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Megawatt solar power systems for lunar surface operationsLunar surface operations require habitation, transportation, life support, scientific, and manufacturing systems, all of which require some form of power. As an alternative to nuclear power, the development of a modular one megawatt solar power system is studied, examining both photovoltaic and dynamic cycle conversion methods, along with energy storage, heat rejection, and power backup subsystems. For photovoltaic power conversion, two systems are examined. First, a substantial increase in photovoltaic conversion efficiency is realized with the use of new GaAs/GaSb tandem photovoltaic cells, offering an impressive overall array efficiency of 23.5 percent. Since these new cells are still in the experimental phase of development, a currently available GaAs cell providing 18 percent efficiency is examined as an alternate to the experimental cells. Both Brayton and Stirling cycles, powered by linear parabolic solar concentrators, are examined for dynamic cycle power conversion. The Brayton cycle is studied in depth since it is already well developed and can provide high power levels fairly efficiently in a compact, low mass system. The dynamic conversion system requires large scale waste heat rejection capability. To provide this heat rejection, a comparison is made between a heat pipe/radiative fin system using advanced composites, and a potentially less massive liquid droplet radiator system. To supply power through the lunar night, both a low temperature alkaline fuel cell system and an experimental high temperature monolithic solid-oxide fuel cell system are considered. The reactants for the fuel cells are stored cryogenically in order to avoid the high tankage mass required by conventional gaseous storage. In addition, it is proposed that the propellant tanks from a spent, prototype lunar excursion vehicle be used for this purpose, therefore resulting in a significant overall reduction in effective storage system mass.
Document ID
19900017075
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Adams, Brian
(Washington Univ. Seattle, WA, United States)
Alhadeff, Sam
(Washington Univ. Seattle, WA, United States)
Beard, Shawn
(Washington Univ. Seattle, WA, United States)
Carlile, David
(Washington Univ. Seattle, WA, United States)
Cook, David
(Washington Univ. Seattle, WA, United States)
Douglas, Craig
(Washington Univ. Seattle, WA, United States)
Garcia, Don
(Washington Univ. Seattle, WA, United States)
Gillespie, David
(Washington Univ. Seattle, WA, United States)
Golingo, Raymond
(Washington Univ. Seattle, WA, United States)
Gonzalez, Drew
(Washington Univ. Seattle, WA, United States)
Date Acquired
September 6, 2013
Publication Date
June 21, 1990
Subject Category
Energy Production And Conversion
Report/Patent Number
AA-420
NASA-CR-186509
AA-421
NAS 1.26:186509
Accession Number
90N26391
Funding Number(s)
CONTRACT_GRANT: NGT-21-002-800
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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