Plug-in electric vehicles are typically either pure battery electric vehicles (BEVs) or plug-in hybrid electric vehicles (PHEVs). Both types of vehicle store energy from the electricity grid in on-board batteries that power an electric motor, providing propulsion. BEVs, like the Nissan LEAF, substitute an electric drivetrain for all conventional drivetrain components, while PHEVs, like the Chevy Volt, retain the use of a down-sized internal combustion engine that supplements battery power.
These vehicles offer a step change improvement in efficiency, converting about 60 percent of the electrical energy from the grid to power at the wheels versus about 20 percent for the energy stored in gasoline. By charging at home or at work, they can also eliminate the need to visit a gasoline station. The electric motor also provides performance benefits including quieter, smoother operation, and stronger acceleration. Finally, by substituting oil for electricity, plug-in electric vehicles generate environmental and energy security benefits.
Both types of vehicle offer savings on operating costs—fuel and maintenance—in exchange for typically higher purchase costs when compared to conventional vehicles. Balancing these factors is a function of several variables, including; purchase price (see also, tax credits), fuel costs, average daily miles traveled, ownership period, and resale value (and economic savings).
U.S. Environmental Protection Agency
Electrification Coalition, Electrification Roadmap