A total of 41 different light-duty plug-in electric vehicle models were available for purchase in model year (MY) 2018 – 27 of which were plug-in hybrid electric vehicles and 14 of which were all-electric vehicles, according to the US Department Of Energy data.
The first two mainstream plug-in electric vehicles, the Chevrolet Volt and the Nissan Leaf, debuted in 2010.
The total number of plug-in electric models has grown for every model year except for 2015, in which the number of PHEV and EV models changed, but the total available stayed constant.
The model counts include only one record per model name, even if some models have multiple configurations (i.e., Tesla Model S has various battery sizes and drive configurations, but it was only counted as one model).
[source: Fuel Economy Website, Power Search]
