Looking to the future, Toyota set up a nationwide system for recycling the nickel-metal hydride batteries used in the Prius. Hybrids may become the ultimate green cars. Fuel cells are the power units of these cars. Fuel cells are very efficient at production energy from chemical reactions between hydrogen and oxygen. And the only by-product of that reaction is water vapor.
Fuel cells are absolutely clean.
Toyota took the Prius's electric power unit and developed an FCHV system that is very close to practical application. When developing a fuel cell-powered vehicle, you can't think of the necessary technology alone. It's vital to look beyond that and consider the big picture, which includes future energy supply capacities and infrastructures, among other things. Besides using pure hydrogen, Toyota is also developing ways to reform such fuels as methanol, gasoline and natural gas. Engines Cleaner and more fuel efficient.