Solar, geothermal, wind, biomass, and hydroelectric power, plus a host of lesser-known energy sources, are discussed here. Heating a barn with cow manure, fermenting sugar-cane stalks, and splitting hydrogen to make auto fuel are some of the more unusual ideas. Interviews with scientists and engineers directly involved in energy projects abound, as do references to scientific papers and specialized energy organizations. But, unfortunately, the technical information is not always well digested, and the reader is seldom given enough information to evaluate the feasibility, cost, efficiency, or environmental impact of the energy sources presented. For the motivated reader with a special interest in science, this does provide a glimpse of state-of-the-art technology, a bibliography of specialized papers and articles, and a list of organizations in the energy field; but the general reader would have been better served by a more thorough discussion of fewer projects. Index.