Fuel cells generate electricity through an electrochemical exchange between oxygen and hydrogen. The devices have long supplied electricity on spacecraft and are becoming the favored backup source in electric power plants. Now, the cells are poised to become the automotive power source of the future.
Fuel cells are comprised of tightly compressed stacks of 12-inch by 12-inch carbon plates, which function as bipolar anode and cathode electrodes. The plates are sandwiched between polymer proton exchange membranes. The bigger the stack, the more power is generated. Three-hundred fuel cells in a stack generate approximately 50 hp.