cuses on methanol, alcohol gasoline mix, and liquid natural gas as fuel alternatives to gasoline, research is also progressing rapidly on solar powered electric vehicles using battery powered electricity produced through photovoltaic conversion (Watanabe, 1992, pp. 60 61). Photovoltaic technology is the principal method through which solar radiation is transformed into electric power (Mersel, 1993, pp. 46 51. Solar power is attracting attention as an inexhaustible source of clean energy (Umemura, 1992, pp. 38 39). A major task involved in gaining acceptance for the development of solar generated electrical power is the improvement of the economic efficiency of the process. Nevertheless, average insolation levels characterizing global areas that are home to the great majority of the world's population suggest that solar conversion technologies hold great potential for the future (Kuhne and Aulich, 1992, pp. 847 860). Insolation is the solar radiation received on earth. On a global basis the level of solar radiation received on earth is between two and four times greater that the primary demand for energy (Kuhne and Aulich, 1992, pp. 847 860). Because the level of solar radiation received is so much greater than the level of energy demanded, the conversion of solar radiation to usable energy is considered to be an alternative source worth investigating.
Biomass fuels are also receiving attention. Biomass energy is energy derived through the distillation of botanical materials into a fuel which can be burned to create energy (Schweitzer, Carnes, Soderstrom, and Braid, 1983, pp. 333 345). Developmental costs for biomass energy are projected at moderate levels, while use costs would be expected to be little more than those associated with fossil fuels. Environmental harm stemming from the use of biomass energy would be less than that associated with the use of fossil fuels. The level of supply of biomass energy would be ess...