California, New York, Florida and Texas will lead the way. The top five metropolitan areas for plug-in electric vehicle sales are expected to be New York City, Los Angeles, the San Francisco Bay Area, Seattle and Portland.

Nationwide, 2.1 percent of total vehicle sales are expected to be plug-in electrics by 2020, compared with 4.5 percent in California and 12% in Hawaii. Hawaii is the most oil-dependent state in the United States, and gets more than 95 percent of its energy from imported fossil fuels.