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Limits to solar power conversion efficiency with applications to quantum and thermal systemsAn analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.
Document ID
19840041253
Document Type
Reprint (Version printed in journal)
Authors
Byvik, C. E. (NASA Langley Research Center Hampton, VA, United States)
Buoncristiani, A. M. (NASA Langley Research Center Hampton, VA, United States)
Smith, B. T. (Christopher Newport College Newport News, VA, United States)
Date Acquired
August 12, 2013
Publication Date
December 1, 1983
Publication Information
Publication: Journal of Energy
Volume: 7
ISSN: 0146-0412
Subject Category
ENERGY PRODUCTION AND CONVERSION
Distribution Limits
Public
Copyright
Other