However, they do generate emissions in other ways like at the power plant during recharging and during the production of the batteries, many of which contain toxic materials. The batteries are also heavy, must be replaced every few years, and take hours to charge. The performance of battery electric vehicles has improved, but they're still far from being widely attractive. A hybrid electric vehicle combines two sources of energy, such as a battery-powered electric motor and a conventional internal combustion engine. A computerized system optimizes the mix of power from the conventional engine and the electric motor depending upon driving conditions.
Hybrid vehicles are far more efficient than conventional gasoline-powered cars.
Major American auto manufacturers are now developing production-feasible hybrid electric vehicles. Some are collaborating on a prototype car that would use fuel cells to produce energy to run the automobile's electric motor. Fuel Cells Types of Fuel Cells Recent Advances in Fuel Cells Emissions from Hydrogen Fuel Cell Vehicles and Battery-Powered Electric Vehicles Versus Conventional Vehicles Internet Resources on Fuel Cells Science for Democratic Action Vol.