When General Motors, the world's largest automaker, attempts to reinvent the world's energy infrastructure-even rethinking notions of the car itself-it's not exactly research as usual. But in recent months, Detroit-based General Motors has integrated and expanded several existing research programs in a concerted effort to provide an alternative to the internal combustion engine. The plan is to use hydrogen to power cars, to tap into the vehicles' idle time to supply residential energy, and eventually to supply the nation's electric grid.

General Motors is pinning its ambitions on fuel cells, which generate electricity through a chemical reaction that starts with hydrogen and emits only water and heat. Other automakers and electricity companies are working on similar fuel-cell technology. Indeed, the first generation of fuel-cell-powered cars will hit the market over the next few years. But Larry Burns, the company's vice president for research, development, and planning, says General Motors is devoting some 600 staffers and "hundreds of millions of dollars" to a far more radical concept for the fuel-cell-powered car in a research program called Hydronomy, shorthand for "hydrogen economy." Burns says, "We think that if this is successful, it will be a much bigger idea than inventing the automobile. It not only reinvents the automobile but our industry."