Hydrogen power and other advanced energy sources are very much on the research agenda these days in the wake of soaring fossil fuel prices and growing concerns about human-induced global warming. A future in which inexpensive hydrogen will power many automobiles and electric generating plants without releasing greenhouse gases is still some decades away. This is mostly due to formidable economic and technological hurdles that still must be overcome. But the promise of a hydrogen economy is so compelling that it has spurred rapid deployment of advanced plastic resins that will be the centerpieces of new fuel cells that can efficiently generate power from hydrogen.
In the past few years, "hybrid" autos, which are propelled by an internal combustion engine and an electric motor, have hit the road. While these vehicles get better fuel economy than standard cars, they still run on gasoline and other petroleum-derived fuels, although they can potentially operate on renewable biofuels. The only waste product of this conversion would be water.