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Photovoltaic module performance and durability following long-term field exposure

Description: 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.
Date: September 8, 1998
Creator: Ellibee, D.E.; Hansen, B.R.; King, D.L.; Kratochvil, J.A. & Quintana, M.A.
Partner: UNT Libraries Government Documents Department

International photovoltaic products and manufacturers directory, 1995

Description: 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.
Date: November 1, 1995
Creator: Shepperd, L.W. & Florida Solar Energy Center, Cocoa, FL (United States)]
Partner: UNT Libraries Government Documents Department

Analysis techniques used on field degraded photovoltaic modules

Description: 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.
Date: September 1, 1995
Creator: Hund, T.D. & King, D.L.
Partner: UNT Libraries Government Documents Department

Photovoltaic system reliability

Description: This paper discusses the reliability of several photovoltaic projects including SMUD`s PV Pioneer project, various projects monitored by Ascension Technology, and the Colorado Parks project. System times-to-failure range from 1 to 16 years, and maintenance costs range from 1 to 16 cents per kilowatt-hour. Factors contributing to the reliability of these systems are discussed, and practices are recommended that can be applied to future projects. This paper also discusses the methodology used to collect and analyze PV system reliability data.
Date: October 1, 1997
Creator: Maish, A.B.; Atcitty, C. & Greenberg, D.
Partner: UNT Libraries Government Documents Department

What Changed in Article 690-Solar Photovoltaic Systems- of the 1999 National Electrical Code?

Description: Article 690, Solar Photovoltaic Power Systems, has been in the National Electrical Code (NEC) since 1984. An NFPA-appointed Task Group for Article 690 proposed changes to Article 690 for both the 1996 and 1999 codes. The Task Group, supported by more than 50 professionals from throughout the photovoltaic (PV) industry, met seven times during the 1999 code cycle to integrate the needs of the industry with the needs of electrical inspectors and end users to ensure the safety of PV systems. The Task Group proposed 57 changes to Article 690, and all the changes were accepted in the review process. The performance and cost of PV installations were always a consideration as these changes were formed but safety was the number-one priority. All of the proposals were well substantiated and coordinated throughout the PV industry and with representatives of Underwriters Laboratories, Inc (UL). The most significant changes that were made in Article 690 for the 1999 NEC along with some of the rationale are discussed in the remainder of this article.
Date: January 12, 1999
Creator: Bower, W. & Wiles, J.
Partner: UNT Libraries Government Documents Department

The New 1999 National Electrical Code Coupled with New Standards Clarify Requirements for Installations of Photovoltaic Systems in the U.S.

Description: The National Electrical Code@ (NEC@) focuses primarily on electrical system installation requirements in the U.S. The NEC addresses both fire and personnel safety. This paper will describe recent efforts of the PV industry in the U.S. and the resulting requirements in the 1999 National Electrical Code-- Article 690 --Solar Photovoltaic Systems. The Article 690 requirements spell out the PV-unique requirements for safe installations of PV systems in the U.S.A. This paper provides an overview of the most significant changes that appear in Article 690 of the 1999 edition of the NEC. The related and coordinated efforts of the other standards- making groups will also be briefly reviewed.
Date: January 8, 1999
Creator: Bower, W.
Partner: UNT Libraries Government Documents Department

Designing PV Incentive Programs to Promote Performance: A Reviewof Current Practice

Description: Increasing levels of financial support for customer-sited photovoltaic (PV) systems, provided through publicly-funded incentive programs, has heightened concerns about the long-term performance of these systems. Given the barriers that customers face to ensuring that their PV systems perform well, and the responsibility that PV incentive programs bear to ensure that public funds are prudently spent, these programs should, and often do, play a critical role in ensuring that PV systems receiving incentives perform well. To provide a point of reference for assessing the current state of the art, and to inform program design efforts going forward, we examine the approaches to encouraging PV system performance used by 32 prominent PV incentive programs in the U.S. We identify eight general strategies or groups of related strategies that these programs have used to address performance issues, and highlight important differences in the implementation of these strategies among programs.
Date: June 1, 2007
Creator: Barbose, Galen; Wiser, Ryan & Bolinger, Mark
Partner: UNT Libraries Government Documents Department

Reliability of Rechargeable Batteries in a Photovoltaic Power Supply System

Description: We investigate the reliability If a rechargeable battery acting as the energy storage component in a photovoltaic power supply system. A model system was constructed for this that includes the solar resource, the photovoltaic power supp Iy system, the rechargeable battery and a load. The solar resource and the system load are modeled as SI ochastic processes. The photovoltaic system and the rechargeable battery are modeled deterministically, imd an artificial neural network is incorporated into the model of the rechargeable battery to simulate dartage that occurs during deep discharge cycles. The equations governing system behavior are solved simultaneously in the Monte Carlo framework and a fwst passage problem is solved to assess system reliability.
Date: November 30, 1998
Creator: Barney, P.; Jungst, R.G., Ingersoll, D.; O'Gorman, C.; Paez, T.L. & Urbina, A.
Partner: UNT Libraries Government Documents Department

Hybrid Power Test Bed

Description: This document describes efforts by the National Renewable Energy Laboratory to simulate hybrid power systems. Hybrid power systems combine multiple power sources such as wind turbines, photovoltaic (PV) arrays, diesel generators, and battery storage systems. They typically are used in remote areas, away from major electric grids. The Hybrid Power Test Bed is designed to assist the U.S. wind industry in developing and testing hybrid power generation systems. Test bed capabilities, features, and equipment are described.
Date: June 1, 1996
Partner: UNT Libraries Government Documents Department

Research on solar heating and cooling. Technical status progress report, March 1996--April 1996

Description: The University of Wisconsin Solar Energy Laboratory is supported by the Department of Energy for the period of April 1995 through March 1996. The grant covers 10 objectives, some of which started in September 1995. Most of the objectives are being worked on as student MS or PhD theses and they form the basis of this report. The students working on some of these projects are not being supported by DOE and are so indicated. A number of additional projects that were not in the grant proposal (and thus are not funded by this DOE Grant), are important to the US solar program, and therefore are included here. Some of the topics discussed in this report are: solar photovoltaic hot water systems; solar heat pump water heating systems; and development of computer simulation model for solar energy systems.
Date: August 1, 1996
Partner: UNT Libraries Government Documents Department

SunSine300 AC module. Annual report, July 25, 1995--December 31, 1996

Description: Under Photovoltaic Manufacturing Technology (PVMaT) 4A1, Ascension Technology (AT) is developing the SunSine300 AC PV module. AT`s goals in this project are to meet Underwriters Laboratory (UL) 1741 requirements, obtain Federal Communications Commission (FCC) Class B verification, complete the AC module system design and development, advance the inverter design, design for manufacture, design for reliability, design for serviceability, and demonstrate commercialization through production and sale of about 100 units. To meet these goals, AT corrected a number of deficiencies identified by UL`s preliminary investigation before proceeding to the full UL investigation; a SunSine300 prototype was tested and found to comply with FCC Class B requirements; AT designed a complete line of balance-of-systems hardware for the SunSine 300; AT`s design and performance advancements include accomplishing a total harmonic distortion drop from 5% to 2%, devising a method to eliminate false detection of zero crossings that could damage the inverter, improving the anti-islanding with the addition of AT`s proprietary ZEBRA technique, and redesigning the enclosure for thermal performance, manufacturability, and UL and FCC approval; performing extensive testing in Phase 2 to discover failure modes and susceptibility to aging; and designing the SunSine300 to be easily and safely serviced. 3 figs., 3 tabs.
Date: August 1, 1997
Creator: Russell, M.C. & Handleman, C.K.P.
Partner: UNT Libraries Government Documents Department

Building-integrated photovoltaics: A case study

Description: In 1992, Kiss Cathcart Anders Architects performed a study for NREL on Building-Integrated Photovoltaics (BIPV) issues as seen from the perspective of the building community. In general, the purpose of the study was to list major issues and potential applications; by it`s nature it asked more questions than it answered. This second phase study was to produce quantitative data on the performance of specific BIPV systems. Only roof systems are evaluated. The energy performance, construction cost and simple payback for five different BIPV roof options are evaluated in six different locations: Oakland, New York, Miami, Phoenix, Chicago, and Cincinnati. The roof options evaluated include the following: single-glazed PV roof using glass-substrate PVs; double-glazed PV roof with insulating PV modules; ballasted roof-mounted system; sawtooth light monitor roof with indirect north daylighting; sawtooth roof with north light and active heat recovery.
Date: March 1, 1995
Creator: Kiss, G.; Kinkead, J. & Raman, M.
Partner: UNT Libraries Government Documents Department

Development of standardized, low-cost AC PV systems. Phase I annual report, 7 September 1995--7 November 1996

Description: The objectives of this two-year program are to improve the reliability and safety and reduce the cost of installed grid-connected PV systems by creating standardized, pre-engineered components and an enhanced, low-cost, 250-Watt micro inverter. These advances will be combined with the new, large area Solarex MSX-240 PV module resulting in standard, modular AC PV {open_quotes}building blocks{close_quotes} used to create utility-interactive PV systems as small as one module to many thousands of modules to suit virtually any application. AC PV building blocks will be developed to meet the requirements of the U.S., Japanese and European markets.
Date: June 1, 1997
Creator: Strong, S.J.; Wohlgemuth, J.H. & Kaelin, M.
Partner: UNT Libraries Government Documents Department

Design, fabrication, and certification of advanced modular PV power systems. Final technical progress report

Description: Solar Electric Specialties Company (SES) has completed a two and a half year effort under the auspices of the US Department of Energy (DOE) PVMaT (Photovoltaic Manufacturing Technology) project. Under Phase 4A1 of the project for Product Driven System and Component Technology, the SES contract ``Design, Fabrication and Certification of Advanced Modular PV Power Systems`` had the goal to reduce installed system life cycle costs through development of certified (Underwriters Laboratories or other listing) and standardized prototype products for two of the product lines, MAPPS{trademark} (Modular Autonomous PV Power Supply) and Photogensets{trademark}. MAPPS are small DC systems consisting of Photovoltaic modules, batteries and a charge controller and producing up to about a thousand watt-hours per day. Photogensets are stand-alone AC systems incorporating a generator as backup for the PV in addition to a DC-AC inverter and battery charger. The program tasks for the two-year contract consisted of designing and fabricating prototypes of both a MAPPS and a Photogenset to meet agency listing requirements using modular concepts that would support development of families of products, submitting the prototypes for listing, and performing functionality testing at Sandia and NREL. Both prototypes were candidates for UL (Underwriters Laboratories) listing. The MAPPS was also a candidate for FM (Factory Mutual) approval for hazardous (incendiary gases) locations.
Date: October 1, 1998
Creator: Lambarski, T. & Minyard, G.
Partner: UNT Libraries Government Documents Department

Solar electric buildings: An overview of today`s applications

Description: This brochure presents a broad look at photovoltaic-powered buildings. It includes residential and commercial systems, both stand-alone and connected to utility power, that are located in urban, near-urban, and rural settings across the country. As photovoltaic systems for buildings, such as those shown here, represent one of the strongest near-term markets.
Date: February 1, 1996
Partner: UNT Libraries Government Documents Department

Progress in photovoltaic system and component improvements

Description: The Photovoltaic Manufacturing Technology (PVMaT) project is a partnership between the US government (through the US Department of Energy [DOE]) and the PV industry. Part of its purpose is to conduct manufacturing technology research and development to address the issues and opportunities identified by industry to advance photovoltaic (PV) systems and components. The project was initiated in 1990 and has been conducted in several phases to support the evolution of PV industrial manufacturing technology. Early phases of the project stressed PV module manufacturing. Starting with Phase 4A and continuing in Phase 5A, the goals were broadened to include improvement of component efficiency, energy storage and manufacturing and system or component integration to bring together all elements for a PV product. This paper summarizes PV manufacturers` accomplishments in components, system integration, and alternative manufacturing methods. Their approaches have resulted in improved hardware and PV system performance, better system compatibility, and new system capabilities. Results include new products such as Underwriters Laboratories (UL)-listed AC PV modules, modular inverters, and advanced inverter designs that use readily available and standard components. Work planned in Phase 5A1 includes integrated residential and commercial roof-top systems, PV systems with energy storage, and 300-Wac to 4-kWac inverters.
Date: August 1, 1998
Creator: Thomas, H.P.; Kroposki, B.; McNutt, P.; Witt, C.E.; Bower, W.; Bonn, R. et al.
Partner: UNT Libraries Government Documents Department

A comparison of photovoltaic module performance evaluation methodologies for energy ratings

Description: The rating of photovoltaic (PV) modules has always been a controversial topic in the PV community. Currently, there is no industry standard methodology to evaluate PV modules for energy production. This issue must be discussed and resolved for the benefit of system planners, utilities, and other consumers. Several methodologies are available to rate a module`s peak power, but do any accurately predict energy output for flat-plate modules? This paper analyzes the energy performance of PV modules using six different energy calculation techniques and compares the results to the measured amount of energy produced. The results indicate which methods are the most effective for predicting energy output in Golden, Colorado, under prevailing meteorological conditions.
Date: October 1, 1995
Creator: Kroposki, B.; Emery, K.; Myers, D. & Mrig, L.
Partner: UNT Libraries Government Documents Department

Hybrid Solar Cells with Prescribed Nanoscale Morphologies Based onHyperbranched Semiconductor Nanocrystals

Description: In recent years, the search to develop large-area solar cells at low cost has led to research on photovoltaic (PV) systems based on nanocomposites containing conjugated polymers. These composite films can be synthesized and processed at lower costs and with greater versatility than the solid state inorganic semiconductors that comprise today's solar cells. However, the best nanocomposite solar cells are based on a complex architecture, consisting of a fine blend of interpenetrating and percolating donor and acceptor materials. Cell performance is strongly dependent on blend morphology, and solution-based fabrication techniques often result in uncontrolled and irreproducible blends, whose composite morphologies are difficult to characterize accurately. Here we incorporate 3-dimensional hyper-branched colloidal semiconductor nanocrystals in solution-processed hybrid organic-inorganic solar cells, yielding reproducible and controlled nanoscale morphology.
Date: September 9, 2006
Creator: Gur, Ilan; Fromer, Neil A.; Chen, Chih-Ping; Kanaras, AntoniosG. & Alivisatos, A. Paul
Partner: UNT Libraries Government Documents Department

Lithographic antennas for enhancement of solar cell efficiency

Description: This report documents proof-of-concept demonstration of the use of lithographic antennas for enhancement of solar-cell efficiency. A micro-sized lithographic antenna array was theoretically modeled, designed and fabricated. Experimental research was performed to validate the ability of the antenna array to concentrate infrared and visible energy onto photovoltaic (PV) materials. The research will serve as the basis for the design of a miniature power source for remote sensors.
Date: April 1, 1998
Creator: Kotter, D.K. & Boreman, G.
Partner: UNT Libraries Government Documents Department

Solar kinetics` photovoltaic concentrator module and tracker development

Description: Solar Kinetics, Inc., has been developing a point-focus concentrating photovoltaic module and tracker system under contract to Sandia National Laboratories. The primary focus of the contract was to achieve a module design that was manufacturable and passed Sandia`s environmental testing. Nine modules of two variations were assembled, tested, and characterized in Phase 1, and results of these tests were promising, with module efficiency approaching the theoretical limit achievable with the components used. The module efficiency was 11.9% at a solar irradiance of 850 W/m{sup 2} and an extrapolated cell temperature of 25{degrees}C. Improvements in module performance are anticipated as cell efficiencies meet their expectations. A 2-kW tracker and controller accommodating 20 modules was designed, built, installed, and operated at Solar Kinetics` test site. The drive used many commercially available components in an innovative arrangement to reduce cost and increase reliability. Backlash and bearing play were controlled by use of preloaded, low slip-stick, synthetic slide bearings. The controller design used a standard industrial programmable logic controller to perform ephemeris calculations, operate the actuators, and monitor encoders.
Date: November 1, 1995
Creator: White, D.L. & Howell, B.
Partner: UNT Libraries Government Documents Department

Overview of PV balance-of-systems technology: Experience and guidelines for utility ties in the United States of America

Description: The U.S. National Photovoltaic Program began in 1975 by supporting the development of terrestrial PV modules and hardware associated with grid-connected PV systems. Early PV-system demonstration programs were also supported and cost shared by the U.S. Department of Energy (DOE). A wide variety of PV systems were deployed, usually with utility participation. The early demonstration projects provided, and continue to provide, valuable PV system experience to utilities, designers and suppliers. As a result of experience gained, several important milestones in codes and standards pertaining to the design, installation and operation of photovoltaic (PV) systems have been completed. These code and standard activities were conducted through collaboration of participants from all sectors of the PV industry, utilities and the US DOE National Photovoltaic Program. Codes and standards that have been proposed, written, or modified include changes and additions for the 1999 National Electric Code{reg_sign} (NEC{reg_sign}), standards for fire and personnel safety, system testing, field acceptance, component qualification, and utility interconnection. Project authorization requests with the Institute of Electrical and Electronic Engineers (IEEE) have resulted in standards for component qualification and were further adapted for standards used to list PV modules and balance-of-system components. Industry collaboration with Underwriter Laboratories, Inc., with the American Society for Testing and Materials, and through critical input and review for international standards with the International Electrotechnical Commission have resulted in new and revised domestic and international standards for PV applications. Activities related to work on codes and standards through the International Energy Agency are also being supported by the PV industry and the US DOE. The paper shows relationships between activities in standards writing.
Date: October 1, 1997
Creator: Bower, W. & Whitaker, C.
Partner: UNT Libraries Government Documents Department

Summary of collaborative photovoltaic industry work to proactively improve codes and standards for photovoltaic power system applications

Description: Several important milestones in codes and standards pertaining to the design, installation and operation of photovoltaic (PV) systems have recently been completed with collaboration of participants from all sectors of the PV industry, utilities and the US Department of Energy`s National Photovoltaic Program. Codes and standards that have been proposed, written or modified include changes and additions for the 1999 National Electrical Code{reg_sign} (NEC{reg_sign}), standards for fire and personnel safety, system testing, component qualification, and utility interconnect. Project authorization requests with the Institute of Electrical and Electronic Engineers (IEEE) have resulted in standards for listing PV modules and balance-of-system components. Industry collaboration with Underwriter Laboratories, Inc. (UL), with the American Society for Testing and Materials (ASTM), and through critical input and review for international standards with the International Electrotechnical Commission (IEC) have resulted in domestic and international standards for PV. Work related to the codes and standards activities through the International Energy Agency (IEA) is also being supported by the PV industry and the US DOE. This paper will concentrate on and summarize the important new NEC proposals for PV systems and will also describe and show the bonds between the activities in other standards writing activities. The paper will also provide an analysis of changes and resulting impacts of selected proposed NEC changes on PV designs, installations and performance.
Date: August 1, 1997
Creator: Bower, W.I.
Partner: UNT Libraries Government Documents Department

Test report on the Abacus 30 kW bimode{reg_sign} inverter and maximum power tracker (MPT)

Description: Sandia National Laboratories conducts the photovoltaic balance of systems (BOS) program, which is sponsored by the US Department of Energy`s Office of Energy Management. Under this program, SNL lets commercialization contracts and conducts a laboratory program designed to advance BOS technology, improve BOS component reliability, and reduce the BOS life-cycle-cost. This report details the testing of the first large US manufactured hybrid inverter and its associated maximum power tracker.
Date: June 1, 1995
Creator: Bonn, R.; Ginn, J. & Zirzow, J.
Partner: UNT Libraries Government Documents Department