What category of electric vehicles has been available to consumers the longest?

The category of Hybrid Electric Vehicles (HEVs) has been available to consumers the longest due to their introduction in the late 1990s, with models such as the Toyota Prius launching in 1997. HEVs combine a traditional internal combustion engine with an electric propulsion system, allowing for improved fuel efficiency without the need for external charging, making them appealing to a wide range of consumers.

In contrast, Battery Electric Vehicles (BEVs) and Plug-in Hybrid Electric Vehicles (PHEVs) emerged later. BEVs rely solely on electric power and can only be charged via an external source, which initially limited their market. PHEVs, which blend features of both HEVs and BEVs by allowing external charging and using both gasoline and electric power, also arrived after HEVs.

Thus, when considering the timeline of availability to consumers, HEVs are the longest-standing option among these vehicle categories.