Eager buyers are waiting up to a year for a new Toyota Prius, the hot hybrid sedan that gets around 50 mpg and has negligible emissions. Imagine, then, the excitement that could be generated by our proposed GreenCar, an eco-mobile that's bigger than the Prius but gets more than twice the mileage--without emitting a single milligram of air pollution. "It's all about resistance and aerodynamics," says Catherine Greener of the Rocky Mountain Institute, a nonprofit energy-policy think tank. Improvements in composite materials will be critical, as will computerized aerodynamic modeling. But it all hinges on fuel cells, which won't proliferate until their cost comes down and their capacity goes up. When that
happens, the impact will be tremendous. With electronic mobility possibly more important than physical mobility in a fuel-constrained future, the electricity-generating GreenCar will be perfect for powering homes. Blackouts? No sweat.