TECHNICAL MEMORANDUM X-73344 SATELLITE POWER SYSTEMS AN ENGINEERING AND ECONOMIC ANALYSIS SUMMARY 1.0 INTRODUCTION 1.1 BACKGROUND Rapidly increasing rates of consumption of the Earth's available fossil and nuclear fuel stores are characteristic of this latter half of the 20th century. Global population is increasing, as is that fraction of the population which forms the energy consuming ''middle class." This is true not only in the United States, Russia, Japan, etc., but also in what are termed emerging nations. Asa consequence, we may expect existing global energy sources to last only to the following approximate dates: oil, 1995 to 2005; coal, 2030 to 2080; and uranium (without breeder reactors), 2020 to 2050. As these energy sources are consumed, four additional factors emerge. First, their cost steadily increases as remaining quantities become more difficult to obtain (e. g., coal veins become thinner). Second, their consumption releases additional pollutants to the biosphere (e.g., CO2 removed from the atmosphere over thousands of years by plants, which formed coal, is now being returned). Third, since energy sources are geographically concentrated (e.g., most coal reserves are in the United States, and most oil resources are in the Middle East), a potential for great international tension and possibly war may be created as reserves dwindle. Fourth, nuclear fission involves byproduct materials that may be used for weapon production by either governments or outlaws. Thus, some attention is now turning to ''renewable" or ''nondepletable" energy sources. Primary candidates for electric power appear to be nuclear breeder reactors, nuclear fusion, and solar energy. These are characterized by varying degrees of complexity, technical risk, pollution, cost, etc. Each could reduce our dependence on imports and, if adopted by other nations, serve to reduce international tensions. Solar power may be used directly for heating and cooling; it may also be used for the production of electricity. Primary concepts for electric power production on Earth are photovoltaic (solar cell arrays or ''farms") and
RkJQdWJsaXNoZXIy MTU5NjU0Mg==