Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final report. Volume VII: Module encapsulation

The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development. The objective of the Encapsulation Task was to develop, demonstrate, and qualify photovoltaic (PV) module encapsulation systems that would provide 20-year (later increased to 30-year) life expectancies in terrestrial environments, and which would be compatible with the cost and performance goals of the FSA Project. The scope of the Encapsulation Task included the identification, development, and evaluation of material systems and configurations required to support and protect the optically and electrically active solar cell circuit components in the PV module operating environment. Encapsulation material technologies summarized in this report include the development of low-cost ultraviolet protection techniques, stable low-cost pottants, soiling resistant coatings, electrical isolation criteria, processes for optimum interface bonding, and analytical and experimental tools for evaluating the long-term durability and structural adequacy of encapsulated modules. Field testing, accelerated stress testing, and design studies have demonstrated that encapsulation materials, processes, and configurations are available that will meet the FSA cost and performance goals. Thirty-year module life expectancies are anticipated based on accelerated stress testing results and on extrapolation of real-time field exposures in excess of 9 years

Design of broadband antireflective layer stacks with low surface energy prepared by sol-gel method on glass for photovoltaic application

236 p.En el Capítulo 1 de este trabajo de investigación, se introducen los aspectos relevantes relativos la tecnología fotovoltaica, tales como los tipos de células solares, así como la forma en la que estas células se integran en el módulo, y algunos requerimientos de los materiales. A continuación, se introducen los materiales, tecnologías y rutas de síntesis más prometedoras que permiten depositar recubrimientos anti-reflectantes mecánicamente robustos, con propiedades combinadas de anti-ensuciamiento. Las técnicas experimentales, sus fundamentos físicos, y el equipamiento utilizado para el desarrollo del trabajo se describen en el Capítulo 2. En el Capítulo 3, se presenta el diseño óptico teórico del sistema de recubrimientos que permiten maximizar la transmitancia óptica, en el rango de longitudes de onda en los que determinados tipos de células solares son activas. A continuación, se presenta el método experimental de síntesis de los recubrimientos cuyas cualidades objetivo has sido obtenidas en el cálculo teórico. En el Capítulo 4 se han preparado recubrimientos ó funcionalizaciones para obtener superficies con baja energía libre superficial que potencialmente repelan el agua, contaminantes y polvo. En el Capítulo 5, los sistemas de recubrimiento más prometedores se han sometido a una batería más completa ensayos de fiabilidad, algunos de ellos utilizados por la industria fotovoltaica para validar los materiales y componentes utilizados en la fabricación de módulos fotovoltaicos. Este trabajo de investigación se concluye con un Capitulo 6 que contiene conclusiones generales, líneas futuras y producción científica

Design of broadband antireflective layer stacks with low surface energy prepared by sol-gel method on glass for photovoltaic application

236 p.En el Capítulo 1 de este trabajo de investigación, se introducen los aspectos relevantes relativos la tecnología fotovoltaica, tales como los tipos de células solares, así como la forma en la que estas células se integran en el módulo, y algunos requerimientos de los materiales. A continuación, se introducen los materiales, tecnologías y rutas de síntesis más prometedoras que permiten depositar recubrimientos anti-reflectantes mecánicamente robustos, con propiedades combinadas de anti-ensuciamiento. Las técnicas experimentales, sus fundamentos físicos, y el equipamiento utilizado para el desarrollo del trabajo se describen en el Capítulo 2. En el Capítulo 3, se presenta el diseño óptico teórico del sistema de recubrimientos que permiten maximizar la transmitancia óptica, en el rango de longitudes de onda en los que determinados tipos de células solares son activas. A continuación, se presenta el método experimental de síntesis de los recubrimientos cuyas cualidades objetivo has sido obtenidas en el cálculo teórico. En el Capítulo 4 se han preparado recubrimientos ó funcionalizaciones para obtener superficies con baja energía libre superficial que potencialmente repelan el agua, contaminantes y polvo. En el Capítulo 5, los sistemas de recubrimiento más prometedores se han sometido a una batería más completa ensayos de fiabilidad, algunos de ellos utilizados por la industria fotovoltaica para validar los materiales y componentes utilizados en la fabricación de módulos fotovoltaicos. Este trabajo de investigación se concluye con un Capitulo 6 que contiene conclusiones generales, líneas futuras y producción científica

Solar Module Packaging

While global demand for photovoltaic (PV) modules has increased approximately 45 percent per year over the past decade, PV modules must be durable and inexpensive to compete with traditional energy resources. Often overlooked as a means to improve solar technology, polymer packaging is not only the key to protecting fragile solar cells from environmental factors, but is also the critical path for increasing the power performance of a PV module Solar Module Packaging: Polymeric Requirements and Selection explores current and future opportunities in PV polymeric packaging, emphasizing how it can simultaneously reduce cost, increase weatherability, and improve a PV module’s power. The book offers an insider’s perspective on the manufacturing processes and needs of the solar industry and reveals opportunities for future material development and processing. A broad survey of the polymeric packaging of solar cells, the text covers various classifications of polymers, their material properties, and optimal processing conditions. Taking a practical approach to material selection, it emphasizes industrial requirements for material development, such as cost reduction, increased material durability, improved module performance, and ease of processing. Addressing cost and profitability, the author examines the economics behind polymeric packaging and how it influences the selection process used by solar companies. Suitable for nonspecialists in polymer science, the book provides a basic understanding of polymeric concepts, fundamental properties, and processing techniques commonly used in solar module packaging. It presents guidelines for using polymers in commercial PV modules as well as the tests required to establish confidence in the selection process

Investigation of test methods, material properties, and processes for solar cell encapsulants

Photovoltaic (PV) modules consist of a string of electrically interconnected silicon solar cells capable of producing practical quantities of electrical power when exposed to sunlight. To insure high reliability and long term performance, the functional components of the solar cell module must be adequately protected from the environment by some encapsulation technique. The encapsulation system must provide mechanical support for the cells and corrosion protection for the electrical components. The goal of the program is to identify and develop encapsulation systems consistent with the PV module operating requirements of 30 year life and a target cost of $0.70 per peak watt ($70 per square meter) (1980 dollars). Assuming a module efficiency of ten percent, which is equivalent to a power output of 100 watts per square meter in midday sunlight, the capital cost of the modules may be calculated to be $70.00 per square meter. Out of this cost goal, only 20 percent is available for encapsulation due to the high cost of the cells, interconnects, and other related components. The encapsulation cost allocation may then be stated as$14.00 per square meter, included all coatings, pottant and mechanical supports for the cells

Mécanisme de salissage et de nettoyage en surface de matériaux polymères

Résumé: Le développement de l’industrie des polymères fourni de plus en plus de choix pour la formulation de matériaux pour les couvre-planchers. Les caoutchoucs, le PVC et le linoleum sont les polymères habituellement utilisés dans l’industrie des couvre-planchers. Ce projet répond à un problème de facilité de nettoyage des couvre-planchers de caoutchouc qui sont reconnus pour être mous, collants et ayant une surface rugueuse. L’INTRODUCTION couvrira l’état actuel de la recherche sur les couvre-planchers, surtout en regard au problème de la «nettoyabilité». La théorie pertinente et les informations générales sur les polymères, les composites polymériques et la science des surfaces seront introduites au CHAPITRE 1. Ensuite, le CHAPITRE 2 couvrira la méthode utilisée pour déterminer la nettoyabilité, l’évaluation des résultats ainsi que l’équipement utilise. Le CHAPITRE 3, discutera des premières expériences sur l’effet de la mouillabilité, la rugosité et la dureté sur la facilité de nettoyage des polymères purs. Plusieurs polymères ayant des surfaces plus ou moins hydrophobes seront investigués afin d’observer leur effet sur la nettoyabilité. L’effet de la rugosité sur la nettoyabilité sera investigué en imprimant une rugosité définie lors du moulage des échantillons; l’influence de la dureté sera également étudiée. Ensuite, un modèle de salissage/nettoyage sera établi à partir de nos résultats et observations afin de rationaliser les facteurs, ou « règles », qui détrminent la facilité de nettoyage des surfaces. Finalement, la réticulation au peroxyde sera étudiée comme une méthode de modification des polymères dans le but d’améliorer leur nettoyabilité; un mécanisme découlant des résultats de ces études sera présenté. Le CHAPITRE 4 étendra cette recherche aux mélanges de polymères; ces derniers servent habituellement à optimiser la performance des polymères purs. Dans ce chapitre, les mêmes tests discutés dans le CHAPITRE 3 seront utilisés pour vérifier le modèle de nettoyabilité établi ci-haut. De plus, l’influence de la non-miscibilité des mélanges de polymères sera discutée du point de vue de la thermodynamique (DSC) et de la morphologie (MEB). L’utilisation de la réticulation par peroxyde sera étudié dans les mélanges EPDM/ (E-ran-MAA(Zn)-ran-BuMA) afin d’améliorer la compatibilité de ces polymères. Les effets du dosage en agent de réticulation et du temps de cuisson seront également examinés. Finalement, un compatibilisant pré-réticulé a été développé pour les mélanges ternaires EPDM/ (E-ran-MAA(Zn)-ran-BuMA)/ HSR; son effet sur la nettoyabilité et sur la morphologie du mélange sera exposé.Abstract: The development of industrial polymers provides more choices to the design of flooring materials. Rubbers, PVC and linoeleum are the most used polymers in the flooring industry. This project stems from the problem of cleanability (ease of cleaning) of the surface of rubber tile flooring which is known as a soft, sticky and rough surface. In the introduction, the current situation of research on the polymer flooring industry, especially the study on the cleaning problem will be introduced. The relevant theory and general information on polymers, polymer composites and surface science will be introduced in CHAPTER 1. In CHAPTER 2 different approaches, protocols and equipment to evaluate cleanability will be presented. The initial experiments and results (CHAPTER 3) will involve various fundamental concepts on surface wettability, roughness and hardness, as these properties can all influence the surface soiling and cleanability. In single-polymer systems, dozens of polymer materials with a hydrophobic or hydrophilic surface were investigated to observe their soiling and cleaning properties. The effect of roughness was also studied by surface printing method which is used to control the surface topography. Likewise, the influence of surface hardness on cleanability was also investigated with different polymer materials. From the above results and observations, a surface soiling/cleaning model is proposed in attempt to simplify the ― rules ‖ which determine the surface cleanability. Finally, peroxide crosslinking was investigated as a matrix modification method to improve the surface cleanability. The second part of the experiments and results (CHAPTER 4) extends to investigations of polymer blends, in attempt to optimize the performance of single-polymer materials. In this chapter, the surface cleaning model and its relevant rules are examined by the wettability, roughness and hardness tests discussed in CHAPTER 3. The influence of immiscibility on cleaning performance will be discussed in polymer blends from the point of view of thermodynamics (DSC) and morphology (SEM). In order to improve the compatibility in polymer blends, peroxide crosslinking was performed in EPDM/ (E-ran-MAA(Zn)-ran-BuMA) blends. The dosage of curing (cross-linking) agent and curing time were investigated to observe the influence of these experimental conditions on cleanability. Finally, a blend compatibilizer was designed to improve the compatibility of the EPDM/ (E-ran-MAA(Zn)-ran-BuMA)/HSR blends.The compatibilizer prepared by partial pre-crosslinking of EPDM (Nordel) and E-ran-MAA(Zn)-ran-BuMA (Surlyn) was incorpo rated in polymer composites and its influence on cleanability was studied and explained on the basis of changes in morphology of the blend polymer matrix

Bibliography of Work on the Heterogeneous Photocatalytic Removal of Hazardous Compounds from Water and Air--Update Number 4 to October 2001

This report is the fifth in a series of bibliographies of work on the photocatalytic oxidation of organic or inorganic compounds in air or water and on the photocatalytic reduction of inorganic compounds in water. This search contains information extracted from 1149 new references to papers, books, and reports from searches conducted between October 1996 and April 2001

Photovoltaic module encapsulation design and materials selection, volume 1

Encapsulation material system requirements, material selection criteria, and the status and properties of encapsulation materials and processes available are presented. Technical and economic goals established for photovoltaic modules and encapsulation systems and their status are described. Available encapsulation technology and data are presented to facilitate design and material selection for silicon flat plate photovoltaic modules, using the best materials available and processes optimized for specific power applications and geographic sites. The operational and environmental loads that encapsulation system functional requirements and candidate design concepts and materials that are identified to have the best potential to meet the cost and performance goals for the flat plate solar array project are described. Available data on encapsulant material properties, fabrication processing, and module life and durability characteristics are presented

Index to 1986 NASA Tech Briefs, volume 11, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1986 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Reliability and Engineering of Thin-Film Photovoltaic Modules. Research forum proceedings

A Research Forum on Reliability and Engineering of Thin Film Photovoltaic Modules, under sponsorship of the Jet Propulsion Laboratory's Flat Plate Solar Array (FSA) Project and the U.S. Department of Energy, was held in Washington, D.C., on March 20, 1985. Reliability attribute investigations of amorphous silicon cells, submodules, and modules were the subjects addressed by most of the Forum presentations. Included among the reliability research investigations reported were: Arrhenius-modeled accelerated stress tests on a Si cells, electrochemical corrosion, light induced effects and their potential effects on stability and reliability measurement methods, laser scribing considerations, and determination of degradation rates and mechanisms from both laboratory and outdoor exposure tests