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Results for “Solar energy conversion”

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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

A low cost high temperature sun tracking solar energy collector

The design and economic evaluation of a low cost high temperature two-axis, sun tracking solar energy collector is described. The collector design was specifically intended for solar energy use with the freedom of motion about its two control axes limited only to the amplitude required to track the sun. An examination of the performance criteria required in order to track the sun and perform the desired solar energy conversion was used as the starting point and guide to the design. This factor, along with its general configuration and structural aspect ratios, was the significant contributor to achieving low cost. The unique mechanical design allowed the control system to counter wide tolerances specified for the fabrication of the azimuth frame and to perform within a small tracking error.

Perkins, G. S.↗
NASA NTRS1979

The NASA Lewis Research Center program in space solar cell research and technology

Progress in space solar cell research and technology is reported. An 18 percent-AMO-efficient silicon solar cell, reduction in the radiation damage suffered by silicon solar cells in space, and high efficiency wrap-around contact and thin (50 micrometer) coplanar back contact silicon cells are among the topics discussed. Reduction in the cost of silicon cells for space use, cost effective GaAs solar cells, the feasibility of 30 percent AMO solar energy conversion, and reliable encapsulants for space blankets are also considered.

Brandhorst, H. W., Jr.↗
NASA NTRS1979

Solar power satellite system definition study. Volume 2, phase 1: Systems analyses tradeoffs.

A systems definition study of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed. Space construction and support systems are examined including a series construction and equipment characteristics analysis. Space transportation for the satellite and the ground receiving station are assessed.

Source record↗
NASA NTRS1979

Solar power satellite system definition study. Volume 3: Reference system description, phase 1

An analysis of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed including the structure, power distribution, thermal control, and energy storage. Space construction and support systems are described including the work support facilities and construction equipment. An assessment of the space transportation system for the satellite and the ground receiving station is presented.

Source record↗
NASA NTRS1980

A quinone-assisted photoformation of energy-rich chemical bonds

In a study of biochemical means of solar energy conversion, ADP and inorganic phosphates were converted to ATP by white light in the nonaqueous solvent dimethylformamide in the presence of tetrachloro-p-quinone or ubiquinone. Conversion of ADP to ATP has been accomplished in aqueous suspension by the use of cell-like structures aggregated from poly(aspartic acid, glutamic acid, tyrosine). This is believed to occur through the formation of dopaquinone in the peptide structure during illumination. The way in which the quantitative yield of ATP has been influenced by pH and by added substances, such as FeCl2, was studied.

Fox, S. W.↗
NASA NTRS1980

An overview on European SPS activities

The organization of space and energy research in Europe is discussed. The European situation is highlighted with emphasis on the dependency of energy imports and on the energy requirements of Europe. The status of SPS research in the countries that form the European Space Agency was reviewed. It is concluded that in view of the unfavorable geographical and climatic situation of large parts of Europe, terrestrial solar energy conversion is unlikely to make a significant contribution to Europe's future energy supply. Thus, SPS development is of special interest to the European community.

Reinhartz, K. K.↗
NASA NTRS1981

Unconventional processes for food regeneration in space - An overview

Alternatives to conventional plant agriculture for the regeneration of food during space missions of extended duration are examined. The options considered, which may be used in combination with conventional agriculture, include the production of food from plant wastes, the chemical synthesis of food from carbon dioxide and other simple molecules or the substitution of edible chemicals, and the use of microrganisms for food and oxygen regeneration, with suitable processing. A comparison of solar energy conversion efficiencies is presented for nonphotosynthetic bacteria grown on hydrogen and algal systems photosynthetically, and it is shown that hydrogen bacteria are potentially more attractive than photosynthetic algae using artificial light. Weight-volume requirements for the conventional plant, algae and hydrogen bacteria systems are also compared to demonstrate the advantages of microbial systems.

Stokes, B. O.↗
NASA NTRS1982

Assessing solar energy and water use efficiencies in winter wheat

The water use and solar energy conversion efficiencies of two cultivars of winter wheat (Triticum aestivum L., vars, Centurk and Newton) planted at three densities, were examined during a growing season. Water use, based on soil moisture depletion, was the lowest under the light, and the highest under the heavy planting densities of both cultivars. Water use efficiency of medium and heavy planting densities were greater than the light planting densities in both cultivars. The canopy radiation extinction coefficients of both cultivars increased with increases in planting density. Efficiency of operation interception of photosynthetically active radiation by both cultivars improved from the time of jointing until anthesis, and then decreased during senescence. The efficiency of the conversion of intercepted radiation to dry matter (biochemical efficiency) decreased throughout the growing season both cultivars. The interception, biochemical, and photosynthetic efficiencies improved as planting density increased.

Asrar, G.↗
NASA NTRS1984

Advanced module development overview

Crystalline silicon solar power modules are examined for reliability and cost effectiveness. A goal of 12% solar energy conversion efficiency is considered feasible at a cost of 12/kWh, and a decision is made to limit consideration to float zone silicon wafer and dendritic web silicone modules. A preliminary module packaging configuration of glass/ethylene vinyl acetate/plastic film is selected. Anticipated module efficiency levels are 12.6% at 25 C and 11.5% at NOCT (Nominal Operating Cell Temperature).

Smokler, M. I.↗
NASA NTRS1984

Status of high-efficiency module design and fabrication

The fabrication of high efficiency solar energy conversion modules (13% efficiency at NOCT - Nominal Operating Cell Temperature) is discussed, with emphasis placed on reducing NOCT, since reduced operating temperature improves both efficiency and module lifetime.

Spitzer, M. B.↗
NASA NTRS1984

Module Hipot and ground continuity test results

Hipot (high voltage potential) and module frame continuity tests of solar energy conversion modules intended for deployment into large arrays are discussed. The purpose of the tests is to reveal potentially hazardous voltage conditions in installed modules, and leakage currents that may result in loss of power or cause ground fault system problems, i.e., current leakage potential and leakage voltage distribution. The tests show a combined failure rate of 36% (69% when environmental testing is included). These failure rates are believed easily corrected by greater care in fabrication.

Griffith, J. S.↗
NASA NTRS1984

Photovoltaic module spread-of-flame testing

Photovoltaic modules used in solar energy conversion are tested for flammability. Class B burning brand tests were conducted with the following results: module glass shattered and hydrocarbon encapsulants ignited. Penetration of back surface material was the prime cause of failure. Materials with greater flame and heat resistance are under consideration to increase back surface integrity up to Class A burning brand standard. The most promising is stainless steel foil.

Sugimura, R. S.↗
NASA NTRS1984

Improved Nominal Operating Cell Temperature (NOCT) test procedure

A procedure is developed to improve testing of Nominal Operating Cell Temperature (NOCT) as it applies to solar energy conversion modules. NOCT is a direct reflection of module thermal design and is closely related to the representative ambient temperature. It is also a key to array energy production and estimates of module lifetimes. Present NOCT test and evaluation procedures are inconsistent, producing significant scatter. Test refinements would specify a clear sky, the addition of 10% to the insolation level for ground reflection, the addition of a ground emission factor of 0.8 (at 30C ground temperature), an effective wind direction of 135 degrees from the North, and a module tilt of 30 degrees from the horizon.

Wen, L.↗
NASA NTRS1984

Thin-film reliability and engineering overview

The reliability and engineering technology base required for thin film solar energy conversions modules is discussed. The emphasis is on the integration of amorphous silicon cells into power modules. The effort is being coordinated with SERI's thin film cell research activities as part of DOE's Amorphous Silicon Program. Program concentration is on temperature humidity reliability research, glass breaking strength research, point defect system analysis, hot spot heating assessment, and electrical measurements technology.

Ross, R. G., Jr.↗
NASA NTRS1988

Condensing, Two-Phase, Contact Heat Exchanger

Two-phase heat exchanger continuously separates liquid and vapor phases of working fluid and positions liquid phase for efficient heat transfer. Designed for zero gravity. Principle is adapted to other phase-separation applications; for example, in thermodynamic cycles for solar-energy conversion.

Cox, R. L.↗
NASA NTRS1992

Global change - Geoengineering and space exploration

Geoengineering options and alternatives are proposed for mitigating the effects of global climate change and depletion of the ozone layer. Geoengineering options were discussed by the National Academy of Science Panel on the Policy Implications of Greenhouse Warming. Several of the ideas conveyed in their published report are space-based or depend on space systems for implementation. Among the geoengineering options using space that are discussed include the use of space power systems as an alternative to fossil fuels for generating electricity, the use of lunar He-3 to aid in the development of fusion energy, and the establishment of a lunar power system for solar energy conversion and electric power beaming back to earth. Other geoengineering options are discussed. They include the space-based modulation of hurricane forces and two space-based approaches in dealing with ozone layer depletion. The engineering challenges and policy implementation issues are discussed for these geongineering options.

Jenkins, Lyle M.↗
NASA NTRS1994

Space power systems technology

Reported here is a series of studies which examine several potential catalysts and electrodes for some fuel cell systems, some materials for space applications, and mathematical modeling and performance predictions for some solid oxide fuel cells and electrolyzers. The fuel cell systems have a potential for terrestrial applications in addition to solar energy conversion in space applications. Catalysts and electrodes for phosphoric acid fuel cell systems and for polymer electrolyte membrane (PEM) fuel cell and electrolyzer systems were examined.

Coulman, George A.↗