Several automakers are planning to produce new, highway-speed electric vehicles (EVs) within a few years, but today the only currently available EVs are the custom-built, highway qualified electric Tesla Roadster, manufactured by Tesla Motors, and low-speed or neighborhood electric vehicles (NEVs). These EVs store electricity in an energy storage device such as a battery. The electricity powers the vehicle’s wheels via an electric motor. The battery power is replenished by plugging the vehicle into a 110-volt outlet overnight. EVs are considered zero tailpipe emission vehicles because their motors produce no exhaust or emissions.