RESOURCE COMPARISONS (LAND, WATER, AND MATERIALS) William B. Wilson Teknekron Research, Inc. - 1483 Chain Bridge Road - McLean, VA 22101 This paper compares and evaluates the land, water, and material requirements of eight energy systems: coal w/FGD, coal gasification c/c, light water reactors, liquid metal fast breeder reactors, centralized and decentralized photovoltaic solar power systems, and satellite power systems (SPS). The assessment involves both a side-by-side comparison of the eight energy systems -- normalized to 1250 MWe of capacity -- and an alternative future analysis in which the resource requirements of the technologies are evaluated across time. Normalized to 1250 MWe, the coal and SPS fuel cycles require the most land: 13,600 and 15,000 acres respectively. Terrestrial photovoltaic solar systems also require large quantities of land. Except for fusion, the nuclear fuel cycles need large contiguous land areas for the disposal of high-level radioactive wastes (some 2,000-18,000 acres) but when this requirement is normalized 1250 MWe, the land impact is small. The decentralized photovoltaic solar system (i.e., the roof-top system) requires almost no land becuase it makes use of land already in use. The alternative futures analysis revealed that development of the coal and SPS technologies will considerably increase the amount of land that must be allocated to the production of electrical power (see Figure 1). For example, a 300 gigawatt SPS system would require some 3.6 million acres of land; this would be approximately a third less if SPS was used to replace coal power plants rather than nuclear. In addition, it may be possible to offset this impact by utilizing lower quality lands for rectenna sites, offshore siting, and multiple uses of the sites. The coal and nuclear fuel cycles require several orders of magnitude more water than any of the photovoltaic technologies (see Figure 2). Water pollution is a relatively insignificant problem with the steam technologies but evaporation losses are critical and limit the siting of coal and nuclear power plants in water short areas -- mainly the West. Under the alternative futures analysis, water requirements for all the steam fuel cycles more than doubled. However, the development of SPS considerably reduces the estimated quantity of water required to produce electrical energy -- by more than that currently used today to produce electrical power. Hence, SPS offers large potential benefits to water short areas; the same areas for which it is also advantageous for other reasons (i.e., high insolation, the presence of large contiguous land areas, and the relative availability of lower quality land). The side-by-side assessment of material requirements showed that all fuel cycles must rely -- to varying degrees -- on imported materials. However, in the near term, materials are not a significant issue since U.S. reserves are adequate to meet the demand. In addition, the alternative futures analysis concluded that all the fuel cycles under consideration may encounter future material problems, especially with respect to aluminum, chromium, gallium, nickel, silver, and tungsten. The major constraint is production (i.e., competition from competing users) rather than availability; the effect of import reliance is uncertain.
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