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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Development of an advanced photovoltaic concentrator system for space applications

Recent studies indicate that significant increases in system performance (increased efficiency and reduced system mass) are possible for high power space based systems by incorporating technological developments with photovoltaic power systems. The Advanced Photovoltaic Concentrator Program is an effort to take advantage of recent advancements in refractive optical elements. By using a domed Fresnel lens concentrator and a prismatic cell cover, to eliminate metallization losses, dramatic reductions in the required area and mass over current space photovoltaic systems are possible. The advanced concentrator concept also has significant advantages when compared to solar dynamic Organic Rankine Cycle power systems in Low Earth Orbit applications where energy storage is required. The program is currently involved in the selection of a material for the optical element that will survive the space environment and a demonstration of the system performance of the panel design.

Piszczor, Michael F., Jr.↗
NASA NTRS1987

Mathematical modeling of a photovoltaic-laser energy converter for iodine laser radiation

Space-based laser power systems will require converters to change laser radiation into electricity. Vertical junction photovoltaic converters are promising devices for this use. A promising laser for the laser power station is the t-C4F9I laser which emits radiation at a wavelength of 1.315 microns. This paper describes the results of mathematical modeling of a photovoltaic-laser energy converter for use with this laser. The material for this photovoltaic converter is Ga(53)In(47)As which has a bandgap energy of 0.94 eV, slightly below the energy of the laser photons (0.943 eV). Results of a study optimizing the converter parameters are presented. Calculated efficiency for a 1000 vertical junction converter is 42.5 percent at a power density of 1 x 10 to the 3d power w/sq cm.

Walker, Gilbert H.↗
NASA NTRS1985

A photovoltaic power system and a low-power satellite earth station for Indonesia

A photovoltaic power system and a low-power, two-way satellite earth station have been installed at Wawotobi, Sulawesi, Indonesia to provide university classroom communications for audio teleconferencing and video graphics. This project is a part of the Agency for International Development's Rural Satellite Program. The purpose of this program is to demonstrate the use of satellite communications for development assistance applications. The purpose of the photovoltaic power system is to demonstrate the suitability of a hybrid photovoltaic/engine-generator power system for a remote satellite earth station. This paper describes the design, installation and initial operation of the photovoltaic power system and the earth station.

Delombard, Richard↗
NASA NTRS1987

Recent progress in space photovoltaic systems

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.

Brandhorst, Henry W., Jr.↗
NASA NTRS1987

Low Earth orbit environmental effects on the space station photovoltaic power generation systems

A summary of the Low Earth Orbital Environment, its impact on the Photovoltaic Power systems of the space station and the solutions implemented to resolve the environmental concerns or issues are described. Low Earth Orbital Environment (LEO) presents several concerns to the Photovoltaic power systems of the space station. These concerns include atomic oxygen interaction with the polymeric substrate of the solar arrays, ionized environment effects on the array operating voltage, the effects of the meteoroids and debris impacts and penetration through the different layers of the solar cells and their circuits, and the high energy particle and radiation effects on the overall solar array performance. Potential solutions to some of the degrading environmental interactions that will provide the photovoltaic power system of the space station with the desired life are also summarized.

Nahra, Henry K.↗
NASA NTRS1987

A novel photovoltaic power system which uses a large area concentrator mirror

A preliminary analysis has been made of a novel photovoltaic power system concept. The system is composed of a small area, dense photovoltaic array, a large area solar concentrator, and a battery system for energy storage. The feasibility of such a system is assessed for space power applications. The orbital efficiency, specific power, mass, and area of the system are calculated under various conditions and compared with those for the organic Rankine cycle solar dynamic system proposed for Space Station. Near term and advanced large area concentrator photovoltaic systems not only compare favorably to solar dynamic systems in terms of performance but offer other benefits as well.

Arrison, Anne↗
NASA NTRS1987

Development of an advanced photovoltaic concentrator system for space applications

Recent studies indicate that significant increases in system performance (increased efficiency and reduced system mass) are possible for high power space based systems by incorporating technological developments with photovoltaic power systems. The Advanced Photovoltaic Concentrator Program is an effort to take advantage of recent advancements in refractive optical elements. By using a domed Fresnel lens concentrator and a prismatic cell cover, to eliminate metallization losses, dramatic reductions in the required area and mass over current space photovoltaic systems are possible. The advanced concentrator concept also has significant advantages when compared to solar dynamic Organic Rankine Cycle power systems in Low Earth Orbit applications where energy storage is required. The program is currently involved in the selection of a material for the optical element that will survive the space environment and a demonstration of the system performance of the panel design.

Piszczor, Michael F., Jr.↗
NASA NTRS1987

Issues in space photovoltaic research and technology

Key issues and opportunities in space photovoltaic research and technology are addressed relative to future NASA mission requirements and drivers. Examples are given of future space missions and/or operational capabilities that are on NASA's planning horizon, presenting major technology challenges to the use of photovoltaic power generation in space. A brief description of the capabilities ascribed to the competing technologies of nuclear and solar thermal power systems are discussed. The performance goals that space photovoltaic power systems must meet to remain competitive are described.

Flood, Dennis J.↗
NASA NTRS1988

Photovoltaics for high capacity space power systems

The anticipated energy requirements of future space missions will grow by factors approaching 100 or more, particularly as a permanent manned presence is established in space. The advances that can be expected in solar array performance and lifetime, when coupled with advanced, high energy density storage batteries and/or fuel cells, will continue to make photovoltaic energy conversion a viable power generating option for the large systems of the future. The specific technologies required to satisfy any particular set of power requirements will vary from mission to mission. Nonetheless, in almost all cases the technology push will be toward lighter weight and higher efficiency, whether of solar arrays or storage devices. This paper will describe the content and direction of the current NASA program in space photovoltaic technology. The paper will also discuss projected system level capabilities of photovoltaic power systems in the context of some of the new mission opportunities under study by NASA, such as a manned lunar base, and a manned visit to Mars.

Flood, Dennis J.↗
NASA NTRS1988

NASA photovoltaic research and technology

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.

Flood, Dennis J.↗
NASA NTRS1989

Space power technology 21: Photovoltaics

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.

Wise, Joseph↗
NASA NTRS1988

Photovoltaics for high capacity space power systems

The anticipated energy requirements of future space missions will grow by factors approaching 100 or more, particularly as a permanent manned presence is established in space. The advances that can be expected in solar array performance and lifetime, when coupled with advanced, high energy density storage batteries and/or fuel cells, will continue to make photovoltaic energy conversion a viable power generating option for the large systems of the future. The specific technologies required to satisfy any particular set of power requirements will vary from mission to mission. Nonetheless, in almost all cases the technology push will be toward lighter weight and higher efficiency, whether of solar arrays of storage devices. This paper will describe the content and direction of the current NASA program in space photovoltaic technology. The paper will also discuss projected system level capabilities of photovoltaic power systems in the context of some of the new mission opportunities under study by NASA, such as a manned lunar base, and a manned visit to Mars.

Flood, Dennis J.↗
NASA NTRS1988

Low earth orbit environmental effects on the Space Station photovoltaic power generation systems

A summary of the low earth orbital environment, its impact on the photovoltaic power systems of the Space Station and the solutions implemented to resolve the environmental concerns or issues are described. Low earth orbital environment (LEO) presents several concerns to the photovoltaic power systems of the Space Station. These concerns include atomic oxygen interaction with the polymeric substrate of the solar arrays, ionized environment effects on the array operating voltage, the effects of the meteoroids and debris impacts and penetration through the different layers of the solar cells and their circuits, and the high energy particle and radiation effects on the overall solar array performance. Potential solutions to some of the degrading environmental interactions that will provide the photovoltaic power system of the Space Station with the desired life are also summarized.

Nahra, H. K.↗
NASA NTRS1991

Space Photovoltaic Research and Technology Conference

The Eleventh Space Photovoltaic Research and Technology conference was held at NASA Lewis Research Center from May 7 to 9, 1991. The papers and workshop summaries presented here report remarkable progress on a wide variety of approaches in space photovoltaics, both near and far term applications. Papers were presented in a variety of technical areas, including multijunction cell technology, GaAs and InP cells, system studies, cell and array development, and photovoltaics for conversion of laser radiation. Three workshops were held to discuss thin film cell development, III-V cell development, and space environmental effects.

Source record↗
NASA NTRS1990

Component and prototype panel testing of the mini-dome Fresnel lens photovoltaic concentrator array

The mini-dome Fresnel lens concentrator array, a high-efficiency, lightweight space photovoltaic array concept, is described. The three critical elements of the array concept are the Fresnel lens concentrator, the prismatic cell power cover, and the photovoltaic cell. Prototype concentrator lenses have been fabricated and tested, with optical efficiencies reaching 90 percent. Work is progressing on the design and fabrication of the panel structure. The impact of recent advances in 30 percent-efficient multijunction photovoltaic cells on array performance is also discussed. Near-term performance goals of 300 w/sq m and 100 w/kg are now feasible.

Piszczor, Michael F.↗
NASA NTRS1990

Design considerations for Mars photovoltaic power systems

Considerations for operation of a photovoltaic power system on Mars are discussed with reference to Viking Lander data. The average solar insolation at Mars is 590 W/sq m, which is reduced yet further by atmospheric dust. Of major concern are dust storms, which have been observed to occur on local as well as on global scales, and their effect on solar array output. While atmospheric opacity may rise to values ranging from 3 to 9, depending on storm severity, there is still an appreciable large diffuse illumination, even at high opacities, so that photovoltaic operation is still possible. If the power system is to continue to generate power even on high-optical-opacity (i.e., dusty atmosphere) days, it is important that the photovoltaic system be designed to collect diffuse irradiance as well as direct. Energy storage will be required for operation during the night. Temperature and wind provide additional considerations for array design.

Landis, Geoffrey A.↗
NASA NTRS1991

A high-performance photovoltaic concentrator array - The mini-dome Fresnel lens concentrator with 30 percent efficient GaAs/GaSb tandem cells

A high-efficiency, lightweight space photovoltaic concentrator array is described. Previous work on the minidome Fresnel lens concentrator concept is being integrated with Boeing's 30 percent efficient tandem GaAs/GaSb concentrator cells into a high-performance photovoltaic array. Calculations indicate that, in the near term, such an array can achieve 300 W/sq m at a specific power of 100 W/kg. Emphasis of the program has now shifted to integrating the concentrator lens, tandem cell, and supporting panel structure into a space-qualifiable array. A description is presented of the current status of component and prototype panel testing and the development of a flight panel for the Photovoltaic Array Space Power Plus Diagnostics (PASP PLUS) flight experiment.

Piszczor, M. F.↗
NASA NTRS1993

Photovoltaic Power Without Batteries for Continuous Cathodic Protection

The objective of this project was to successfully demonstrate that renewable energy can efficiently and economically replace dedicated non-renewable power sources. The COASTSYSTA designed, installed, and started up on 20 Jan. 1990, a state-of-the-art photovoltaic powered impressed current cathodic protection system (PVCPSYS) for steel and iron submerged structures. This system does not require any auxiliary/battery backup power. The PVCPSYS installed on 775 ft. of steel sheet piling of a Navy bulkhead is continuing to provide complete, continuous corrosion protection. This installation is well documented by COASTSYSTA and was verified on-site by the U.S. Army Corps of Engineers. The PVCPSYS uses only renewable energy and is environmentally clean. A patent is pending on the new technology. Other possible PVCPSYS applications are mothballed ships, docks, dams, locks, bridges, marinas, and pipelines. The Department of Defense Photovoltaic Review Committee and Sandia National Laboratories consider this successful and cost effective system a major advance in the application of photovoltaics.

Muehl, W. W., Sr.↗