeons dominated within five subclusters, whereas isolates from domestic animals and the environment belonged to many different subclusters with no predominance. The results support earlier results that passerines constitute an important source of infection to humans in Norway, whereas it is suggested that gulls and pigeons, based on PFGE analysis, represent only a minor source of human serovar Typhimurium infections. Passerines, gulls, and pigeons may also constitute a source of infection of domestic animals and feed plants or vice versa. Three isolates from cattle and a grain source, of which two were multiresistant, were confirmed as serovar Typhimurium phage type DT 104. These represent the first reported phage type DT 104 isolates from other sources than humans in Norway. PMID:12406755

  11. Notes from the field: measles transmission at a domestic terminal gate in an international airport - United States, January 2014.

    PubMed

    Vega, Jared S; Escobedo, Miguel; Schulte, Cynthia R; Rosen, Jennifer B; Schauer, Stephanie; Wiseman, Rachel; Lippold, Susan A; Regan, Joanna J

    2014-12-19

    In March 2014, CDC identified a possible cluster of four laboratory-confirmed measles cases among passengers transiting a domestic terminal in a U.S. international airport. Through epidemiologic assessments conducted by multiple health departments and investigation of flight itineraries by CDC, all four patients were linked to the same terminal gate during a 4-hour period on January 17, 2014. Patient 1, an unvaccinated man aged 21 years with rash onset February 1, traveled on two domestic flights on January 17 and 18 that connected at the international airport. Patient 2, an unvaccinated man aged 49 years with rash onset February 1, traveled from the airport on January 17. Patient 3, an unvaccinated man aged 19 years with rash onset January 30, traveled domestically with at least a 4-hour layover at the airport on January 17. Patient 4, an unvaccinated man aged 63 years with rash onset February 5, traveled on a flight to the airport on January 17.

  12. Domestic violence.

    PubMed

    Bennett, B

    1997-01-01

    This article explores the usefulness of white feminist domestic intervention to Aboriginal women who are victims of domestic violence. The discussion opens with a brief history of Aboriginal society before the age of colonization, followed by a summary of feminist intervention to fight domestic violence and the reactions of the Aboriginal women and communities towards this. It also presents a brief description of works conducted overseas where more appropriate frameworks are being used in intervening against domestic violence such as anti-racist social work. Towards the end, this paper explores some future possibilities for workers, in both Aboriginal and non-Aboriginal societies.

  13. Basic photovoltaics

    SciTech Connect

    Zweibel, K.

    1984-01-01

    Here is a photovoltaics guide that converts highly technical information into language that can be understood by both scientists and non-scientists. It provides an introduction to solar cell technology, explaining how PV cells work, how they are manufactured, and how they are put together into effective energy-producing systems. The authors investigate a new PV technology based on an altered form of silicon capable of producing conversion efficiencies of 10% to 15%. They explain the PV effect, loss mechanisms, and advances in fabrication methods.

  14. Photovoltaics: New opportunities for utilities

    SciTech Connect

    Not Available

    1991-07-01

    This publication presents information on photovoltaics. The following topics are discussed: Residential Photovoltaics: The New England Experience Builds Confidence in PV; Austin's 300-kW Photovoltaic Power Station: Evaluating the Breakeven Costs; Residential Photovoltaics: The Lessons Learned; Photovoltaics for Electric Utility Use; Least-Cost Planning: The Environmental Link; Photovoltaics in the Distribution System; Photovoltaic Systems for the Rural Consumer; The Issues of Utility-Intertied Photovoltaics; and Photovoltaics for Large-Scale Use: Costs Ready to Drop Again.

  15. The new alchemy of photovoltaics

    SciTech Connect

    Jeffries, J.P.

    1983-01-01

    The work is a review. The expanding field of use of photovoltaic electric power plants includes single family homes. Solar batteries with a surface area of less than 90 square meters mounted on a roof totally or partially satisfy their daily requirement for electric power. The cost of a single family, approximately 220 square meter home built near Sante Fe and equipped with a passive solar system with a photovoltaic power plant with a power production of 6,500 kilovolthours per year is 190,000 dollars. The cost of a solar battery has been reduced to 7 to 15 dollars per watt of peak power, which is totally insufficient for buy back even over forth years. The threshold of cost, when the solar battery is competitive is 3 dollars per watt. Nevertheless, approximately 6,000 single family dwelling passive solar systems with a photovoltaic power plant are in operation in the United States. The previous opponents of the photovoltaic method, the oil companies, have become suporters of the development and production of solar energy. After the decline in 1982 as a result of the five fold reduction of government financing in works in the field of renewable energy sources, the photovoltaic industry enjoyed a new rise in popularity.

  16. Photovoltaic solar concentrator

    DOEpatents

    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.

  17. Organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Demming, Anna; Krebs, Frederik C.; Chen, Hongzheng

    2013-12-01

    Energy inflation, the constant encouragement to economize on energy consumption and the huge investments in developing alternative energy resources might seem to suggest that there is a global shortage of energy. Far from it, the energy the Sun beams on the Earth each hour is equivalent to a year's supply, even at our increasingly ravenous rate of global energy consumption [1]. But it's not what you have got it's what you do with it. Hence the intense focus on photovoltaic research to find more efficient ways to harness energy from the Sun. Recently much of this research has centred on organic solar cells since they offer simple, low-cost, light-weight and large-area flexible photovoltaic structures. This issue with guest editors Frederik C Krebs and Hongzheng Chen focuses on some of the developments at the frontier of organic photovoltaic technology. Improving the power conversion efficiency of organic photovoltaic systems, while maintaining the inherent material, economic and fabrication benefits, has absorbed a great deal of research attention in recent years. Here significant progress has been made with reports now of organic photovoltaic devices with efficiencies of around 10%. Yet operating effectively across the electromagnetic spectrum remains a challenge. 'The trend is towards engineering low bandgap polymers with a wide optical absorption range and efficient hole/electron transport materials, so that light harvesting in the red and infrared region is enhanced and as much light of the solar spectrum as possible can be converted into an electrical current', explains Mukundan Thelakkat and colleagues in Germany, the US and UK. In this special issue they report on how charge carrier mobility and morphology of the active blend layer in thin film organic solar cells correlate with device parameters [2]. The work contributes to a better understanding of the solar-cell characteristics of polymer:fullerene blends, which form the material basis for some of the most

  18. "Domestic violence".

    PubMed

    Davidhizar, Ruth; Giger, Joy Newman

    2002-01-01

    Domestic violence is no respector of persons but may involve spouses or cohabiting adults across all socioeconomic, ethnic, and religious groups. It is no respect or of community. The abuse can be physical, sexual, or emotional/psychological. It can be economic and be demonstrated by neglect. Nursing care for the problem of domestic abuse needs to be directed at primary, secondary, and tertiary prevention. Care for victims and victimizers of domestic violence involves a collaborative relationship with other professionals as well as interagency cross referrals that involve health, welfare, refuge, and judicial protective services.

  19. Photovoltaic cell and production thereof

    DOEpatents

    Narayanan, Srinivasamohan; Kumar, Bikash

    2008-07-22

    An efficient photovoltaic cell, and its process of manufacture, is disclosed wherein the back surface p-n junction is removed from a doped substrate having an oppositely doped emitter layer. A front surface and edges and optionally the back surface periphery are masked and a back surface etch is performed. The mask is not removed and acts as an anti-reflective coating, a passivating agent, or both. The photovoltaic cell retains an untextured back surface whether or not the front is textured and the dopant layer on the back surface is removed to enhance the cell efficiency. Optionally, a back surface field is formed.

  20. Battery testing for photovoltaic applications

    SciTech Connect

    Hund, T.

    1996-11-01

    Battery testing for photovoltaic (PV) applications is funded at Sandia under the Department of Energy`s (DOE) Photovoltaic Balance of Systems (BOS) Program. The goal of the PV BOS program is to improve PV system component design, operation, reliability, and to reduce overall life-cycle costs. The Sandia battery testing program consists of: (1) PV battery and charge controller market survey, (2) battery performance and life-cycle testing, (3) PV charge controller development, and (4) system field testing. Test results from this work have identified market size and trends, PV battery test procedures, application guidelines, and needed hardware improvements.

  1. Photovoltaic Current in Quantum Dots

    NASA Astrophysics Data System (ADS)

    Switkes, M.; Marcus, C. M.; Campman, K.; Gossard, A. C.

    1998-03-01

    We investigate the DC photovoltaic current, I_pv, due to coherent ``pumping'' in open ( g >= e^2/h ) quantum dots with radio-frequency modulation of the confining potential(B. Spivak, F. Zhou, and M. T. Beal Monod, Phys. Rev. B 51), p. 13226 (1995). I_pv is on the order of 20 pA≈ 10ef for a modulation frequency f = 15 MHz. The photovoltaic current exhibits mesoscopic fluctuations with magnetic field and with the static shape of the confining potential which do not appear to be correlated with fluctuations in the conductance of the dot. The photovoltaic current induced by pumping with two independent shape distortion gates depends on their relative phase; the relationship of this phase to time reversal symmetry is investigated with a view toward defining a generalized Landauer-Büttiker relation.

  2. Photovoltaic evaluation study

    NASA Astrophysics Data System (ADS)

    Johnson, G.; Heikkilae, M.; Melasuo, T.; Spanner, S.

    Realizing the value and potential of PV-power as well as the growing need for increased cooperation and sharing of knowledge in the field of photovoltaics, FINNIDA and UNICEF decided to undertake a study of selected PV-projects. There were two main objectives for the study: To gather, compile, evaluate and share information on the photovoltaic technology appropriate to developing countries, and to promote the interest and competence of Finnish research institutes, consultants and manufacturers in photovoltaic development. For this purpose a joint evaluation of significant, primarily UN-supported projects providing for the basic needs of rural communities was undertaken. The Gambia and Kenya offered a variety of such projects, and were chosen as target countries for the study. The projects were chosen to be both comparable and complimentary. In the Gambia, the main subject was a partially integrated health and telecommunications project, but a long-operating drinking water pumping system was also studied. In Kenya, a health project in the Turkana area was examined, and also a large scale water pumping installation for fish farming. Field visits were made in order to verify and supplement the data gathered through document research and earlier investigations. Individual data gathering sheets for the project form the core of this study and are intended to give the necessary information in an organized and accessible format. The findings could practically be condensed into one sentence: PV-systems work very well, if properly designed and installed, but the resources and requirements of the recipients must be considered to a higher degree.

  3. Photovoltaic performance and reliability workshop

    SciTech Connect

    Mrig, L.

    1993-12-01

    This workshop was the sixth in a series of workshops sponsored by NREL/DOE under the general subject of photovoltaic testing and reliability during the period 1986--1993. PV performance and PV reliability are at least as important as PV cost, if not more. In the US, PV manufacturers, DOE laboratories, electric utilities, and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in the field were brought together to exchange the technical knowledge and field experience as related to current information in this evolving field of PV reliability. The papers presented here reflect this effort since the last workshop held in September, 1992. The topics covered include: cell and module characterization, module and system testing, durability and reliability, system field experience, and standards and codes.

  4. A water-budget approach to estimating potential groundwater recharge from two domestic sewage disposal fields in eastern Bernalillo County, New Mexico, 2011-12

    USGS Publications Warehouse

    Crilley, Dianna M.; Collison, Jake W.

    2015-08-04

    During this study, the disposal fields at sites A and B received a measured volume of effluent from two-person domestic residences equipped with an onsite low-pressure dosing system. A combined evapotranspiration measurement and modeling technique was used to estimate the amount of evapotranspirative loss from the disposal field and from the surrounding terrain. A portable hemispherical flux chamber was used to measure evapotranspiration at fixed locations on the disposal fields and on the surrounding terrain at sites A and B. Data from hemispherical flux chamber measurements were used to calibrate a Penman-Monteith modeled evapotranspiration rate on the disposal field and on the surrounding terrain at site A from January 1, 2011, to December 31, 2011, and from January 1, 2012, to December 31, 2012, and at site B from January 1, 2011, to December 31, 2011. Micrometeorological and soil data from instrumentation on the disposal fields and on the surrounding terrain at sites A and B were used as input data into the Penman-Monteith equation. The mean potential recharge from disposal field effluent during 2011–12 at sites A and B was 63 percent of the volume of effluent dosed to the disposal field.

  5. Impact to Underground Sources of Drinking Water and Domestic Wells from Production Well Stimulation and Completion Practices in the Pavillion, Wyoming, Field.

    PubMed

    DiGiulio, Dominic C; Jackson, Robert B

    2016-04-19

    A comprehensive analysis of all publicly available data and reports was conducted to evaluate impact to Underground Sources of Drinking Water (USDWs) as a result of acid stimulation and hydraulic fracturing in the Pavillion, WY, Field. Although injection of stimulation fluids into USDWs in the Pavillion Field was documented by EPA, potential impact to USDWs at the depths of stimulation as a result of this activity was not previously evaluated. Concentrations of major ions in produced water samples outside expected levels in the Wind River Formation, leakoff of stimulation fluids into formation media, and likely loss of zonal isolation during stimulation at several production wells, indicates that impact to USDWs has occurred. Detection of organic compounds used for well stimulation in samples from two monitoring wells installed by EPA, plus anomalies in major ion concentrations in water from one of these monitoring wells, provide additional evidence of impact to USDWs and indicate upward solute migration to depths of current groundwater use. Detections of diesel range organics and other organic compounds in domestic wells <600 m from unlined pits used prior to the mid-1990s to dispose diesel-fuel based drilling mud and production fluids suggest impact to domestic wells as a result of legacy pit disposal practices.

  6. Photovoltaic fundamentals

    SciTech Connect

    Pitchford, P.; Jones, J.; Glenn, B.; Cook, G.; Billman, L.; Adcock, R.

    1991-09-01

    This booklet describes how PV devices and systems work. It also describes the specific materials and devices that are most widely used commercially as of 1990 and those that have the brightest prospects. Students, engineers, scientists, and others needing an introduction to basic PV technology, and manufacturers and consumers who want more information about PV systems should find this booklet helpful. We begin with an overview and then explain the rudimentary physical process of the technology, the photovoltaic effect. Next, we consider how scientists and engineers have harnessed this process to generate electricity in silicon solar cells, thin-film devices, and high-efficiency cells. We then look at how these devices are incorporated into modules, arrays, and power-producing systems. We have written and designed this book so that the reader may approach the subject on three different levels. First, for the person who is in a hurry or needs a very cursory overview, in the margins of each page we generalize the important points of that page. Second, for a somewhat deeper understanding, we have provided ample illustrations, photographs, and captions. And third, for a thorough introduction to the subject, the reader can resort to reading the text.

  7. Thermionic photovoltaic energy converter

    NASA Technical Reports Server (NTRS)

    Chubb, D. L. (Inventor)

    1985-01-01

    A thermionic photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or gallium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

  8. Photovoltaic Incentive Design Handbook

    SciTech Connect

    Hoff, T. E.

    2006-12-01

    Investments in customer-owned grid-connected photovoltaic (PV) energy systems are growing at a steady pace. This is due, in part, to the availability of attractive economic incentives offered by public state agencies and utilities. In the United States, these incentives have largely been upfront lump payments tied to the system capacity rating. While capacity-based ''buydowns'' have stimulated the domestic PV market, they have been criticized for subsidizing systems with potentially poor energy performance. As a result, the industry has been forced to consider alternative incentive structures, particularly ones that pay based on long-term measured performance. The industry, however, lacks consensus in the debate over the tradeoffs between upfront incentive payments versus longer-term payments for energy delivery. This handbook is designed for agencies and utilities that offer or intend to offer incentive programs for customer-owned PV systems. Its purpose is to help select, design, and implement incentive programs that best meet programmatic goals. The handbook begins with a discussion of the various available incentive structures and then provides qualitative and quantitative tools necessary to design the most appropriate incentive structure. It concludes with program administration considerations.

  9. A molecular spin-photovoltaic device

    NASA Astrophysics Data System (ADS)

    Sun, Xiangnan; Vélez, Saül; Atxabal, Ainhoa; Bedoya-Pinto, Amilcar; Parui, Subir; Zhu, Xiangwei; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.

    2017-08-01

    We fabricated a C60 fullerene–based molecular spin-photovoltaic device that integrates a photovoltaic response with the spin transport across the molecular layer. The photovoltaic response can be modified under the application of a small magnetic field, with a magnetophotovoltage of up to 5% at room temperature. Device functionalities include a magnetic current inverter and the presence of diverging magnetocurrent at certain illumination levels that could be useful for sensing. Completely spin-polarized currents can be created by balancing the external partially spin-polarized injection with the photogenerated carriers.

  10. Photovoltaic device and method

    DOEpatents

    Cleereman, Robert; Lesniak, Michael J.; Keenihan, James R.; Langmaid, Joe A.; Gaston, Ryan; Eurich, Gerald K.; Boven, Michelle L.

    2015-11-24

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  11. Photovoltaic device and method

    DOEpatents

    Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L

    2015-01-27

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  12. Amorphous silicon photovoltaic devices

    DOEpatents

    Carlson, David E.; Lin, Guang H.; Ganguly, Gautam

    2004-08-31

    This invention is a photovoltaic device comprising an intrinsic or i-layer of amorphous silicon and where the photovoltaic device is more efficient at converting light energy to electric energy at high operating temperatures than at low operating temperatures. The photovoltaic devices of this invention are suitable for use in high temperature operating environments.

  13. High density photovoltaic

    SciTech Connect

    Haigh, R.E.; Jacobson, G.F.; Wojtczuk, S.

    1997-10-14

    Photovoltaic technology can directly generate high voltages in a solid state material through the series interconnect of many photovoltaic diodes. We are investigating the feasibility of developing an electrically isolated, high-voltage power supply using miniature photovoltaic devices that convert optical energy to electrical energy.

  14. Current topics in photovoltaics

    SciTech Connect

    Coutts, T.J. ); Meakin, J.D. . Inst. of Energy Conversion)

    1990-01-01

    This book contains papers on current research in photovoltaics. Areas include: outdoor spectral odor radiation variations and their relationship to photovoltaic device performance, numerical modeling for analysis and design of solar cells, radiation damage mechanisms in GaAs and Si solar cells, and health and safety issues in the manufacturing of photovoltaic cells.

  15. Construction and evaluation of photovoltaic power generation and power storage system using SiC field-effect transistor inverter

    SciTech Connect

    Oku, Takeo Matsumoto, Taisuke; Ohishi, Yuya; Hiramatsu, Koichi; Yasuda, Masashi; Shimono, Akio; Takeda, Yoshikazu; Murozono, Mikio

    2016-02-01

    A power storage system using spherical silicon (Si) solar cells, maximum power point tracking charge controller, lithium-ion battery and a direct current-alternating current (DC-AC) inverter was constructed. Performance evaluation of the DC-AC inverter was carried out, and the DC-AC conversion efficiencies of the SiC field-effect transistor (FET) inverter was improved compared with those of the ordinary Si-FET based inverter.

  16. On Field-Effect Photovoltaics: Gate Enhancement of the Power Conversion Efficiency in a Nanotube/Silicon-Nanowire Solar Cell.

    PubMed

    Petterson, Maureen K; Lemaitre, Maxime G; Shen, Yu; Wadhwa, Pooja; Hou, Jie; Vasilyeva, Svetlana V; Kravchenko, Ivan I; Rinzler, Andrew G

    2015-09-30

    Recent years have seen a resurgence of interest in crystalline silicon Schottky junction solar cells distinguished by the use of low density of electronic states (DOS) nanocarbons (nanotubes, graphene) as the metal contacting the Si. Recently, unprecedented modulation of the power conversion efficiency in a single material system has been demonstrated in such cells by the use of electronic gating. The gate field induced Fermi level shift in the low-DOS carbon serves to enhance the junction built-in potential, while a gate field induced inversion layer at the Si surface, in regions remote from the junction, keeps the photocarriers well separated there, avoiding recombination at surface traps and defects (a key loss mechanism). Here, we extend these results into the third dimension of a vertical Si nanowire array solar cell. A single wall carbon nanotube layer engineered to contact virtually each n-Si nanowire tip extracts the minority carriers, while an ionic liquid electrolytic gate drives the nanowire body into inversion. The enhanced light absorption of the vertical forest cell, at 100 mW/cm(2) AM1.5G illumination, results in a short-circuit current density of 35 mA/cm(2) and associated power conversion efficiency of 15%. These results highlight the use of local fields as opposed to surface passivation as a means of avoiding front surface recombination. A deleterious electrochemical reaction of the silicon due to the electrolyte gating is shown to be caused by oxygen/water entrained in the ionic liquid electrolyte. While encapsulation can avoid the issue, a nonencapsulation-based approach is also implemented.

  17. On Field-Effect Photovoltaics: Gate Enhancement of the Power Conversion Efficiency in a Nanotube/Silicon-Nanowire Solar Cell

    DOE PAGES

    Petterson, Maureen K.; Lemaitre, Maxime G.; Shen, Yu; ...

    2015-09-09

    Recent years have seen a resurgence of interest in crystalline silicon Schottky junction solar cells distinguished by the use of low density of electronic states (DOS) nanocarbons (nanotubes, graphene) as the metal contacting the Si. Recently, unprecedented modulation of the power conversion efficiency in a single material system has been demonstrated in such cells by the use of electronic gating. The gate field induced Fermi level shift in the low-DOS carbon serves to enhance the junction built-in potential, while a gate field induced inversion layer at the Si surface, in regions remote from the junction, keeps the photocarriers well separatedmore » there, avoiding recombination at surface traps and defects (a key loss mechanism). Here, we extend these results into the third dimension of a vertical Si nanowire array solar cell. A single wall carbon nanotube layer engineered to contact virtually each n-Si nanowire tip extracts the minority carriers, while an ionic liquid electrolytic gate drives the nanowire body into inversion. The enhanced light absorption of the vertical forest cell, at 100 mW/cm2 AM1.5G illumination, results in a short-circuit current density of 35 mA/cm2 and associated power conversion efficiency of 15%. These results highlight the use of local fields as opposed to surface passivation as a means of avoiding front surface recombination. Finally, a deleterious electrochemical reaction of the silicon due to the electrolyte gating is shown to be caused by oxygen/water entrained in the ionic liquid electrolyte. While encapsulation can avoid the issue, a nonencapsulation-based approach is also implemented.« less

  18. On Field-Effect Photovoltaics: Gate Enhancement of the Power Conversion Efficiency in a Nanotube/Silicon-Nanowire Solar Cell

    SciTech Connect

    Petterson, Maureen K.; Lemaitre, Maxime G.; Shen, Yu; Wadhwa, Pooja; Hou, Jie; Vasilyeva, Svetlana V.; Kravchenko, Ivan I.; Rinzler, Andrew G.

    2015-09-09

    Recent years have seen a resurgence of interest in crystalline silicon Schottky junction solar cells distinguished by the use of low density of electronic states (DOS) nanocarbons (nanotubes, graphene) as the metal contacting the Si. Recently, unprecedented modulation of the power conversion efficiency in a single material system has been demonstrated in such cells by the use of electronic gating. The gate field induced Fermi level shift in the low-DOS carbon serves to enhance the junction built-in potential, while a gate field induced inversion layer at the Si surface, in regions remote from the junction, keeps the photocarriers well separated there, avoiding recombination at surface traps and defects (a key loss mechanism). Here, we extend these results into the third dimension of a vertical Si nanowire array solar cell. A single wall carbon nanotube layer engineered to contact virtually each n-Si nanowire tip extracts the minority carriers, while an ionic liquid electrolytic gate drives the nanowire body into inversion. The enhanced light absorption of the vertical forest cell, at 100 mW/cm2 AM1.5G illumination, results in a short-circuit current density of 35 mA/cm2 and associated power conversion efficiency of 15%. These results highlight the use of local fields as opposed to surface passivation as a means of avoiding front surface recombination. Finally, a deleterious electrochemical reaction of the silicon due to the electrolyte gating is shown to be caused by oxygen/water entrained in the ionic liquid electrolyte. While encapsulation can avoid the issue, a nonencapsulation-based approach is also implemented.

  19. Transparent ultraviolet photovoltaic cells.

    PubMed

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

  20. Photovoltaics: electricity from sunlight

    SciTech Connect

    Not Available

    1984-09-01

    The role of photovoltaic power in the world's energy mix is discussed. The role of the US federal government in the research and development of photovoltaic technology is described as one of undertaking long-range, high-risk research and development in areas that industry is not likely to pursue because of the costs and risks involved. The commercial growth of photovoltaic technology is alluded to briefly, and the basic operating theory of photovoltaic conversion is introduced. Numerous applications of photovoltaic technology are described, including uses in communications, rural electrification, waer pumping, corrosion protectio, navigational aids, and railroads, as well as utility network power. The economics of photovoltaic power are discussed, and the products and technology of the US photovoltaic industry are described. (LEW)

  1. NREL Photovoltaic Program FY 1993

    SciTech Connect

    Not Available

    1994-08-01

    This report reviews the in-house and subcontracted research and development (R&D) activities under the National Renewable Energy Laboratory (NREL) Photovoltaic (PV) Program from October 1, 1992, through September 30, 1993 (fiscal year [FY] 1993). The NREL PV Program is part of the U.S. Department of Energy`s (DOE`s) National Photovoltaics Program, as described in the DOE Photovoltaics Program Plan, FY 1991 - FY 1995. The FY 1993 budget authority (BA) for carrying out the NREL PV Program was $40.1 million in operating funds and $0.9 million in capital equipment funds. An additional $4.8 million in capital equipment funds were made available for the new Solar Energy Research Facility (SERF) that will house the in-house PV laboratories beginning in FY 1994. Subcontract activities represent a major part of the NREL PV Program, with more than $23.7 million (nearly 59%) of the FY 1993 operating funds going to 70 subcontractors. In FY 1993, DOE assigned certain other PV subcontracting efforts to the DOE Golden Field Office (DOE/GO), and assigned responsibility for their technical support to the NREL PV Program. An example is the PV:BONUS (Building Opportunities in the U.S. for Photovoltaics) Project. These DOE/GO efforts are also reported in this document.

  2. Influence of Magnetic Field on the Mesoporous Structure of Fe-Cu Compounds in Dye-Sensitized Photovoltaic Cells

    NASA Astrophysics Data System (ADS)

    Alami, Abdul Hai; Zhang, Di; Aokal, Camilia; Abed, Jehad; Abdoun, Ideisan Abu; Alawadhi, Hussain

    2016-03-01

    This paper investigates the effect of applying static and dynamic magnetic fields on the deposition of Fe-Cu compound on the working electrode of a dye-sensitized solar cell. The deposition of this compound on glass is complicated due to the fact that it cannot be evaporated or sintered beyond the dissociation temperature of 973 K (700 °C), and the doctor blade technique causes detrimental layer inconsistencies. The Fe-Cu compound is relatively easy to produce and is significantly cheaper and more absorptive (>81 pct) in the Vis-NIR than the standard TiO2 mesoporous material used for solar cells. It also behaves as a semiconductor due to the high diffusion of the Fe into the Cu lattice that a bandgap of 1.8 eV is obtained. The use of a Schiff base dye with a compatible bandgap of 1.68 eV is used as a sensitizer for the production of a test cell that generated more photocurrent than its TiO2 counterpart, which is a promising result for an alternative mesoporous layer in solar cells.

  3. The future of organic photovoltaics.

    PubMed

    Mazzio, Katherine A; Luscombe, Christine K

    2015-01-07

    Increasing global demand for energy, along with dwindling fossil fuel resources and a better understanding of the hidden costs associated with these energy sources, have spurred substantial political, academic, and industrial interest in alternative energy resources. Photovoltaics based on organic semiconductors have emerged as promising low-cost alternatives for electricity generation that relies on sunlight. In this tutorial review we discuss the relevance of these organic photovoltaics beginning with some of the economic drivers for these technologies. We then examine the basic properties of these devices, including operation and materials requirements, in addition to presenting the development of the field from a historical perspective. Potential future directions are also briefly discussed. This tutorial review is intended to be an essential overview of the progress of the field, in addition to aiding in the discussion of the future of OPV technologies.

  4. Concentrating photovoltaic technology

    SciTech Connect

    Edenburn, M.W.

    1984-01-01

    This paper will summarize the status and discuss likely future directions of photovoltaic concentrator technology. A current commercial Si cell module has a peak efficiency of 15.5%, and 17% has been reached with an experimental module. Advanced cells and module design improvements offer still higher efficiencies. Concentrator Fresnel lens array fields installed several years ago have all demonstrated very good electrical performance with little performance degradation. Fresnel lens arrays were commercially available and prices of $7/watt for installed one megawatt systems have been quoted. Cost projections predict that current technology concentrating PV arrays can be installed for less than $2/watt if they are manufactured in large, steady quantities. More advanced designs may cost even less.

  5. Photon management modeling and beyond for photovoltaics

    NASA Astrophysics Data System (ADS)

    Bermel, Peter

    2014-03-01

    Improving the performance of photovoltaics is important for increased deployment in a broad range of applications. In this article, it is shown that combining detailed models for full-wave optics with one or more other physics models represents an emerging field of research. In particular, connections are made with geometric optics, electronic transport, and thermal transport. First, structures combining random texturing and periodic gratings offer the promise of higher light-trapping performance for a broad range of thin-film photovoltaic systems. Second, combining full-wave optics with electronic transport creates an opportunity to accurately model the limits of performance for devices approaching the Shockley-Queisser limit. Finally, combining optical with thermal modeling creates the potential for a physics-based understanding of intrinsic photovoltaic module failures, necessary to ensure a long life for photovoltaic cells.

  6. Photovoltaic refrigeration application: Assessment of the near-term market

    NASA Technical Reports Server (NTRS)

    Rosenblum, L.; Bifano, W. J.; Poley, W. A.; Scudder, L. R.

    1977-01-01

    This foreign and domestic market assessment was performed as part of the Tests and Applications Project being conducted by NASA-LeRC as part of the Department of Energy's (DOE) National Photovoltaic Program. One of the objectives of that program was to stimulate the demand for photovoltaic power systems so that appropriate markets would be developed in concert with the increasing photovoltaic production capacity. The refrigeration application represented a possible market for photovoltaics; hence, a brief survey of potential applications was conducted. Both refrigerators and refrigeration systems were considered in the assessment although the primary emphasis is on refrigerators of 9 cu ft of less. Three user sectors were examined: (1) government, (2) commercial/institutional, and (3) general public.

  7. Residential photovoltaic system designs

    SciTech Connect

    Russell, M. C.

    1981-01-01

    A project to develop Residential Photovoltaic Systems has begun at Massachusetts Institute of Technology Lincoln Laboratory with the construction and testing of five Prototype Systems. All of these systems utilize a roof-mounted photovoltaic array and allow excess solar-generated electric energy to be fed back to the local utility grid, eliminating the need for on-site storage. Residential photovoltaic system design issues are discussed and specific features of the five Prototype Systems now under test are presented.

  8. Photovoltaic technology assessment

    SciTech Connect

    Backus, C.E.

    1981-01-01

    After a brief review of the history of photovoltaic devices and a discussion of the cost goals set for photovoltaic modules, the status of photovoltaic technology is assessed. Included are discussions of: current applications, present industrial production, low-cost silicon production techniques, energy payback periods for solar cells, advanced materials research and development, concentrator systems, balance-of-system components. Also discussed are some nontechnical aspects, including foreign markets, US government program approach, and industry attitudes and approaches. (LEW)

  9. Surveillance and characterisation by pulsed-field gel electrophoresis of Cronobacter spp. in farming and domestic environments, food production animals and retail foods.

    PubMed

    Molloy, Catherine; Cagney, Claire; O'Brien, Stephen; Iversen, Carol; Fanning, Séamus; Duffy, Geraldine

    2009-12-31

    Cronobacter spp. (formally Enterobacter sakazakii) has been linked to illness in infants from contaminated powdered infant formula, however, there is limited information on the environmental sources and potential transmission routes of this pathogen. The aim of this study was to establish if food production animals (cattle, pigs), and the wider farm environment were playing a role in the transmission of Cronobacter spp. and also to assess the risk of cross contamination in the home where infant formula is prepared, from the presence of the pathogen on other foods and the general domestic environment. A wide range of samples (n=518) was collected at dairy farms, meat abattoirs, retail food stores and domestic environs and examined for the pathogen using an adapted ISO/DTS 22964 cultural protocol. The modified method included incubation at 42 degrees C instead of 44 degrees C and serial dilution of the enriched media prior to plating on Druggan-Forsythe-Iversen agar. Presumptive Cronobacter spp. colonies were confirmed by Real Time PCR targeting the dnaG on the MMS operon. All Cronobacter spp. isolated were speciated using biochemical tests, tested for resistance to 8 antibiotics and characterised using pulsed field gel electrophoresis. Cronobacter spp. was not recovered from cattle faeces, farm soil or trough water but isolates (n=33) were recovered from a variety of other sample types including cattle feed, pork and beef cuts, beef burgers and beef mince, green vegetables as well as organic breakfast cereals and domestic vacuum cleaner dust. The species recovered included C. Sakazakii (n=21), C. malonaticus (n=1) and C. turicensis (n=1). Of the 33 isolates 51% were resistant to Cephalothin but sensitive to all other 7 tested antibiotics. Sub-typing of the recovered isolates by PFGE showed considerable clonal diversity, though a number of persistent PFGE profiles were observed. In conclusion the study showed that Cronobacter spp. was not carried by food production

  10. Photovoltaic development in Argentina

    SciTech Connect

    Godfrin, E.M.; Duran, J.C.; Frigerio, A.; Moragues, J.A.

    1994-12-31

    A critical assessment of the photovoltaic program in Argentina is presented. Research and development activities on photovoltaic cells as well as industrial and technological development are still in the initial stages. Activities accomplished by the Atomic Energy Commission (CNEA) and the Institute of Technology Development for the Chemical industry (INTEC) are briefly described. The evolution of photovoltaic installations in Argentina is analyzed and accumulative data up to 1993 are given. A summary of the potential market for photovoltaic systems in the short and medium term is presented.

  11. Analysis of field test data from domestic solar water heaters in the southern United States, period through March, 1983

    SciTech Connect

    Not Available

    1984-03-01

    During the field test program there were over 160 solar water heaters monitored for energy performance. The actual installation of the monitoring equipment was divided into two phases. Phase I of the program consisted of the installation of monitoring equipment on solar waterheater sites located in Florida. Phase II called for system monitoring in the state of North Carolina, Virginia, South Carolina, Georgia, Kentucky, Texas, and Alabama. Phase I was implemented in mid 1981 while Phase II began in early 1982.

  12. Photovoltaic research and development in Japan

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1983-01-01

    The status of the Japanese photovoltaic (PV) R&D activities was surveyed through literature searches, private communications, and site visits in 1982. The results show that the Japanese photovoltaic technology is maturing rapidly, consistent with the steady government funding under the Sunshine Project. Two main thrusts of the Project are: (1) completion of the solar panel production pilot plants using cast ingot and sheet silicon materials, and (2) development of large area amorphous silicon solar cells with acceptable efficiency (10 to 12%). An experimental automated solar panel production plant rated at 500 kW/yr is currently under construction for the Sunshine Project for completion in March 1983. Efficiencies demonstrated by experimental large are amorphous silicon solar cells are approaching 8%. Small area amorphous silicon solar cells are, however, currently being mass produced and marketed by several companies at an equivalent annual rate of 2 MW/yr for consumer electronic applications. There is no evidence of an immediate move by the Japanese PV industry to enter extensively into the photovoltaic power market, domestic or otherwise. However, the photovoltaic technology itself could become ready for such an entry in the very near future, especially by making use of advanced process automation technologies.

  13. Photovoltaic energy program overview, fiscal year 1991

    SciTech Connect

    Not Available

    1992-02-01

    The Photovoltaics Program Plan, FY 1991--FY 1995 builds on the accomplishments of the past 5 years and broadens the scope of program activities for the future. The previous plan emphasized materials and PV cell research. Under the balanced new plan, the PV Program continues its commitment to strategic research and development (R D) into PV materials and processes, while also beginning work on PV systems and helping the PV industry encourage new markets for photovoltaics. A major challenge for the program is to assist the US PV industry in laying the foundation for at least 1000 MW of installed PV capacity in the United States and 500 MW internationally by 2000. As part of the new plan, the program expanded the scope of its activities in 1991. The PV Program is now addressing many new aspects of developing and commercializing photovoltaics. It is expanding activities with the US PV industry through the PV Manufacturing Technology (PVMaT) project, designed to address US manufacturers' immediate problems; providing technical assistance to potential end users such as electric utilities; and the program is turning its attention to encouraging new markets for PV. In 1991, for example, the PV Program initiated a new project with the PV industry to encourage a domestic market for PV applications in buildings and began cooperative ventures to support other countries such as Mexico to use PV in their rural electrification programs. This report reviews some of the development, fabrication and manufacturing advances in photovoltaics this year.

  14. Photovoltaic energy program overview, fiscal year 1991

    NASA Astrophysics Data System (ADS)

    1992-02-01

    The Photovoltaics Program Plan, FY 1991 to FY 1995 builds on the accomplishments of the past 5 years and broadens the scope of program activities for the future. The previous plan emphasized materials and PV cell research. Under the balanced new plan, the PV Program continues its commitment to strategic research and development (R&D) into PV materials and processes, while also beginning work on PV systems and helping the PV industry encourage new markets for photovoltaics. A major challenge for the program is to assist the US PV industry in laying the foundation for at least 1000 MW of installed PV capacity in the United States and 500 MW internationally by 2000. As part of the new plan, the program expanded the scope of its activities in 1991. The PV Program is now addressing many new aspects of developing and commercializing photovoltaics. It is expanding activities with the US PV industry through the PV Manufacturing Technology (PVMaT) project, designed to address US manufacturers' immediate problems; providing technical assistance to potential end users such as electric utilities; and the program is turning its attention to encouraging new markets for PV. In 1991, for example, the PV Program initiated a new project with the PV industry to encourage a domestic market for PV applications in buildings and began cooperative ventures to support other countries such as Mexico to use PV in their rural electrification programs. This report reviews some of the development, fabrication and manufacturing advances in photovoltaics this year.

  15. On the plasmonic photovoltaic.

    PubMed

    Mubeen, Syed; Lee, Joun; Lee, Woo-Ram; Singh, Nirala; Stucky, Galen D; Moskovits, Martin

    2014-06-24

    The conversion of sunlight into electricity by photovoltaics is currently a mature science and the foundation of a lucrative industry. In conventional excitonic solar cells, electron-hole pairs are generated by light absorption in a semiconductor and separated by the "built in" potential resulting from charge transfer accompanying Fermi-level equalization either at a p-n or a Schottky junction, followed by carrier collection at appropriate electrodes. Here we report a stable, wholly plasmonic photovoltaic device in which photon absorption and carrier generation take place exclusively in the plasmonic metal. The field established at a metal-semiconductor Schottky junction separates charges. The negative carriers are high-energy (hot) electrons produced immediately following the plasmon's dephasing. Some of the carriers are energetic enough to clear the Schottky barrier or quantum mechanically tunnel through it, thereby producing the output photocurrent. Short circuit photocurrent densities in the range 70-120 μA cm(-2) were obtained for simulated one-sun AM1.5 illumination with devices based on arrays of parallel gold nanorods, conformally coated with 10 nm TiO2 films and fashioned with a Ti metal collector. For the device with short circuit currents of 120 μA cm(-2), the internal quantum efficiency is ∼2.75%, and its wavelength response tracks the absorption spectrum of the transverse plasmon of the gold nanorods indicating that the absorbed photon-to-electron conversion process resulted exclusively in the Au, with the TiO2 playing a negligible role in charge carrier production. Devices fabricated with 50 nm TiO2 layers had open-circuit voltages as high as 210 mV, short circuit current densities of 26 μA cm(-2), and a fill factor of 0.3. For these devices, the TiO2 contributed a very small but measurable fraction of the charge carriers.

  16. Photovoltaic rural electrification in France

    SciTech Connect

    Claverie, A.; Courtiade, P.; Vezin, P.

    1994-12-31

    The promotional programs sponsored by ADEME to encourage the use of off-grid photovoltaic power systems have evolved over the last ten years. From the first year-round residences that were equipped in the early 1980s, to those that are now participating in the program set up jointly by ADEME and the electricity utility Electricite de France (EDF), the notions of service quality and longevity are now better adapted to users` needs. This article outlines the evolution of ADEME`s approach in mainland France, describes the program undertaken in the French territory of New Caledonia, and lastly summarizes the results of a field survey of users of stand-alone photovoltaic systems in the French overseas department of Guadeloupe.

  17. Light Harvesting for Organic Photovoltaics.

    PubMed

    Hedley, Gordon J; Ruseckas, Arvydas; Samuel, Ifor D W

    2017-01-25

    The field of organic photovoltaics has developed rapidly over the last 2 decades, and small solar cells with power conversion efficiencies of 13% have been demonstrated. Light absorbed in the organic layers forms tightly bound excitons that are split into free electrons and holes using heterojunctions of electron donor and acceptor materials, which are then extracted at electrodes to give useful electrical power. This review gives a concise description of the fundamental processes in photovoltaic devices, with the main emphasis on the characterization of energy transfer and its role in dictating device architecture, including multilayer planar heterojunctions, and on the factors that impact free carrier generation from dissociated excitons. We briefly discuss harvesting of triplet excitons, which now attracts substantial interest when used in conjunction with singlet fission. Finally, we introduce the techniques used by researchers for characterization and engineering of bulk heterojunctions to realize large photocurrents, and examine the formed morphology in three prototypical blends.

  18. Light Harvesting for Organic Photovoltaics

    PubMed Central

    2016-01-01

    The field of organic photovoltaics has developed rapidly over the last 2 decades, and small solar cells with power conversion efficiencies of 13% have been demonstrated. Light absorbed in the organic layers forms tightly bound excitons that are split into free electrons and holes using heterojunctions of electron donor and acceptor materials, which are then extracted at electrodes to give useful electrical power. This review gives a concise description of the fundamental processes in photovoltaic devices, with the main emphasis on the characterization of energy transfer and its role in dictating device architecture, including multilayer planar heterojunctions, and on the factors that impact free carrier generation from dissociated excitons. We briefly discuss harvesting of triplet excitons, which now attracts substantial interest when used in conjunction with singlet fission. Finally, we introduce the techniques used by researchers for characterization and engineering of bulk heterojunctions to realize large photocurrents, and examine the formed morphology in three prototypical blends. PMID:27951633

  19. Photovoltaic research opportunities. Final report

    SciTech Connect

    Macaleer, B.; Bowers, J.; Hurlburt, B.

    1985-11-19

    The purpose of this study is to identify opportunities for photovoltaic (PV) research projects to capitalize on related but non-PV research. The study is performed under the assumption that a considerable body of ongoing semiconductor research in non-PV areas could be of value to its PV Program and the PV community in general. Research related to III-V compounds, thin films, and crystalline silicon materials is included. Research that is known to be PV-related or sponsored by DOE was excluded from consideration. The study resulted in 11 recommendations (research areas) and a subset of 58 specific research projects. In addition, over 75 non-PV research managers in the semiconductor field are identified as potential sources of ideas which could benefit photovoltaics.

  20. Bimolecular Recombination in Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    Lakhwani, Girish; Rao, Akshay; Friend, Richard H.

    2014-04-01

    The recombination of electrons and holes is a major loss mechanism in photovoltaic devices that controls their performance. We review scientific literature on bimolecular recombination (BR) in bulk heterojunction organic photovoltaic devices to bring forward existing ideas on the origin and nature of BR and highlight both experimental and theoretical work done to quantify its extent. For these systems, Langevin theory fails to explain BR, and recombination dynamics turns out to be dependent on mobility, temperature, electric field, charge carrier concentration, and trapped charges. Relationships among the photocurrent, open-circuit voltage, fill factor, and morphology are discussed. Finally, we highlight the recent emergence of a molecular-level picture of recombination, taking into account the spin and delocalization of charges. Together with the macroscopic picture of recombination, these new insights allow for a comprehensive understanding of BR and provide design principles for future materials and devices.

  1. Endurance Tests Of Amorphous-Silicon Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Ross, Ronald G., Jr.; Sugimura, Russell S.

    1989-01-01

    Failure mechanisms in high-power service studied. Report discusses factors affecting endurance of amorphous-silicon solar cells. Based on field tests and accelerated aging of photovoltaic modules. Concludes that aggressive research needed if amorphous-silicon modules to attain 10-year life - value U.S. Department of Energy established as goal for photovoltaic modules in commercial energy-generating plants.

  2. Endurance Tests Of Amorphous-Silicon Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Ross, Ronald G., Jr.; Sugimura, Russell S.

    1989-01-01

    Failure mechanisms in high-power service studied. Report discusses factors affecting endurance of amorphous-silicon solar cells. Based on field tests and accelerated aging of photovoltaic modules. Concludes that aggressive research needed if amorphous-silicon modules to attain 10-year life - value U.S. Department of Energy established as goal for photovoltaic modules in commercial energy-generating plants.

  3. A ten year review of performance of photovoltaic systems

    SciTech Connect

    Rosenthal, A.L.; Durand, S.J.; Thomas, M.G.

    1993-06-01

    This paper presents data compiled by the Photovoltaic Design Assistance Center at Sandia National Laboratories from more than eighty field tests performed at over thirty-five photovoltaic systems in the United States during the last ten years. The recorded performance histories, failure rates, and degradation of post-Block IV modules and balance-of-system (BOS) components are described in detail.

  4. Efficacy study and field application of an inactivated new type gosling viral enteritis virus vaccine for domestic geese.

    PubMed

    Chen, S; Ma, G P; Wang, M S; Cheng, A C; Zhu, D K; Luo, Q H; Jia, R Y; Liu, F; Chen, X Y; Han, X F; Bo, Y; Zhou, D C

    2011-04-01

    New type gosling viral enteritis virus (NGVEV) caused a serious disease in naive juvenile goslings. In the described studies the performance of 2 vaccines was analyzed: a vaccine containing adjuvanted inactivated NGVEV and a vaccine containing adjuvanted inactivated NGVEV and recombinant goose IL-2. Breeder geese were subcutaneously vaccinated at the beginning of the egg production period with the vaccines. Breeder geese sham vaccinated with PBS served as control. The cellular and humoral immune responses of the vaccinated breeder geese, as well as the presence of maternally derived antibody to NGVEV, were investigated by ELISA, virus neutralization test, and lymphocyte proliferation assay, respectively. A significantly higher immunogenicity (P < 0.05) was induced by the inactivated NGVEV-recombinant goose IL-2 adjuvant vaccine compared with the inactivated NGVEV vaccine. The offspring of the vaccinated birds were challenged with virulent NGVEV (100 50% lethal dose) and the protective efficacy of the vaccines was determined. Furthermore, in a field trial the efficacy of the inactivated NGVEV vaccine was recorded from years 2003 to 2007. No clinical signs or abnormal health status were observed in the vaccinated breeder geese and the progeny. After a single application, >80% protection was shown in the progeny of geese vaccinated against NGVEV challenge for approximately 5 mo. The extensive field trials further demonstrated that vaccination of breeder geese with the inactivated NGVEV vaccine could be a safe and efficacious means to control NGVE disease. Moreover, the level of maternally derived NGVEV antibody titer in the egg yolk reflected the level of NGVEV antibodies in the breeder geese, suggesting that the egg yolk could be used to monitor the vaccination efficacy in commercial goose breeder flocks.

  5. Electrical isolation design of photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Kallis, J. M.; Trucker, D. C.; Szeto, R. K.; Cuddihy, E. F.; Garcia, A., III

    A method was developed for calculating the magnitude and location of the maximum electric field for a family of solar-cell-like shapes. Simple formulas for use by photovoltaic module designers were developed. They provide quantitative information on the effects of the cell shape, cell thickness, and pottant thickness on the electrical stress intensification at the cell edge. A method for calculating the lines of force for three-dimensional electric fields was developed and applied to a geometry of interest to the photovoltaic program.

  6. Electrical isolation design of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Kallis, J. M.; Trucker, D. C.; Szeto, R. K.; Cuddihy, E. F.; Garcia, A., III

    1984-01-01

    A method was developed for calculating the magnitude and location of the maximum electric field for a family of solar-cell-like shapes. Simple formulas for use by photovoltaic module designers were developed. They provide quantitative information on the effects of the cell shape, cell thickness, and pottant thickness on the electrical stress intensification at the cell edge. A method for calculating the lines of force for three-dimensional electric fields was developed and applied to a geometry of interest to the photovoltaic program.

  7. Solar Photovoltaic Energy.

    ERIC Educational Resources Information Center

    Ehrenreich, Henry; Martin, John H.

    1979-01-01

    The goals of solar photovoltaic technology in contributing to America's future energy needs are presented in this study conducted by the American Physical Society. Although the time needed for photovoltaics to become popular is several decades away, according to the author, short-range applications are given. (Author/SA)

  8. Photovoltaics for residential applications

    SciTech Connect

    Not Available

    1984-02-01

    Information is given about the parts of a residential photovoltaic system and considerations relevant to photovoltaic power use in homes that are also tied to utility lines. In addition, factors are discussed that influence implementation, including legal and environmental factors such as solar access and building codes, insurance, utility buyback, and system longevity. (LEW)

  9. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  10. Solar Photovoltaic Energy.

    ERIC Educational Resources Information Center

    Ehrenreich, Henry; Martin, John H.

    1979-01-01

    The goals of solar photovoltaic technology in contributing to America's future energy needs are presented in this study conducted by the American Physical Society. Although the time needed for photovoltaics to become popular is several decades away, according to the author, short-range applications are given. (Author/SA)

  11. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  12. Microsystems Enabled Photovoltaics

    ScienceCinema

    Gupta, Vipin; Nielson, Greg; Okandan, Murat, Granata, Jennifer; Nelson, Jeff; Haney, Mike; Cruz-Campa, Jose Luiz

    2016-07-12

    Sandia's microsystems enabled photovoltaic advances combine mature technology and tools currently used in microsystem production with groundbreaking advances in photovoltaics cell design, decreasing production and system costs while improving energy conversion efficiency. The technology has potential applications in buildings, houses, clothing, portable electronics, vehicles, and other contoured structures.

  13. Microsystems Enabled Photovoltaics

    SciTech Connect

    Gupta, Vipin; Nielson, Greg; Okandan, Murat, Granata, Jennifer; Nelson, Jeff; Haney, Mike; Cruz-Campa, Jose Luiz

    2012-07-02

    Sandia's microsystems enabled photovoltaic advances combine mature technology and tools currently used in microsystem production with groundbreaking advances in photovoltaics cell design, decreasing production and system costs while improving energy conversion efficiency. The technology has potential applications in buildings, houses, clothing, portable electronics, vehicles, and other contoured structures.

  14. [Detection of verotoxin-producing E. coli in field isolates from domestic and agricultural animals in Sachsen-Anhalt].

    PubMed

    Gallien, P; Klie, H; Lehmann, S; Protz, D; Helmuth, R; Schäfer, R; Ehrler, M

    1994-10-01

    A report is given on the detection of verotoxin-producing E. coli (VTEC) strains from field isolates of healthy or ill cattle (n = 141), pigs (n = 306), sheep (n = 15), cats (n = 29) and dogs (n = 25) in the region of the new federal land Sachsen-Anhalt. 5% of the strains isolated from cattle, 32% from pigs, 20% from sheep, 4% from dogs and 0% from cats have shown VTEC. The E. coli-strains were checked for the presence of other factors of virulence, too. A good correlation (82%) was found between the colonization factor F107 and SLT 2/2v-containing strains from pigs in the region of Sachsen-Anhalt, too. Enterohemolysin was not found in SLT 2/2v-positive strains. 91% of the VTEC, isolated from pigs, produced alpha-Hemolysin. The correlation of SLT-containing strains and the production of enterohemolysin was confirmed for ruminants, only. Plasmidprofilings of VTEC from pigs showed mainly a 60 MDa or a 68 MDa plasmid or both, too. The occurrence of heat labile (LT) and in some cases of heat stable (ST) toxin was also checked, to differentiate the VTEC-strains from the enterotoxigenic E. coli strains (ETEC). These investigations showed, that VTEC produce SLT almost without exception. Correlations and conclusions on the pathogenicity for humans are discussed.

  15. Effect of perphenazine enanthate on open-field test behaviour and stress-induced hyperthermia in domestic sheep.

    PubMed

    Pedernera-Romano, Cecilia; Ruiz de la Torre, José L; Badiella, Llorenç; Manteca, Xavier

    2010-01-01

    The open-field test (OFT) and stress-induced hyperthermia (SIH) have been used to measure individual differences in fear. The present study has been designed as a pharmacological validation of OFT and SIH as indicators of fear in sheep using perphenazine enanthate (PPZ), a long-acting neuroleptic. Twenty four ewes of two breeds, Lacaune and Ripollesa, were tested in an arena measuring 5mx2.5m. Treatment group received one dose of 1.5mg/kg of PPZ and control group received sterile sesame oil. All animals were tested for 10min and behaviours were recorded. Rectal temperature was measured at the beginning (T1) and at the end (T2) of the test. SIH was defined as the difference between T2 and T1. Sheep were tested on days 1, 2, 3, 4, 7 and 9 after PPZ injection. Variables were analysed using a mixed model. PPZ decreased bleats on days 2, 3, 4 and the SIH response on days 2 and 3. Breed differences were observed. Treated animals showed positive correlations between SIH and bleats; squares entered; attempts to escape and negative correlation between SIH and visits to the food bucket. Our results suggest that behaviour and SIH on the OFT are useful measures of fear in sheep.

  16. Residues of azoxystrobin, fenhexamid and pyrimethanil in strawberry following field treatments and the effect of domestic washing.

    PubMed

    Angioni, A; Schirra, M; Garau, V L; Melis, M; Tuberoso, C I G; Cabras, P

    2004-11-01

    Residues of the pesticides azoxystrobin, fenhexamid and pyrimethanil were determined in strawberry after field treatment. The effect of 'home' washing with tap water and a commercially available vegetable detergent on residue levels was also studied. After treatment, azoxystrobin and pyrimethanil residues on strawberry were on average 0.55 and 2.98 mg kg(-1), respectively, values below the maximum residue level (MRL) fixed by the European Union (2.0 and 5 mg kg(-1), respectively), while fenhexamid residues were on average 2.99 mg kg(-1), which is very close to the MRL of 3.0 mg kg(-1), but some samples were over the MRL. Thereafter, all residues declined, with a half-life of about 8 days (azoxystrobin and fenhexamid) and 4.8 days (pyrimethanil). Washing the fruit with tap water reduced the residues of azoxystrobin and fenhexamid but did not affect pyrimethanil residues. Finally, when fruits were washed with a commercial detergent, greater amounts were removed (about 45% of azoxystrobin and pyrimethanil and 60% of fenhexamid).

  17. Molecular Photovoltaics in Nanoscale Dimension

    PubMed Central

    Burtman, Vladimir; Zelichonok, Alexander; Pakoulev, Andrei V.

    2011-01-01

    This review focuses on the intrinsic charge transport in organic photovoltaic (PVC) devices and field-effect transistors (SAM-OFETs) fabricated by vapor phase molecular self-assembly (VP-SAM) method. The dynamics of charge transport are determined and used to clarify a transport mechanism. The 1,4,5,8-naphthalene-tetracarboxylic diphenylimide (NTCDI) SAM devices provide a useful tool to study the fundamentals of polaronic transport at organic surfaces and to discuss the performance of organic photovoltaic devices in nanoscale. Time-resolved photovoltaic studies allow us to separate the charge annihilation kinetics in the conductive NTCDI channel from the overall charge kinetic in a SAM-OFET device. It has been demonstrated that tuning of the type of conductivity in NTCDI SAM-OFET devices is possible by changing Si substrate doping. Our study of the polaron charge transfer in organic materials proposes that a cation-radical exchange (redox) mechanism is the major transport mechanism in the studied SAM-PVC devices. The role and contribution of the transport through delocalized states of redox active surface molecular aggregates of NTCDI are exposed and investigated. This example of technological development is used to highlight the significance of future technological development of nanotechnologies and to appreciate a structure-property paradigm in organic nanostructures. PMID:21339983

  18. Photovoltaic Power Plants

    NASA Astrophysics Data System (ADS)

    Berman, Elliot

    1986-11-01

    To demonstrate technical viability of photovoltaic modules in central, grid connected energy systems, ARCO Solar, Inc. has designed, installed and is operating two photovoltaic power plants on the megawatt scale. These systems use two-axis tracking. The first generation plant in Lugo (Hesperia), California, with a nominal rating of one MWpk (DC)" was installed in 1982 in the Southern California Edison Company grid. The second system, rated at 6.4 MWDk (DC), is located in the Carrisa Plain in California and connected to the Pacific Gas and Electric Company grid. Based on the cost and performance data from these installations, an assessment of the current status and future needs of large scale photovoltaic energy systems is made. With each new system, improved techniques of design, installation and system integration have been developed. Expectations have been confirmed as to the performance and adaptability of solar cells, especially the ease of incremental increases in capacity when needed. Modular photovoltaic systems have been found to be easy to build and operate, and to be highly reliable. Prologue: Technological advancement usually requires good science and logical engineering. In the main, faith, persistence and feel are also required. Rule: The balance-of-system costs for photovoltaic energy systems equal photovoltaic module costs. Photovoltaic systems have progressed to their current stage of high promise because of faith, persistence, feel and belief in this rule.

  19. PV Standards Work: Photovoltaic System and Component Certification, Test Facility Accreditation, and Solar Photovoltaic Energy Systems International Standards

    SciTech Connect

    Basso, T. S.; Chalmers, S.; Barikmo, H. O.

    2005-11-01

    This paper discusses efforts led by two companies (PowerMark Corporation and Sunset Technologies Inc.) to support both U.S. domestic and international photovoltaic (PV) system and component certification and test facility accreditation programs and the operation of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC-82) Photovoltaic Energy Systems. International and national PV certification/accreditation programs are successfully facilitating entry of only the highest quality PV products into the marketplace. Standards also continue to be a cornerstone for assuring global PV product conformity assessment, reducing non-tariff trade barriers, and ultimately improving PV products while lowering cost.

  20. Photovoltaic systems perspective

    NASA Technical Reports Server (NTRS)

    Sutton, P. D.; Jones, G. J.

    1979-01-01

    This paper summarizes the elements of photovoltaic power system and clarifies the terminology currently used. The relationship of system efficiency and cost is described particularly for the Balance of Photovoltaic System (BOPS) area. The current status of the BOPS development activity is described. The photovoltaic systems terminology is found to be on the road to standardization. Power conditioning, energy storage, and support structure are found to be BOPS cost and/or efficiency drivers. Although the current BOPS activity has identified low-cost/high-efficiency components, further development work is necessary.

  1. Micro-concentrators for a microsystems-enabled photovoltaic system.

    PubMed

    Jared, Bradley H; Saavedra, Michael P; Anderson, Ben J; Goeke, Ron S; Sweatt, William C; Nielson, Gregory N; Okandan, Murat; Elisberg, Brenton; Snively, Dave; Duncan, John; Gu, Tian; Agrawal, Gautam; Haney, Michael W

    2014-03-10

    A 100X magnification, ± 2.5° field of view micro-concentrating optical system has been developed for a microsystems-enabled photovoltaic (MEPV) prototype module using 250 µm diameter multi-junction "stacked" PV cells.

  2. Tandem junction amorphous semiconductor photovoltaic cell

    DOEpatents

    Dalal, V.L.

    1983-06-07

    A photovoltaic stack comprising at least two p[sup +]i n[sup +] cells in optical series, said cells separated by a transparent ohmic contact layer(s), provides a long optical path for the absorption of photons while preserving the advantageous field-enhanced minority carrier collection arrangement characteristic of p[sup +]i n[sup +] cells. 3 figs.

  3. Tandem junction amorphous semiconductor photovoltaic cell

    DOEpatents

    Dalal, Vikram L.

    1983-01-01

    A photovoltaic stack comprising at least two p.sup.+ i n.sup.+ cells in optical series, said cells separated by a transparent ohmic contact layer(s), provides a long optical path for the absorption of photons while preserving the advantageous field-enhanced minority carrier collection arrangement characteristic of p.sup.+ i n.sup.+ cells.

  4. Giant photovoltaic effects driven by residual polar field within unit-cell-scale LaAlO3 films on SrTiO3

    PubMed Central

    Liang, Haixing; Cheng, Long; Zhai, Xiaofang; Pan, Nan; Guo, Hongli; Zhao, Jin; Zhang, Hui; Li, Lin; Zhang, Xiaoqiang; Wang, Xiaoping; Zeng, Changgan; Zhang, Zhenyu; Hou, J. G.

    2013-01-01

    For polar/nonpolar heterostructures, Maxwell's theory dictates that the electric potential in the polar components will increase divergently with the film thickness. For LaAlO3/SrTiO3, a conceptually intriguing route, termed charge reconstruction, has been proposed to avert such “polar catastrophe”. The existence of a polar potential in LaAlO3 is a prerequisite for the validity of the charge reconstruction picture, yet to date, its direct measurement remains a major challenge. Here we establish unambiguously the existence of the residual polar potential in ultrathin LaAlO3 films on SrTiO3, using a novel photovoltaic device design as an effective probe. The measured lower bound of the residual polar potential is 1.0 V. Such a direct observation of the giant residual polar potential within the unit-cell-scale LaAlO3 films amounts to a definitive experimental evidence for the charge reconstruction picture, and also points to new technological significance of oxide heterostructures in photovoltaic and sensing devices with atomic-scale control. PMID:23756918

  5. Nanostructures in photovoltaics.

    PubMed

    Catchpole, Kylie R

    2006-12-15

    The world has recently been waking up to the urgent need to move away from fossil fuels and towards a low-carbon economy. To achieve this, we need a way of producing electricity that is efficient, widely applicable and cheap. At the same time, there has recently been an appreciation of the tremendous scope for making entirely new types of devices, and even seeing new physics, by structuring matter at the nanoscale. Furthermore, the occurrence of self-assembly in nature suggests that a range of types of nanoscale structures could be made simply and cheaply. The application of nanostructures to photovoltaics combines a field of almost limitless possibilities with a problem of vital urgency. In this paper, some of the newer ideas emerging from this trend are described, along with how they challenge our ideas on what a solar cell looks like. We are at the beginning of a time of radically rethinking the design of the solar cell, which may lead to the exploitation of completely new physical ideas in achieving a sustainable energy future.

  6. Photovoltaic module and interlocked stack of photovoltaic modules

    DOEpatents

    Wares, Brian S.

    2014-09-02

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

  7. Photonic Design for Photovoltaics

    SciTech Connect

    Kosten, E.; Callahan, D.; Horowitz, K.; Pala, R.; Atwater, H.

    2014-08-28

    We describe photonic design approaches for silicon photovoltaics including i) trapezoidal broadband light trapping structures ii) broadband light trapping with photonic crystal superlattices iii) III-V/Si nanowire arrays designed for broadband light trapping.

  8. Photovoltaic solar cell

    DOEpatents

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

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  9. Photovoltaic solar cell

    DOEpatents

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

    2014-05-20

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electricity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  10. Singlet exciton fission photovoltaics.

    PubMed

    Lee, Jiye; Jadhav, Priya; Reusswig, Philip D; Yost, Shane R; Thompson, Nicholas J; Congreve, Daniel N; Hontz, Eric; Van Voorhis, Troy; Baldo, Marc A

    2013-06-18

    Singlet exciton fission, a process that generates two excitons from a single photon, is perhaps the most efficient of the various multiexciton-generation processes studied to date, offering the potential to increase the efficiency of solar devices. But its unique characteristic, splitting a photogenerated singlet exciton into two dark triplet states, means that the empty absorption region between the singlet and triplet excitons must be filled by adding another material that captures low-energy photons. This has required the development of specialized device architectures. In this Account, we review work to develop devices that harness the theoretical benefits of singlet exciton fission. First, we discuss singlet fission in the archetypal material, pentacene. Pentacene-based photovoltaic devices typically show high external and internal quantum efficiencies. They have enabled researchers to characterize fission, including yield and the impact of competing loss processes, within functional devices. We review in situ probes of singlet fission that modulate the photocurrent using a magnetic field. We also summarize studies of the dissociation of triplet excitons into charge at the pentacene-buckyball (C60) donor-acceptor interface. Multiple independent measurements confirm that pentacene triplet excitons can dissociate at the C60 interface despite their relatively low energy. Because triplet excitons produced by singlet fission each have no more than half the energy of the original photoexcitation, they limit the potential open circuit voltage within a solar cell. Thus, if singlet fission is to increase the overall efficiency of a solar cell and not just double the photocurrent at the cost of halving the voltage, it is necessary to also harvest photons in the absorption gap between the singlet and triplet energies of the singlet fission material. We review two device architectures that attempt this using long-wavelength materials: a three-layer structure that uses

  11. Photovoltaic systems and applications

    SciTech Connect

    Not Available

    1982-01-01

    Abstracts are given of presentations given at a project review meeting held at Albuquerque, NM. The proceedings cover the past accomplishments and current activities of the Photovoltaic Systems Research, Balance-of-System Technology Development and System Application Experiments Projects at Sandia National Laboratories. The status of intermediate system application experiments and residential system analysis is emphasized. Some discussion of the future of the Photovoltaic Program in general, and the Sandia projects in particular is also presented.

  12. Solar photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Forney, R. G.

    1978-01-01

    The Department of Energy's photovoltaic program is outlined. The main objective of the program is the development of low cost reliable terrestrial photovoltaic systems. A second objective is to foster widespread use of the system in residential, industrial and commercial application. The system is reviewed by examining each component; silicon solar cell, silicon solar cell modules, advanced development modules and power systems. Cost and applications of the system are discussed.

  13. Concentrating photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Dupas, A.

    1982-11-01

    Various configurations for concentrating photovoltaic systems are described and their operating principles are explained. The effects of temperature and series resistance on system efficiency are discussed. As an example, the french family of photovoltaic concentrating systems, SOPHOCLE, is described. The SOPHOCLE family of generators is characterized by the use of a heliostat with altazimuth mounting and by the choice of medium concentration (C=45) by fresnel lenses on silicon cells.

  14. Research Opportunities in Reliability of Photovoltaic Modules (Presentation)

    SciTech Connect

    Hacke, P.

    2010-05-01

    The motivation for an increased scope and a more proactive effort in reliability research of photovoltaic modules and systems includes reducing the levelized cost of energy and gaining better confidence in the energy and financial payback for photovoltaic systems. This increased reliability and confidence will lead to greater penetration of photovoltaics in the energy portfolio and greater employment in photovoltaics and related industries. Present research needs include the fundamental degradation mechanisms of polymers, connectors and other module components, mapping of failure mechanisms observed in the field to those in accelerated lifetime tests, determining the acceleration factors, and improving standards for modules such that tests can appropriately be assigned to evaluate their long term durability. Specific mechanisms discussed are corrosion in module components, metastability in thin-film active layers, delamination and loss of elastic properties in module polymeric materials, and inverter failure. Presently, there is hiring of reliability scientists and engineers at many levels of the value chain for photovoltaics.

  15. A molecular spin-photovoltaic device.

    PubMed

    Sun, Xiangnan; Vélez, Saül; Atxabal, Ainhoa; Bedoya-Pinto, Amilcar; Parui, Subir; Zhu, Xiangwei; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E

    2017-08-18

    We fabricated a C60 fullerene-based molecular spin-photovoltaic device that integrates a photovoltaic response with the spin transport across the molecular layer. The photovoltaic response can be modified under the application of a small magnetic field, with a magnetophotovoltage of up to 5% at room temperature. Device functionalities include a magnetic current inverter and the presence of diverging magnetocurrent at certain illumination levels that could be useful for sensing. Completely spin-polarized currents can be created by balancing the external partially spin-polarized injection with the photogenerated carriers. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  16. Long-term leaching of photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Nover, Jessica; Zapf-Gottwick, Renate; Feifel, Carolin; Koch, Michael; Metzger, Jörg W.; Werner, Jürgen H.

    2017-08-01

    Some photovoltaic module technologies use toxic materials. We report long-term leaching on photovoltaic module pieces of 5 × 5 cm2 size. The pieces are cut out from modules of the four major commercial photovoltaic technologies: crystalline and amorphous silicon, cadmium telluride as well as from copper indium gallium diselenide. To simulate different environmental conditions, leaching occurs at room temperature in three different water-based solutions with pH 3, 7, and 11. No agitation is performed to simulate more representative field conditions. After 360 days, about 1.4% of lead from crystalline silicon module pieces and 62% of cadmium from cadmium telluride module pieces are leached out in acidic solutions. The leaching depends heavily on the pH and the redox potential of the aqueous solutions and it increases with time. The leaching behavior is predictable by thermodynamic stability considerations. These predictions are in good agreement with the experimental results.

  17. Variations in clinical presentation and anatomical distribution of gross lesions of African swine fever in domestic pigs in the southern highlands of Tanzania: a field experience.

    PubMed

    Kipanyula, Maulilio John; Nong'ona, Solomon Wilson

    2017-02-01

    African swine fever is a contagious viral disease responsible for up to 100% mortality among domestic pigs. A longitudinal study was carried out to determine the clinical presentation and anatomical distribution of gross lesions in affected pigs in Mbeya region, Tanzania during the 2010 to 2014 outbreaks. Data were collected during clinical and postmortem examination by field veterinarians and using a structured questionnaire. A total of 118 respondents (100%) showed awareness about African swine fever. During previous outbreaks, the mortality rate was almost 100%, while in 2014 it was estimated to be less than 50%.The clinical picture of the 2010-2012 outbreaks was characterized by high fever, depression, inappetance, mucosal congestion, hemorrhages, erythematous lesions in different body parts, and abortion. Several internal organs including the kidneys, spleen, and liver were congested and edematous. During the 2014 outbreak, a number of pigs (49.7%) were asymptomatic when brought to slaughter slabs but were found to have African swine fever gross lesions at postmortem examination as compared to 12.3% in 2010-2012. Bluish discoloration, which is normally distributed on the non-hairy parts of the body, was not apparent in some pigs except at postmortem examination. Some pigs (36.1%) presented nasal and/or oral bloody discharges which were uncommon (9.1%) during previous outbreaks. Moreover, other gross features included enlarged dark red renal lymph nodes and spleen. Clinical signs such as anorexia, diarrhea, and pyrexia were mainly observed when affected pigs reached moribund stage. The majority of pregnant sows died without presenting abortions. In some litters, suckling piglets (3-6 weeks) survived from the disease. These findings indicated that in 2014, African swine fever outbreak in Mbeya region was characterized by a different clinical picture.

  18. Customized color patterning of photovoltaic cells

    SciTech Connect

    Cruz-Campa, Jose Luis; Nielson, Gregory N.; Okandan, Murat; Lentine, Anthony L.; Resnick, Paul J.; Gupta, Vipin P.

    2016-11-15

    Photovoltaic cells and photovoltaic modules, as well as methods of making and using such photovoltaic cells and photovoltaic modules, are disclosed. More particularly, embodiments of the photovoltaic cells selectively reflect visible light to provide the photovoltaic cells with a colorized appearance. Photovoltaic modules combining colorized photovoltaic cells may be used to harvest solar energy while providing a customized appearance, e.g., an image or pattern.

  19. Photovoltaic water pumping applications: Assessment of the near-term market

    NASA Technical Reports Server (NTRS)

    Rosenblum, L.; Bifano, W. J.; Scudder, L. R.; Poley, W. A.; Cusick, J. P.

    1978-01-01

    Water pumping applications represent a potential market for photovoltaics. The price of energy for photovoltaic systems was compared to that of utility line extensions and diesel generators. The potential domestic demand was defined in the government, commercial/institutional and public sectors. The foreign demand and sources of funding for water pumping systems in the developing countries were also discussed briefly. It was concluded that a near term domestic market of at least 240 megawatts and a foreign market of about 6 gigawatts exist.

  20. Photovoltaic village power application: Assessment of the near-term market

    NASA Technical Reports Server (NTRS)

    Rosenblum, L.; Bifano, W. J.; Poley, W. A.; Scudder, L. R.

    1978-01-01

    The village power application represents a potential market for photovoltaics. The price of energy for photovoltaic systems was compared to that of utility line extensions and diesel generators. The potential domestic demand was defined in both the government and commercial sectors. The foreign demand and sources of funding for village power systems in the developing countries were also discussed briefly. It was concluded that a near term domestic market of at least 12 MW min and a foreign market of about 10 GW exists.

  1. Photovoltaic effect in Bi{sub 2}TeO{sub 5} photorefractive crystal

    SciTech Connect

    Oliveira, Ivan de Capovilla, Danilo Augusto

    2015-10-12

    We report on the presence of a strong photovoltaic effect on nominally undoped photorefractive Bi{sub 2}TeO{sub 5} crystals and estimated their Glass photovoltaic constant and photovoltaic field for λ = 532 nm illumination. We directly measured the photovoltaic-based photocurrent in this material under λ = 532 nm wavelength laser light illumination and compared its behavior with that of a well known photovoltaic Fe-doped Lithium Niobate crystal. We also show the photovoltaic current to strongly depend on the polarization direction of light. Holographic diffraction efficiency oscillation during recording and the behavior of fringe-locked running holograms in self-stabilized experiments are also demonstrated here as additional indirect proofs of the photovoltaic nature of this material.

  2. Benchmarking concentrating photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Duerr, Fabian; Muthirayan, Buvaneshwari; Meuret, Youri; Thienpont, Hugo

    2010-08-01

    Integral to photovoltaics is the need to provide improved economic viability. To achieve this goal, photovoltaic technology has to be able to harness more light at less cost. A large variety of concentrating photovoltaic concepts has provided cause for pursuit. To obtain a detailed profitability analysis, a flexible evaluation is crucial for benchmarking the cost-performance of this variety of concentrating photovoltaic concepts. To save time and capital, a way to estimate the cost-performance of a complete solar energy system is to use computer aided modeling. In this work a benchmark tool is introduced based on a modular programming concept. The overall implementation is done in MATLAB whereas Advanced Systems Analysis Program (ASAP) is used for ray tracing calculations. This allows for a flexible and extendable structuring of all important modules, namely an advanced source modeling including time and local dependence, and an advanced optical system analysis of various optical designs to obtain an evaluation of the figure of merit. An important figure of merit: the energy yield for a given photovoltaic system at a geographical position over a specific period, can be calculated.

  3. Photovoltaic industry progress through 1984

    NASA Astrophysics Data System (ADS)

    Watts, R. L.; Smith, S. A.; Dirks, J. A.

    1985-04-01

    The growth of the US photovoltaics (PV) industry over the past decade has been impressive. First designed to provide power for satellites using high-cost production techniques, PV is now the economical choice in many remote terrestrial applications. The remarkable growth of PV in terms of quality of cells and modules, production techniques, and system design, was initiated by a cooperative effort of the US Government and the domestic PV manufacturers. European and Japanese firms entered the PV industry later, but are also growing rapidly. The Europeans continue to supply PV systems for village electrification and water pumping to many Third World countries. The Japanese have been developing the amorphous silicon (A-Si) technology by expanding its use in consumer goods. The objective of this report is to present information on the developments of the world PV industry and focuses on developments occurring in 1984. Information is presented on a regional basis (US, Europe, Japan, other) to avoid disclosing company-confidential data. All information was gleaned from several sources, including a review of the technical literature and direct contacts with PV manufacturers. Prior to publishing the regional totals, all numbers were compared with those of other sources.

  4. An evaluation facility for photovoltaic water pumping systems

    NASA Astrophysics Data System (ADS)

    Chamberlin, J. L.

    A facility for the evaluation of photovoltaic-powered water pumping systems has been installed at Sandia's Photovoltaic Advanced Systems Test Facility (PASTF). This paper describes the facility which consists of an instrumented flow loop capable of handling pumps with capacities up to 90 gpm at simulated well depths up to 400 feet. The pumps can be operated either by a power supply, which permits rapid determination of a pump's operational characteristics, or by a photovoltaic array, which permits simulation of field operation. Data are collected and processed by means of a computer-based data acquisition system. Examples of tests results demonstrating some of the facility's capabilities are presented.

  5. Laser generated nanoparticles based photovoltaics.

    PubMed

    Petridis, C; Savva, K; Kymakis, E; Stratakis, E

    2017-03-01

    The exploitation of nanoparticles (NP), synthesized via laser ablation in liquids, in photovoltaic devices is reviewed. In particular, the impact of NPs' incorporation into various building blocks within the solar cell architecture on the photovoltaic performance and stability is presented and analysed for the current state of the art photovoltaic technologies.

  6. Photovoltaic Subcontract Program

    SciTech Connect

    Surek, Thomas; Catalano, Anthony

    1993-03-01

    This report summarizes the fiscal year (FY) 1992 progress of the subcontracted photovoltaic (PV) research and development (R D) performed under the Photovoltaic Advanced Research and Development Project at the National Renewable Energy Laboratory (NREL)-formerly the Solar Energy Research Institute (SERI). The mission of the national PV program is to develop PV technology for large-scale generation of economically competitive electric power in the United States. The technical sections of the report cover the main areas of the subcontract program: the Crystalline Materials and Advanced Concepts project, the Polycrystalline Thin Films project, Amorphous Silicon Research project, the Photovoltaic Manufacturing Technology (PVMaT) project, PV Module and System Performance and Engineering project, and the PV Analysis and Applications Development project. Technical summaries of each of the subcontracted programs provide a discussion of approaches, major accomplishments in FY 1992, and future research directions.

  7. Nanowires enabling strained photovoltaics

    SciTech Connect

    Greil, J.; Bertagnolli, E.; Lugstein, A.; Birner, S.

    2014-04-21

    Photovoltaic nano-devices have largely been relying on charge separation in conventional p-n junctions. Junction formation via doping, however, imposes major challenges in process control. Here, we report on a concept for photovoltaic energy conversion at the nano scale without the need for intentional doping. Our approach relies on charge carrier separation in inhomogeneously strained germanium nanowires (Ge NWs). This concept utilizes the strain-induced gradient in bandgap along tapered NWs. Experimental data confirms the feasibility of strain-induced charge separation in individual vapor-liquid-solid grown Ge NW devices with an internal quantum efficiency of ∼5%. The charge separation mechanism, though, is not inherently limited to a distinct material. Our work establishes a class of photovoltaic nano-devices with its opto-electronic properties engineered by size, shape, and applied strain.

  8. Designing future photovoltaic systems

    SciTech Connect

    Jones, G.J.

    1984-01-01

    The large scale use of photovoltaic systems to generate our electricity is a dream for the future; but if this dream is to be realized, we must understand these systems today. As a result, there has been extensive research into the design and economic tradeoffs of utility interconnected photovoltaic applications. The understanding gained in this process has shown that photovoltaic system design can be a very simple and straight-forward endeavor. This paper reviews those past studies and shows how we have reached the present state of system design evolution. The concept of the utility interactive PV system with energy value determined by the utility's avoided cost will be explored. This concept simplifies the screening of potential applications for economic viability, and we will present several rules-of-thumb for this purpose.

  9. Asphaltene based photovoltaic devices

    DOEpatents

    Chianelli, Russell R.; Castillo, Karina; Gupta, Vipin; Qudah, Ali M.; Torres, Brenda; Abujnah, Rajib E.

    2016-03-22

    Photovoltaic devices and methods of making the same, are disclosed herein. The cell comprises a photovoltaic device that comprises a first electrically conductive layer comprising a photo-sensitized electrode; at least one photoelectrochemical layer comprising metal-oxide particles, an electrolyte solution comprising at least one asphaltene fraction, wherein the metal-oxide particles are optionally dispersed in a surfactant; and a second electrically conductive layer comprising a counter-electrode, wherein the second electrically conductive layer comprises one or more conductive elements comprising carbon, graphite, soot, carbon allotropes or any combinations thereof.

  10. Concentrating photovoltaic solar panel

    DOEpatents

    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.

  11. A photovoltaic array simulator

    NASA Astrophysics Data System (ADS)

    Vachtsevanos, G. J.; Grimbas, E. J.

    A system simulating the output voltage-current characteristics of a photovoltaic array is described. The simulator may be used to test the performance of PV arrays and associated power conditioning equipment necessary for the autonomous or interconnected operation of photovoltaic energy sources. The simulator's main features include simplicity of construction, wide parametric variability and low cost. It is capable of reproducing the output characteristics of commercially available arrays at varying solar irradiation levels with sufficient accuracy. The design ensures the lowest possible power dissipation and minimal thermal drift. It is estimated that the cost of the simulator is an insignificant fraction of the actual array cost in the kilowatt power range.

  12. Photovoltaic power systems workshop

    NASA Technical Reports Server (NTRS)

    Killian, H. J.; Given, R. W.

    1978-01-01

    Discussions are presented on apparent deficiencies in NASA planning and technology development relating to a standard power module (25-35 kW) and to future photovoltaic power systems in general. Topics of discussion consider the following: (1) adequate studies on power systems; (2) whether a standard power system module should be developed from a standard spacecraft; (3) identification of proper approaches to cost reduction; (4) energy storage avoidance; (5) attitude control; (6) thermal effects of heat rejection on solar array configuration stability; (7) assembly of large power systems in space; and (8) factoring terrestrial photovoltaic work into space power systems for possible payoff.

  13. High efficiency photovoltaic device

    DOEpatents

    Guha, Subhendu; Yang, Chi C.; Xu, Xi Xiang

    1999-11-02

    An N-I-P type photovoltaic device includes a multi-layered body of N-doped semiconductor material which has an amorphous, N doped layer in contact with the amorphous body of intrinsic semiconductor material, and a microcrystalline, N doped layer overlying the amorphous, N doped material. A tandem device comprising stacked N-I-P cells may further include a second amorphous, N doped layer interposed between the microcrystalline, N doped layer and a microcrystalline P doped layer. Photovoltaic devices thus configured manifest improved performance, particularly when configured as tandem devices.

  14. Efficacy against nematode infections and safety of afoxolaner plus milbemycin oxime chewable tablets in domestic dogs under field conditions in Europe.

    PubMed

    Rehbein, Steffen; Knaus, Martin; Mallouk, Yasmina; Breiltgens, Tatjana; Brianti, Emanuele; Capári, Balázs; Dantas-Torres, Filipe; Gau, Michel; Joachim, Anja; Kaulfuß, Karl-Heinz; Kirkova, Zvezdelina; Lechner, Joerg; Mihalca, Andrei D; Mirabito, Rosamaria; Petkevičius, Saulius; Rapti, Dhimitër; Shukullari, Enstela; Sedeilhan, Michel; Dollhofer, Doris; Kley, Katrin; Lebon, Wilfried; Visser, Martin; Jeannin, Philippe

    2017-01-01

    Afoxolaner (AFX) plus milbemycin oxime (MO) combination chewable tablets (NexGard Spectra®, Merial) were evaluated for safety and efficacy against naturally acquired nematode infections in domestic dogs in a multi-centre, positive control, blinded field study using a randomized block design based on the order of presentation for allocation. In total, 408 dogs confirmed positive for naturally acquired infections of intestinal nematodes by pre-treatment faecal examination were studied in ten countries in Europe (Albania, Austria, Bulgaria, France, Germany, Hungary, Italy, Lithuania, Romania and Slovakia). Pre-treatment faecal examination revealed Toxocara, Toxascaris, hookworm, Trichuris and/or Capillaria nematode infections in 134, 30, 223, 155 and 14 dogs, respectively. Dogs were allocated to one of two treatment groups in a ratio of 1, AFX + MO chewables (≥2.5 mg AFX + ≥0.5 mg MO per kg body weight, according to dose bands; 207 dogs), and 1, MO plus praziquantel (PRZ) chewables (Milbemax®, Novartis; ≥0.5 mg MO + ≥5 mg PRZ per kg body weight, according to the manufacturer's instructions; 201 dogs) and treated once. For evaluation of efficacy based on reduction of faecal nematode egg counts, two faecal samples, one collected prior to treatment and one collected 9 to 21 days after treatment, were examined using modified McMaster techniques. For evaluation of systemic safety, dogs were examined by a veterinarian before treatment administration and at study end, and dog owners observed the health status of their dogs until the end of the study and reported any abnormal observation. For dogs treated with AFX + MO chewables, the efficacy was 99.7, 99.7, 97.2, 99.7 and 99.7 % for Toxocara, Toxascaris, hookworm, Trichuris and Capillaria, respectively; and the efficacy was 99.5, 99.4, 94.3, 99.9 and 98.0 %, respectively, for the MO + PRZ-treated dogs (p ≤ 0.002 for all nematodes and both treatments). For Toxocara, hookworm and Trichuris, non

  15. Photovoltaic properties of polymer films

    NASA Astrophysics Data System (ADS)

    Reucroft, P. J.; Ullal, H.

    1980-03-01

    The effect of metal electrode and film thickness on the photovoltaic energy conversion efficiency in (1:1) mole ratio films of poly (N-vinylcarbazole) (PVK) and 2,4,7-trinitrofluorenone (TNF) has been investigated. Low work function metals increase the Schottky barrier height which leads to increases in the photovoltaic energy conversion efficiency. A ten-fold decrease in film thickness produces a thousand-fold increase in photovoltaic energy conversion efficiency. A theoretical model which assumes that the photovoltaic current is limited by Child's law predicts photovoltaic efficiencies which are in good agreement with the measured efficiencies.

  16. Photovoltaic failure and degradation modes

    DOE PAGES

    Jordan, Dirk C.; Silverman, Timothy J.; Wohlgemuth, John H.; ...

    2017-01-30

    The extensive photovoltaic field reliability literature was analyzed and reviewed. Future work is prioritized based upon information assembled from recent installations, and inconsistencies in degradation mode identification are discussed to help guide future publication on this subject. Reported failure rates of photovoltaic modules fall mostly in the range of other consumer products; however, the long expected useful life of modules may not allow for direct comparison. In general, degradation percentages are reported to decrease appreciably in newer installations that are deployed after the year 2000. However, these trends may be convoluted with varying manufacturing and installation quality world-wide. Modules inmore » hot and humid climates show considerably higher degradation modes than those in desert and moderate climates, which warrants further investigation. Delamination and diode/j-box issues are also more frequent in hot and humid climates than in other climates. The highest concerns of systems installed in the last 10 years appear to be hot spots followed by internal circuitry discoloration. Encapsulant discoloration was the most common degradation mode, particularly in older systems. In newer systems, encapsulant discoloration appears in hotter climates, but to a lesser degree. Lastly, thin-film degradation modes are dominated by glass breakage and absorber corrosion, although the breadth of information for thin-film modules is much smaller than for x-Si.« less

  17. Qualification testing of flat-plate photovoltaic modules

    SciTech Connect

    Hoffman, A.R.; Griffith, J.S.; Ross, R.G. Jr.

    1982-08-01

    The placement of photovoltaic modules in various applications, in climates and locations throughout the world, results in different degrees and combinations of environmental and electrical stress. Early detection of module reliability deficiencies via laboratory testing is necessary for achieving long, satisfactory field service. This overview paper describes qualification testing techniques being used in the US Department of Energy's flat-plate terrestrial photovoltaic development program in terms of their significance, rationale for specified levels and durations, and test results.

  18. Qualification testing of flat-plate photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Hoffman, A. R.; Griffith, J. S.; Ross, R. G., Jr.

    1982-01-01

    The placement of photovoltaic modules in various applications, in climates and locations throughout the world, results in different degrees and combinations of environmental and electrical stress. Early detection of module reliability deficiencies via laboratory testing is necessary for achieving long, satisfactory field service. This overview paper describes qualification testing techniques being used in the US Department of Energy's flat-plate terrestrial photovoltaic development program in terms of their significance, rationale for specified levels and durations, and test results.

  19. Domestic Violence - Multiple Languages

    MedlinePlus

    ... Are Here: Home → Multiple Languages → All Health Topics → Domestic Violence URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Domestic Violence - Multiple Languages To use the sharing features on ...

  20. Photovoltaic system criteria documents. Volume 2: Quality assurance criteria for photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Koenig, John C.; Billitti, Joseph W.; Tallon, John M.

    1979-01-01

    Quality assurance criteria are described for manufacturers and installers of solar photovoltaic tests and applications. Quality oriented activities are outlined to be pursued by the contractor/subcontractor to assure the physical and operational quality of equipment produced is included. In the broad sense, guidelines are provided for establishing a QA organization if none exists. Mainly, criteria is provided to be considered in any PV quality assurance plan selected as appropriate by the responsible Field Center. A framework is established for a systematic approach to ensure that photovoltaic tests and applications are constructed in a timely and cost effective manner.

  1. Photovoltaics technology program summary

    NASA Astrophysics Data System (ADS)

    1985-05-01

    An adequate supply of energy at reasonable price is discussed. Economic efficiency and the following strategies to obtain it are suggested: (1) minimization of federal regulation in energy pricing; and (2) promote a balanced and mixed energy resource system. The development of photovoltaic energy conversion technology is summarized.

  2. BMDO photovoltaics program overview

    NASA Technical Reports Server (NTRS)

    Caveny, Leonard H.; Allen, Douglas M.

    1994-01-01

    This is an overview of the Ballistic Missile Defense Organization (BMDO) Photovoltaic Program. Areas discussed are: (1) BMDO advanced Solar Array program; (2) Brilliant Eyes type satellites; (3) Electric propulsion; (4) Contractor Solar arrays; (5) Iofee Concentrator and Cell development; (6) Entech linear mini-dome concentrator; and (7) Flight test update/plans.

  3. Photovoltaics in Japan

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1985-01-01

    Report surveys status of research and development on photovoltaics in Japan. Report based on literature searches, private communications, and visits by author to Japanese facilities. Included in survey are Sunshine Project, national program to develop energy sources; industrial development at private firms; and work at academic institutions.

  4. Multiple gap photovoltaic device

    DOEpatents

    Dalal, Vikram L.

    1981-01-01

    A multiple gap photovoltaic device having a transparent electrical contact adjacent a first cell which in turn is adjacent a second cell on an opaque electrical contact, includes utilizing an amorphous semiconductor as the first cell and a crystalline semiconductor as the second cell.

  5. Thin film photovoltaic cell

    DOEpatents

    Meakin, John D.; Bragagnolo, Julio

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  6. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, Dimitrios C.

    1983-01-01

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein the edge of which closely approaches but is spaced from the current collector strips.

  7. Integrated photovoltaic electrolytic cell

    SciTech Connect

    Ohkawa, T.

    1982-10-05

    A photovoltaic-electrolytic unit is provided to produce an electric current from solar energy and utilize the current to produce hydrogen by the electrolysis of water. The unit floats in an aqueous medium so that photoelectric cells are exposed to solar radiation, and electrodes submerged in the medium produce oxygen which is vented and hydrogen which is collected in the unit.

  8. Formed photovoltaic module busbars

    DOEpatents

    Rose, Douglas; Daroczi, Shan; Phu, Thomas

    2015-11-10

    A cell connection piece for a photovoltaic module is disclosed herein. The cell connection piece includes an interconnect bus, a plurality of bus tabs unitarily formed with the interconnect bus, and a terminal bus coupled with the interconnect bus. The plurality of bus tabs extend from the interconnect bus. The terminal bus includes a non-linear portion.

  9. The impact of photovoltaic (PV) installations on downwind particulate matter concentrations: Results from field observations at a 550-MWAC utility-scale PV plant.

    PubMed

    Ravikumar, Dwarakanath; Sinha, Parikhit

    2017-10-01

    With utility-scale photovoltaic (PV) projects increasingly developed in dry and dust-prone geographies with high solar insolation, there is a critical need to analyze the impacts of PV installations on the resulting particulate matter (PM) concentrations, which have environmental and health impacts. This study is the first to quantify the impact of a utility-scale PV plant on PM concentrations downwind of the project site. Background, construction, and post-construction PM2.5 and PM10 (PM with aerodynamic diameters <2.5 and <10 μm, respectively) concentration data were collected from four beta attenuation monitor (BAM) stations over 3 yr. Based on these data, the authors evaluate the hypothesis that PM emissions from land occupied by a utility-scale PV installation are reduced after project construction through a wind-shielding effect. The results show that the (1) confidence intervals of the mean PM concentrations during construction overlap with or are lower than background concentrations for three of the four BAM stations; and (2) post-construction PM2.5 and PM10 concentrations downwind of the PV installation are significantly lower than the background concentrations at three of the four BAM stations. At the fourth BAM station, downwind post-construction PM2.5 and PM10 concentrations increased marginally by 5.7% and 2.6% of the 24-hr ambient air quality standards defined by the U.S. Environmental Protection Agency, respectively, when compared with background concentrations, with the PM2.5 increase being statistically insignificant. This increase may be due to vehicular emissions from an access road near the southwest corner of the site or a drainage berm near the south station. The findings demonstrate the overall environmental benefit of downwind PM emission abatement from a utility-scale PV installation in desert conditions due to wind shielding. With PM emission reductions observed within 10 months of completion of construction, post

  10. Engineered Emitters for Improved Silicon Photovoltaics

    NASA Astrophysics Data System (ADS)

    Kamat, Ronak A.

    In 2014, installation of 5.3GW of new Photovoltaic (PV) systems occurred in the United States, raising the total installed capacity to 16.36GW. Strong growth is predicted for the domestic PV market with analysts reporting goals of 696GW by 2020. Conventional single crystalline silicon cells are the technology of choice, accounting for 90% of the installations in the global commercial market. Cells made of GaAs offer higher efficiencies, but at a substantially higher cost. Thin film technologies such as CIGS and CdTe compete favorably with multi-crystalline Si (u-Si), but at 20% efficiency, still lag the c-Si cell in performance. The c-Si cell can be fabricated to operate at approximately 25% efficiency, but commercially the efficiencies are in the 18-21% range, which is a direct result of cost trade-offs between process complexity and rapid throughput. With the current cost of c-Si cell modules at nearly 0.60/W. The technology is well below the historic metric of 1/W for economic viability. The result is that more complex processes, once cost-prohibitive, may now be viable. An example is Panasonic's HIT cell which operates in the 22-24% efficiency range. To facilitate research and development of novel PV materials and techniques, RIT has developed a basic solar cell fabrication process. Student projects prior to this work had produced cells with 12.8% efficiency using p type substrates. This thesis reports on recent work to improve cell efficiencies while simultaneously expanding the capability of the rapid prototyping process. In addition to the p-Si substrates, cells have been produced using n-Si substrates. The cell emitter, which is often done with a single diffusion or implant has been re-engineered using a dual implant of the same dose. This dual-implanted emitter has been shown to lower contact resistance, increase Voc, and increase the efficiency. A p-Si substrate cell has been fabricated with an efficiency of 14.6% and n-Si substrate cell with a 13

  11. Tests Of Amorphous-Silicon Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Ross, Ronald G., Jr.

    1988-01-01

    Progress in identification of strengths and weaknesses of amorphous-silicon technology detailed. Report describes achievements in testing reliability of solar-power modules made of amorphous-silicon photovoltaic cells. Based on investigation of modules made by U.S. manufacturers. Modules subjected to field tests, to accelerated-aging tests in laboratory, and to standard sequence of qualification tests developed for modules of crystalline-silicon cells.

  12. Recent trends in concentrated photovoltaics concentrators' architecture

    NASA Astrophysics Data System (ADS)

    Buljan, Marina; Mendes-Lopes, João; Benítez, Pablo; Miñano, Juan Carlos

    2014-01-01

    The field of concentrated photovoltaics (CPV) has met some remarkable advances in recent years. The continuous increase in conversion efficiency of multijunction solar cells and new advancements in optics have led to new demands and opportunities for optical design in CPV. This paper is a mini-review on current requirements for CPV optical design, and it presents some of the main trends in recent years on CPV systems architecture.

  13. Photovoltaics: The next ten years

    SciTech Connect

    Yerkes, J.W.

    1984-08-01

    By 1984 companies manufacturing photovoltaics had been doing serious business making low cost solar arrays for twelve years. Grid connected systems of megawatt size are operating in California, and more are on the drawing board. At least six companies in the USA have produced thin film cells of over ten percent and more are working in the field. New short term goals for thin film efficiency in the twelve to fifteen percent range promise to challenge the single crystal silicon cell which has dominated the business since 1972. ARCO Solar believes that a new class of ULTRA GENERATORS twenty percent efficient and selling for two dollars per peak watt can be deployed by utilities in the 1990's.

  14. Development of photovoltaic array and module safety requirements

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Safety requirements for photovoltaic module and panel designs and configurations likely to be used in residential, intermediate, and large-scale applications were identified and developed. The National Electrical Code and Building Codes were reviewed with respect to present provisions which may be considered to affect the design of photovoltaic modules. Limited testing, primarily in the roof fire resistance field was conducted. Additional studies and further investigations led to the development of a proposed standard for safety for flat-plate photovoltaic modules and panels. Additional work covered the initial investigation of conceptual approaches and temporary deployment, for concept verification purposes, of a differential dc ground-fault detection circuit suitable as a part of a photovoltaic array safety system.

  15. Design and fabrication of a photovoltaic power system for the Papago Indian village of Schuchuli (Gunsight), Arizona

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Ratajczak, A. F.; Ice, W. J.

    1978-01-01

    A stand alone photovoltaic power system for installation in the Papago Indian village of Schuchuli is being designed and fabricated to provide electricity for village water pumping and basic domestic needs. The system will consist of a 3.5 kW (peak) photovoltaic array; controls, instrumentations, and storage batteries located in an electrical equipment building and a 120 volt dc village distribution network. The system will power a 2 HP dc electric motor.

  16. Environmental and Economic Performance of Commercial-scale Solar Photovoltaic Systems: A Field Study of Complex Energy Systems at the Desert Research Institute (DRI)

    NASA Astrophysics Data System (ADS)

    Liu, X.

    2014-12-01

    Solar photovoltaic (PV) systems are being aggressively deployed at residential, commercial, and utility scales to complement power generation from conventional sources. This is motivated both by the desire to reduce carbon footprints and by policy-driven financial incentives. Although several life cycle analyses (LCA) have investigated environmental impacts and energy payback times of solar PV systems, most results are based on hypothetical systems rather than actual, deployed systems that can provide measured performance data. Over the past five years, Desert Research Institute (DRI) in Nevada has installed eight solar PV systems of scales from 3 to 1000 kW, the sum of which supply approximately 40% of the total power use at DRI's Reno and Las Vegas campuses. The goal of this work is to explore greenhouse gas (GHG) impacts and examine the economic performance of DRI's PV systems by developing and applying a comprehensive LCA and techno-economic (TEA) model. This model is built using data appropriate for each type of panel used in the DRI systems. Power output is modeled using the National Renewable Energy Laboratory (NREL) model PVWatts. The performance of PVWatts is verified by the actual measurements from DRI's PV systems. Several environmental and economic metrics are quantified for the DRI systems, including life cycle GHG emissions and energy return. GHG results are compared with Nevada grid-based electricity. Initial results indicate that DRI's solar-derived electricity offers clear GHG benefits compared to conventional grid electricity. DRI's eight systems have GHG intensity values of 29-56 gCO2e/kWh, as compared to the GHG intensity of 212 gCO2e/kWh of national average grid power. The major source of impacts (82-92% of the total) is the upstream life cycle burden of manufacturing PV panels, which are made of either mono-crystalline or multi-crystalline silicon. Given the same type of PV panel, GHG intensity decreases as the scale of the system increases

  17. Photovoltaic module and interlocked stack of photovoltaic modules

    SciTech Connect

    Wares, Brian S.

    2012-09-04

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame having at least a top member and a bottom member. A plurality of alignment features are included on the top member of each frame, and a plurality of alignment features are included on the bottom member of each frame. Adjacent photovoltaic modules are interlocked by the alignment features on the top member of a lower module fitting together with the alignment features on the bottom member of an upper module. Other embodiments, features and aspects are also disclosed.

  18. Photovoltaic industry progress through 1984

    SciTech Connect

    Watts, R.L.; Smith, S.A.; Dirks, J.A.

    1985-04-01

    The growth of the US photovoltaics (PV) industry over the past decade has been impressive. First designed to provide power for satellites using high-cost production techniques, PV is now the economical choice in many remote terrestrial applications. The remarkable growth of PV in terms of quality of cells and modules, production techniques, and system design, was initiated by a cooperative effort of the US Government and the domestic PV manufacturers. European and Japanese firms entered the PV industry later, but are also growing rapidy. The Europeans continue to supply PV systems for village electrification and water pumping to many Third World countries. The Japanese have been developing the amorphous silicon (A-Si) technology by expanding its use in consumer goods. The world PV industry saw dramatic changes in industry ownership and in the emphasis on developing new and improved technology during 1984. The objective of this report is to present information on the developments of the world PV industry and focuses on developments occurring in 1984. Information is presented on a regional basis (US, Europe, Japan, other) to avoid disclosing company-confidential data. All information was gleaned from several sources, including a review of the technical literature and direct contacts with PV manufacturers. Prior to publishing the regional totals, all numbers were compared with those of other sources. The information contained in this report is prepared for use by the Department of Energy for their use in long-term R and D planning. However, this information should also be of interest by PV manufacturers and to those who may be contemplating entering the PV market. PV shipments for 1984, government supports for PV, and various PV market sectors are discussed.

  19. Temperature compensated photovoltaic array

    DOEpatents

    Mosher, Dan Michael

    1997-11-18

    A temperature compensated photovoltaic module (20) comprised of a series of solar cells (22) having a thermally activated switch (24) connected in parallel with several of the cells (22). The photovoltaic module (20) is adapted to charge conventional batteries having a temperature coefficient (TC) differing from the temperature coefficient (TC) of the module (20). The calibration temperatures of the switches (24) are chosen whereby the colder the ambient temperature for the module (20), the more switches that are on and form a closed circuit to short the associated solar cells (22). By shorting some of the solar cells (22) as the ambient temperature decreases, the battery being charged by the module (20) is not excessively overcharged at lower temperatures. PV module (20) is an integrated solution that is reliable and inexpensive.

  20. Temperature compensated photovoltaic array

    DOEpatents

    Mosher, D.M.

    1997-11-18

    A temperature compensated photovoltaic module comprises a series of solar cells having a thermally activated switch connected in parallel with several of the cells. The photovoltaic module is adapted to charge conventional batteries having a temperature coefficient differing from the temperature coefficient of the module. The calibration temperatures of the switches are chosen whereby the colder the ambient temperature for the module, the more switches that are on and form a closed circuit to short the associated solar cells. By shorting some of the solar cells as the ambient temperature decreases, the battery being charged by the module is not excessively overcharged at lower temperatures. PV module is an integrated solution that is reliable and inexpensive. 2 figs.

  1. Superstructure high efficiency photovoltaics

    NASA Technical Reports Server (NTRS)

    Wagner, M.; So, L. C.; Leburton, J. P.

    1987-01-01

    A novel class of photovoltaic cascade structures is introduced which features multijunction upper subcells. These superstructure high efficiency photovoltaics (SHEP's) exhibit enhanced upper subcell spectral response because of the additional junctions which serve to reduce bulk recombination losses by decreasing the mean collection distance for photogenerated minority carriers. Two possible electrical configurations were studied and compared: a three-terminal scheme that allows both subcells to be operated at their individual maximum power points and a two-terminal configuration with an intercell ohmic contact for series interconnection. The three-terminal devices were found to be superior both in terms of beginning-of-life expectancy and radiation tolerance. Realistic simulations of three-terminal AlGaAs/GaAs SHEP's show that one sun AMO efficiencies in excess of 26 percent are possible.

  2. Inverted organic photovoltaic cells.

    PubMed

    Wang, Kai; Liu, Chang; Meng, Tianyu; Yi, Chao; Gong, Xiong

    2016-05-21

    The advance in lifestyle, modern industrialization and future technological revolution are always at high expense of energy consumption. Unfortunately, there exist serious issues such as limited storage, high cost and toxic contamination in conventional fossil fuel energy sources. Instead, solar energy represents a renewable, economic and green alternative in the future energy market. Among the photovoltaic technologies, organic photovoltaics (OPVs) demonstrate a cheap, flexible, clean and easy-processing way to convert solar energy into electricity. However, OPVs with a conventional device structure are still far away from industrialization mainly because of their short lifetime and the energy-intensive deposition of top metal electrode. To address the stability and cost issue simultaneously, an inverted device structure has been introduced into OPVs, bridging laboratory research with practical application. In this review, recent progress in device structures, working mechanisms, functions and advances of each component layer as well their correlations with the efficiency and stability of inverted OPVs are reviewed and illustrated.

  3. Photovoltaic prospects in Europe

    NASA Astrophysics Data System (ADS)

    Starr, M. R.

    The economics of solar cells is reviewed with an eye to potential cost reductions in processing, and potential markets are explored. Current solar cell systems costs are noted to be on the road to achieving the U.S. DoE goals of $0.40/kWp by 1990. Continued progress will depend on technical developments in cheaper materials and processes, scaling up production, and the success of sales programs. Various consumer and professional markets are outlined, with a prediction that a 12 MWp deman will be reached as a steady state by 1995. Photovoltaic panels may conceivably replace conventional roofing materials, resulting in the projection that, if grid-supplied power continues to inflate in price, then all new European homes would be equipped with photovoltaics by the year 2000. Further, accomplishment of the cost goals could generate a 1 GWp/yr industrial market at the same time.

  4. Photovoltaic-thermal collectors

    DOEpatents

    Cox, III, Charles H.

    1984-04-24

    A photovoltaic-thermal solar cell including a semiconductor body having antireflective top and bottom surfaces and coated on each said surface with a patterned electrode covering less than 10% of the surface area. A thermal-absorbing surface is spaced apart from the bottom surface of the semiconductor and a heat-exchange fluid is passed between the bottom surface and the heat-absorbing surface.

  5. Photovoltaic panel support assembly

    SciTech Connect

    Barker, J.M.; Underwood, J.C.; Shingleton, J.

    1993-07-20

    A solar energy electrical power source is described comprising in combination at least two flat photovoltaic panels disposed side-by-side in co-planar relation with one another, a pivot shaft extending transversely across the panels, at least two supports spaced apart lengthwise of the pivot shaft, means for connecting the pivot shaft to the at least two supports, attachment means for connecting the at least two panels to the pivot shaft so that the panels can pivot about the longitudinal axis of the shaft, coupling means mechanically coupling all of the panels together so as to form a unified flat array, and selectively operable drive means for mechanically pivoting the unified flat array about the axis; wherein each of the flat photovoltaic panels comprises at least two modules each comprising a plurality of electrically interconnected photovoltaic cells, the at least two modules being aligned along a line extending at a right angle to the pivot shaft, and the coupling means comprises (a) an elongate member extending parallel to and spaced from the pivot shaft and (b) means for attaching the elongate member to the panels; and further wherein each flat photovoltaic panel comprises a unitary frame consisting of a pair of end frame members extending parallel to the pivot shaft, a pair of side frame members extending between and connected to the end frame members, and a pair of spaced apart cross frame members, with one of the two modules being embraced by and secured to the side frame members and a first one of each of the end and cross frame members, and the other of the two modules being embraced by and secured to the side frame members and the second one of each of the end and cross frame members, whereby the gap created by the spaced apart cross frame members allow air to pass between them in order to reduce the sail effect when the solar array is subjected to buffeting winds.

  6. Increased voltage photovoltaic cell

    NASA Technical Reports Server (NTRS)

    Ross, B.; Bickler, D. B.; Gallagher, B. D. (Inventor)

    1985-01-01

    A photovoltaic cell, such as a solar cell, is provided which has a higher output voltage than prior cells. The improved cell includes a substrate of doped silicon, a first layer of silicon disposed on the substrate and having opposite doping, and a second layer of silicon carbide disposed on the first layer. The silicon carbide preferably has the same type of doping as the first layer.

  7. Photovoltaics. III - Concentrators

    NASA Astrophysics Data System (ADS)

    Backus, C. E.

    1980-02-01

    Photovoltaic concentration systems that redirect sunlight falling on a surface to a smaller solar-cell surface concentrating the intensity of sunlight many times are examined. It is noted that solar cells for concentrating systems must be designed for low internal resistance as well as for high sunlight intensities. Two designs of silicon cells are presented that perform well at high concentrations; these are interdigitated back-contact cells and vertical multijunction cells. Attention is given to heat tapping of reemitted light.

  8. Do photovoltaics have a future

    NASA Technical Reports Server (NTRS)

    Williams, B. F.

    1979-01-01

    There is major concern as to the economic practicality of widespread terrestrial use because of the high cost of the photovoltaic arrays themselves. Based on their high efficiency, photovoltaic collectors should be one of the cheapest forms of energy generators known. Present photovoltaic panels are violating the trend of lower costs with increasing efficiency due to their reliance on expensive materials. A medium technology solution should provide electricity competitive with the existing medium to high technology energy generators such as oil, coal, gas, and nuclear fission thermal plants. Programs to reduce the cost of silicon and develop reliable thin film materials have a realistic chance of producing cost effective photovoltaic panels.

  9. Utility-scale photovoltaic concentrators

    SciTech Connect

    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.

  10. Solar photovoltaics for development applications

    SciTech Connect

    Shepperd, L.W.; Richards, E.H.

    1993-08-01

    This document introduces photovoltaic technology to individuals and groups specializing in development activities. Examples of actual installations illustrate the many services supplied by photovoltaic systems in development applications, including water pumping, lighting, health care, refrigeration, communications, and a variety of productive uses. The various aspects of the technology are explored to help potential users evaluate whether photovoltaics can assist them in achieving their organizational goals. Basic system design, financing techniques, and the importance of infrastructure are included, along with additional sources of information and major US photovoltaic system suppliers.

  11. Solar photovoltaics for development applications

    NASA Astrophysics Data System (ADS)

    Shepperd, L. W.; Richards, E. H.

    1993-08-01

    This document introduces photovoltaic technology to individuals and groups specializing in development activities. Examples of actual installations illustrate the many services supplied by photovoltaic systems in development applications including water pumping, lighting, health care, refrigeration, communications, and a variety of productive uses. The various aspects of the technology are explored to help potential users evaluate whether photovoltaics can assist them in achieving their organizational goals. Basic system design, financing techniques, and the importance of infrastructure are included, along with additional sources of information and major U.S. photovoltaic system suppliers.

  12. Photovoltaic research needs industry perspective

    NASA Technical Reports Server (NTRS)

    Ravi, K. V.

    1982-01-01

    An industries perspective of photovoltaic research needs is presented. Objectives and features of industry needs are discussed for the materials, devices, processes, and reliability research categories.

  13. Spatial solitons in biased photovoltaic photorefractive materials with the pyroelectric effect

    NASA Astrophysics Data System (ADS)

    Katti, Aavishkar; Yadav, R. A.

    2017-01-01

    Spatial solitons in biased photorefractive media due to the photovoltaic effect and the pyroelectric effect are investigated. The pyroelectric field considered is induced due to the heating by the incident beam's energy. These solitons can be called screening photovoltaic pyroelectric solitons. It is shown that the solitons can exist in the bright and dark realizations. The conditions for formation of these solitons are discussed. Relevant example is considered to illustrate the self trapping of such solitons. The external electric field interacts with the photovoltaic field and the pyroelectric field to either support or oppose the self trapping.

  14. Photovoltaics and the automobile

    SciTech Connect

    Young, W.R. Jr.

    1994-12-31

    For years people have been in love with the automobile. Some people just enjoy using the automobile as transportation while others also enjoy the workings and operation of this fascinating machine. The automobile is not without problems of pollution and energy consumption. These problems are changing its design and construction. New clean energy sources are being analyzed and applied to power the modern automobile. A space age energy source now being considered by some and used by others to power the automobile is photovoltaics. Photovoltaics (PV) is the direct conversion of sunlight to electricity. There are a number of devices in the modern car that are electrically powered. PV could provide a clean endless supply of electricity for air conditioning, radios and other electrical components of a car. Most people have never heard of photovoltaics (PV). There has been a great deal of research in PV among energy experts. The automobile is known the world over in both use and operation. The author describes how the merging of these two technologies will benefit mankind and without damaging the environment. 12 refs.

  15. Photovoltaic self-assembly.

    SciTech Connect

    Lavin, Judith; Kemp, Richard Alan; Stewart, Constantine A.

    2010-10-01

    This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilic interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry.

  16. Quo Vadis photovoltaics 2011

    NASA Astrophysics Data System (ADS)

    Jäger-Waldau, A.

    2011-10-01

    Since more than 10 years photovoltaics is one of the most dynamic industries with growth rates well beyond 40% per annum. This growth is driven not only by the progress in materials knowledge and processing technology, but also by market introduction programmes in many countries around the world. Despite the negative impacts on the economy by the financial crisis since 2009, photovoltaics is still growing at an extraordinary pace and had in 2010 an extraordinary success, as both production and markets doubled. The open question is what will happen in 2011 and the years after as the situation is dominated by huge manufacturing overcapacities and an increasing unpredictability of policy support. How can the PV industry continue their cost reduction to ensure another 10 to 20 years of sustained and strong growth necessary to make PV to one of the main pillars of a sustainable energy supply in 2030. Despite the fact, that globally the share of electricity from photovoltaic systems is still small, at local level it can be already now above 30% of the demand at certain times of the year. Future research in PV has to provide intelligent solutions not only on the solar cell alone, but also on the module and the system integration level in order to permit a 5 to 10% share of electricity in 2020.

  17. Photocurrent of Photovoltaic Cells

    NASA Astrophysics Data System (ADS)

    Peeler, Seth; McIntyre, Max; Cossel, Raquel; Bowser, Chris; Tzolov, Marian

    Photovoltaic cells can be used to harness clean, renewable energy from light. Examined in this project were photovoltaic cells based on a bulk heterojunction between PCPDTBT and PCBM sandwiched between an ITO anode and an Al cathode. Current-voltage characteristics and impedance spectra for multiple photovoltaic devices were taken under varying DC electrical bias and different level of illumination. This data was interpreted in terms of an equivalent circuit with linear elements, e.g. capacitance, series resistance, and parallel resistance. A physical interpretation of each circuit element will be presented. The spectral response of the devices was characterized by optical transmission and photocurrent spectroscopy using a spectrometer in the spectral range from 300 to 900 nm. The DC measurements confirmed that the devices are electrically rectifying. The AC measurements allowed modeling of the devices as a dielectric between two electrodes with injection current passing through it. The characteristic peaks for both PCBDTBT and PCBM are clearly visible in both the photocurrent and transmission data. The good correlation between the photocurrent and transmission data indicates photocurrent generation due to absorption in both materials constituting the heterojunction.

  18. A theoretical study of photovoltaic converters

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.

    1987-01-01

    Mathematical models for the photovoltaic conversion of laser power were developed. These models simulate the operation of planar and vertical junction photovoltaic converters and are described in detail.

  19. Photovoltaics with Ferroelectrics: Current Status and Beyond.

    PubMed

    Paillard, Charles; Bai, Xiaofei; Infante, Ingrid C; Guennou, Maël; Geneste, Grégory; Alexe, Marin; Kreisel, Jens; Dkhil, Brahim

    2016-07-01

    Ferroelectrics carry a switchable spontaneous electric polarization. This polarization is usually coupled to strain, making ferroelectrics good piezoelectrics. When coupled to magnetism, they become so-called multiferroic systems, a field that has been widely investigated since 2003. While ferroelectrics are birefringent and non-linear optically transparent materials, the coupling of polarization with optical properties has received, since 2009, renewed attention, triggered notably by low-bandgap ferroelectrics suitable for sunlight spectrum absorption and original photovoltaic effects. Consequently, power conversion efficiencies up to 8.1% were recently achieved and values of 19.5% were predicted, making photoferroelectrics promising photovoltaic alternatives. This article aims at providing an up-to-date review on this emerging and rapidly progressing field by highlighting several important issues and parameters, such as the role of domain walls, ways to tune the bandgap, consequences arising from the polarization switchability, and the role of defects and contact electrodes, as well as the downscaling effects. Beyond photovoltaicity, other polarization-related processes are also described, like light-induced deformation (photostriction) or light-assisted chemical reaction (photostriction). It is hoped that this overview will encourage further avenues to be explored and challenged and, as a byproduct, will inspire other research communities in material science, e.g., so-called hybrid halide perovskites.

  20. Measurement of Global Radiation using Photovoltaic Panels

    NASA Astrophysics Data System (ADS)

    Veroustraete, Frank; Bronders, Jan; Lefevre, Filip; Mensink, Clemens

    2014-05-01

    The Vito Unit - Environmental and Spatial Aspects (RMA) - for many of its models makes use of global solar radiation. From this viewpoint and also from the notion that this variable is seldom measured or available at the local scale and at high multi-temporal frequencies, it can be stated that many models are fed with low quality estimates of global solar radiation at the local to regional scales. A project was initiated called SUNSPIDER with the following objective. To make use of photovoltaic solar panels to measure solar radiation at the highest spatio-temporal resolution, from the local to the regional scales and from minutes to years. To integrate the measured solar fields in different application fields like, plant systems and agriculture, agro-meteorology and hydrology and last but not least solar energy applications. In Belgium about 250.000 PV installations have been built leading to about 6% electric power supply from photovoltaics on a yearly basis. Last year in June, the supply reached a peak of more than 20% of the total power input on the Belgian grid. A database of Belgian residential solar panel sites will be compiled. The database will serve as an input to an inverted PV model to be able to perform radiation calculations specifically for each of the validated panel sites based on minutely logged power data. Data acquisition for these sites will start each time a site is validated and hence imported in the database. Keywords: Photovoltaic Panels; PV modelling; Global Radiation.

  1. Microsystem enabled photovoltaic modules and systems

    DOEpatents

    Nielson, Gregory N; Sweatt, William C; Okandan, Murat

    2015-05-12

    A microsystem enabled photovoltaic (MEPV) module including: an absorber layer; a fixed optic layer coupled to the absorber layer; a translatable optic layer; a translation stage coupled between the fixed and translatable optic layers; and a motion processor electrically coupled to the translation stage to controls motion of the translatable optic layer relative to the fixed optic layer. The absorber layer includes an array of photovoltaic (PV) elements. The fixed optic layer includes an array of quasi-collimating (QC) micro-optical elements designed and arranged to couple incident radiation from an intermediate image formed by the translatable optic layer into one of the PV elements such that it is quasi-collimated. The translatable optic layer includes an array of focusing micro-optical elements corresponding to the QC micro-optical element array. Each focusing micro-optical element is designed to produce a quasi-telecentric intermediate image from substantially collimated radiation incident within a predetermined field of view.

  2. Natural sunlight accelerated weathering of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Zerlaut, G. A.; Anderson, T. B.; Arnett, J. C.

    1981-01-01

    Photovoltaic modules are exposed to the equivalent of ten years of sunlight aging in an accelerated exposure testing and evaluation program, the objective being to determine the long-term durability characteristics of flat plate modules in comparatively short periods of time. The modules are illuminated with concentrated sunlight in a large, sun-tracking, Fresnel-reflecting solar concentrator. The effects of the accelerated exposure are assessed by performing periodic visual inspections and electrical measurements. It is found that field-experienced failure modes are duplicated, that acceleration factors of 6x to 8x are readily attainable, and that the test method is feasible as a predictive tool for photovoltaic module lifetime durability.

  3. Interim performance criteria for photovoltaic energy systems. [Glossary included

    SciTech Connect

    DeBlasio, R.; Forman, S.; Hogan, S.; Nuss, G.; Post, H.; Ross, R.; Schafft, H.

    1980-12-01

    This document is a response to the Photovoltaic Research, Development, and Demonstration Act of 1978 (P.L. 95-590) which required the generation of performance criteria for photovoltaic energy systems. Since the document is evolutionary and will be updated, the term interim is used. More than 50 experts in the photovoltaic field have contributed in the writing and review of the 179 performance criteria listed in this document. The performance criteria address characteristics of present-day photovoltaic systems that are of interest to manufacturers, government agencies, purchasers, and all others interested in various aspects of photovoltaic system performance and safety. The performance criteria apply to the system as a whole and to its possible subsystems: array, power conditioning, monitor and control, storage, cabling, and power distribution. They are further categorized according to the following performance attributes: electrical, thermal, mechanical/structural, safety, durability/reliability, installation/operation/maintenance, and building/site. Each criterion contains a statement of expected performance (nonprescriptive), a method of evaluation, and a commentary with further information or justification. Over 50 references for background information are also given. A glossary with definitions relevant to photovoltaic systems and a section on test methods are presented in the appendices. Twenty test methods are included to measure performance characteristics of the subsystem elements. These test methods and other parts of the document will be expanded or revised as future experience and needs dictate.

  4. Chapter 3: Photovoltaic Module Stability and Reliability

    SciTech Connect

    Jordan, Dirk; Kurtz, Sarah

    2017-01-01

    Profits realized from investment in photovoltaic will benefit from decades of reliable operation. Service life prediction through accelerated tests is only possible if indoor tests duplicate power loss and failure modes observed in fielded systems. Therefore, detailing and quantifying power loss and failure modes is imperative. In the first section, we examine recent trends in degradation rates, the gradual power loss observed for different technologies, climates and other significant factors. In the second section, we provide a summary of the most commonly observed failure modes in fielded systems.

  5. Graphite-based photovoltaic cells

    DOEpatents

    Lagally, Max; Liu, Feng

    2010-12-28

    The present invention uses lithographically patterned graphite stacks as the basic building elements of an efficient and economical photovoltaic cell. The basic design of the graphite-based photovoltaic cells includes a plurality of spatially separated graphite stacks, each comprising a plurality of vertically stacked, semiconducting graphene sheets (carbon nanoribbons) bridging electrically conductive contacts.

  6. Photovoltaics: solar electric power systems

    SciTech Connect

    1980-02-01

    The operation and uses of solar cells and the National Photovoltaic Program are briefly described. Eleven DOE photovoltaic application projects are described including forest lookout towers; Wilcox Memorial Hospital in Hawaii; WBNO daytime AM radio station; Schuchuli Indian Village; Meade, Nebraska, agricultural experiment; Mt. Laguna Air Force Station; public schools and colleges; residential applications; and Sea World of Florida. (WHK)

  7. Photovoltaics: Solar electric power systems

    NASA Astrophysics Data System (ADS)

    1980-02-01

    The operation and uses of solar cells and the National Photovoltaic Program are briefly described. Eleven DOE photovoltaic application projects are described including forest lookout towers; Wilcox Memorial Hospital in Hawaii; WBNO daytime AM radio station; Schuchuli Indian Village; Meade, Nebraska, agricultural experiment; Mt. Laguna Air Force Station; public schools and colleges; residential applications; and Sea World of Florida.

  8. Solid State Photovoltaics Research Branch

    NASA Astrophysics Data System (ADS)

    1983-09-01

    The major areas of in-house photovoltaic research covered include: semiconductor crystal growth and devices; material preparation and purification; solid state theory; amorphous materials; thin film compound semiconductor solar cells; and high efficiency multijunction solar cells. The purpose and major accomplishments of the work is explained in the context of the overall goals of the national photovoltaics program.

  9. Photovoltaic conversion of laser energy

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.

    1976-01-01

    The Schottky barrier photovoltaic converter is suggested as an alternative to the p/n junction photovoltaic devices for the conversion of laser energy to electrical energy. The structure, current, output, and voltage output of the Schottky device are summarized. The more advanced concepts of the multilayer Schottky barrier cell and the AMOS solar cell are briefly considered.

  10. Maintenance of photovoltaic power systems

    NASA Astrophysics Data System (ADS)

    Hall, M. R.

    1984-08-01

    This publication establishes standard practices for inspection, testing, and maintenance of photovoltaic power systems at Dept. of the Navy installations. The practices and procedures are recommended to ensure reliable operation of the power systems. The manual covers photovoltaic-array, battery, voltage-regulator, inverter, and wiring subsystems. In addition, this manual provides a troubleshooting guide and self-study questions and answers.

  11. Domestic violence against men.

    PubMed

    Barber, Christopher F

    This article reviews the literature relating to domestic violence against men and examines some of the reasons why men are reluctant to report violent episodes. The article focuses on men as the victims and women as the perpetrators of domestic violence and identifies gaps in service provision. The role of the nurse in supporting male victims is also discussed.

  12. The Study of Electron Coherence Effects in Metallic Systems with High Frequency AC Electric Fields: Weak Localization and Mesoscopic Photovoltaic Effects.

    NASA Astrophysics Data System (ADS)

    Liu, Jin

    We have studied the effect of a high-frequency microwave electric field on electron phase coherence in thin Sb films and wires. The phase coherence is monitored through the effect of weak localization on the conductance. Through careful experimental design, we were able to calibrate the high frequency electric field. The ac effect was separated from the Joule heating with either dc measurements or the application of a magnetic field. This has made it possible to make a detailed, quantitative comparison with the theory with no free parameters. We have found good agreements between the experiments and the theory for both one and two dimensional cases. We have used the simple dc heating experiment to study the electron heating effects in Sb films. The electron temperature was reflected in the resistance, as an especially striking manner, to be quite different from the lattice temperature. This experiment was also used to study the electron-phonon scattering time in thin Sb films in the temperature range 1-4K. The magnitude of the scattering time is in reasonable accord with the theory, while the temperature dependence is of the form tau_{E_{ph}} ~ T^{-alpha }, with alpha ~ 1.4. The value of alpha appears to be significantly smaller than predicted by the theory, and is not understood. We have also studied the high frequency heating effects of thin AuPd, AuFe, and Au films at low temperatures. The analysis of the experiments yield consistent results with the theory for AuPd films with high values of the sheet resistance. However, for low-sheet-resistance films of AuPd, AuFe, and Au, the analysis suggests either that Joule heating is suppressed at microwave frequencies (as compared with that found for the same field strength at lower frequencies), or that a microwave field enhances the contribution of electron-electron interactions to the resistance. Either of these results would be at odds with current theories. Another experiment in which we were involved was the

  13. Photovoltaic tests and applications project

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The activities and accomplishments of the Photovoltaic Tests and Applications Project during the period April 1976 through June 1977 are summarized. Results of efforts to identify potential near-term photovoltaic applications and users are discussed, including the outcome of an extensive survey of Federal government agencies. The status of application experiments is presented. Various general engineering efforts are reported, including the design and construction of a photovoltaic Systems Test Facility. Efforts to develop a high efficiency 10 kVA self-commutated inverter and controller specifically designed for photovoltaic systems are also discussed. The results of a wide variety of activities in the area of photovoltaic measurements and standards are related. Documents generated by the Project during the reporting period are listed in an Appendix.

  14. Thin film photovoltaic device

    DOEpatents

    Catalano, Anthony W.; Bhushan, Manjul

    1982-01-01

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

  15. Photovoltaic Degradation Risk: Preprint

    SciTech Connect

    Jordan, D. C.; Kurtz, S. R.

    2012-04-01

    The ability to accurately predict power delivery over the course of time is of vital importance to the growth of the photovoltaic (PV) industry. Important cost drivers include the efficiency with which sunlight is converted into power, how this relationship changes over time, and the uncertainty in this prediction. An accurate quantification of power decline over time, also known as degradation rate, is essential to all stakeholders - utility companies, integrators, investors, and researchers alike. In this paper we use a statistical approach based on historical data to quantify degradation rates, discern trends and quantify risks related to measurement uncertainties, number of measurements and methodologies.

  16. Bracket for photovoltaic modules

    SciTech Connect

    Ciasulli, John; Jones, Jason

    2014-06-24

    Brackets for photovoltaic ("PV") modules are described. In one embodiment, a saddle bracket has a mounting surface to support one or more PV modules over a tube, a gusset coupled to the mounting surface, and a mounting feature coupled to the gusset to couple to the tube. The gusset can have a first leg and a second leg extending at an angle relative to the mounting surface. Saddle brackets can be coupled to a torque tube at predetermined locations. PV modules can be coupled to the saddle brackets. The mounting feature can be coupled to the first gusset and configured to stand the one or more PV modules off the tube.

  17. Thin film photovoltaic device

    DOEpatents

    Catalano, A.W.; Bhushan, M.

    1982-08-03

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids. 5 figs.

  18. Photovoltaic panel clamp

    SciTech Connect

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  19. Photovoltaic panel clamp

    SciTech Connect

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  20. Europe's space photovoltaics programme

    NASA Technical Reports Server (NTRS)

    Bogus, Klaus P.

    1994-01-01

    The current space PV (photovoltaic) technology development program of ESA is described. The program is closely coupled to the European space mission scenario for the next 10 year period and has as its main objective to make the most effective use of the limited resources available for technology in the present economical climate. This requires a well-balanced approach between concentration on very few options and keeping the competition alive if more than one promising technology exists. The paper describes ESA's main activities in the areas of solar array technology, solar cell technology, solar cell assembly technology, and special test and verification activities including the in-orbit demonstration of new technologies.

  1. Photosynthetic Photovoltaic Cells

    DTIC Science & Technology

    2007-06-21

    PHOTOSYNTHETIC PHOTOVOLTAIC CELLS 5b. GRANT NUMBER F49620-02-1-0399 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER MARC A. BALDO 5e. TASK...building an ’antenna’ on top of a conventional solar cell. Biomimetic organic solar cells operate as follows: The antenna absorbs the light, and acts to...no longer must absorb all the light. Thus, its quantum efficiency can approach 100% potentially doubling the performance of organic solar cells. 15

  2. Impact of small-scale storage systems on the photovoltaic penetration potential at the municipal scale

    NASA Astrophysics Data System (ADS)

    Ramirez Camargo, Luis; Dorner, Wolfgang

    2016-04-01

    The yearly cumulated technical energy generation potential of grid-connected roof-top photovoltaic power plants is significantly larger than the demand of domestic buildings in sparsely populated municipalities in central Europe. However, an energy balance with cumulated annual values does not deliver the right picture about the actual potential for photovoltaics since these run on a highly variable energy source as solar radiation. The mismatch between the periods of generation and demand creates hard limitations for the deployment of the theoretical energy generation potential of roof-top photovoltaics. The actual penetration of roof-top photovoltaic is restricted by the energy quality requirements of the grid and/or the available storage capacity for the electricity production beyond the coverage of own demands. In this study we evaluate in how far small-scale storage systems can contribute to increment the grid-connected roof-top photovoltaic penetration in domestic buildings at a municipal scale. To accomplish this, we calculate, in a first step, the total technical roof-top photovoltaic energy generation potential of a municipality in a high spatiotemporal resolution using a procedure that relies on geographic information systems. Posteriorly, we constrain the set of potential photovoltaic plants to the ones that would be necessary to cover the total yearly demand of the municipality. We assume that photovoltaic plants with the highest yearly yield are the ones that should be installed. For this sub-set of photovoltaic plants we consider five scenarios: 1) no storage 2) one 7 kWh battery is installed in every building with a roof-top photovoltaic plant 3) one 10 kWh battery is installed in every building with a roof-top photovoltaic plant 4) one 7 kWh battery is installed in every domestic building in the municipality 5) one 10 kWh battery is installed in every domestic building in the municipality. Afterwards we evaluate the energy balance of the

  3. Nonlinear photovoltaic effect in Sillenite photorefractive crystals

    NASA Astrophysics Data System (ADS)

    de Oliveira, Ivan; Capovilla, Danilo Augusto; Moura, André L.; Timóteo, Varese S.; Carvalho, Jesiel F.; Frejlich, Jaime

    2017-04-01

    We report on the presence of photovoltaic effect in some Sillenite photorefractive crystals and compare their behavior with that of the well known photovoltaic LiNbO3:Fe crystal. Nonlinear photovoltaic behavior of these Sillenites are also reported here for the first time and explained by the presence of shallow along with deep photovoltaic centers.

  4. Photovoltaic Product Directory and Buyers Guide

    SciTech Connect

    Watts, R.L.; Smith, S.A.; Dirks, J.A.; Mazzucchi, R.P.; Lee, V.E.

    1984-04-01

    The directory guide explains photovoltaic systems briefly and shows what products are available off-the-shelf. Information is given to assist in designing a photovoltaic system and on financial incentives. Help is given for determining if photovoltaic products can meet a particular buyer's needs, and information is provided on actual photovoltaic user's experiences. Detailed information is appended on various financial incentives available from state and federal governments, sources of additional information on photovoltaics, sources of various photovoltaic products, and a listing of addresses of photovoltaic products suppliers. (LEW)

  5. Photovoltaic system criteria documents. Volume 1: Guidelines for evaluating the management and operations planning of photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Koenig, John C.; Billitti, Joseph W.; Tallon, John M.

    1979-01-01

    Guidelines are provided to the Field Centers for organization, scheduling, project and cost control, and performance in the areas of project management and operations planning for Photovoltaics Test and Applications. These guidelines may be used in organizing a T and A Project Team for system design/test, site construction and operation, and as the basis for evaluating T and A proposals. The attributes are described for project management and operations planning to be used by the Field Centers. Specifically, all project management and operational issues affecting costs, schedules and performance of photovoltaic systems are addressed. Photovoltaic tests and applications include residential, intermediate load center, central station, and stand-alone systems. The sub-categories of system maturity considered are: Initial System Evaluation Experiments (ISEE); System Readiness Experiments (SRE); and Commercial Readiness Demonstration Projects (CRDP).

  6. Nanocarbon-based photovoltaics.

    PubMed

    Bernardi, Marco; Lohrman, Jessica; Kumar, Priyank V; Kirkeminde, Alec; Ferralis, Nicola; Grossman, Jeffrey C; Ren, Shenqiang

    2012-10-23

    Carbon materials are excellent candidates for photovoltaic solar cells: they are Earth-abundant, possess high optical absorption, and maintain superior thermal and photostability. Here we report on solar cells with active layers made solely of carbon nanomaterials that present the same advantages of conjugated polymer-based solar cells, namely, solution processable, potentially flexible, and chemically tunable, but with increased photostability and the possibility to revert photodegradation. The device active layer composition is optimized using ab initio density functional theory calculations to predict type-II band alignment and Schottky barrier formation. The best device fabricated is composed of PC(70)BM fullerene, semiconducting single-walled carbon nanotubes, and reduced graphene oxide. This active-layer composition achieves a power conversion efficiency of 1.3%-a record for solar cells based on carbon as the active material-and we calculate efficiency limits of up to 13% for the devices fabricated in this work, comparable to those predicted for polymer solar cells employing PCBM as the acceptor. There is great promise for improving carbon-based solar cells considering the novelty of this type of device, the high photostability, and the availability of a large number of carbon materials with yet untapped potential for photovoltaics. Our results indicate a new strategy for efficient carbon-based, solution-processable, thin film, photostable solar cells.

  7. Integrated organic photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Potscavage, William J.; Yoo, Seunghyup; Domercq, Benoit; Kim, Jungbae; Holt, Joe; Kippelen, Bernard

    2007-09-01

    Methods for scalable output voltage and encapsulation of organic photovoltaic cells are addressed in this paper. To obtain scalable output voltages, integrated photovoltaic modules comprised of a bulk heterojunction of poly(3- hexylthiophene) (P3HT) and a soluble C 70 derivative, [6,6]-phenyl C 71 butyric acid methyl ester (PCBM-70), were fabricated. Power conversion efficiency of individual P3HT/PCBM-70 cells was estimated to be 4.1 % for AM1.5 G illumination. Modules of one to four cells connected in series produced open-circuit voltages V OC that linearly depend on the number of cells N as V OC = N × 0.621 V with a nearly constant short-circuit current of 1.4 +/- 0.1 mA. Separately, shelf lifetimes of more than one year were achieved for pentacene/C 60 solar cells by encapsulation with a 200-nm-thick layer of Al IIO 3 deposited by atomic layer deposition (ALD). In addition, the ALD process improved the open-circuit voltage and power conversion efficiency of the solar cells by thermal annealing that occurs during the process.

  8. NREL Center for Photovoltaics

    ScienceCinema

    None

    2016-07-12

    Solar cells, also called photovoltaics (PV) by solar cell scientists, convert sunlight directly into electricity. Solar cells are often used to power calculators and watches. The performance of a solar cell is measured in terms of its efficiency at turning sunlight into electricity. Only sunlight of certain energies will work efficiently to create electricity, and much of it is reflected or absorbed by the material that make up the cell. Because of this, a typical commercial solar cell has an efficiency of 15%—about one-sixth of the sunlight striking the cell generates electricity. Low efficiencies mean that larger arrays are needed, and that means higher cost. Improving solar cell efficiencies while holding down the cost per cell is an important goal of the PV industry, researchers at the National Renewable Energy Laboratory (NREL) and other U.S. Department of Energy (DOE) laboratories, and they have made significant progress. The first solar cells, built in the 1950s, had efficiencies of less than 4%. For a text version of this video visit http://www.nrel.gov/learning/re_photovoltaics_video_text.html

  9. NREL Center for Photovoltaics

    SciTech Connect

    2009-01-01

    Solar cells, also called photovoltaics (PV) by solar cell scientists, convert sunlight directly into electricity. Solar cells are often used to power calculators and watches. The performance of a solar cell is measured in terms of its efficiency at turning sunlight into electricity. Only sunlight of certain energies will work efficiently to create electricity, and much of it is reflected or absorbed by the material that make up the cell. Because of this, a typical commercial solar cell has an efficiency of 15%—about one-sixth of the sunlight striking the cell generates electricity. Low efficiencies mean that larger arrays are needed, and that means higher cost. Improving solar cell efficiencies while holding down the cost per cell is an important goal of the PV industry, researchers at the National Renewable Energy Laboratory (NREL) and other U.S. Department of Energy (DOE) laboratories, and they have made significant progress. The first solar cells, built in the 1950s, had efficiencies of less than 4%. For a text version of this video visit http://www.nrel.gov/learning/re_photovoltaics_video_text.html

  10. Photovoltaics information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marie, T.L.; Reinhardt, C.L.

    1980-10-01

    The results of a series of telephone interviews with groups of users of information on photovoltaics (PV) are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. It covers these technological areas: photovoltaics, passive solar heating and cooling, active solar heating and cooling, biomass energy, solar thermal electric power, solar industrial and agricultural process heat, wind energy, ocean energy, and advanced energy storage. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven PV groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Researchers Working for Manufacturers, Representatives of Other Manufacturers, Representatives of Utilities, Electric Power Engineers, and Educators.

  11. Parametric study of laser photovoltaic energy converters

    NASA Technical Reports Server (NTRS)

    Walker, G. H.; Heinbockel, J. H.

    1987-01-01

    Photovoltaic converters are of interest for converting laser power to electrical power in a space-based laser power system. This paper describes a model for photovoltaic laser converters and the application of this model to a neodymium laser silicon photovoltaic converter system. A parametric study which defines the sensitivity of the photovoltaic parameters is described. An optimized silicon photovoltaic converter has an efficiency greater than 50 percent for 1000 W/sq cm of neodymium laser radiation.

  12. Innovative photovoltaic application for residences experiment

    NASA Astrophysics Data System (ADS)

    Atmaram, G. H.; Litka, A. H.

    1982-06-01

    Operational results on the performance of the 5 kilowatt peak photovoltaic residential system at the Florida Solar Energy Center (FSEC) described. Operational performance results of 1 year on the FSEC photovoltaic residential system are presented. The description of the residence, photovoltaic system, instrumentation and data collection procedure is included. The performance of the photovoltaic array, inverters and total photovoltaic system is detailed. The instrumentation upgrading, system diagnostics, and any failures or system downtime are described.

  13. Spectral analysis of magnetic fields from domestic appliances and corresponding induced current densities in an anatomically based model of the human head

    SciTech Connect

    Tofani, S.; Anglesio, L.; Ossola, P.; d`Amore, G.

    1995-12-31

    Magnetic fields emitted by electric appliances such as razors, hair dryers, and drills were measured in the frequency domain. Results show the presence of high-frequency components (up to 96 kHz for razors, up to 3.4 kHz for hair dryers, and up to 8.6 kHz for drills) in the harmonic content of the fields. The measured fields were used to calculate the induced current densities in an anatomically based model of the human head (resolution 1.31 cm) by using the impedance method. The harmonic field contribution to the current density was higher than that from the carrier frequency for all the tested appliances.

  14. Photovoltaic Systems Modeling and Analysis

    NASA Astrophysics Data System (ADS)

    Ali, Mir Shahed

    2010-11-01

    This thesis deals with the implementation of generalized photovoltaic model and integration of the same with 7-bus electrical utility system to evaluate the impact that the photovoltaic generator have on the utility system. Among all the impacts that the photovoltaic generator have on the utility system, voltage rise of the power distribution line at the position where the Photovoltaic generator is connected due to reverse power flow from the photovoltaic model has been one of the major problem. Therefore, this thesis proposes the steady-state simulations to evaluate the effectiveness of battery-integrated PV system on avoiding the over voltage problem. Further, fault analysis is done to study the effect of the PV model on the utility network during faults and it is deduced that the impact of the PV model on the utility system voltage during faults is nominal. The photovoltaic model/generator and the 7-bus utility system is developed using Matlab/Simulink software package. The developed photovoltaic model can be represented as PV cell, module or an array. The model is developed with icons that are easy to understand. The developed model takes into consideration cell's working temperature, amount of sunlight (irradiance) available, voltage of the circuit when the circuit is open and current of the circuit when it is shorted. The developed Photovoltaic model is then integrated with a Li-ion battery, over here battery serves two purposes first it will store the excess power from the Photovoltaic generator if any, during the day time and in night the battery acts as an generator and deliver the power to the utility or connected load with the help of an invertors.

  15. Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems

    SciTech Connect

    Not Available

    1980-07-01

    This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

  16. DOE project review Massachusetts Photovoltaic Program. Annual report, June 1989--July 1990

    SciTech Connect

    1996-06-01

    This is the third year of operations for work under the Cooperative Agreement between the Commonwealth of Massachusetts Photovoltaic Center and the U.S. Department of Energy. As a collaborative effort with shared resources, the activity at the Photovoltaic Center and the University of Lowell Photovoltaic Program has continued to advance the utilization and implementation of photovoltaic-powered systems into society. The programs and activities developed over the past three years have supported strategies that cover both international utilization as well as domestic application. Three major areas of activities have centered around the following themes: (1) The identification of market opportunities to enlarge sales potential for the photovoltaic industry. (2) The development of a knowledgeable infrastructure to support PV diffusion in Massachusetts, in the United States, and around the world. (3) The analysis of the physical, economic, and regulatory environment in which PV must compete with mature energy technologies. This past year has been an experience of contrasts for the Photovoltaic Center. Projects and activities have resulted in the successful completion of programs goals.

  17. Photovoltaic module with adhesion promoter

    SciTech Connect

    Xavier, Grace

    2013-10-08

    Photovoltaic modules with adhesion promoters and methods for fabricating photovoltaic modules with adhesion promoters are described. A photovoltaic module includes a solar cell including a first surface and a second surface, the second surface including a plurality of interspaced back-side contacts. A first glass layer is coupled to the first surface by a first encapsulating layer. A second glass layer is coupled to the second surface by a second encapsulating layer. At least a portion of the second encapsulating layer is bonded directly to the plurality of interspaced back-side contacts by an adhesion promoter.

  18. Plasmonic Backscattering Enhanced Inverted Photovoltaics

    SciTech Connect

    Dissanayake, D. M. N. M.; Roberts, B.; Ku, P.C.

    2011-01-01

    A plasmonic nanoparticle incorporated inverted organic photovoltaic structure was demonstrated where a monolayer of Ag nanoparticles acted as a wavelength selective reflector. Enhanced light harvesting via plasmonic backscattering into the photovoltaic absorber was observed, resulting in a two-fold improvement in the photocurrent and increased open-circuit voltage. Further, utilizing an optical spacer, the plasmonic backscattering was spectrally controlled, thereby modulating the external quantum efficiency and the photocurrent. Unlike a regular thin-film metallic back reflector, excellent off-resonance optical transmission in excess of 80% was observed from the Ag nanoparticles, making this structure highly suitable for semi-transparent and multi-junction photovoltaic applications.

  19. Domestic Communication Satellites

    ERIC Educational Resources Information Center

    Horowitz, Andrew

    1974-01-01

    A discussion of the Federal Communications Commission's new policy on domestic satellites in light of our 1) military and economic history; 2) corporate interests; 3) citizen surveillance; and 4) media control. (HB)

  20. Domestic Communication Satellites

    ERIC Educational Resources Information Center

    Horowitz, Andrew

    1974-01-01

    A discussion of the Federal Communications Commission's new policy on domestic satellites in light of our 1) military and economic history; 2) corporate interests; 3) citizen surveillance; and 4) media control. (HB)

  1. Do experiments with captive non-domesticated animals make sense without population field studies? A case study with blue tits' breeding time

    PubMed Central

    Lambrechts, M. M.; Perret, P.; Maistre, M.; Blondel, J.

    1999-01-01

    A complete understanding of the spatio-temporal variation in phenotypic traits in natural populations requires a combination long-term field studies with experiments using captive animals. Field studies allow the formulation of realistic hypotheses, but have the disadvantage that they do not allow the complete control of many potential confounding variables. Studies with captive animals allow tests of hypotheses that cannot be examined in the field, but have the disadvantage that artificial environments may provoke abnormal behaviour. Long-term studies that follow simultaneously captive and wild bird populations are rare. In a study lasting several years, we show here the unexpected patterns that two populations with a similar breeding time in the wild have non-overlapping breeding times in outdoor aviaries, and that two wild populations separated by a short geographical distance show differences in the expression of natural behaviour in captivity. The experimental design used is exceptional in the sense that the captive populations were held at similar latitudes and altitudes as the wild populations. Our case study shows that studies with captive animals can lead to wrong conclusions if they are carried out without population field studies, and without knowledge of the natural habits and habitats of the species involved. To examine the reliability of experiments with captive animals, comparisons with findings from population field studies are essential.

  2. Development of design criteria and qualification tests for bypass diodes in photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Otth, D. H.; Sugimura, R. S.; Ross, R. G., Jr.

    1985-01-01

    Design criteria have been developed for bypass diodes in p-n and Schottky barrier in photovoltaic applications. A test method for assessing conformity to the design criteria is described. Junction temperatures are defined in terms of expected worst-case field conditions, including ambient temperature and solar irradiance on the photovoltaic module. The rating criteria address the maximum allowable current and heat-sink characteristics of diodes mounted inside or outside the photovoltaic module. The method establishes worst-case module-to-diode thermal interfaces and may be adapted for laboratory or field-site experiments. A list of the design criteria is given.

  3. Development of design criteria and qualification tests for bypass diodes in photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Otth, D. H.; Sugimura, R. S.; Ross, R. G., Jr.

    1985-01-01

    Design criteria have been developed for bypass diodes in p-n and Schottky barrier in photovoltaic applications. A test method for assessing conformity to the design criteria is described. Junction temperatures are defined in terms of expected worst-case field conditions, including ambient temperature and solar irradiance on the photovoltaic module. The rating criteria address the maximum allowable current and heat-sink characteristics of diodes mounted inside or outside the photovoltaic module. The method establishes worst-case module-to-diode thermal interfaces and may be adapted for laboratory or field-site experiments. A list of the design criteria is given.

  4. High performance organic photovoltaics with plasmonic-coupled metal nanoparticle clusters.

    PubMed

    Park, Hyung Il; Lee, Seunghoon; Lee, Ju Min; Nam, Soo Ah; Jeon, Taewoo; Han, Sang Woo; Kim, Sang Ouk

    2014-10-28

    Performance enhancement of organic photovoltaics using plasmonic nanoparticles has been limited without interparticle plasmon coupling. We demonstrate high performance organic photovoltaics employing gold nanoparticle clusters with controlled morphology as a plasmonic component. Near-field coupling at the interparticle gaps of nanoparticle clusters gives rise to strong enhancement in localized electromagnetic field, which led to the significant improvement of exciton generation and dissociation in the active layer of organic solar cells. A power conversion efficiency of 9.48% is attained by employing gold nanoparticle clusters at the bottom of the organic active layer. This is one of the highest efficiency values reported thus far for the single active layer organic photovoltaics.

  5. Low-frequency switching voltage regulators for terrestrial photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Delombard, R.

    1984-01-01

    The photovoltaic technology project and the stand alone applications project are discussed. Two types of low frequency switching type regulators were investigated. The design, operating characteristics and field application of these regulators is described. The regulators are small in size, low in cost, very low in power dissipation, reliable and allow considerable flexibility in system design.

  6. You're a What? Solar Photovoltaic Installer

    ERIC Educational Resources Information Center

    Torpey, Elka Maria

    2009-01-01

    This article talks about solar photovoltaic (PV) installer and features Rebekah Hren, a solar PV installer who puts solar panels on roofs and in other sunny places to turn the sun's power into electricity. Hren enjoys promoting renewable energy, in part because it's an emerging field. In solar PV systems, solar cells--devices that convert sunlight…

  7. 16th Space Photovoltaic Research and Technology Conference. Revised

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila (Editor)

    2005-01-01

    The purpose of the SPRAT conference is to bring members of the space solar cell community together in a relatively informal conference setting to discuss the recent developments in solar cell technology and to discuss the future directions of the field. The conference is sponsored by the Photovoltaic and Space Environmental Effects Branch at the NASA Glenn Research Center.

  8. Photovoltaic Degradation Rates -- An Analytical Review

    SciTech Connect

    Jordan, D. C.; Kurtz, S. R.

    2012-06-01

    As photovoltaic penetration of the power grid increases, accurate predictions of return on investment require accurate prediction of decreased power output over time. Degradation rates must be known in order to predict power delivery. This article reviews degradation rates of flat-plate terrestrial modules and systems reported in published literature from field testing throughout the last 40 years. Nearly 2000 degradation rates, measured on individual modules or entire systems, have been assembled from the literature, showing a median value of 0.5%/year. The review consists of three parts: a brief historical outline, an analytical summary of degradation rates, and a detailed bibliography partitioned by technology.

  9. Photovoltaic applications of Compound Parabolic Concentrator (CPC)

    NASA Technical Reports Server (NTRS)

    Winston, R.

    1975-01-01

    The use of a compound parabolic concentrator as field collector, in conjunction with a primary focusing concentrator for photovoltaic applications is studied. The primary focusing concentrator can be a parabolic reflector, an array of Fresnel mirrors, a Fresnel lens or some other lens. Silicon solar cell grid structures are proposed that increase efficiency with concentration up to 10 suns. A ray tracing program has been developed to determine energy distribution at the exit of a compound parabolic concentrator. Projected total cost of a CPC/solar cell system will be between 4 and 5 times lower than for flat plate silicon cell arrays.

  10. High-efficiency organic solar concentrators for photovoltaics.

    PubMed

    Currie, Michael J; Mapel, Jonathan K; Heidel, Timothy D; Goffri, Shalom; Baldo, Marc A

    2008-07-11

    The cost of photovoltaic power can be reduced with organic solar concentrators. These are planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges. Light is absorbed by the coating and reemitted into waveguide modes for collection by the solar cells. We report single- and tandem-waveguide organic solar concentrators with quantum efficiencies exceeding 50% and projected power conversion efficiencies as high as 6.8%. The exploitation of near-field energy transfer, solid-state solvation, and phosphorescence enables 10-fold increases in the power obtained from photovoltaic cells, without the need for solar tracking.

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

    SciTech Connect

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

    2011-04-01

    Presented at the 7th International Conference on Concentrating Photovoltaic Systems (CPV-7), 4-6 April 2011, Las Vegas, Nevada. Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple an optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interfaces(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.

  12. Photovoltaic solar cell

    DOEpatents

    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.

  13. Photovoltaic solar concentrator

    DOEpatents

    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.

  14. Photovoltaic solar concentrator

    DOEpatents

    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.

  15. Photovoltaics Fact Sheet

    SciTech Connect

    2016-02-01

    This fact sheet is an overview of the Photovoltaics (PV) subprogram at the U.S. Department of Energy SunShot Initiative. The U.S. Department of Energy (DOE)’s Solar Energy Technologies Office works with industry, academia, national laboratories, and other government agencies to advance solar PV, which is the direct conversion of sunlight into electricity by a semiconductor, in support of the goals of the SunShot Initiative. SunShot supports research and development to aggressively advance PV technology by improving efficiency and reliability and lowering manufacturing costs. SunShot’s PV portfolio spans work from early-stage solar cell research through technology commercialization, including work on materials, processes, and device structure and characterization techniques.

  16. NASA photovoltaic technology program

    SciTech Connect

    Mullin, J.P.; Loria, J.C.; Brandhorst, H.W. Jr.

    1984-01-01

    The NASA Office of Aeronautical and Space Technology OAST Program in space photovoltaics is reviewed. From the perspective of national landmark mission requirements and five year and 25-year long range plans, the texture of the program is revealed. Planar silicon and concentrator GaAs array technology advances are discussed. Advances in lightweight (50 micro cell) arrays and radiation tolerance research are presented. Recent progress in cascade cells and ultralightweight GaAs planar cells is noted. Progress in raising silicon cell voltage to its theoretical maximum is detailed. Advanced concepts such as plasmon converters and the Long Duration Exposure Facility LDEF flight experiments pertaining to solar cell and array technology are also shown.

  17. Recent advances in photovoltaics

    SciTech Connect

    Carlson, D.E.

    1995-12-31

    Photovoltaic energy conversion has been widely used for over three decades in the space program to power satellites and in the last two decades has also found widespread use in remote applications such as powering microwave communication repeaters, providing cathodic protection for wells and pipelines, pumping water in remote locations, etc. With continued improvements in performance and ongoing reductions in manufacturing costs, PV systems are expected to become cost effective for grid-connected applications in the next few years. While crystalline silicon technology accounts for the majority of the present PV business, new thin film PV technologies such as multifunction amorphous silicon, copper-indium-diselenide and cadmium telluride have progressed to a point where several companies are building multi-megawatt production facilities. High efficiency concentrator arrays may also prove to be cost effective for grid-connected applications in regions of the world with significant direct sunlight.

  18. On photovoltaic electrolysis

    SciTech Connect

    Murphy, O.J.; Bockris, J.O.M.

    1983-12-01

    Photoelectrochemical conversion of light to stored energy in a convenient medium--hydrogen--has been researched extensively. There are no cases where, without the use of external power sources, efficiencies of energy conversion of better than 1-2% have been achieved. For this reason, the present research concerns itself with photovoltaic couples and the use of the resultant electrical power to electrolyze water. The novelty is in the arrangement. An arrangement, consisting of the two GaAs couples, separated by aqueous solution, was irradiated, using solar-simulated light. Hydrogen, oxygen and electricity were produced. The current was varied by using the cell as a light-driven fuel cell passing electric current through an external load which could be varied. The maximum efficiency of conversion of solar light to H2 occurred with the external load at zero ohms.

  19. Chalcogenide perovskites for photovoltaics.

    PubMed

    Sun, Yi-Yang; Agiorgousis, Michael L; Zhang, Peihong; Zhang, Shengbai

    2015-01-14

    Chalcogenide perovskites are proposed for photovoltaic applications. The predicted band gaps of CaTiS3, BaZrS3, CaZrSe3, and CaHfSe3 with the distorted perovskite structure are within the optimal range for making single-junction solar cells. The predicted optical absorption properties of these materials are superior compared with other high-efficiency solar-cell materials. Possible replacement of the alkaline-earth cations by molecular cations, e.g., (NH3NH3)(2+), as in the organic-inorganic halide perovskites (e.g., CH3NH3PbI3), are also proposed and found to be stable. The chalcogenide perovskites provide promising candidates for addressing the challenging issues regarding halide perovskites such as instability in the presence of moisture and containing the toxic element Pb.

  20. Photovoltaic spectral responsivity measurements

    SciTech Connect

    Emery, K.; Dunlavy, D.; Field, H.; Moriarty, T.

    1998-09-01

    This paper discusses the various elemental random and nonrandom error sources in typical spectral responsivity measurement systems. The authors focus specifically on the filter and grating monochrometer-based spectral responsivity measurement systems used by the Photovoltaic (PV) performance characterization team at NREL. A variety of subtle measurement errors can occur that arise from a finite photo-current response time, bandwidth of the monochromatic light, waveform of the monochromatic light, and spatial uniformity of the monochromatic and bias lights; the errors depend on the light source, PV technology, and measurement system. The quantum efficiency can be a function of he voltage bias, light bias level, and, for some structures, the spectral content of the bias light or location on the PV device. This paper compares the advantages and problems associated with semiconductor-detector-based calibrations and pyroelectric-detector-based calibrations. Different current-to-voltage conversion and ac photo-current detection strategies employed at NREL are compared and contrasted.

  1. Photovoltaic module mounting system

    DOEpatents

    Miros, Robert H. J. [Fairfax, CA; Mittan, Margaret Birmingham [Oakland, CA; Seery, Martin N [San Rafael, CA; Holland, Rodney H [Novato, CA

    2012-04-17

    A solar array mounting system having unique installation, load distribution, and grounding features, and which is adaptable for mounting solar panels having no external frame. The solar array mounting system includes flexible, pedestal-style feet and structural links connected in a grid formation on the mounting surface. The photovoltaic modules are secured in place via the use of attachment clamps that grip the edge of the typically glass substrate. The panel mounting clamps are then held in place by tilt brackets and/or mid-link brackets that provide fixation for the clamps and align the solar panels at a tilt to the horizontal mounting surface. The tilt brackets are held in place atop the flexible feet and connected link members thus creating a complete mounting structure.

  2. Photovoltaic module mounting system

    DOEpatents

    Miros, Robert H. J.; Mittan, Margaret Birmingham; Seery, Martin N; Holland, Rodney H

    2012-09-18

    A solar array mounting system having unique installation, load distribution, and grounding features, and which is adaptable for mounting solar panels having no external frame. The solar array mounting system includes flexible, pedestal-style feet and structural links connected in a grid formation on the mounting surface. The photovoltaic modules are secured in place via the use of attachment clamps that grip the edge of the typically glass substrate. The panel mounting clamps are then held in place by tilt brackets and/or mid-link brackets that provide fixation for the clamps and align the solar panels at a tilt to the horizontal mounting surface. The tilt brackets are held in place atop the flexible feet and connected link members thus creating a complete mounting structure.

  3. Photovoltaic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, James; Mathieson, Keith; Kamins, Ted; Wang, Lele; Galambos, Ludwig; Huie, Philip; Sher, Alexander; Harris, James; Palanker, Daniel

    2011-03-01

    Electronic retinal prostheses seek to restore sight to patients suffering from retinal degenerative disorders. Implanted electrode arrays apply patterned electrical stimulation to surviving retinal neurons, producing visual sensations. All current designs employ inductively coupled coils to transmit power and/or data to the implant. We present here the design and initial testing of a photovoltaic retinal prosthesis fabricated with a pixel density of up to 177 pixels/mm2. Photodiodes within each pixel of the subretinal array directly convert light to stimulation current, avoiding the use of bulky coil implants, decoding electronics, and wiring, and thereby reducing surgical complexity. A goggles-mounted camera captures the visual scene and transmits the data stream to a pocket processor. The resulting images are projected into the eyes by video goggles using pulsed, near infrared (~900 nm) light. Prostheses with three pixel densities (15, 55, and 177 pix/mm2) are being fabricated, and tests indicate a charge injection limit of 1.62 mC/cm2 at 25Hz. In vitro tests of the photovoltaic retinal stimulation using a 512-element microelectrode array have recorded stimulated spikes from the ganglion cells, with latencies in the 1-100ms range, and with peak irradiance stimulation thresholds varying from 0.1 to 1 mW/mm2. With 1ms pulses at 25Hz the average irradiance is more than 100 times below the IR retinal safety limit. Elicited retinal response disappeared upon the addition of synaptic blockers, indicating that the inner retina is stimulated rather than the ganglion cells directly, and raising hopes that the prosthesis will preserve some of the retina's natural signal processing.

  4. Intermediate photovoltaic system/utility interface experience

    NASA Astrophysics Data System (ADS)

    Biringer, K. L.; McDowell, J. F.; Rogers, C. B.; Haskins, D. E.

    A description is given of 11 intermediate photovoltaic application projects, including the Arizona Public Service Company project, the E-Systems 27 kW photovoltaic concentrator application experiment, a 110 kW photovoltaic application experiment in Orlando, Florida, the Lea County photovoltaic flat plate photovoltaic experiment in southeastern New Mexico, the Mt. Laguna photovoltaic flat plate installation in California, the San Bernardino 35 kW photovoltaic flat plate project in California, and the Solar Power flat plate photovoltaic experiment in Massachusetts. It is pointed out that the most significant point to be made relative to the interface of photovoltaic systems with the utility grid is that it can be done successfully.

  5. Microscopic Perspective on Photovoltaic Reciprocity in Ultrathin Solar Cells

    NASA Astrophysics Data System (ADS)

    Aeberhard, Urs; Rau, Uwe

    2017-06-01

    The photovoltaic reciprocity theory relates the electroluminescence spectrum of a solar cell under applied bias to the external photovoltaic quantum efficiency of the device as measured at short circuit conditions. Its derivation is based on detailed balance relations between local absorption and emission rates in optically isotropic media with nondegenerate quasiequilibrium carrier distributions. In many cases, the dependence of density and spatial variation of electronic and optical device states on the point of operation is modest and the reciprocity relation holds. In nanostructure-based photovoltaic devices exploiting confined modes, however, the underlying assumptions are no longer justifiable. In the case of ultrathin absorber solar cells, the modification of the electronic structure with applied bias is significant due to the large variation of the built-in field. Straightforward use of the external quantum efficiency as measured at short circuit conditions in the photovoltaic reciprocity theory thus fails to reproduce the electroluminescence spectrum at large forward bias voltage. This failure is demonstrated here by numerical simulation of both spectral quantities at normal incidence and emission for an ultrathin GaAs p -i -n solar cell using an advanced quantum kinetic formalism based on nonequilibrium Green's functions of coupled photons and charge carriers. While coinciding with the semiclassical relations under the conditions of their validity, the theory provides a consistent microscopic relationship between absorption, emission, and charge carrier transport in photovoltaic devices at arbitrary operating conditions and for any shape of optical and electronic density of states.

  6. Trapping and patterning of biological objects using photovoltaic tweezers

    NASA Astrophysics Data System (ADS)

    Jubera, M.; Elvira, I.; García-Cabañes, A.; Bella, J. L.; Carrascosa, M.

    2016-01-01

    Photovoltaic tweezers are a recently proposed technique for manipulation and patterning of micro- and nano-objects. It is based in the dielectrophoretic forces associated to the electric fields induced by illumination of certain ferroelectrics due to the bulk photovoltaic effect. The technique has been applied to the patterning of dielectric and metal micro- and nano-particles. In this work, we report the use of photovoltaic tweezers to pattern biological objects on LiNbO3:Fe. Specifically, spores and pollen grains and their nanometric fragments have been trapped and patterned. 1D and 2D arrangements have been achieved by deposition in air or from a hexane suspension. The quality of patterns obtained with nanometric fragments is even better than previous results using photovoltaic tweezers with inorganic micro- and nano-particles. In fact, 1D patterns with a period of 2 μm, almost half of the minimum reported period achieved with photovoltaic tweezers, have been obtained with pollen fragments.

  7. Microscopic Perspective on Photovoltaic Reciprocity in Ultrathin Solar Cells.

    PubMed

    Aeberhard, Urs; Rau, Uwe

    2017-06-16

    The photovoltaic reciprocity theory relates the electroluminescence spectrum of a solar cell under applied bias to the external photovoltaic quantum efficiency of the device as measured at short circuit conditions. Its derivation is based on detailed balance relations between local absorption and emission rates in optically isotropic media with nondegenerate quasiequilibrium carrier distributions. In many cases, the dependence of density and spatial variation of electronic and optical device states on the point of operation is modest and the reciprocity relation holds. In nanostructure-based photovoltaic devices exploiting confined modes, however, the underlying assumptions are no longer justifiable. In the case of ultrathin absorber solar cells, the modification of the electronic structure with applied bias is significant due to the large variation of the built-in field. Straightforward use of the external quantum efficiency as measured at short circuit conditions in the photovoltaic reciprocity theory thus fails to reproduce the electroluminescence spectrum at large forward bias voltage. This failure is demonstrated here by numerical simulation of both spectral quantities at normal incidence and emission for an ultrathin GaAs p-i-n solar cell using an advanced quantum kinetic formalism based on nonequilibrium Green's functions of coupled photons and charge carriers. While coinciding with the semiclassical relations under the conditions of their validity, the theory provides a consistent microscopic relationship between absorption, emission, and charge carrier transport in photovoltaic devices at arbitrary operating conditions and for any shape of optical and electronic density of states.

  8. Advancing colloidal quantum dot photovoltaic technology

    NASA Astrophysics Data System (ADS)

    Cheng, Yan; Arinze, Ebuka S.; Palmquist, Nathan; Thon, Susanna M.

    2016-06-01

    Colloidal quantum dots (CQDs) are attractive materials for solar cells due to their low cost, ease of fabrication and spectral tunability. Progress in CQD photovoltaic technology over the past decade has resulted in power conversion efficiencies approaching 10%. In this review, we give an overview of this progress, and discuss limiting mechanisms and paths for future improvement in CQD solar cell technology.We briefly summarize nanoparticle synthesis and film processing methods and evaluate the optoelectronic properties of CQD films, including the crucial role that surface ligands play in materials performance. We give an overview of device architecture engineering in CQD solar cells. The compromise between carrier extraction and photon absorption in CQD photovoltaics is analyzed along with different strategies for overcoming this trade-off. We then focus on recent advances in absorption enhancement through innovative device design and the use of nanophotonics. Several light-trapping schemes, which have resulted in large increases in cell photocurrent, are described in detail. In particular, integrating plasmonic elements into CQD devices has emerged as a promising approach to enhance photon absorption through both near-field coupling and far-field scattering effects. We also discuss strategies for overcoming the single junction efficiency limits in CQD solar cells, including tandem architectures, multiple exciton generation and hybrid materials schemes. Finally, we offer a perspective on future directions for the field and the most promising paths for achieving higher device efficiencies.

  9. Solid State Photovoltaic Research Branch

    SciTech Connect

    Not Available

    1990-09-01

    This report summarizes the progress of the Solid State Photovoltaic Research Branch of the Solar Energy Research Institute (SERI) from October 1, 1988, through September 30,l 1989. Six technical sections of the report cover these main areas of SERIs in-house research: Semiconductor Crystal Growth, Amorphous Silicon Research, Polycrystalline Thin Films, III-V High-Efficiency Photovoltaic Cells, Solid-State Theory, and Laser Raman and Luminescence Spectroscopy. Sections have been indexed separately for inclusion on the data base.

  10. Photovoltaic sub-cell interconnects

    DOEpatents

    van Hest, Marinus Franciscus Antonius Maria; Swinger Platt, Heather Anne

    2017-05-09

    Photovoltaic sub-cell interconnect systems and methods are provided. In one embodiment, a photovoltaic device comprises a thin film stack of layers deposited upon a substrate, wherein the thin film stack layers are subdivided into a plurality of sub-cells interconnected in series by a plurality of electrical interconnection structures; and wherein the plurality of electrical interconnection structures each comprise no more than two scribes that penetrate into the thin film stack layers.

  11. Photovoltaic research and development status

    NASA Technical Reports Server (NTRS)

    Feucht, D. L.

    1978-01-01

    The goals of the Photovoltaic R&D Program are to develop thin film semiconductor and novel photovoltaic conversion concepts, and to demonstrate the feasibility of producing these cells for a price of $100 - $300 per peak electric output (in 1975) by FY1985. The approaches that are used to determine which research should be funded are formal solicitations, an innovative concepts program which will be launched in FY79, and the review of unsolicited proposals.

  12. Natural Flow Air Cooled Photovoltaics

    NASA Astrophysics Data System (ADS)

    Tanagnostopoulos, Y.; Themelis, P.

    2010-01-01

    Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

  13. Photovoltaic energy program in the State of Minas Gerais, Brazil

    SciTech Connect

    Diniz, A.S.A.C.; Prado, A.E.; Mendonca, M.S.C.C.; Almeida, F.Q.; Alvarenga, C.A.

    1997-12-31

    This paper describes the work done over the last years in the field of photovoltaic technology in the State of Minas Gerais, from its R and D to the Rural Electrification Program. The analysis of the global solar radiation data (over 5 kWh/m{sup 2}/day) has shown that photovoltaic systems can perform well all over the State, mainly in the north and Northeast regions of the state. The potential for the utilization of PV systems in Minas Gerais is large, mainly when considering the high number of consumers in rural remote areas that are not and cannot be supplied from CEMIG`s grid in the immediate future or in the long term. As a consequence of the demonstration projects, which have shown that photovoltaics can perform well and be cost effective in rural areas, a Rural Electrification Program was launched. To support it a training program has been set up.

  14. Recent Advances in Wide-Bandgap Photovoltaic Polymers.

    PubMed

    Cai, Yunhao; Huo, Lijun; Sun, Yanming

    2017-03-29

    The past decade has witnessed significant advances in the field of organic solar cells (OSCs). Ongoing improvements in the power conversion efficiency of OSCs have been achieved, which were mainly attributed to the design and synthesis of novel conjugated polymers with different architectures and functional moieties. Among various conjugated polymers, the development of wide-bandgap (WBG) polymers has received less attention than that of low-bandgap and medium-bandgap polymers. Here, we briefly summarize recent advances in WBG polymers and their applications in organic photovoltaic (PV) devices, such as tandem, ternary, and non-fullerene solar cells. Addtionally, we also dissuss the application of high open-circuit voltage tandem solar cells in PV-driven electrochemical water dissociation. We mainly focus on the molecular design strategies, the structure-property correlations, and the photovoltaic performance of these WBG polymers. Finally, we extract empirical regularities and provide invigorating perspectives on the future development of WBG photovoltaic materials.

  15. Photovoltaic/diesel hybrid systems: The design process

    NASA Astrophysics Data System (ADS)

    Jones, G. J.; Chapman, R. N.

    A photovoltaic/storage system by itself may be uneconomical for stand-alone applications with large energy demands. However, by combining the PV system with a back-up energy source, such as a diesel, gasoline, or propane/thermoelectric generator, system economics can be improved. Such PV/fossil hybrid systems are being used, but their design has required detailed modeling to determine the optimal mix of photovoltaics and back-up energy. Recent data on diesel field reliability and a new design technique for stand-alone systems have overcome this problem. The approach provides the means for sizing the photovoltaic system to obtain a near optimal hybrid system, with about a 90% savings in back-up fuel costs. System economics are determined by comparing PV capital cost to the present value of the displaced diesel operation and maintenance costs.

  16. Liquid Crystals for Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    O'Neill, Mary; Kelly, Stephen M.

    As discussed in Chaps. 2 (10.1007/978-90-481-2873-0_2), 3 (10.1007/978-90-481-2873-3), 5 (10.1007/978-90-481-2873-5) and 6 (10.1007/978-90-481-2873-6), columnar, smectic and, more recently, nematic liquid crystals are widely recognized as very promising charge-transporting organic semiconductors due to their ability to spontaneously self-assemble into highly ordered domains in uniform thin films over large areas. This and their broad absorption spectra make them suitable as active materials for organic photovoltaic devices. In this chapter, we discuss the use of liquid crystals in such devices. Firstly, we examine the principle of power generation via the photovoltaic effect in organic materials and the various device configurations that can optimise efficiency. Then we discuss photovoltaic devices incorporating columnar liquid crystals combined with electron accepting materials based on either perylene or fullerene. The use of nematic and sanditic liquid crystals in photovoltaics is investigated as well as a novel solar cell concentrator incorporating liquid crystals. Finally, we analyse the benefits and limitations of liquid-crystal-based photovoltaics in the context of the state-of-the-art for organics photovoltaics.

  17. Plasmonic nanostructures for electronic designs of photovoltaic devices: plasmonic hot-carrier photovoltaic architectures and plasmonic electrode structures

    NASA Astrophysics Data System (ADS)

    Zhang, Tong; Su, Dan; Li, Ruo-Zhou; Wang, Shan-Jiang; Shan, Feng; Xu, Jia-Jia; Zhang, Xiao-Yang

    2016-10-01

    The tunable and amazing properties of plasmonic nanostructures have received significant attentions in the fields of solar energy conversion. Plasmonic nanostructures provide pathways to directly convert solar energy into electric energy by hot-carrier generation. They can also serve as economical electrodes for high-efficient carrier collection. Both have promising potential for manufacturing new generation solar cells. Here, we review recent advances in plasmonic nanostructures for electronic designs of photovoltaic devices and specially focus on plasmonic hot-carrier photovoltaic architectures and plasmonic electrode structures. Technical challenges toward low-cost and high-performance plasmonics-based solar cells are also discussed.

  18. Photovoltaic array mounting apparatus, systems, and methods

    DOEpatents

    West, Jack Raymond; Atchley, Brian; Hudson, Tyrus Hawkes; Johansen, Emil

    2016-01-05

    A photovoltaic array, including: (a) supports laid out on a surface in rows and columns; (b) photovoltaic modules positioned on top of the supports; and (c) fasteners connecting the photovoltaic modules to the supports, wherein the supports have an upper pedestal surface and a lower pedestal surface such that the photovoltaic modules are positioned at a non-horizontal angle when edges of the photovoltaic modules are positioned on top of the upper and lower pedestal surfaces, and wherein a portion of the fasteners rotate to lock the photovoltaic modules onto the supports.

  19. Photovoltaic array mounting apparatus, systems, and methods

    DOEpatents

    West, Jack Raymond; Atchley, Brian; Hudson, Tyrus Hawkes; Johansen, Emil

    2015-04-14

    A photovoltaic array, including: (a) supports laid out on a surface in rows and columns; (b) photovoltaic modules positioned on top of the supports; and (c) fasteners connecting the photovoltaic modules to the supports, wherein the supports have an upper pedestal surface and a lower pedestal surface such that the photovoltaic modules are positioned at a non-horizontal angle when edges of the photovoltaic modules are positioned on top of the upper and lower pedestal surfaces, and wherein a portion of the fasteners rotate to lock the photovoltaic modules onto the supports.

  20. Giant switchable photovoltaic effect in organometal trihalide perovskite devices

    DOE PAGES

    Xiao, Zhengguo; Yuan, Yongbo; Shao, Yuchuan; ...

    2014-12-08

    Organolead trihalide perovskite (OTP) materials are emerging as naturally abundant materials for low-cost, solution-processed and highly efficient solar cells. Here, we show that, in OTP-based photovoltaic devices with vertical and lateral cell configurations, the photocurrent direction can be switched repeatedly by applying a small electric field of <1 V μm–1. The switchable photocurrent, generally observed in devices based on ferroelectric materials, reached 20.1 mA cm–2 under one sun illumination in OTP devices with a vertical architecture, which is four orders of magnitude larger than that measured in other ferroelectric photovoltaic devices. This field-switchable photovoltaic effect can be explained by themore » formation of reversible p–i–n structures induced by ion drift in the perovskite layer. Furthermore, the demonstration of switchable OTP photovoltaics and electric-field-manipulated doping paves the way for innovative solar cell designs and for the exploitation of OTP materials in electrically and optically readable memristors and circuits.« less

  1. Giant switchable photovoltaic effect in organometal trihalide perovskite devices

    NASA Astrophysics Data System (ADS)

    Xiao, Zhengguo; Yuan, Yongbo; Shao, Yuchuan; Wang, Qi; Dong, Qingfeng; Bi, Cheng; Sharma, Pankaj; Gruverman, Alexei; Huang, Jinsong

    2015-02-01

    Organolead trihalide perovskite (OTP) materials are emerging as naturally abundant materials for low-cost, solution-processed and highly efficient solar cells. Here, we show that, in OTP-based photovoltaic devices with vertical and lateral cell configurations, the photocurrent direction can be switched repeatedly by applying a small electric field of <1 V μm-1. The switchable photocurrent, generally observed in devices based on ferroelectric materials, reached 20.1 mA cm-2 under one sun illumination in OTP devices with a vertical architecture, which is four orders of magnitude larger than that measured in other ferroelectric photovoltaic devices. This field-switchable photovoltaic effect can be explained by the formation of reversible p-i-n structures induced by ion drift in the perovskite layer. The demonstration of switchable OTP photovoltaics and electric-field-manipulated doping paves the way for innovative solar cell designs and for the exploitation of OTP materials in electrically and optically readable memristors and circuits.

  2. Giant switchable photovoltaic effect in organometal trihalide perovskite devices

    SciTech Connect

    Xiao, Zhengguo; Yuan, Yongbo; Shao, Yuchuan; Wang, Qi; Dong, Qingfeng; Bi, Cheng; Sharma, Pankaj; Gruverman, Alexei; Huang, Jinsong

    2014-12-08

    Organolead trihalide perovskite (OTP) materials are emerging as naturally abundant materials for low-cost, solution-processed and highly efficient solar cells. Here, we show that, in OTP-based photovoltaic devices with vertical and lateral cell configurations, the photocurrent direction can be switched repeatedly by applying a small electric field of <1 V μm–1. The switchable photocurrent, generally observed in devices based on ferroelectric materials, reached 20.1 mA cm–2 under one sun illumination in OTP devices with a vertical architecture, which is four orders of magnitude larger than that measured in other ferroelectric photovoltaic devices. This field-switchable photovoltaic effect can be explained by the formation of reversible p–i–n structures induced by ion drift in the perovskite layer. Furthermore, the demonstration of switchable OTP photovoltaics and electric-field-manipulated doping paves the way for innovative solar cell designs and for the exploitation of OTP materials in electrically and optically readable memristors and circuits.

  3. Giant switchable photovoltaic effect in organometal trihalide perovskite devices.

    PubMed

    Xiao, Zhengguo; Yuan, Yongbo; Shao, Yuchuan; Wang, Qi; Dong, Qingfeng; Bi, Cheng; Sharma, Pankaj; Gruverman, Alexei; Huang, Jinsong

    2015-02-01

    Organolead trihalide perovskite (OTP) materials are emerging as naturally abundant materials for low-cost, solution-processed and highly efficient solar cells. Here, we show that, in OTP-based photovoltaic devices with vertical and lateral cell configurations, the photocurrent direction can be switched repeatedly by applying a small electric field of <1 V μm(-1). The switchable photocurrent, generally observed in devices based on ferroelectric materials, reached 20.1 mA cm(-2) under one sun illumination in OTP devices with a vertical architecture, which is four orders of magnitude larger than that measured in other ferroelectric photovoltaic devices. This field-switchable photovoltaic effect can be explained by the formation of reversible p-i-n structures induced by ion drift in the perovskite layer. The demonstration of switchable OTP photovoltaics and electric-field-manipulated doping paves the way for innovative solar cell designs and for the exploitation of OTP materials in electrically and optically readable memristors and circuits.

  4. Domestic violence in America.

    PubMed

    Bash, K L; Jones, F

    1994-09-01

    Domestic violence is an underrecognized problem of immense cost. It is a crime; its victims must be identified and protected. The medical and judicial communities share responsibility in addressing this issue and providing support for victims. The role of health care workers in recognizing and preventing domestic violence cannot be overestimated. Direct questioning of patients, especially about the source of any injuries and about safety at home, is the first step in uncovering abuse. Educational programs for health care providers and the general public can change society's view and tolerance of this problem. Physicians must take an active role in changing community attitudes about domestic violence and in instituting programs to reduce its incidence. Medical treatment of the injuries resulting from domestic violence is not sufficient. Abused women need the care of a team of professionals who can address psychological, emotional, and physical injuries. They must also be provided with safe housing and financial and legal assistance in order to escape the abusive relationship. Physicians and legislators must work together to effect change. Domestic violence is a public health menace. We need to break the cycle of abuse that has become an integral part of our society.

  5. Solid domestic wastes as a renewable resource: European experience

    NASA Astrophysics Data System (ADS)

    Fridland, V. S.; Livshits, I. M.

    2011-01-01

    Ways in which different types of solid domestic wastes, such as wastepaper, crushed glass, plastics and worn-out tires, can be efficiently included into the production, raw-material, and energy balances of the national economy are shown taking Germany and other European countries an example. Methods for recycling these solid domestic wastes and application fields of the obtained products are discussed.

  6. Surrogate Final Technical Report for "Solar: A Photovoltaic Manufacturing Development Facility"

    SciTech Connect

    Farrar, Paul

    2014-06-27

    The project goal to create a first-of-a-kind crystalline Silicon (c-Si) photovoltaic (PV) Manufacturing & Technology Development Facility (MDF) that will support the growth and maturation of a strong domestic PV manufacturing industry, based on innovative and differentiated technology, by ensuring industry participants can, in a timely and cost-effective manner, access cutting-edge manufacturing equipment and production expertise needed to accelerate the transition of innovative technologies from R&D into manufacturing.

  7. Inkjet technology for crystalline silicon photovoltaics.

    PubMed

    Stüwe, David; Mager, Dario; Biro, Daniel; Korvink, Jan G

    2015-01-27

    The world's ever increasing demand for energy necessitates technologies that generate electricity from inexhaustible and easily accessible energy sources. Silicon photovoltaics is a technology that can harvest the energy of sunlight. Its great characteristics have fueled research and development activities in this exciting field for many years now. One of the most important activities in the solar cell community is the investigation of alternative fabrication and structuring technologies, ideally serving both of the two main goals: device optimization and reduction of fabrication costs. Inkjet technology is practically evaluated along the whole process chain. Research activities cover many processes, such as surface texturing, emitter formation, or metallization. Furthermore, the inkjet technology itself is manifold as well. It can be used to apply inks that serve as a functional structure, present in the final device, as mask for subsequent structuring steps, or even serve as a reactant source to activate chemical etch reactions. This article reviews investigations of inkjet-printing in the field of silicon photovoltaics. The focus is on the different inkjet processes for individual fabrication steps of a solar cell. A technological overview and suggestions about where future work will be focused on are also provided. The great variety of the investigated processes highlights the ability of the inkjet technology to find its way into many other areas of functional printing and printed electronics.

  8. Acetylene-Based Materials in Organic Photovoltaics

    PubMed Central

    Silvestri, Fabio; Marrocchi, Assunta

    2010-01-01

    Fossil fuel alternatives, such as solar energy, are moving to the forefront in a variety of research fields. Organic photovoltaic systems hold the promise of a lightweight, flexible, cost-effective solar energy conversion platform, which could benefit from simple solution-processing of the active layer. The discovery of semiconductive polyacetylene by Heeger et al. in the late 1970s was a milestone towards the use of organic materials in electronics; the development of efficient protocols for the palladium catalyzed alkynylation reactions and the new conception of steric and conformational advantages of acetylenes have been recently focused the attention on conjugated triple-bond containing systems as a promising class of semiconductors for OPVs applications. We review here the most important and representative (poly)arylacetylenes that have been used in the field. A general introduction to (poly)arylacetylenes, and the most common synthetic approaches directed toward making these materials will be firstly given. After a brief discussion on working principles and critical parameters of OPVs, we will focus on molecular arylacetylenes, (co)polymers containing triple bonds, and metallopolyyne polymers as p-type semiconductor materials. The last section will deal with hybrids in which oligomeric/polymeric structures incorporating acetylenic linkages such as phenylene ethynylenes have been attached onto C60, and their use as the active materials in photovoltaic devices. PMID:20480031

  9. Acetylene-based materials in organic photovoltaics.

    PubMed

    Silvestri, Fabio; Marrocchi, Assunta

    2010-04-08

    Fossil fuel alternatives, such as solar energy, are moving to the forefront in a variety of research fields. Organic photovoltaic systems hold the promise of a lightweight, flexible, cost-effective solar energy conversion platform, which could benefit from simple solution-processing of the active layer. The discovery of semiconductive polyacetylene by Heeger et al. in the late 1970s was a milestone towards the use of organic materials in electronics; the development of efficient protocols for the palladium catalyzed alkynylation reactions and the new conception of steric and conformational advantages of acetylenes have been recently focused the attention on conjugated triple-bond containing systems as a promising class of semiconductors for OPVs applications. We review here the most important and representative (poly)arylacetylenes that have been used in the field. A general introduction to (poly)arylacetylenes, and the most common synthetic approaches directed toward making these materials will be firstly given. After a brief discussion on working principles and critical parameters of OPVs, we will focus on molecular arylacetylenes, (co)polymers containing triple bonds, and metallopolyyne polymers as p-type semiconductor materials. The last section will deal with hybrids in which oligomeric/polymeric structures incorporating acetylenic linkages such as phenylene ethynylenes have been attached onto C(60), and their use as the active materials in photovoltaic devices.

  10. Photovoltaic Reliability and Engineering (Revised) (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Photovoltaic Reliability and Engineering. One-sided sheet that includes Scope, Core Competencies and Capabilities, and Contact/Web information.

  11. ULTRA BARRIER TOPSHEET (UBT) FOR FLEXIBLE PHOTOVOLTAICS

    SciTech Connect

    DeScioli, Derek

    2013-06-01

    This slide-show presents 3M photovoltaic-related products, particularly flexible components. Emphasis is on the 3M Ultra Barrier Solar Films. Topics covered include reliability and qualification testing and flexible photovoltaic encapsulation costs.

  12. Thin film photovoltaic panel and method

    DOEpatents

    Ackerman, Bruce; Albright, Scot P.; Jordan, John F.

    1991-06-11

    A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

  13. Transparent contacts for stacked compound photovoltaic cells

    DOEpatents

    Tauke-Pedretti, Anna; Cederberg, Jeffrey; Nielson, Gregory N.; Okandan, Murat; Cruz-Campa, Jose Luis

    2016-11-29

    A microsystems-enabled multi-junction photovoltaic (MEM-PV) cell includes a first photovoltaic cell having a first junction, the first photovoltaic cell including a first semiconductor material employed to form the first junction, the first semiconductor material having a first bandgap. The MEM-PV cell also includes a second photovoltaic cell comprising a second junction. The second photovoltaic cell comprises a second semiconductor material employed to form the second junction, the second semiconductor material having a second bandgap that is less than the first bandgap, the second photovoltaic cell further comprising a first contact layer disposed between the first junction of the first photovoltaic cell and the second junction of the second photovoltaic cell, the first contact layer composed of a third semiconductor material having a third bandgap, the third bandgap being greater than or equal to the first bandgap.

  14. Mounting support for a photovoltaic module

    DOEpatents

    Brandt, Gregory Michael; Barsun, Stephan K.; Coleman, Nathaniel T.; Zhou, Yin

    2013-03-26

    A mounting support for a photovoltaic module is described. The mounting support includes a foundation having an integrated wire-way ledge portion. A photovoltaic module support mechanism is coupled with the foundation.

  15. Photovoltaic technology development at Sandia National Laboratories

    SciTech Connect

    1981-12-31

    This report describes the following investigations being pursued under photovoltaic technology development at Sandia National Laboratories: photovoltaic systems technology; concentrator technology; concentrator arrays and tracking structures; concentrator solar cell development; system engineering; subsystem development; and test and applications.

  16. Testing flat plate photovoltaic modules for terrestrial environment

    NASA Technical Reports Server (NTRS)

    Hoffman, A. R.; Arnett, J. C.; Ross, R. G., Jr.

    1979-01-01

    New qualification tests have been developed for flat plate photovoltaic modules. Temperature cycling, cyclic pressure load, and humidity exposure are especially useful for detecting design and fabrication deficiencies. There is positive correlation between many of the observed field effects, such as power loss, and qualification test induced degradation. The status of research efforts for the development of test methodology for field-related problems is reviewed.

  17. Nanowire Photovoltaic Devices

    NASA Technical Reports Server (NTRS)

    Forbes, David

    2015-01-01

    Firefly Technologies, in collaboration with the Rochester Institute of Technology and the University of Wisconsin-Madison, developed synthesis methods for highly strained nanowires. Two synthesis routes resulted in successful nanowire epitaxy: direct nucleation and growth on the substrate and a novel selective-epitaxy route based on nanolithography using diblock copolymers. The indium-arsenide (InAs) nanowires are implemented in situ within the epitaxy environment-a significant innovation relative to conventional semiconductor nanowire generation using ex situ gold nanoparticles. The introduction of these nanoscale features may enable an intermediate band solar cell while simultaneously increasing the effective absorption volume that can otherwise limit short-circuit current generated by thin quantized layers. The use of nanowires for photovoltaics decouples the absorption process from the current extraction process by virtue of the high aspect ratio. While no functional solar cells resulted from this effort, considerable fundamental understanding of the nanowire epitaxy kinetics and nanopatterning process was developed. This approach could, in principle, be an enabling technology for heterointegration of dissimilar materials. The technology also is applicable to virtual substrates. Incorporating nanowires onto a recrystallized germanium/metal foil substrate would potentially solve the problem of grain boundary shunting of generated carriers by restricting the cross-sectional area of the nanowire (tens of nanometers in diameter) to sizes smaller than the recrystallized grains (0.5 to 1 micron(exp 2).

  18. Solar photovoltaic power stations

    NASA Technical Reports Server (NTRS)

    Chowaniec, C. R.; Pittman, P. F.; Ferber, R. R.; Marshall, B. W.

    1977-01-01

    The subsystems of a solar photovoltaic central power system are identified and the cost of major components are estimated. The central power system, which would have a peak power capability in the range of 50 to 1000 MW, utilizes two types of subsystems - a power conditioner and a solar array. Despite differences in costs of inverters, the overall cost of the total power conditioning subsystem is about the same for all approaches considered. A combination of two inverters operating from balanced dc buses as a pair of 6-pulse groups is recommended. A number of different solar cell modules and tracking array structures were analyzed. It is concluded that when solar cell costs are high (greater than $500/kW), high concentration modules are more cost effective than those with low concentration. Vertical-axis tracking is the most effective of the studied tracking modes. For less expensive solar cells (less than $400/kW), fixed tilt collector/reflector modules are more cost effective than those which track.

  19. Photovoltaic Roof Heat Flux

    NASA Astrophysics Data System (ADS)

    Samady, Mezhgan Frishta

    Solar panels were mounted with different designs onto 1:800 scale building models while temperature and radiation were measured. While there have been other studies aimed at finding the optimal angles for solar panels [9], in this study both the angle and the mounting method were tested. The three PV mounting designs that were considered to provide the most insulation to a building's rooftop were flush, offset (control), and angled. The solar panel offset height became a key component for rooftop insulation as well as the performance of the actual solar panel. Experimental results were given to verify the thermal behavior of the heat loads from the different designs of the photovoltaic panel. From the results, the angled PV design needed 16Z more heat extraction than the offset and flush PV design needed 60% more heat extracted than the offset. In addition to the heat transfer analysis, thermal models were performed to incorporate main atmospheric conditions which were based on the effects of PV mounting structure.

  20. Photovoltaic solar concentrator module

    SciTech Connect

    Chiang, C.J.

    1991-05-16

    This invention consists of a planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation which 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.

  1. The DOE photovoltaics program

    NASA Technical Reports Server (NTRS)

    Ferber, R. R.

    1980-01-01

    As part of the National Solar Energy program, the US Department of Energy is now engaged in the development of technically feasible, low cost candidate component and system technologies to the point where technical readiness can be demonstrated by 1982. The overall strategy is to pursue parallel options that continue to show promise of meeting the program goals, thus increasing the probability that at least one technology will be successful. Included in technology development are both flat plate solar collectors and concentrator solar collectors, as well as the balance of system components, such as structures, power conditioning, power controls, protection, and storage. Generally, these last items are common to both flat plate and concentrator systems, but otherwise there is considerable disparity in design philosophy, photovoltaic cell requirements, and possible applications between the two systems. Objectives for research activities at NASA Lewis for stand alone applications, and at Sandia Laboratories where intermediate load center applications are addressed, are highlighted as well as college projects directed by Oak Ridge National Laboratory, and international applications managed by the Solar Energy Research Institute. Joint DOD/DOE effects for military applications are also summarized.

  2. Nanoplasmonics for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Mammo, Eliyas D.; Marques-Hueso, Jose; Richards, Bryce S.

    2012-06-01

    Plasmonics has become a focus of recent research in photovoltaic applications primarily due to their effects in enhancing the absorption performance of solar cells. In this paper a review of different approaches that have been proposed to integrate plasmonics technologies into solar cells is presented. It has been observed that a range of metallic nanostructures that show plasmon resonance wavelength in the visible and near-infrared regime can be utilized to increase the coupling of light into the solar cell. This is widely used to increase the coupling of light that can be trapped in thin layers of active regions as in thin film technologies. In this review paper, more attention is given to the techniques of fabricating the metallic nanoparticles and the ways to control their plasmon resonance wavelengths. The role of the shape, size, dielectric permittivity of the host and the type of the metallic nanoparticles on tuning the resonance wavelength are analyzed. Furthermore, the cluster of nanoparticles gives different resonance wavelength from the individual nanoparticles due to dipolar coupling among the nanoparticles. In conclusion, we show how the plasmon resonance can be engineered to increase the absorption performance of conventional solar cells.

  3. Photovoltaics for municipal planners

    SciTech Connect

    Not Available

    1993-04-01

    This booklet is intended for city and county government personnel, as well as community organizations, who deal with supplying, regulating, or recommending electric power resources. Specifically, this document deals with photovoltaic (PV) power, or power from solar cells, which is currently the most cost-effective energy source for electricity requirements that are relatively small, located in isolated areas, or difficult to serve with conventional technology. Recently, PV has been documented to be more cost-effective than conventional alternatives (such as line extensions or engine generators) in dozens of applications within the service territories of electric, gas, and communications utilities. Here, we document numerous cost-effective urban applications, chosen by planners and utilities because they were the most cost-effective option or because they were appropriate for environmental or logistical reasons. These applications occur within various municipal departments, including utility, parks and recreation, traffic engineering, transportation, and planning, and they include lighting applications, communications equipment, corrosion protection, irrigation control equipment, remote monitoring, and even portable power supplies for emergency situations.

  4. Photovoltaic cell with thin CS layer

    SciTech Connect

    Jordan, J.F.; Albright, S.P.

    1994-01-18

    An improved photovoltaic panel and method of forming a photovoltaic panel are disclosed for producing a high efficiency CdS/CdTe photovoltaic cell. The photovoltaic panel of the present invention is initially formed with a substantially thick CdS layer, and the effective thickness of the CdS layer is substantially reduced during regrowth to both form larger diameter CdTe crystals and substantially reduce the effective thickness of the CdS layer. 4 figures.

  5. Study on photovoltaic power system on ships

    SciTech Connect

    Katagi, Takeshi; Fujii, Yoshimi; Nishikawa, Eiichi; Hashimoto, Takeshi

    1995-11-01

    This paper presents the application of photovoltaic power systems to ships. Two types of leisure or fishing boats powered by photovoltaics are designed. The boats described are single hull and catamaran type with twin hulls. The design of a new electric power system using a photovoltaic power system in a harbor ship having 20 tons is also proposed. The results of this study show that the photovoltaic power system can apply to small ships.

  6. Design and development of sustainable remediation process for mitigation of fluoride contamination in ground water and field application for domestic use.

    PubMed

    Gwala, Poonam; Andey, Subhash; Nagarnaik, Pranav; Ghosh, Sarika Pimpalkar; Pal, Prashant; Deshmukh, Prashant; Labhasetwar, Pawan

    2014-08-01

    Decentralised household chemo defluoridation unit (CDU) was developed and designed based on a combination of coagulation and sorption processes. Chemo-defluoridation process was optimised to reduce use of chemicals and increase acceptability among beneficiaries without affecting palatability of water. Chemical dose optimization undertaken in the laboratory using jar test revealed the optimum calcium salt to initial fluoride ratio of 60 for fluoride removal. Performance of CDU was evaluated in the laboratory for removal efficiency, water quality parameters, filter bed cleaning cycle and desorption of fluoride. CDU evaluation in the laboratory with spiked water (5 mg/L) and field water (~4.2 mg/L) revealed treated water fluoride concentration of less than 1mg/L. Seventy five CDUs were installed in households at Sakhara Village, Yavatmal District in Maharashtra State of India. Monthly monitoring of CDUs for one year indicated reduction of the raw water fluoride concentration from around 4 mg/L to less than 1mg/L. Post implementation survey after regular consumption of treated drinking water by the users for one year indicated user satisfaction and technological sustainability. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Process Development for Nanostructured Photovoltaics

    SciTech Connect

    Elam, Jeffrey W.

    2015-01-01

    Photovoltaic manufacturing is an emerging industry that promises a carbon-free, nearly limitless source of energy for our nation. However, the high-temperature manufacturing processes used for conventional silicon-based photovoltaics are extremely energy-intensive and expensive. This high cost imposes a critical barrier to the widespread implementation of photovoltaic technology. Argonne National Laboratory and its partners recently invented new methods for manufacturing nanostructured photovoltaic devices that allow dramatic savings in materials, process energy, and cost. These methods are based on atomic layer deposition, a thin film synthesis technique that has been commercialized for the mass production of semiconductor microelectronics. The goal of this project was to develop these low-cost fabrication methods for the high efficiency production of nanostructured photovoltaics, and to demonstrate these methods in solar cell manufacturing. We achieved this goal in two ways: 1) we demonstrated the benefits of these coatings in the laboratory by scaling-up the fabrication of low-cost dye sensitized solar cells; 2) we used our coating technology to reduce the manufacturing cost of solar cells under development by our industrial partners.

  8. Analysis of batteries for use in photovoltaic systems. Final report

    SciTech Connect

    Podder, A; Kapner, M

    1981-02-01

    An evaluation of 11 types of secondary batteries for energy storage in photovoltaic electric power systems is given. The evaluation was based on six specific application scenarios which were selected to represent the diverse requirements of various photovoltaic systems. Electrical load characteristics and solar insulation data were first obtained for each application scenario. A computer-based simulation program, SOLSIM, was then developed to determine optimal sizes for battery, solar array, and power conditioning systems. Projected service lives and battery costs were used to estimate life-cycle costs for each candidate battery type. The evaluation considered battery life-cycle cost, safety and health effects associated with battery operation, and reliability/maintainability. The 11 battery types were: lead-acid, nickel-zinc, nickel-iron, nickel-hydrogen, lithium-iron sulfide, calcium-iron sulfide, sodium-sulfur, zinc-chlorine, zinc-bromine, Redox, and zinc-ferricyanide. The six application scenarios were: (1) a single-family house in Denver, Colorado (photovoltaic system connected to the utility line); (2) a remote village in equatorial Africa (stand-alone power system); (3) a dairy farm in Howard County, Maryland (onsite generator for backup power); (4) a 50,000 square foot office building in Washington, DC (onsite generator backup); (5) a community in central Arizona with a population of 10,000 (battery to be used for dedicated energy storage for a utility grid-connected photovoltaic power plant); and (6) a military field telephone office with a constant 300 W load (trailer-mounted auxiliary generator backup). Recommendations for a research and development program on battery energy storage for photovoltaic applications are given, and a discussion of electrical interfacing problems for utility line-connected photovoltaic power systems is included. (WHK)

  9. Performance Evaluation of Photovoltaic Solar Air Conditioning

    NASA Astrophysics Data System (ADS)

    Snegirjovs, A.; Shipkovs, P.; Lebedeva, K.; Kashkarova, G.; Migla, L.; Gantenbein, P.; Omlin, L.

    2016-12-01

    Information on the electrical-driven solar air conditioning (SAC) is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC) systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average) systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW). In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  10. Domestic Research at Rand.

    ERIC Educational Resources Information Center

    Rand Corp., Santa Monica, CA.

    This third descriptive inventory of the Rand Corporation's domestic non-military research covers all projects since 1972, as well as its special 1969-1975 program for New York City. For each of over 300 research projects in nine program areas, brief summaries identify the project title and sponsor, beginning and ending dates, person-years of work…

  11. Domestic Research at Rand.

    ERIC Educational Resources Information Center

    Rand Corp., Santa Monica, CA.

    This third descriptive inventory of the Rand Corporation's domestic non-military research covers all projects since 1972, as well as its special 1969-1975 program for New York City. For each of over 300 research projects in nine program areas, brief summaries identify the project title and sponsor, beginning and ending dates, person-years of work…

  12. Domestic Communications Satellites.

    ERIC Educational Resources Information Center

    Network Project Notebook, 1972

    1972-01-01

    The June, 1972 Federal Communications Commission's (FCC) decision allowed an "open skies" policy in regard to domestic communication satellites and raised Liberal opposition to a situation where exclusive and unchecked communications power is now in the hands of private entrepreneurs, primarily the big Defense Department oriented…

  13. Challenging Domestic Violence.

    ERIC Educational Resources Information Center

    Scarlett, Chris

    2002-01-01

    In Britain, a Women's Aid program offers practical support and assistance to abused women. Survivors of domestic abuse can benefit from the opportunity afforded by an objective appraisal of the social context of their personal experiences, facilitated by trained volunteers. (JOW)

  14. Signs of domestic abuse.

    PubMed

    Pearce, Lynne

    2017-07-13

    Essential facts The government's definition of domestic violence and abuse, published in 2016 by the Home Office, is: 'Any incident or pattern of incidents of controlling, coercive, threatening behaviour, violence or abuse between those 16 years or over who are, or have been, intimate partners or family members, regardless of gender or sexuality.'

  15. Domestic Communications Satellites.

    ERIC Educational Resources Information Center

    Network Project Notebook, 1972

    1972-01-01

    The June, 1972 Federal Communications Commission's (FCC) decision allowed an "open skies" policy in regard to domestic communication satellites and raised Liberal opposition to a situation where exclusive and unchecked communications power is now in the hands of private entrepreneurs, primarily the big Defense Department oriented…

  16. International photovoltaic products and manufacturers directory, 1995

    SciTech Connect

    Shepperd, L.W.

    1995-11-01

    This international directory of more than 500 photovoltaic-related manufacturers is intended to guide potential users of photovoltaics to sources for systems and their components. Two indexes help the user to locate firms and materials. A glossary describes equipment and terminology commonly used in the photovoltaic industry.

  17. Production and Characterization of Novel Photovoltaic Materials

    SciTech Connect

    Wu, Marvin

    2016-06-07

    This project has three major objectives: exploring the potential nanostructured materials in photovoltaic applications; providing photovoltaic research experiences to NCCU students, who are largely members of underrepresented minority groups; and enhancing the photovoltaic research infrastructure at NCCU to increase faculty and student competitiveness. Significant progress was achieved in each of these areas during the project period, as summarized in this report.

  18. Detection of beta2 and major toxin genes by PCR in Clostridium perfringens field isolates of domestic animals suffering from enteritis or enterotoxaemia.

    PubMed

    Sting, Reinhard

    2009-01-01

    The production of Clostridium (C.) perfringens toxins in the intestine is an important cause of enteritis and enterotoxaemia in livestock. In the present study, the alpha toxin and the genes encoding beta2 and epsilon toxin could be frequently detected by means of phenotypical and PCR examinations in these bacteria. The C. perfringens isolates originated from 1213 field samples taken from diseased or perished livestock located in the north-eastern administrative districts of Baden-Württemberg (Germany) from 2005 to 2008. The beta2 toxin gene of C perfringens was detected in all animal species examined, comprising pigs, the small ruminants sheep and goats, cattle, horses, rabbits, alpacas and lamas, and fallow deer. Among all the animal species included in this study, pigs attracted attention by a high quota of 74.2% (610 of 822) cpb2-positive C. perfringens isolates in comparison to the other animal species tested, revealing a quota of 20.8% (72 of 346). Beta2 toxigenic isolates could be predominantly cultivated from the faeces of young piglets. The beta toxin gene was detected in isolates from piglets and small ruminants only, amounting to 82.5% (33 of 40) in piglets in combination with the cpb2 gene. In this context, cpb2/cpb-positive C. perfringens isolates of piglets could be clearly detected more often in the intestine of perished animals (18 of 158) than in faeces (15 of 629). Furthermore, cpb2-bearing C. perfringens isolates were detected in cattle, horses, rabbits, alpacas and lamas, and fallow deer to a notable degree. The detection of C. perfringens isolates carrying the epsilon toxin gene was restricted to sheep and goats. Of a total of 242 small ruminants that succumbed to sudden death, 71 (29.3%) harboured epsilon toxin-positive C. perfringens isolates in their intestines. These cases clustered seasonally in the second quarter (April, May, and June) of the year. Neither the isolates bearing the beta2 nor beta toxin gene nor those carrying the epsilon

  19. Induction soldering of photovoltaic system components

    SciTech Connect

    Kumaria, Shashwat; de Leon, Briccio

    2015-11-17

    A method comprises positioning a pair of photovoltaic wafers in a side-by-side arrangement. An interconnect is placed on the pair of wafers such that the interconnect overlaps both wafers of the pair, solder material being provided between the interconnect and the respective wafers. A solder head is then located adjacent the interconnect, and the coil is energized to effect inductive heating of the solder material. The solder head comprises an induction coil shaped to define an eye, and a magnetic field concentrator located at least partially in the eye of the coil. The magnetic field concentrator defines a passage extending axially through the eye of the coil, and may be of a material with a high magnetic permeability.

  20. National Orange Show Photovoltaic Demonstration

    SciTech Connect

    Dan Jimenez Sheri Raborn, CPA; Tom Baker

    2008-03-31

    National Orange Show Photovoltaic Demonstration created a 400KW Photovoltaic self-generation plant at the National Orange Show Events Center (NOS). The NOS owns a 120-acre state fairground where it operates an events center and produces an annual citrus fair known as the Orange Show. The NOS governing board wanted to employ cost-saving programs for annual energy expenses. It is hoped the Photovoltaic program will result in overall savings for the NOS, help reduce the State's energy demands as relating to electrical power consumption, improve quality of life within the affected grid area as well as increase the energy efficiency of buildings at our venue. In addition, the potential to reduce operational expenses would have a tremendous effect on the ability of the NOS to service its community.

  1. Photovoltaic Subcontract Program, FY 1991

    SciTech Connect

    Not Available

    1992-03-01

    This report summarizes the fiscal year (FY) 1991 (October 1, 1990, through September 30, 1991) progress of the subcontracted photovoltaic (PV) research and development (R D) performed under the Photovoltaic Advanced Research and Development Project at the National Renewable Energy Laboratory (NREL) -- formerly the Solar Energy Research Institute (SERI). The mission of the national PV program is to develop PV technology for large-scale generation of economically competitive electric power in the United States. The technical sections of the report cover the main areas of the subcontract program: the Amorphous Silicon Research Project, Polycrystalline Thin Films, Crystalline Silicon Materials Research, High-Efficiency Concepts, the New Ideas Program, the University Participation Program, and the Photovoltaic Manufacturing Technology (PVMaT) project. Technical summaries of each of the subcontracted programs provide a discussion of approaches, major accomplishments in FY 1991, and future research directions.

  2. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, Dimitrios C.; Fox, Richard J.

    1981-01-01

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semiconductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  3. Photovoltaic effect in Ferroelectric Materials

    NASA Astrophysics Data System (ADS)

    Katiyar, Rajesh K.; Panwar, Neeraj; Morell, G.; Katiyar, Ram S.

    2010-03-01

    Photovoltaic effect in ferroelectric materials is of much interest due to the anomalously large open circuit photovoltages when illuminated. It is concluded that this unprecedented high value of photovoltaic effect is due to the presence of non-centrosymmetry in the ferroelectric materials which gives rise to electron excitation, relaxation, and scattering processes. The photovoltaic efficiencies are, however, limited due to small current densities and the large band gap values of the ferroelectric materials. We have synthesized thin films of BiFeO3 (a low band gap material ˜2.67eV) and ferroelectric material SrBi2Ta2O9(SBT) on silicon substrates with ITO as the bottom electrode. The band gap of the SBT has been decreased by incorporating metallic particles Ag, Pt. in the ferroelectric matrix. The results will be presented.

  4. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, D.C.; Fox, R.J.

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semi-conductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  5. Photovoltaics, the solar electric solution

    NASA Astrophysics Data System (ADS)

    Beach, C. D.; Litka, A. H.

    Direct conversion of solar energy to electricity by photovoltaic devices (solar cells) may be the most promising solution to the current energy problem. Photovoltaic energy systems provide a clean, simple method of energy conversion, and are reliable, safe, and flexible with respect to size (modular). The federal government is trying to commercialize photovoltaics by funding research on new materials and manufacturing processes. Earliest commercialization will be in residential systems, where the power grid back-up provides for a reliable electrical system without storage costs. The Florida Solar Energy Center has been operating a 5 kW experimental residential facility since 1980. The facility showed an average solar irradiance in the 62.5 sq m panels of 264 kw-hours/day from December 1980 through February 1981. The overall system efficiency was 7%, and the inverter operated with an ac output/dc input efficiency of 85-90%, depending on input levels.

  6. Residential solar photovoltaic systems: Final report for the Northeast Residential Experiment Station

    SciTech Connect

    Kern, E.C. Jr.

    1986-06-01

    This report covers research and development work conducted by the MIT Energy Lab. from July 1982 through June 1986. This Energy Lab. work in the field of solar photovoltaic systems followed six years of similar work at the MIT Lincoln Lab. under the same contract with the US DOE. The final report from the Lincoln Lab. period was published by Lincoln Lab. in 1983. During the period of Energy Lab. involvement, the project focused on the refinement of residential scale, roof-mounted photovoltaic systems for application in the northeastern US. Concurrent with the conclusion of MIT`s involvement, the New England Electric Co. is building a major field test of residential photovoltaics in Gardner, Massachusetts to determine experimentally the effects of photovoltaics on electric power company operations. Using systems designs and technology developed at MIT, the long-term performance of these thirty residential systems in Gardner will provide a measure of our success.

  7. Genetic testing in domestic cats

    PubMed Central

    Lyons, Leslie A.

    2012-01-01

    Varieties of genetic tests are currently available for the domestic cat that support veterinary health care, breed management, species identification, and forensic investigations. Approximately thirty-five genes contain over fifty mutations that cause feline health problems or alterations in the cat’s appearance. Specific genes, such as sweet and drug receptors, have been knocked-out of Felidae during evolution and can be used along with mtDNA markers for species identification. Both STR and SNP panels differentiate cat race, breed, and individual identity, as well as gender-specific markers to determine sex of an individual. Cat genetic tests are common offerings for commercial laboratories, allowing both the veterinary clinician and the private owner to obtain DNA test results. This article will review the genetic tests for the domestic cat, and their various applications in different fields of science. Highlighted are genetic tests specific to the individual cat, which are a part of the cat’s genome. PMID:22546621

  8. Know Your Rights: Domestic Violence

    MedlinePlus

    ... of work • harassing telephone calls • spying on you • child abuse Domestic violence can be handled in three different ... or visitation privileges) Domestic violence might also involve child abuse and neglect and might impact on other areas ...

  9. Know Your Rights: Domestic Violence

    MedlinePlus

    ... of work • harassing telephone calls • spying on you • child abuse Domestic violence can be handled in three different ... or visitation privileges) Domestic violence might also involve child abuse and neglect and might impact on other areas ...

  10. Photovoltaic hydrogen production

    SciTech Connect

    Hiser, H.W.; Memory, S.B.; Veziroglu, T.N.; Padin, J.

    1996-10-01

    This is a new project, which started in June 1995, and involves photovoltaic hydrogen production as a fuel production method for the future. In order to increase the hydrogen yield, it was decided to use hybrid solar collectors to generate D.C. electricity, as well as high temperature steam for input to the electrolyzer. In this way, some of the energy needed to dissociate the water is supplied in the form of heat (or low grade energy), to generate steam, which results in a reduction of electrical energy (or high grade energy) needed. As a result, solar to hydrogen conversion efficiency is increased. In the above stated system, the collector location, the collector tracking sub-system (i.e., orientation/rotation), and the steam temperature have been taken as variables. Five locations selected - in order to consider a variety of latitudes, altitudes, cloud coverage and atmospheric conditions - are Atlanta, Denver, Miami, Phoenix and Salt Lake City. Plain PV and hybrid solar collectors for a stationary south facing system and five different collector rotation systems have been analyzed. Steam temperatures have been varied between 200{degrees}C and 1200{degrees}C. During the first year, solar to hydrogen conversion efficiencies have been considered. The results show that higher steam temperatures, 2 dimensional tracking system, higher elevations and dryer climates causes higher conversion efficiencies. Cost effectiveness of the sub-systems and of the overall system will be analyzed during the second year. Also, initial studies will be made of an advanced high efficiency hybrid solar hydrogen production system.

  11. Interband Cascade Photovoltaic Cells

    SciTech Connect

    Yang, Rui Q.; Santos, Michael B.; Johnson, Matthew B.

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  12. Amorphous carbon for photovoltaics

    NASA Astrophysics Data System (ADS)

    Risplendi, Francesca; Grossman, Jeffrey C.

    2015-03-01

    All-carbon solar cells have attracted attention as candidates for innovative photovoltaic devices. Carbon-based materials such as graphene, carbon nanotubes (CNT) and amorphous carbon (aC) have the potential to present physical properties comparable to those of silicon-based materials with advantages such as low cost and higher thermal stability.In particular a-C structures are promising systems in which both sp2 and sp3 hybridization coordination are present in different proportions depending on the specific density, providing the possibility of tuning their optoelectronic properties and achieving comparable sunlight absorption to aSi. In this work we employ density functional theory to design suitable device architectures, such as bulk heterojunctions (BHJ) or pn junctions, consisting of a-C as the active layer material.Regarding BHJ, we study interfaces between aC and C nanostructures (such as CNT and fullerene) to relate their optoelectronic properties to the stoichiometry of aC. We demonstrate that the energy alignment between the a-C mobility edges and the occupied and unoccupied states of the CNT or C60 can be widely tuned by varying the aC density to obtain a type II interface.To employ aC in pn junctions we analyze the p- and n-type doping of a-C focusingon an evaluation of the Fermi level and work function dependence on doping.Our results highlight promising features of aC as the active layer material of thin-film solar cells.

  13. MOD silver metallization for photovoltaics

    NASA Technical Reports Server (NTRS)

    Vest, G. M.; Vest, R. W.

    1984-01-01

    The development of flat plate solar arrays is reported. Photovoltaic cells require back side metallization and a collector grid system on the front surface. Metallo-organic decomposition (MOD) silver films can eliminate most of the present problems with silver conductors. The objectives are to: (1) identify and characterize suitable MO compounds; (2) develop generic synthesis procedures for the MO compounds; (3) develop generic fabrication procedures to screen printable MOD silver inks; (4) optimize processing conditions to produce grid patterns and photovoltaic cells; and (5) develop a model which describes the adhesion between the fired silver film and the silicon surface.

  14. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    An advanced, universally-mountable, integrated residential photovoltaic array concept was defined based upon an in-depth formulation and evaluation of three candidate approaches which were synthesized from existing or proposed residential array concepts. The impact of module circuitry and process sequence is considered and technology gaps and performance drivers associated with residential photovoltaic array concepts are identified. The actual learning experience gained from the comparison of the problem areas of the hexagonal shingle design with the rectangular module design led to what is considered an advanced array concept. Building the laboratory mockup provided actual experience and the opportunity to uncover additional technology gaps.

  15. Photovoltaic Energy: Electricity from Sunlight

    SciTech Connect

    Cason, D.L.; Pitsenbarger, J.

    1996-03-01

    Photovoltaic Energy: Electricity from Sunlight (PHV) announces on a bimonthly basis the current worldwide information available on all aspects of photovoltaic amorphous technology, polycrystalline thin films, gallium arsenide, crystalline silicon, concentrator technology, and systems research. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past two months. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements.

  16. Photovoltaic systems sizing for Algeria

    SciTech Connect

    Arab, A.H.; Driss, B.A.; Amimeur, R.; Lorenzo, E.

    1995-02-01

    The purpose of this work is to develop an optimization method applicable to stand-alone photovoltaic systems as a function of its reliability. For a given loss-of-load probability (LLP), there are many combinations of battery capacity and photovoltaic array peak power. The problem consists in determining the couple which corresponds to a minimum total system cost. The method has been applied to various areas all over Algeria taking into account various climatic zones. The parameter used to define the different climatic zones is the clearness index KT for all the considered sites. The period of the simulation system is 10 years. 5 refs., 4 figs., 5 tabs.

  17. Recycling Of Cis Photovoltaic Waste

    DOEpatents

    Drinkard, Jr., William F.; Long, Mark O.; Goozner; Robert E.

    1998-07-14

    A method for extracting and reclaiming metals from scrap CIS photovoltaic cells and associated photovoltaic manufacturing waste by leaching the waste with dilute nitric acid, skimming any plastic material from the top of the leaching solution, separating glass substrate from the leachate, electrolyzing the leachate to plate a copper and selenium metal mixture onto a first cathode, replacing the cathode with a second cathode, re-electrolyzing the leachate to plate cadmium onto the second cathode, separating the copper from selenium, and evaporating the depleted leachate to yield a zinc and indium containing solid.

  18. Silicon solar photovoltaic power stations

    NASA Technical Reports Server (NTRS)

    Chowaniec, C. R.; Ferber, R. R.; Pittman, P. F.; Marshall, B. W.

    1977-01-01

    Modular design of components and arrays, cost estimates for modules and support structures, and cost/performance analysis of a central solar photovoltaic power plant are discussed. Costs of collector/reflector arrays are judged the dominant element in the total capital investment. High-concentration solar tracking arrays are recommended as the most economic means for producing solar photovoltaic energy when solar cells costs are high ($500 per kW generated). Capital costs for power conditioning subsystem components are itemized and system busbar energy costs are discussed at length.

  19. A Photovoltaic System Payback Calculator

    SciTech Connect

    Riley, Daniel M.; Fleming, Jeffrey E.; Gallegos, Gerald R.

    2016-06-01

    The Roof Asset Management Program (RAMP) is a DOE NNSA initiative to manage roof repairs and replacement at NNSA facilities. In some cases, installation of a photovoltaic system on new roofs may be possible and desired for financial reasons and to meet federal renewable energy goals. One method to quantify the financial benefits of PV systems is the payback period, or the length of time required for a PV system to generate energy value equivalent to the system's cost. Sandia Laboratories created a simple spreadsheet-based solar energy valuation tool for use by RAMP personnel to quickly evaluate the estimated payback period of prospective or installed photovoltaic systems.

  20. Voltage Regulators for Photovoltaic Systems

    NASA Technical Reports Server (NTRS)

    Delombard, R.

    1986-01-01

    Two simple circuits developed to provide voltage regulation for highvoltage (i.e., is greater than 75 volts) and low-voltage (i.e., is less than 36 volts) photovoltaic/battery power systems. Use of these circuits results in voltage regulator small, low-cost, and reliable, with very low power dissipation. Simple oscillator circuit controls photovoltaic-array current to regulate system voltage and control battery charging. Circuit senses battery (and system) voltage and adjusts array current to keep battery voltage from exceeding maximum voltage.

  1. The Harvard organic photovoltaic dataset

    PubMed Central

    Lopez, Steven A.; Pyzer-Knapp, Edward O.; Simm, Gregor N.; Lutzow, Trevor; Li, Kewei; Seress, Laszlo R.; Hachmann, Johannes; Aspuru-Guzik, Alán

    2016-01-01

    The Harvard Organic Photovoltaic Dataset (HOPV15) presented in this work is a collation of experimental photovoltaic data from the literature, and corresponding quantum-chemical calculations performed over a range of conformers, each with quantum chemical results using a variety of density functionals and basis sets. It is anticipated that this dataset will be of use in both relating electronic structure calculations to experimental observations through the generation of calibration schemes, as well as for the creation of new semi-empirical methods and the benchmarking of current and future model chemistries for organic electronic applications. PMID:27676312

  2. Silicon solar photovoltaic power stations

    NASA Technical Reports Server (NTRS)

    Chowaniec, C. R.; Ferber, R. R.; Pittman, P. F.; Marshall, B. W.

    1977-01-01

    Modular design of components and arrays, cost estimates for modules and support structures, and cost/performance analysis of a central solar photovoltaic power plant are discussed. Costs of collector/reflector arrays are judged the dominant element in the total capital investment. High-concentration solar tracking arrays are recommended as the most economic means for producing solar photovoltaic energy when solar cells costs are high ($500 per kW generated). Capital costs for power conditioning subsystem components are itemized and system busbar energy costs are discussed at length.

  3. The Harvard organic photovoltaic dataset.

    PubMed

    Lopez, Steven A; Pyzer-Knapp, Edward O; Simm, Gregor N; Lutzow, Trevor; Li, Kewei; Seress, Laszlo R; Hachmann, Johannes; Aspuru-Guzik, Alán

    2016-09-27

    The Harvard Organic Photovoltaic Dataset (HOPV15) presented in this work is a collation of experimental photovoltaic data from the literature, and corresponding quantum-chemical calculations performed over a range of conformers, each with quantum chemical results using a variety of density functionals and basis sets. It is anticipated that this dataset will be of use in both relating electronic structure calculations to experimental observations through the generation of calibration schemes, as well as for the creation of new semi-empirical methods and the benchmarking of current and future model chemistries for organic electronic applications.

  4. The Harvard organic photovoltaic dataset

    NASA Astrophysics Data System (ADS)

    Lopez, Steven A.; Pyzer-Knapp, Edward O.; Simm, Gregor N.; Lutzow, Trevor; Li, Kewei; Seress, Laszlo R.; Hachmann, Johannes; Aspuru-Guzik, Alán

    2016-09-01

    The Harvard Organic Photovoltaic Dataset (HOPV15) presented in this work is a collation of experimental photovoltaic data from the literature, and corresponding quantum-chemical calculations performed over a range of conformers, each with quantum chemical results using a variety of density functionals and basis sets. It is anticipated that this dataset will be of use in both relating electronic structure calculations to experimental observations through the generation of calibration schemes, as well as for the creation of new semi-empirical methods and the benchmarking of current and future model chemistries for organic electronic applications.

  5. Aternating current photovoltaic building block

    DOEpatents

    Bower, Ward Issac; Thomas, Michael G.; Ruby, Douglas S.

    2004-06-15

    A modular apparatus for and method of alternating current photovoltaic power generation comprising via a photovoltaic module, generating power in the form of direct current; and converting direct current to alternating current and exporting power via one or more power conversion and transfer units attached to the module, each unit comprising a unitary housing extending a length or width of the module, which housing comprises: contact means for receiving direct current from the module; one or more direct current-to-alternating current inverters; an alternating current bus; and contact means for receiving alternating current from the one or more inverters.

  6. Basic photovoltaic principles and methods

    SciTech Connect

    Hersch, P.; Zweibel, K.

    1982-02-01

    This book presents a nonmathematical explanation of the theory and design of photovoltaic (PV) solar cells and systems. The basic elements of PV are introduced: the photovoltaic effect, physical aspects of solar cell efficiency, the typical single-crystal silicon solar cell, advances in single-crystal silicon solar cells. This is followed by the designs of systems constructed from individual cells, including possible constructions for putting cells together and the equipment needed for a practical producer of electrical energy. The future of PV is then discussed. (LEW)

  7. Handbook for Domestic Violence Victims.

    ERIC Educational Resources Information Center

    Illinois Coalition Against Domestic Violence, Springfield.

    This handbook provides guidance for women in Illinois who are victims of domestic violence and spouse abuse. It consists of facts about domestic violence, a survival sheet telling what to do before, during, and after incidents of domestic violence, and advice on seeking emergency assistance and shelter. It then provides advice and resources on…

  8. Domestic fuelwood use in Louisiana

    Treesearch

    Victor A. Rudis

    1986-01-01

    A telephone survey of Louisiana households and commercial vendors of domestic fuelwood was conducted in 1984 to assess domestic fuelwood use and sources of production.Twenty-two percent of the households surveyed used fuelwood during the 1983-84 heating season.Domestic fuelwood production amounted to 981,000 m3, an amount comparable to 10% of Louisiana's 1982...

  9. Handbook for Domestic Violence Victims.

    ERIC Educational Resources Information Center

    Illinois Coalition Against Domestic Violence, Springfield.

    This handbook provides guidance for women in Illinois who are victims of domestic violence and spouse abuse. It consists of facts about domestic violence, a survival sheet telling what to do before, during, and after incidents of domestic violence, and advice on seeking emergency assistance and shelter. It then provides advice and resources on…

  10. Rapid screening buffer layers in photovoltaics

    SciTech Connect

    List, III, Frederick Alyious; Tuncer, Enis

    2014-09-09

    An apparatus and method of testing electrical impedance of a multiplicity of regions of a photovoltaic surface includes providing a multi-tipped impedance sensor with a multiplicity of spaced apart impedance probes separated by an insulating material, wherein each impedance probe includes a first end adapted for contact with a photovoltaic surface and a second end in operable communication with an impedance measuring device. The multi-tipped impedance sensor is used to contact the photovoltaic surface and electrical impedance of the photovoltaic material is measured between individual first ends of the probes to characterize the quality of the photovoltaic surface.

  11. Combination solar photovoltaic heat engine energy converter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.

    1987-01-01

    A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

  12. Combination solar photovoltaic heat engine energy converter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.

    1987-01-01

    A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

  13. Photovoltaic Power Station with Ultracapacitors for Storage

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Kolacz, John S.; Soltis, Richard F.; Tavernelli, Paul F.

    2003-01-01

    A solar photovoltaic power station in which ultracapacitors, rather than batteries, are used to store energy is discussed. Developments in the semiconductor industry have reduced the cost and increased the attainable efficiency of commercially available photovoltaic panels; as a result, photovoltaic generation of power for diverse applications has become practical. Photovoltaic generation can provide electric power in remote locations where electric power would otherwise not be available. Photovoltaic generation can also afford independence from utility systems. Applications include supplying power to scientific instruments and medical equipment in isolated geographical regions.

  14. Photovoltaic Systems Test Facilities: Existing capabilities compilation

    NASA Technical Reports Server (NTRS)

    Volkmer, K.

    1982-01-01

    A general description of photovoltaic systems test facilities (PV-STFs) operated under the U.S. Department of Energy's photovoltaics program is given. Descriptions of a number of privately operated facilities having test capabilities appropriate to photovoltaic hardware development are given. A summary of specific, representative test capabilities at the system and subsystem level is presented for each listed facility. The range of system and subsystem test capabilities available to serve the needs of both the photovoltaics program and the private sector photovoltaics industry is given.

  15. Improved performance in polymer - inorganic composite photovoltaics

    NASA Astrophysics Data System (ADS)

    Breeze, Alison J.

    It has become increasingly clear over the past few decades that some form of alternative energy is needed to replace the traditional fossil fuels. I briefly discuss a few of the possible alternative sources, why solar energy is one of the more promising ones, give a short history of the development of the solar cell, and explain the motivations for research into polymer - inorganic composite solar cells. An introduction to conducting and semiconducting polymers, as well as the basics of polymer solar cell operation, is given. I present experimental results on the variation of several parameters such as polymer thickness, TiO2 and polymer morphology, and choice of electrodes for devices of the type ITO/TiO2/photoactive polymer/Au in order to probe the effects of charge transport, carrier mobility, light absorption and direction of the internal field on device efficiency. The results demonstrate that short exciton diffusion lengths, low carrier mobilities, and low absorption are the main factors limiting performance in plain polymer photovoltaics. Nanoparticle - polymer and polymer - polymer blend devices are explored as possible solutions for the first two deficiencies, with the polymer - polymer blend devices achieving the best results with an overall 0.6% power conversion efficiency. Many of the experimental results of polymer photovoltaics can be simulated using a simple model which includes terms for Schottky-like injection, ohmic current leakage, and collected photogenerated current. I discuss both the successes and failures of this model, as well as areas for future improvements.

  16. Current perspectives and the future of domestication studies

    PubMed Central

    Larson, Greger; Piperno, Dolores R.; Allaby, Robin G.; Purugganan, Michael D.; Andersson, Leif; Arroyo-Kalin, Manuel; Barton, Loukas; Climer Vigueira, Cynthia; Denham, Tim; Dobney, Keith; Doust, Andrew N.; Gepts, Paul; Gilbert, M. Thomas P.; Gremillion, Kristen J.; Lucas, Leilani; Lukens, Lewis; Marshall, Fiona B.; Olsen, Kenneth M.; Pires, J. Chris; Richerson, Peter J.; Rubio de Casas, Rafael; Sanjur, Oris I.; Thomas, Mark G.; Fuller, Dorian Q.

    2014-01-01

    It is difficult to overstate the cultural and biological impacts that the domestication of plants and animals has had on our species. Fundamental questions regarding where, when, and how many times domestication took place have been of primary interest within a wide range of academic disciplines. Within the last two decades, the advent of new archaeological and genetic techniques has revolutionized our understanding of the pattern and process of domestication and agricultural origins that led to our modern way of life. In the spring of 2011, 25 scholars with a central interest in domestication representing the fields of genetics, archaeobotany, zooarchaeology, geoarchaeology, and archaeology met at the National Evolutionary Synthesis Center to discuss recent domestication research progress and identify challenges for the future. In this introduction to the resulting Special Feature, we present the state of the art in the field by discussing what is known about the spatial and temporal patterns of domestication, and controversies surrounding the speed, intentionality, and evolutionary aspects of the domestication process. We then highlight three key challenges for future research. We conclude by arguing that although recent progress has been impressive, the next decade will yield even more substantial insights not only into how domestication took place, but also when and where it did, and where and why it did not. PMID:24757054

  17. Enhancement of Local Photovoltaic Current at Ferroelectric Domain Walls in BiFeO3

    NASA Astrophysics Data System (ADS)

    Yang, Ming-Min; Bhatnagar, Akash; Luo, Zheng-Dong; Alexe, Marin

    2017-02-01

    Domain walls, which are intrinsically two dimensional nano-objects exhibiting nontrivial electronic and magnetic behaviours, have been proven to play a crucial role in photovoltaic properties of ferroelectrics. Despite this recognition, the electronic properties of domain walls under illumination until now have been accessible only to macroscopic studies and their effects upon the conduction of photovoltaic current still remain elusive. The lack of understanding hinders the developing of nanoscale devices based on ferroelectric domain walls. Here, we directly characterize the local photovoltaic and photoconductive properties of 71° domain walls on BiFeO3 thin films with a nanoscale resolution. Local photovoltaic current, proven to be driven by the bulk photovoltaic effect, has been probed over the whole illuminated surface by using a specially designed photoelectric atomic force microscopy and found to be significantly enhanced at domain walls. Additionally, spatially resolved photoconductive current distribution reveals a higher density of excited carriers at domain walls in comparison with domains. Our measurements demonstrate that domain wall enhanced photovoltaic current originates from its high conduction rather than the internal electric field. This photoconduction facilitated local photovoltaic current is likely to be a universal property of topological defects in ferroelectric semiconductors.

  18. Enhancement of Local Photovoltaic Current at Ferroelectric Domain Walls in BiFeO3.

    PubMed

    Yang, Ming-Min; Bhatnagar, Akash; Luo, Zheng-Dong; Alexe, Marin

    2017-02-20

    Domain walls, which are intrinsically two dimensional nano-objects exhibiting nontrivial electronic and magnetic behaviours, have been proven to play a crucial role in photovoltaic properties of ferroelectrics. Despite this recognition, the electronic properties of domain walls under illumination until now have been accessible only to macroscopic studies and their effects upon the conduction of photovoltaic current still remain elusive. The lack of understanding hinders the developing of nanoscale devices based on ferroelectric domain walls. Here, we directly characterize the local photovoltaic and photoconductive properties of 71° domain walls on BiFeO3 thin films with a nanoscale resolution. Local photovoltaic current, proven to be driven by the bulk photovoltaic effect, has been probed over the whole illuminated surface by using a specially designed photoelectric atomic force microscopy and found to be significantly enhanced at domain walls. Additionally, spatially resolved photoconductive current distribution reveals a higher density of excited carriers at domain walls in comparison with domains. Our measurements demonstrate that domain wall enhanced photovoltaic current originates from its high conduction rather than the internal electric field. This photoconduction facilitated local photovoltaic current is likely to be a universal property of topological defects in ferroelectric semiconductors.

  19. Enhancement of Local Photovoltaic Current at Ferroelectric Domain Walls in BiFeO3

    PubMed Central

    Yang, Ming-Min; Bhatnagar, Akash; Luo, Zheng-Dong; Alexe, Marin

    2017-01-01

    Domain walls, which are intrinsically two dimensional nano-objects exhibiting nontrivial electronic and magnetic behaviours, have been proven to play a crucial role in photovoltaic properties of ferroelectrics. Despite this recognition, the electronic properties of domain walls under illumination until now have been accessible only to macroscopic studies and their effects upon the conduction of photovoltaic current still remain elusive. The lack of understanding hinders the developing of nanoscale devices based on ferroelectric domain walls. Here, we directly characterize the local photovoltaic and photoconductive properties of 71° domain walls on BiFeO3 thin films with a nanoscale resolution. Local photovoltaic current, proven to be driven by the bulk photovoltaic effect, has been probed over the whole illuminated surface by using a specially designed photoelectric atomic force microscopy and found to be significantly enhanced at domain walls. Additionally, spatially resolved photoconductive current distribution reveals a higher density of excited carriers at domain walls in comparison with domains. Our measurements demonstrate that domain wall enhanced photovoltaic current originates from its high conduction rather than the internal electric field. This photoconduction facilitated local photovoltaic current is likely to be a universal property of topological defects in ferroelectric semiconductors. PMID:28216672

  20. [Domestic violence in Chile].

    PubMed

    León, Tomás; Grez, Marcela; Prato, Juan Andrés; Torres, Rafael; Ruiz, Sergio

    2014-08-01

    According to recent surveys, there is a high prevalence of domestic violence (DV) in Chile. A systematic review was conducted in PubMed, Scielo, and Lilacs with the MesH terms "Chile", "Mental Health", "Health", "Domestic Violence", to explore the impact of DV on health in Chile. Eleven studies fulfilled the inclusion criteria. Two studies were prospective, exploring the influence of DV on maternal-infant health. Nine studies explored the influence of DV on mental health in adults. DV was associated with deranged mental health indicators specially anxiety and depressive symptoms and suicidal ideation. Similar results were observed among mothers who were victims of violence and their children. It is concluded that DV is a complex phenomenon with serious effects on health. However the number of studies on the subject is low and new follow up studies are required. Predictive models for DV and effective preventive measures are urgently needed.

  1. Satellite Surveillance: Domestic Issues

    DTIC Science & Technology

    2008-06-27

    Council in Los Angeles, California, July 25, 1996. 9 Robert B Murrett, “NGA — Then and Now; Celebrating 10 Years of GEOINT,” Pathfinder , September/October...Domestic Spy Satellites before the House Committee on Homeland Security, September 6, 2007; also, Statement of Lisa Graves, Deputy Director of the Center...United States House of Representatives, September 1, 2007. 24 Lisa Graves, Deputy Director of the Center for National Security Studies, Statement before

  2. Dermatophytoses in domesticated animals.

    PubMed

    Nweze, Emeka I

    2011-01-01

    Dermatophytes are among the most frequent causes of ringworm infections in domesticated animals. They are known to serve as reservoirs of the zoophilic dermatophytes and these infections have important zoonotic implication. In Nigeria and probably West Africa, there are not many studies on the incidence of dermatophytosis in domesticated animals. In the current study, 538 domesticated animals with clinically suggestive lesions were investigated for dermatophytes. Identification of dermatophyte species was performed by macro- and micro morphological examination of colonies and by biochemical methods. In the cases of isolates that had atypical morphology and/or biochemical test results, the rDNA internal transcribed spacer region 2 (ITS 2) sequencing was performed. Out of this number, 214 (39.8%) were found to be colonized by a variety of ten species of dermatophytes. M. canis was the most frequently isolated species (37.4%), followed by T. mentagrophytes (22.9%) and T. verrucosum (15.9%). M. persicolor and T. gallinae were jointly the least species isolated with a frequency of 0.55% respectively. The recovery of dermatophyte isolates previously shown to be common etiological agents of dermatophytosis especially from children in the same region suggests that animal to human transmission may be common. Possible implications and recommendations are discussed.

  3. Photovoltaic cells employing zinc phosphide

    DOEpatents

    Barnett, Allen M.; Catalano, Anthony W.; Dalal, Vikram L.; Masi, James V.; Meakin, John D.; Hall, Robert B.

    1984-01-01

    A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

  4. MOD silver metallization for photovoltaics

    NASA Technical Reports Server (NTRS)

    Vest, G. M.; Vest, R. W.

    1984-01-01

    Photovoltaic cells require back side metallization and a collector grid system on the front surface. Both front and back surface metallizations should have good adhesion, low contact resistance, low sheet resistance, long term stability, and their deposition methods should not degrade the n-p junction. Advantages and disadvantages of different deposition methods are discussed.

  5. Breakthrough: micro-electronic photovoltaics

    ScienceCinema

    Okandan, Murat; Gupta, Vipin

    2016-07-12

    Sandia developed tiny glitter-sized photovoltaic (PV) cells that could revolutionize solar energy collection. The crystalline silicon micro-PV cells will be cheaper and have greater efficiencies than current PV collectors. Micro-PV cells require relatively little material to form well-controlled, highly efficient devices. Cell fabrication uses common microelectric and micro-electromechanical systems (MEMS) techniques.

  6. Electrochemical photovoltaic cells and electrodes

    DOEpatents

    Skotheim, Terje A.

    1984-01-01

    Improved electrochemical photovoltaic cells and electrodes for use therein, particularly electrodes employing amorphous silicon or polyacetylene coating are produced by a process which includes filling pinholes or porous openings in the coatings by electrochemical oxidation of selected monomers to deposit insulating polymer in the openings.

  7. Photovoltaics radiometric issues and needs

    SciTech Connect

    Myers, D.R.

    1995-11-01

    This paper presents a summary of issues discussed at the photovoltaic radiometric measurements workshop. Topics included radiometric measurements guides, the need for well-defined goals, documentation, calibration checks, accreditation of testing laboratories and methods, the need for less expensive radiometric instrumentation, data correlations, and quality assurance.

  8. Photovoltaic Systems for Government Agencies

    DTIC Science & Technology

    1994-02-01

    i -- • • ;__ S• .... S,<, - Loca ted in the Adirondacks this photovoltaic system powers a facility offering visitors a clean, odorless, and...current depends on type of metal, composition of the soil, salinity of water, and surface area of metal to be protected. Historically, cathodic

  9. SAM Photovoltaic Model Technical Reference

    SciTech Connect

    Gilman, P.

    2015-05-27

    This manual describes the photovoltaic performance model in the System Advisor Model (SAM). The U.S. Department of Energy’s National Renewable Energy Laboratory maintains and distributes SAM, which is available as a free download from https://sam.nrel.gov. These descriptions are based on SAM 2015.1.30 (SSC 41).

  10. Sunlight Simulator for Photovoltaic Testing

    NASA Technical Reports Server (NTRS)

    Mueller, R. L.

    1986-01-01

    Light with normalized spectral irradiance resembling that of airmass 1.5 sunlight striking surface of Earth produced by use of ultraviolet filter to modify output of set of flashlamps used as large-area pulsed solar simulator (LAPSS). Filtered LAPSS light allows more realistic measurements of output of photovoltaic devices when using silicon reference cell having different spectral response characteristic.

  11. Photovoltaic Subcontract Program, FY 1990

    SciTech Connect

    Summers, K.A.

    1991-03-01

    This report summarizes the progress of the subcontracted photovoltaic (PV) research and development (R D) performed under the Photovoltaics Program at the Solar Energy Research Institute (SERI). The SERI subcontracted PV research and development represents most of the subcontracted R D that is funded by the US Department of Energy (DOE) National Photovoltaics Program. This report covers fiscal year (FY) 1990: October 1, 1989 through September 30, 1990. During FY 1990, the SERI PV program started to implement a new DOE subcontract initiative, entitled the Photovoltaic Manufacturing Technology (PVMaT) Project.'' Excluding (PVMaT) because it was in a start-up phase, in FY 1990 there were 54 subcontracts with a total annualized funding of approximately $11.9 million. Approximately two-thirds of those subcontracts were with universities, at a total funding of over $3.3 million. Cost sharing by industry added another $4.3 million to that $11.9 million of SERI PV subcontracted R D. The six technical sections of this report cover the previously ongoing areas of the subcontracted program: the Amorphous Silicon Research Project, Polycrystalline Thin Films, Crystalline Silicon Materials Research, High-Efficiency Concepts, the New Ideas Program, and the University Participation Program. Technical summaries of each of the subcontracted programs discuss approaches, major accomplishments in FY 1990, and future research directions. Another section introduces the PVMaT project and reports the progress since its inception in FY 1990. Highlights of technology transfer activities are also reported.

  12. Photovoltaic power generation system free of bypass diodes

    SciTech Connect

    Lentine, Anthony L.; Okandan, Murat; Nielson, Gregory N.

    2015-07-28

    A photovoltaic power generation system that includes a solar panel that is free of bypass diodes is described herein. The solar panel includes a plurality of photovoltaic sub-modules, wherein at least two of photovoltaic sub-modules in the plurality of photovoltaic sub-modules are electrically connected in parallel. A photovoltaic sub-module includes a plurality of groups of electrically connected photovoltaic cells, wherein at least two of the groups are electrically connected in series. A photovoltaic group includes a plurality of strings of photovoltaic cells, wherein a string of photovoltaic cells comprises a plurality of photovoltaic cells electrically connected in series. The strings of photovoltaic cells are electrically connected in parallel, and the photovoltaic cells are microsystem-enabled photovoltaic cells.

  13. Genetic perspectives on crop domestication

    PubMed Central

    Gross, Briana L.; Olsen, Kenneth M.

    2010-01-01

    The process of crop domestication has long been a topic of active research for biologists, anthropologists and others. Genetic data have proved a powerful resource for drawing inferences on questions regarding the geographical origins of crops, the numbers of independent domestication events for a given crop species, the specific molecular changes underlying domestication traits, and the nature of artificial selection during domestication and subsequent crop improvement. We would argue that these genetic inferences are fundamentally compatible with recent archaeological data that support a view of domestication as a geographically diffuse, gradual process. In this review, we summarize methodologies ranging from QTL mapping to resequencing used in genetic analyses of crop evolution. We also highlight recent major insights regarding the timing and spatial patterning of crop domestication and the distinct genetic underpinnings of domestication, diversification, and improvement traits. PMID:20541451

  14. Advanced Rainbow Solar Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    Mardesich, Nick; Shields, Virgil

    2003-01-01

    Photovoltaic arrays of the rainbow type, equipped with light-concentrator and spectral-beam-splitter optics, have been investigated in a continuing effort to develop lightweight, high-efficiency solar electric power sources. This investigation has contributed to a revival of the concept of the rainbow photovoltaic array, which originated in the 1950s but proved unrealistic at that time because the selection of solar photovoltaic cells was too limited. Advances in the art of photovoltaic cells since that time have rendered the concept more realistic, thereby prompting the present development effort. A rainbow photovoltaic array comprises side-by-side strings of series-connected photovoltaic cells. The cells in each string have the same bandgap, which differs from the bandgaps of the other strings. Hence, each string operates most efficiently in a unique wavelength band determined by its bandgap. To obtain maximum energy-conversion efficiency and to minimize the size and weight of the array for a given sunlight input aperture, the sunlight incident on the aperture is concentrated, then spectrally dispersed onto the photovoltaic array plane, whereon each string of cells is positioned to intercept the light in its wavelength band of most efficient operation. The number of cells in each string is chosen so that the output potentials of all the strings are the same; this makes it possible to connect the strings together in parallel to maximize the output current of the array. According to the original rainbow photovoltaic concept, the concentrated sunlight was to be split into multiple beams by use of an array of dichroic filters designed so that each beam would contain light in one of the desired wavelength bands. The concept has since been modified to provide for dispersion of the spectrum by use of adjacent prisms. A proposal for an advanced version calls for a unitary concentrator/ spectral-beam-splitter optic in the form of a parabolic curved Fresnel-like prism

  15. Photovoltaic restoration of sight with high visual acuity.

    PubMed

    Lorach, Henri; Goetz, Georges; Smith, Richard; Lei, Xin; Mandel, Yossi; Kamins, Theodore; Mathieson, Keith; Huie, Philip; Harris, James; Sher, Alexander; Palanker, Daniel

    2015-05-01

    Patients with retinal degeneration lose sight due to the gradual demise of photoreceptors. Electrical stimulation of surviving retinal neurons provides an alternative route for the delivery of visual information. We demonstrate that subretinal implants with 70-μm-wide photovoltaic pixels provide highly localized stimulation of retinal neurons in rats. The electrical receptive fields recorded in retinal ganglion cells were similar in size to the natural visual receptive fields. Similarly to normal vision, the retinal response to prosthetic stimulation exhibited flicker fusion at high frequencies, adaptation to static images and nonlinear spatial summation. In rats with retinal degeneration, these photovoltaic arrays elicited retinal responses with a spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in healthy rats. The ease of implantation of these wireless and modular arrays, combined with their high resolution, opens the door to the functional restoration of sight in patients blinded by retinal degeneration.

  16. Progress of genome wide association study in domestic animals.

    PubMed

    Zhang, Hui; Wang, Zhipeng; Wang, Shouzhi; Li, Hui

    2012-08-22

    Domestic animals are invaluable resources for study of the molecular architecture of complex traits. Although the mapping of quantitative trait loci (QTL) responsible for economically important traits in domestic animals has achieved remarkable results in recent decades, not all of the genetic variation in the complex traits has been captured because of the low density of markers used in QTL mapping studies. The genome wide association study (GWAS), which utilizes high-density single-nucleotide polymorphism (SNP), provides a new way to tackle this issue. Encouraging achievements in dissection of the genetic mechanisms of complex diseases in humans have resulted from the use of GWAS. At present, GWAS has been applied to the field of domestic animal breeding and genetics, and some advances have been made. Many genes or markers that affect economic traits of interest in domestic animals have been identified. In this review, advances in the use of GWAS in domestic animals are described.

  17. Photovoltaic subsystem optimization and design tradeoff study. Final report

    SciTech Connect

    Stolte, W.J.

    1982-03-01

    Tradeoffs and subsystem choices are examined in photovoltaic array subfield design, power-conditioning sizing and selection, roof- and ground-mounted structure installation, energy loss, operating voltage, power conditioning cost, and subfield size. Line- and self-commutated power conditioning options are analyzed to determine the most cost-effective technology in the megawatt power range. Methods for reducing field installation of flat panels and roof mounting of intermediate load centers are discussed, including the cost of retrofit installations.

  18. Entropy production in a photovoltaic cell

    NASA Astrophysics Data System (ADS)

    Ansari, Mohammad H.

    2017-05-01

    We evaluate entropy production in a photovoltaic cell that is modeled by four electronic levels resonantly coupled to thermally populated field modes at different temperatures. We use a formalism recently proposed, the so-called multiple parallel worlds, to consistently address the nonlinearity of entropy in terms of density matrix. Our result shows that entropy production is the difference between two flows: a semiclassical flow that linearly depends on occupational probabilities, and another flow that depends nonlinearly on quantum coherence and has no semiclassical analog. We show that entropy production in the cells depends on environmentally induced decoherence time and energy detuning. We characterize regimes where reversal flow of information takes place from a cold to hot bath. Interestingly, we identify a lower bound on entropy production, which sets limitations on the statistics of dissipated heat in the cells.

  19. Solar photovoltaics: current state and trends

    NASA Astrophysics Data System (ADS)

    Milichko, V. A.; Shalin, A. S.; Mukhin, I. S.; Kovrov, A. E.; Krasilin, A. A.; Vinogradov, A. V.; Belov, P. A.; Simovski, C. R.

    2016-08-01

    Basic aspects of current solar photovoltaics (PVs) are reviewed, starting from the recently developed already-on-the-market first-generation solar cells and ending with promising but not yet commercialized third-generation cells and materials possibly leading to new cell designs. The emphasis is on the physical principles of operation of various solar cells, which are divided into several groups according to our classification scheme. To make the picture complete, some technological and economic aspects of the field are discussed. A separate chapter considers antireflection coatings and light-trapping textures — structures which, while not having appeared yet in the PV review literature, are an integral part of the solar cells.

  20. Prospects of graphene electrodes in photovoltaics

    NASA Astrophysics Data System (ADS)

    Khatami, Yasin; Liu, Wei; Kang, Jiahao; Banerjee, Kaustav

    2013-09-01

    Transparent conductors (TCs) are becoming extremely popular in many different electronic applications such as touch panels, displays, light emitting devices, light sensors and solar cells. The commonly used electrode in these applications is Indium Tin Oxide (ITO). However, the cost of ITO is increasing rapidly due to the limited supply of Indium. Other issues such as lack of flexibility and cost of the deposition process make ITO less favorable in transparent electrode applications. Graphene has been under exploration as an alternative material for TC applications in the recent years. Graphene based TCs have been shown experimentally to exhibit promising electrical and optical properties. In this paper, the prospects of graphene for transparent conductors in photovoltaics are discussed. The recent advancements in this field as well as the theoretical predictions and possible pathways for improvements are presented. In the process section, we discuss methods to synthesize few-layer graphene (FLG) with high quality in a controllable manner.

  1. Photovoltaic 1-5 curve measurement techniques

    NASA Astrophysics Data System (ADS)

    Cox, C. H., III; Warner, T. H.

    1982-08-01

    Performance evaluation of photovoltaic (PV) arrays under actual field conditions provides important feedback to the module design process. One of the principal methods for assessing an array's performance is to plot its current, I, versus voltage, V, curve. Following a brief review of techniques for measuring the I-V curve, a new, capacitive-based approach is presented. It use a rapid sweep of the I-V curve that substantially reduced the average power transfer between array and load, and in turn, substantially reduced the size and weight of the curve tracer. Both theoretical and practical aspects of the approach are presented for a 10-kW unit. Performance is verified by comparison with I-V curves obtained by using a conventional load. The agreement is found to be excellent. Approximately an order of magnitude reduction in size, weight and power consumption over conventional units was realized with the experimental I-V curve tracer.

  2. Plasmonic nanostructures for organic photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Ahn, Sungmo; Rourke, Devin; Park, Wounjhang

    2016-03-01

    Due to the increasing demand on high-efficiency organic photovoltaic (OPV) devices, light management technique has become an active research subject. Especially, plasmonic approach was proven to be suitable for application in OPV and has shown lots of successful results. In this review, we summarize recent studies on plasmonic nanostructures for OPV with their underlying enhancement mechanisms. Optical absorption enhancement by the resonant scattering and the strong plasmonic near field will be discussed for various implementation geometries including metal nanoparticles, patterned electrodes, and plasmonic metamaterials. In addition, we will also look into the electrical effects originating from plasmonic nanostructures, which inevitably affect the device’s efficiency. Future research directions will be also discussed.

  3. Ultrathin optical design for organic photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Man, J. X.; Luo, D. Y.; Yu, L. M.; Wang, D. K.; Liu, Z.; Lu, Z. H.

    2015-05-01

    A trilayer ultrathin-film model concept had been adapted to maximize optical absorption of organic photovoltaic cells (OPVs) with a structure of transparent-electrode/highly-absorbing active material/metal. As demonstrated, device with the structure of ITO/Lead phthalocyanine (SubPc):Buckerminster fullerene (C60) (1:4 wt%)/Al had been studied. It is found that more than 90% optical absorption can be obtained in the device with a broaden wavelength range of 480-620 nm. The calculated optical electric fields shows that the unusually high optical absorption is due to the enhanced optical interference inside the OPVs device. This work paved a new way to design the OPVs device.

  4. Photovoltaic systems for Canadian prairie regions

    SciTech Connect

    Nigrin, J.

    1983-10-01

    The communications industry has a need for economic low power generators for their remote sites, with minimized power consumption. Photovoltaic generators (PV) promising hardware simplicity, low cost and low maintenance have the potential to fill this need. The operational record of PV generators is rather poor in harsh environment of the Canadian prairies. The authors' analysis of long term radiation data, field and laboratory tests show that often ignored cyclic winter radiation extremes and poor selection, operation and maintenance of batteries are the most frequent causes of PV system failures. They derive a reliable PV sizing curve for Edmonton (53/sup 0/N, 114/sup 0/W) and study various PV designs. At a cost of $20,000 per 100W a hybrid PV-TEG generator is shown to promise reliable operation which is not affected by extreme weather fluctuations of the Canadian prairies.

  5. Photovoltaic Engineering Testbed Designed for Calibrating Photovoltaic Devices in Space

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.

    2002-01-01

    Accurate prediction of the performance of solar arrays in space requires that the cells be tested in comparison with a space-flown standard. Recognizing that improvements in future solar cell technology will require an ever-increasing fidelity of standards, the Photovoltaics and Space Environment Branch at the NASA Glenn Research Center, in collaboration with the Ohio Aerospace Institute, designed a prototype facility to allow routine calibration, measurement, and qualification of solar cells on the International Space Station, and then the return of the cells to Earth for laboratory use. For solar cell testing, the Photovoltaic Engineering Testbed (PET) site provides a true air-mass-zero (AM0) solar spectrum. This allows solar cells to be accurately calibrated using the full spectrum of the Sun.

  6. Animal evolution during domestication: the domesticated fox as a model.

    PubMed

    Trut, Lyudmila; Oskina, Irina; Kharlamova, Anastasiya

    2009-03-01

    We review the evolution of domestic animals, emphasizing the effect of the earliest steps of domestication on its course. Using the first domesticated species, the dog (Canis familiaris), for illustration, we describe the evolutionary peculiarities during the historical domestication, such as the high level and wide range of diversity. We suggest that the process of earliest domestication via unconscious and later conscious selection of human-defined behavioral traits may accelerate phenotypic variations. The review is based on the results of a long-term experiment designed to reproduce early mammalian domestication in the silver fox (Vulpes vulpes) selected for tameability or amenability to domestication. We describe changes in behavior, morphology and physiology that appeared in the fox during its selection for tameability, which were similar to those observed in the domestic dog. Based on the data of the fox experiment and survey of relevant data, we discuss the developmental, genetic and possible molecular genetic mechanisms underlying these changes. We ascribe the causative role in evolutionary transformation of domestic animals to the selection for behavior and to the neurospecific regulatory genes it affects.

  7. Efficacy against nematode and cestode infections and safety of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination product in domestic cats under field conditions in Europe.

    PubMed

    Rehbein, Steffen; Capári, Balazs; Duscher, Georg; Keidane, Dace; Kirkova, Zvezdelina; Petkevičius, Saulius; Rapti, Dhimiter; Wagner, Annegret; Wagner, Thomas; Chester, S Theodore; Rosentel, Joseph; Tielemans, Eric; Visser, Martin; Winter, Renate; Kley, Katrin; Knaus, Martin

    2014-04-28

    A novel topical combination product (BROADLINE(®), Merial) composed of fipronil, (S)-methoprene, eprinomectin and praziquantel was evaluated for safety and efficacy against nematode and cestode infections in domestic cats. The study comprised a multi-centre, positive control, blinded, field study, using a randomized block design based on order of presentation for allocation. In total 196 client-owned cats, confirmed as positive for naturally acquired infections of nematodes and/or cestodes by pre-treatment faecal examination, were studied in seven countries in Europe. Pre-treatment faecal examination revealed the presence of Toxocara, hookworm, Capillaria and/or spirurid nematode infections in 129, 73, 33 or 1 cat(s), respectively; infections with taeniid and Dipylidium cestodes were demonstrated in 39 and 17 cats, respectively. Cats were allocated randomly to one of two treatments in a ratio of 2, topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINE(®), Merial; 130 cats); and 1, topical PROFENDER(®) Spot-On (Bayer; 66 cats) and treated once on Day 0. For evaluation of efficacy, two faecal samples were collected, one prior to treatment (Day -4 ± 4 days) and one at the end of the study (Day 14 ± 5 days). These were examined for fecal forms of nematode and cestode parasites. For evaluation of safety, cats were examined by a veterinarian before treatment and at the end of the study, and cat owners recorded the health status of their cats daily until the end of the study. For cats treated with Broadline(®), the efficacy was >99.9%, 100%, and 99.6% for Toxocara, hookworms, and Capillaria, respectively; and the efficacy was >99.9%, >99.9%, and 98.5%, respectively, for the cats treated with Profender(®) (p<0.001 for all nematodes and both treatments). Efficacy was 100% for both cestodes for both treatments (p<0.001). No treatment related adverse experiences were observed throughout the study. For

  8. US photovoltaic patents: 1991--1993

    SciTech Connect

    Pohle, L

    1995-03-01

    This document contains US patents on terrestrial photovoltaic (PV) power applications, including systems, components, and materials as well as manufacturing and support functions. The patent entries in this document were issued from 1991 to 1993. The entries were located by searching USPA, the database of the US Patent Office. The final search retrieved all patents under the class ``Batteries, Thermoelectric and Photoelectric`` and the subclasses ``Photoelectric,`` ``Testing,`` and ``Applications.`` The search also located patents that contained the words ``photovoltaic(s)`` or ``solar cell(s)`` and their derivatives. After the initial list was compiled, most of the patents on the following subjects were excluded: space photovoltaic technology, use of the photovoltaic effect for detectors, and subjects only peripherally concerned with photovoltaic. Some patents on these three subjects were included when ft appeared that those inventions might be of use in terrestrial PV power technologies.

  9. Diverse faces of domestic violence.

    PubMed

    Anderson, Tanya R; Aviles, Ann M

    2006-01-01

    Domestic violence is one of the most common causes of serious injury among women. Domestic violence victims endure physical and psychological sequelae that often go undetected by the health care professionals they encounter. There are many barriers women who are victims of domestic violence face. Women of color encounter additional barriers such as stereotypes that construct domestic violence as a "minority" issue. This article surveys the relevant literature to provide the reader with a review of the current state of knowledge for this special sub-population of domestic violence victims. Health care professionals need to be aware of the issues of this sub-population and be appropriately educated and trained to actively screen them. In addition, health care professionals need to be culturally sensitive to the needs of women of color who may experience domestic violence in order to appropriately screen and refer women for services that meet their needs.

  10. Selection signature in domesticated animals.

    PubMed

    Zhangyuan, Pan; Xiaoyun, He; Xiangyu, Wang; Xiaofei, Guo; Xiaohan, Cao; Wenping, Hu; Ran, Di; Qiuyue, Liu; Mingxing, Chu

    2016-12-20

    Domesticated animals play an important role in the life of humanity. All these domesticated animals undergo same process, first domesticated from wild animals, then after long time natural and artificial selection, formed various breeds that adapted to the local environment and human needs. In this process, domestication, natural and artificial selection will leave the selection signal in the genome. The research on these selection signals can find functional genes directly, is one of the most important strategies in screening functional genes. The current studies of selection signal have been performed in pigs, chickens, cattle, sheep, goats, dogs and other domestic animals, and found a great deal of functional genes. This paper provided an overview of the types and the detected methods of selection signal, and outlined researches of selection signal in domestic animals, and discussed the key issues in selection signal analysis and its prospects.

  11. Core questions in domestication research

    PubMed Central

    Zeder, Melinda A.

    2015-01-01

    The domestication of plants and animals is a key transition in human history, and its profound and continuing impacts are the focus of a broad range of transdisciplinary research spanning the physical, biological, and social sciences. Three central aspects of domestication that cut across and unify this diverse array of research perspectives are addressed here. Domestication is defined as a distinctive coevolutionary, mutualistic relationship between domesticator and domesticate and distinguished from related but ultimately different processes of resource management and agriculture. The relative utility of genetic, phenotypic, plastic, and contextual markers of evolving domesticatory relationships is discussed. Causal factors are considered, and two leading explanatory frameworks for initial domestication of plants and animals, one grounded in optimal foraging theory and the other in niche-construction theory, are compared. PMID:25713127

  12. Natural conditions and administrative settings for concentrating photovoltaics in China

    NASA Astrophysics Data System (ADS)

    Fu, Ling; Chen, Xiaoyuan; Leutz, Ralf

    2012-10-01

    It is an inevitable trend for China to develop green technologies to help the country to produce cleaner energy and to consume it more efficiently, under the pressure of energy security concern, the nation's emissions trajectory and sustainable economic development. The abundant solar resources in West China provide a big potential to utilize the solar energy. Under the promotion of key incentive policies including both feed-in-tariff (FIT) mechanisms and government rebate programs, China has become a major global solar force in photovoltaic (PV) industry both in manufacturing and in the installation of flat-plate products, with 16 GW production and 2.75 GW installation achieved in the year 2011. As a branch of PV technology, concentrating photovoltaics (CPV) technology with several years' development history in China is presently moving from pilot facilities to commercial-scale applications. Several MW-CPV power plants have been installed by both domestic and western companies in China, factories with several hundred-MW production capacity are being planned or built. Sustainable performance and reliability improvement of CPV modules, a vertical integration of supply chain in CPV industry aiming at a cost reduction, a sufficient grid infrastructure for facilitating the West-East and North-South electricity transmission will promote Chinese CPV market to actually initiate, develop and mature.

  13. Interconnect fatigue design for terrestrial photovoltaic modules

    SciTech Connect

    Mon, G. R.; Moore, D. M.; Ross, Jr., R. G.

    1982-03-01

    Fatigue of solar cell electrical interconnects due to thermal cycling has historically been a major failure mechanism in photovoltaic arrays; the results of a comprehensive investigation of interconnect fatigue that has led to the definition of useful reliability-design and life-prediction algorithms are presented. Experimental data gathered in this study indicate that the classical strain-cycle (fatigue) curve for the interconnect material is a good model of mean interconnect fatigue performance, but it fails to account for the broad statistical scatter, which is critical to reliability prediction. To fill this shortcoming the classical fatigue curve is combined with experimental cumulative interconnect failure rate data to yield statistical fatigue curves (having failure probability as a parameter) which enable: (1) the prediction of cumulative interconnect failures during the design life of an array field; and (2) the unambiguous - i.e., quantitative - interpretation of data from field-service qualification (accelerated thermal cycling) tests. Optimal interconnect cost-reliability design algorithms are derived based on minimizing the cost of energy over the design life of the array field. This procedure yields not only the minimum break-even cost of delivered energy, but also the required degree of interconnect redundancy and an estimate of array power degradation during the design life of the array field. The usefulness of the design algorithms is demonstrated with realistic examples of design optimization, prediction, and service qualification testing.

  14. Photovoltaic system criteria documents. Volume 5: Safety criteria for photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Koenig, John C.; Billitti, Joseph W.; Tallon, John M.

    1979-01-01

    Methodology is described for determining potential safety hazards involved in the construction and operation of photovoltaic power systems and provides guidelines for the implementation of safety considerations in the specification, design and operation of photovoltaic systems. Safety verification procedures for use in solar photovoltaic systems are established.

  15. Photovoltaic Energy Program Overview Fiscal Year 1996

    SciTech Connect

    1997-05-01

    Significant activities in the National Photovoltaic Program are reported for each of the three main program elements. In Research and Development, advances in thin-film materials and crystalline silicon materials are described. The Technology Development report describes activities in photovoltaic manufacturing technology, industrial expansion, module and array development, and testing photovoltaic system components. Systems Engineering and Applications projects described include projects with government agencies, projects with utilities, documentation of performance for international applications, and product certification.

  16. Recent progress in space photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.; Flood, Dennis J.; Weinberg, Irving

    1987-01-01

    Key issues and opportunities in space photovoltaic research and technology relative to future NASA mission requirements and drivers are addressed. Examples are given of space missions and/or operational capabilities on NASA's planning horizon presenting major technology challenges to the use of photovoltaic power generation in space. The status of cell R and D and the performance goals to be met by space photovoltaic power systems to remain competitive are described.

  17. Photovoltaics: Program overview, fiscal year 1992

    SciTech Connect

    Not Available

    1993-03-01

    The US DOE`s Photovoltaics program has helped photovoltaic technologies evolve from materials and concepts in the laboratories to competitive products rolling off automated assembly lines. This document is divided into the following sections: 1992 PV program accomplishments, expanding markets for photovoltaic systems, developing today`s systems with utilities and industry, working with industry to advance the technology, cooperative research to improve materials and devices, selected achievements in cooperative R and D, and PV program services. Figs, tabs.

  18. Flexible Photovoltaics: Mission Power from the Sun

    DTIC Science & Technology

    2009-11-01

    UNCLASSIFIED Flexible Photovoltaics : Mission Power from the Sun NSRDEC Project Officer: Steven Tucker Senior Engineer, EE COMM 508-233-6962 DSN 256...NOV 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Flexible Photovoltaics : Mission Power from the Sun...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 UNCLASSIFIED Flexible Photovoltaics – Why? Travel Lighter, Stay Longer! Known

  19. High voltage photovoltaic power converter

    DOEpatents

    Haigh, Ronald E.; Wojtczuk, Steve; Jacobson, Gerard F.; Hagans, Karla G.

    2001-01-01

    An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

  20. Photovoltaic materials and devices 2016

    DOE PAGES

    Sopori, Bhushan; Basnyat, Prakash; Mehta, Vishal

    2016-01-01

    Photovoltaic energy continues to grow with about 59 GW of solar PV installed in 2015. While most of the PV production (about 93%) was Si wafer based, both CdTe and CI(G)S are growing in their shares. There is also continued progress at the laboratory scale in OPV and dye sensitized solar cells. As the market grows, emphasis on reducing the cost of modules and systems continues to grow. This is the fourth special issue of this journal that is dedicated to gathering selected papers on recent advances in materials, devices, and modules/PV systems. This issue contains sixteen papers on variousmore » aspects of photovoltaics. As a result, these fall in four broad categories of novel materials, device design and fabrication, modules, and systems.« less

  1. Photovoltaic/thermal hybrid projects

    NASA Astrophysics Data System (ADS)

    Kush, E. A.

    1980-03-01

    Systems which utilize a combination of photovoltaic and thermal collection in the same solar collectors (PV/T Systems) can have advantages over PV or thermal only systems in that the cost effectiveness of the collectors and their support structure may be improved, active cooling may allow the cells to run at lower temperatures-hence higher conversion efficiency, and space limitations on side by side collectors can be avoided. Evaluation of such systems requires formulation and assessment of collector concepts, power conditioning, storage, and control strategies, and their interactions when combined into a total system. Systems with flat plate PV/T collectors and vapor compression heat pump driven by the photovoltaic electric output are considered along with PV/T concentrating collectors and their potential applications, particularly to solar driven absorption chillers.

  2. Performance of photovoltaic electrolysis system

    NASA Astrophysics Data System (ADS)

    Esteve, D.; Ganibal, C.; Steinmetz, D.; Vialaron, A.

    A photovoltaic generator with concentrated light is combined with a water electrolysis cell in an effort to further the development of solar energy utilization. SOPHOCLE, a photovoltaic generator with limited concentration of energy, is a heliostat of the altazimuth type, consisting of an optical device to focus the sunlight on the photocells, a tracking device to follow the position of the sun, and a cooling device to allow dissipation of thermal energy. The combined cost and performance of SOPHOCLE gives an overall efficiency of 9 percent (for direct solar radiation). A power conditioning device matches the generator photocell characteristics with the electrolysis cell to give maximum hydrogen production. Hydrogen can be produced by this method with an overall efficiency of 7 percent.

  3. Photovoltaic materials and devices 2016

    SciTech Connect

    Sopori, Bhushan; Basnyat, Prakash; Mehta, Vishal

    2016-01-01

    Photovoltaic energy continues to grow with about 59 GW of solar PV installed in 2015. While most of the PV production (about 93%) was Si wafer based, both CdTe and CI(G)S are growing in their shares. There is also continued progress at the laboratory scale in OPV and dye sensitized solar cells. As the market grows, emphasis on reducing the cost of modules and systems continues to grow. This is the fourth special issue of this journal that is dedicated to gathering selected papers on recent advances in materials, devices, and modules/PV systems. This issue contains sixteen papers on various aspects of photovoltaics. As a result, these fall in four broad categories of novel materials, device design and fabrication, modules, and systems.

  4. Semiconductor electrolyte photovoltaic energy converter

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Anderson, L. B.

    1975-01-01

    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  5. Linearity Testing of Photovoltaic Cells

    SciTech Connect

    Pinegar, S.; Nalley, D.; Emery, K.

    2006-01-01

    Photovoltaic devices are rated in terms of their power output or efficiency with respect to a specific spectrum, total irradiance, and temperature. In order to rate photovoltaic devices, a reference detector whose response is linear with total irradiance is needed. This procedure documents a procedure to determine if a detector is linear over the irradiance range of interest. Testing the short circuit current versus the total irradiance is done by illuminating a reference cell candidate with two lamps that are fitted with programmable filter wheels. The purpose is to reject nonlinear samples as determined by national and international standards from being used as primary reference cells. A calibrated linear reference cell tested by the two lamp method yields a linear result.

  6. Space Station Photovoltaic power modules

    NASA Technical Reports Server (NTRS)

    Tatro, Charles A.

    1988-01-01

    Silicon cell Photovoltaic (PV) power modules are key components of the Space Station Electrical Power System (EPS) scheduled to begin deployment in 1994. Four PV power modules, providing 75 KWe of user ac power, form the cornerstone of the EPS; which is comprised of Photovoltaic (PV) power modules, Solar Dynamic (SD) power modules, and the Power Management and Distribution (PMAD) system. The PV modules are located on rotating outboard sections of the Space Station (SS) structure and each module incorporates its own nickel-hydrogen energy storage batteries, its own thermal control system, and some autonomous control features. The PV modules are a cost-effective and technologically mature approach for providing reliable SS electrical power and are a solid base for EPS growth, which is expected to reach 300 KWe by the end of the Space Station's 30-year design lifetime.

  7. Remote applications of photovoltaic systems

    SciTech Connect

    Post, H.N.; Jones, G.J.; Thomas, M.G.; Casbarro, J.J.; Firor, K.

    1989-01-01

    Photovoltaic (PV) systems can meet the energy needs of small and remote grid-independent applications. These applications are characterized by the need for a highly reliable source of electrical energy to meet relatively small loads in areas where conventional sources are too costly to install and/or cannot be maintained. A major application for PV is for use in rural electrification both in the US and in the developing countries. 7 refs., 2 figs.

  8. Reliability Research for Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Ross, Ronald J., Jr.

    1986-01-01

    Report describes research approach used to improve reliability of photovoltaic modules. Aimed at raising useful module lifetime to 20 to 30 years. Development of cost-effective solutions to module-lifetime problem requires compromises between degradation rates, failure rates, and lifetimes, on one hand, and costs of initial manufacture, maintenance, and lost energy, on other hand. Life-cycle costing integrates disparate economic terms, allowing cost effectiveness to be quantified, allowing comparison of different design alternatives.

  9. Advanced photovoltaic solar array development

    NASA Technical Reports Server (NTRS)

    Kurland, Richard M.; Stella, Paul

    1989-01-01

    Phase 2 of the Advanced Photovoltaic Solar Array (APSA) program, started in mid-1987, is currently in progress to fabricate prototype wing hardware that will lead to wing integration and testing in 1989. The design configuration and key details are reviewed. A status of prototype hardware fabricated to date is provided. Results from key component-level tests are discussed. Revised estimates of array-level performance as a function of solar cell device technology for geosynchronous missions are given.

  10. Polycrystalline thin film photovoltaic technology

    SciTech Connect

    Ullal, H.S.; Zweibel, K.; Mitchell, R.L.; Noufi, R.

    1991-03-01

    Low-cost, high-efficiency thin-film modules are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. In this paper we review the significant technical progress made in the following thin films: copper indium diselenide, cadmium telluride, and polycrystalline thin silicon films. Also, the recent US DOE/SERI initiative to commercialize these emerging technologies is discussed. 6 refs., 9 figs.

  11. Decentalized solar photovoltaic energy systems

    SciTech Connect

    Krupka, M. C.

    1980-09-01

    Environmental data for decentralized solar photovoltaic systems have been generated in support of the Technology Assessment of Solar Energy Systems program (TASE). Emphasis has been placed upon the selection and use of a model residential photovoltaic system to develop and quantify the necessary data. The model consists of a reference home located in Phoenix, AZ, utilizing a unique solar cell array-roof shingle combination. Silicon solar cells, rated at 13.5% efficiency at 28/sup 0/C and 100 mW/cm/sup 2/ (AMI) insolation are used to generate approx. 10 kW (peak). An all-electric home is considered with lead-acid battery storage, dc-ac inversion and utility backup. The reference home is compared to others in regions of different insolation. Major material requirements, scaled to quad levels of end-use energy include significant quantities of silicon, copper, lead, antimony, sulfuric acid and plastics. Operating residuals generated are negligible with the exception of those from the storage battery due to a short (10-year) lifetime. A brief general discussion of other environmental, health, and safety and resource availability impacts is presented. It is suggested that solar cell materials production and fabrication may have the major environmental impact when comparing all facets of photovoltaic system usage. Fabrication of the various types of solar cell systems involves the need, handling, and transportation of many toxic and hazardous chemicals with attendant health and safety impacts. Increases in production of such materials as lead, antimony, sulfuric acid, copper, plastics, cadmium and gallium will be required should large scale usage of photovoltaic systems be implemented.

  12. Reliability Research for Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Ross, Ronald J., Jr.

    1986-01-01

    Report describes research approach used to improve reliability of photovoltaic modules. Aimed at raising useful module lifetime to 20 to 30 years. Development of cost-effective solutions to module-lifetime problem requires compromises between degradation rates, failure rates, and lifetimes, on one hand, and costs of initial manufacture, maintenance, and lost energy, on other hand. Life-cycle costing integrates disparate economic terms, allowing cost effectiveness to be quantified, allowing comparison of different design alternatives.

  13. Solar photovoltaic reflective trough collection structure

    DOEpatents

    Anderson, Benjamin J.; Sweatt, William C.; Okandan, Murat; Nielson, Gregory N.

    2015-11-19

    A photovoltaic (PV) solar concentration structure having at least two troughs encapsulated in a rectangular parallelepiped optical plastic structure, with the troughs filled with an optical plastic material, the troughs each having a reflective internal surface and approximately parabolic geometry, and the troughs each including photovoltaic cells situated so that light impinging on the optical plastic material will be concentrated onto the photovoltaic cells. Multiple structures can be connected to provide a solar photovoltaic collection system that provides portable, efficient, low-cost electrical power.

  14. Photovoltaic cell with thin CS layer

    DOEpatents

    Jordan, John F.; Albright, Scot P.

    1994-01-18

    An improved photovoltaic panel and method of forming a photovoltaic panel are disclosed for producing a high efficiency CdS/CdTe photovoltaic cell. The photovoltaic panel of the present invention is initially formed with a substantially thick Cds layer, and the effective thickness of the CdS layer is substantially reduced during regrowth to both form larger diameter CdTe crystals and substantially reduce the effective thickness of the C This invention was made with Government support under Subcontract No. ZL-7-06031-3 awarded by the Department of Energy. The Government has certain rights in this invention.

  15. Space power technology 21: Photovoltaics

    NASA Technical Reports Server (NTRS)

    Wise, Joseph

    1989-01-01

    The Space Power needs for the 21st Century and the program in photovoltaics needed to achieve it are discussed. Workshops were conducted in eight different power disciplines involving industry and other government agencies. The Photovoltaics Workshop was conducted at Aerospace Corporation in June 1987. The major findings and recommended program from this workshop are discussed. The major finding is that a survivable solar power capability is needed in photovoltaics for critical Department of Defense missions including Air Force and Strategic Defense Initiative. The tasks needed to realize this capability are described in technical, not financial, terms. The second finding is the need for lightweight, moderately survivable planar solar arrays. High efficiency thin III-V solar cells can meet some of these requirements. Higher efficiency, longer life solar cells are needed for application to both future planar and concentrator arrays with usable life up to 10 years. Increasing threats are also anticipated and means for avoiding prolonged exposure, retraction, maneuvering and autonomous operation are discussed.

  16. Photovoltaic manufacturing technology, Phase 1

    SciTech Connect

    Not Available

    1992-10-01

    This report describes subcontracted research by the Chronar Corporation, prepared by Advanced Photovoltaic Systems, Inc. (APS) for Phase 1 of the Photovoltaic Manufacturing Technology Development project. Amorphous silicon is chosen as the PV technology that Chronar Corporation and APS believe offers the greatest potential for manufacturing improvements, which, in turn, will result in significant cost reductions and performance improvements in photovoltaic products. The APS Eureka'' facility was chosen as the manufacturing system that can offer the possibility of achieving these production enhancements. The relationship of the Eureka'' facility to Chronar's batch'' plants is discussed. Five key areas are also identified that could meet the objectives of manufacturing potential that could lead to improved performance, reduced manufacturing costs, and significantly increased production. The projected long-term potential benefits of these areas are discussed, as well as problems that may impede the achievement of the hoped-for developments. A significant number of the problems discussed are of a generic nature and could be of general interest to the industry. The final section of this document addresses the cost and time estimates for achieving the solutions to the problems discussed earlier. Emphasis is placed on the number, type, and cost of the human resources required for the project.

  17. Nanochemistry and nanomaterials for photovoltaics.

    PubMed

    Chen, Guanying; Seo, Jangwon; Yang, Chunhui; Prasad, Paras N

    2013-11-07

    Nanochemistry and nanomaterials provide numerous opportunities for a new generation of photovoltaics with high solar energy conversion efficiencies at low fabrication cost. Quantum-confined nanomaterials and polymer-inorganic nanocomposites can be tailored to harvest sun light over a broad range of the spectrum, while plasmonic structures offer effective ways to reduce the thickness of light-absorbing layers. Multiple exciton generation, singlet exciton fission, photon down-conversion, and photon up-conversion realized in nanostructures, create significant interest for harvesting underutilized ultraviolet and currently unutilized infrared photons. Nanochemical interface engineering of nanoparticle surfaces and junction-interfaces enable enhanced charge separation and collection. In this review, we survey these recent advances employed to introduce new concepts for improving the solar energy conversion efficiency, and reduce the device fabrication cost in photovoltaic technologies. The review concludes with a summary of contributions already made by nanochemistry. It then describes the challenges and opportunities in photovoltaics where the chemical community can play a vital role.

  18. NASA photovoltaic research and technology

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1988-01-01

    NASA photovoltaic R and D efforts address future Agency space mission needs through a comprehensive, integrated program. Activities range from fundamental studies of materials and devices to technology demonstrations of prototype hardware. The program aims to develop and apply an improved understanding of photovoltaic energy conversion devices and systems that will increase the performance, reduce the mass, and extend the lifetime of photovoltaic arrays for use in space. To that end, there are efforts aimed at improving cell efficiency, reducing the effects of space particulate radiation damage (primarily electrons and protons), developing ultralightweight cells, and developing advanced ray component technology for high efficiency concentrator arrays and high performance, ultralightweight arrays. Current goals that have been quantified for the program are to develop cell and array technology capable of achieving 300 watts/kg for future missions for which mass is a critical factor, or 300 watts/sq m for future missions for which array size is a major driver (i.e., Space Station). A third important goal is to develop cell and array technology which will survive the GEO space radiation environment for at least 10 years.

  19. Space power technology 21: Photovoltaics

    NASA Astrophysics Data System (ADS)

    Wise, Joseph

    1989-04-01

    The Space Power needs for the 21st Century and the program in photovoltaics needed to achieve it are discussed. Workshops were conducted in eight different power disciplines involving industry and other government agencies. The Photovoltaics Workshop was conducted at Aerospace Corporation in June 1987. The major findings and recommended program from this workshop are discussed. The major finding is that a survivable solar power capability is needed in photovoltaics for critical Department of Defense missions including Air Force and Strategic Defense Initiative. The tasks needed to realize this capability are described in technical, not financial, terms. The second finding is the need for lightweight, moderately survivable planar solar arrays. High efficiency thin III-V solar cells can meet some of these requirements. Higher efficiency, longer life solar cells are needed for application to both future planar and concentrator arrays with usable life up to 10 years. Increasing threats are also anticipated and means for avoiding prolonged exposure, retraction, maneuvering and autonomous operation are discussed.

  20. Resolution in Photovoltaic Potential Computation

    NASA Astrophysics Data System (ADS)

    Alam, N.; Coors, V.; Zlatanova, S.; Oosterom, P. J. M.

    2016-09-01

    In this paper, an analysis of the effect of the various types of resolution involved in photovoltaic potential computation is presented. To calculate solar energy incident on a surface, shadow from surrounding buildings has been considered. The incident energy on a surface has been calculated taking the orientation, tilt and position into consideration. Different sky visibility map has been created for direct and diffuse radiation and only the effect of resolution of the factors has been explored here. The following four resolutions are considered: 1. temporal resolution (1, 10, 60 minutes time interval for calculating visibility of sun), 2. object surface resolution (0.01, 0.1, 0.375, 0.75, 1.25, 2.5 and 5 m2 as maximum triangle size of a surface to be considered), 3. blocking obstacle resolution (number of triangles from LoD1, LoD2, or LoD3 CityGML building models), and 4. sky resolution (ranging from 150 to 600 sky-patches used to divide the sky-dome). Higher resolutions result in general in more precise estimation of the photovoltaic potential, but also the computation time is increasing, especially as realizes that this computation has to be done for every building with its object surface (both roofs and façades). This paper is the first in depth analysis ever of the effect of resolution and will help to configure the proper settings for effective photovoltaic potential computations.