Hybrid Electric Vehicles
Hybrid and plug-in electric vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. This new generation of vehicles, often called electric drive vehicles, can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and all-electric vehicles (EVs). Together, they have great potential to reduce U.S. petroleum use.
HEVs are powered by an internal combustion engine or other propulsion source that runs on conventional or alternative fuel and an electric motor that uses energy stored in a battery. The extra power provided by the electric motor allows for a smaller engine, resulting in better fuel economy and low emissions with the power and range of conventional vehicles.
HEVs do not require a plug to charge the battery;; instead, they charge using regenerative braking and the internal combustion engine. They capture energy normally lost during braking by using the electric motor as a generator, storing the captured energy in the battery. The energy from the battery provides extra power during acceleration and auxiliary power when idling.