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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

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

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

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

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

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

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

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

Tracking the Sun: The Installed Cost of Photovoltaics in the U.S. from 1998-2007

Description: As installations of grid-connected solar photovoltaic (PV) systems have grown, so too has the desire to track the installed cost of these systems over time, by system characteristics, by system location, and by component. This report helps to fill this need by summarizing trends in the installed cost of grid-connected PV systems in the United States from 1998 through 2007. The report is based on an analysis of installed cost data from nearly 37,000 residential and non-residential PV systems, totaling 363 MW of capacity, and representing 76percent of all grid-connected PV capacity installed in the U.S. through 2007.
Date: February 11, 2009
Creator: Wiser, Ryan; Barbose, Galen & Peterman, Carla
Partner: UNT Libraries Government Documents Department

Experimental optimization of the FireFly 600 photovoltaic off-grid system.

Description: A comprehensive evaluation and experimental optimization of the FireFly{trademark} 600 off-grid photovoltaic system manufactured by Energia Total, Ltd. was conducted at Sandia National Laboratories in May and June of 2001. This evaluation was conducted at the request of the manufacturer and addressed performance of individual system components, overall system functionality and performance, safety concerns, and compliance with applicable codes and standards. A primary goal of the effort was to identify areas for improvement in performance, reliability, and safety. New system test procedures were developed during the effort.
Date: October 1, 2003
Creator: Boyson, William Earl; Orozco, Ron (Energia Total, Ltd., Corrales, NM); Ralph, Mark E.; Brown, Marlene Laura; King, David L. & Hund, Thomas D.
Partner: UNT Libraries Government Documents Department

UPVG phase 2 report

Description: The Utility PhotoVoltaic Group (UPVG), supported by member dues and a grant from the US Department of Energy, has as its mission the acceleration of the use of cost-effective small-scale and emerging large-scale applications of photovoltaics for the benefit of electric utilities and their customers. Formed in October, 1992, with the support of the American Public Power Association, Edison Electric Institute, and the National Rural Electric Cooperative Association, the UPVG currently has 90 members from all sectors of the electric utility industry. The UPVG`s efforts as conceived were divided into four phases: Phase 0--program plan; Phase 1--organization and strategy development; Phase 2--creating market assurance; and Phase 3--higher volume purchases. The Phase 0 effort developed the program plan and was completed early in 1993. The Phase 1 goal was to develop the necessary background information and analysis to lead to a decision as to which strategies could be undertaken by utilities to promote greater understanding of PV markets and achieve increased volumes of PV purchases. This report provides the details of the UPVG`s Phase 2 efforts to initiate TEAM-UP, its multiyear, 50-MW hardware initiative.
Date: August 1, 1995
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

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

Description: 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.
Date: September 1, 1996
Creator: Al-Ibrahim, A.M.; Klein, S.A.; Mitchell, J.W. & Beckman, W.A.
Partner: UNT Libraries Government Documents Department

Phase II-photovoltaics for utility scale applications (PVUSA). Second quarterly technical report, 1996

Description: PVUSA transition and project planning activities continued, but the CEC/SMUD assumption of project management duties will likely be delayed until the end of 1996 while the California Public Utilities Commission (CPUC) evaluates PG&E`s filing for transferring project assets to the CEC.
Date: September 1, 1996
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

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

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

Joint DOE/industry photovoltaic system reliability program

Description: To achieve the lowest life-cycle cost (LCC), photovoltaic (PV) systems must have the optimum mix of low first cost, low operation and maintenance (O&M) cost, and high availability. Additionally, the long-term health of the photovoltaic (PV) industry requires that PV systems work as expected. Although PV modules now enjoy high reliability due to a significant multi-year effort by both the U.S. Department of Energy (DOE) and industry, the same is not always true of PV systems. Even for systems that do operate reliably, customers, suppliers, and manufacturers can benefit from knowing what O&M expenses to expect. This knowledge will reduce technology risk to the customer and improve likelihood of commitment to PV projects. System integrators and utilities may benefit from O&M cost information to improve system designs, to properly price service agreements and warranties, and to optimize maintenance strategies. The DOE and component manufacturers may benefit from identifying cost drivers to optimally focus research and quality assurance resources to improve product reliability. This paper discusses the first of five tasks identified for this project, quantifying system reliability and life cycle cost by collecting, analyzing and reporting data on PV system reliability and cost. Industry participants collect the necessary O&M data on systems they are monitoring. Sandia provides support in the form of assistance identifying data that needs to be collected, helping develop forms or databases to collect the data, and analyzing the data.
Date: June 1, 1997
Creator: Maish, A.B.; Atcitty, C. & Hester, S.
Partner: UNT Libraries Government Documents Department

Blocking diodes and fuses in low-voltage PV systems

Description: Instructions and labels supplied with listed PV modules and the requirements of the National Electrical Code (NEC) dictate that a series fuse shall be used to protect the module against backfeed currents. Few of the hundreds of thousands of low-voltage (12, 24, and 48-volt) stand-alone photovoltaic (PV) power systems use series fuses on each module or string of modules. Tests and simulations at the Southwest Technology Development Institute (TDI) and at Sandia National Laboratories (SNL) have established that the absence of these fuses can pose significant fire and safety hazards even on 12-volt PV systems. If the system has sufficient backfeed voltage and current, it is possible that a ground fault in the wiring or inside a module can result in the destruction of a PV module.
Date: November 1, 1997
Creator: Wiles, J.C. & King, D.L.
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

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