Plug-in vehicles fall into one of two main categories: Plug-in Hybrid Electric Vehicles (PHEVs) or Plug-in Electric Vehicles (PEVs) sometimes referred to as Battery Electric Vehicle (BEVs). PEVs/BEVs are all-electric vehicles with no internal combustion engine (ICE). Collectively, all of these are more commonly referred to as Electric Vehicles (EVs). Both categories of electric vehicles differ from fossil fuel-powered vehicles in that they are able to consume electricity which could be generated from a wide range of sources, including fossil fuels, nuclear power, renewable sources (such as tidal, solar, or wind power) or any combination of these.
A plug-in hybrid's all-electric range is designated as PHEV-[miles] or PHEV [kilometers] km in which the number represents the distance the vehicle can travel on battery power alone. For example, a PHEV-20, also designated as a PHEV32km, can travel twenty miles (32 km) without using its combustion engine. The Energy Independence and Security Act of 2007 defines a plug-in electric drive vehicle as one that:
--draws motive power from a battery with a capacity of at least 4 kilowatt hours
--can be recharged from an external source of electricity for motive power, and
--is a light-, medium-, or heavy-duty motor vehicle or non-road vehicle.
This distinguishes PHEVs from regular hybrid cars mass marketed today, which do not use any electricity from the grid. The Institute of Electrical and Electronics Engineers (IEEE) defines PHEVs similarly, but also requires that hybrid electric vehicle have the ability to be driven at least ten miles (16 km) in all-electric mode (PHEV-10; PHEV16km), while consuming no gasoline or diesel fuel. General Motors is referring to its Chevrolet Volt series plug-in hybrid as an "Extended-Range Electric Vehicle".