Oh, the irony and pity, as Hemingway would say. This review coincides with New York's latest power blackout--one that Con Ed assured couldn't possibly happen. Denis Hayes, of Worldwatch Institute in Washington, explains how it can--as long as we rely on centralized systems and hitch our wagon to one star, petroleum (or its sisters, coal and gas), instead of to the star: the sun. His is a useful addition to the spate of books on the energy crisis, the nuclear debate, and alternate sources of energy. There is a wealth of absorbable statistics (including the quote from the economist who said ""GNP measures only what can be counted, not what counts,"" technological savvy (Which presumes the reader is familiar with some of the ingenious wind, water, or solar devices), and interesting insights on the relation between energy, employment, and the social and political structure of society. Hayes is particularly thorough in his discussion of transportation. One ingenious experiment is the Witcar, an electrically-powered vehicle being tried in Amsterdam. It is multiply-owned, multiply-used: you pick up and leave a Witcar at any recharging station, paying for mileage and leaving it for other co-owners. Hayes' point of view can be summed up in his post-petroleum world priorities: ""thrift, renewability, decentralization, simplicity and safety."" He discusses the inefficiency of using high-cost electricity for such things as heating water, the hazards to the environment and the pocketbook of exploiting coal reserves and the problems of harnessing either fission of fusion power. He also explains how simple conservation--the recycling of waste heat in power plants or industry in addition to the reuse of materials--may be one of the most efficient ""alternate energy"" sources we have available. To his credit he delineates the problems of wind, water and solar energy as well as their virtues. A good solid exposition, indispensable for the energy shelf.