Electric car sales have gone up steadily over the past few years, but they have jumped unexpectedly in some states like Tennessee, John Upton reports for Climate Central.

In Tennessee, few electric car consumers are basing their purchase in concern for the environment or worries about climate change. In fact, many consumers in the widely conservative state reported that they didn’t consider the climate at all in their purchases. So what is driving their decision? In many cases, Tennessee residents bought electric cars because they could be certain their car was fueled with American energy, not foreign oil, Upton explains.

Whether the jump in electric car sales has been for environmental reasons (as in California) or in American interest (as in Tennessee), more and more electric cars are finding their way onto American roads. As the American energy system becomes greener and renewable, electric cars do as well, lessening the impact cars have on the environment.

Image: Three converted Prius Plug-In Hybrids Charging at San Francisco City Hall public recharging station | Image Credit: Felix Kramer (CalCars) / Wikimedia Commons