|MadSci Network: Other|
You have hit upon the central problem with alternative-powered vehicles; the power to move them must come from somewhere. There are newer designs of nuclear power plants, but regardless of design the waste product must be disposed of somehow. Solar power is, as yet, still impractical. Hydroelectric power, while largely nonpolluting, still has a tremendous environmental impact. Wind power is only practical in certain areas.
However, coal powered plants are not as bad as you might think. While burning coal is a dirty process, advances in the treatment of the reaction products are continually being made. It is a matter of scale; scrubbers and filters that would be impractical or impossible to fit onto an individual automobile can be used for a large coal plant, effectively cutting the polution per automobile. Try doing a search at Yahoo for "coal power" and look at some of the research sites that come up.
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