According to Climate Central, your electric car is getting greener as the sources of energy you use to charge it become greener themselves.

With the rising number of plug-in models available in the U.S., many at increasingly affordable prices, and with electricity getting greener, the climate benefits of electric cars are growing.

Analysis by Climate Central shows that at least one variety of 2017 all-electric or plug-in hybrid electric car will have a smaller impact on the climate after 100,000 miles of driving than any of its gas-fueled competitors in 37 states, including Tennessee. That’s up from 16 states in 2013 as power grids have become greener.

The most climate-friendly car option in any state depends on its electricity grid. This map shows the top 2017 car type for each state in the U.S. based on its 2015 electricity grid.
Source: EIA

In California, the nation’s leading market for electric cars, where aggressive renewables policies have boosted the environmental benefits of the vehicles, one out of every 50 cars sold last year was a plug-in. In Alabama, which shares its northern border with Tennessee, it was one out of every 1,000.

Electric cars are only as clean as the electricity they’re charged with. Solar, wind and nuclear power are the most climate-friendly sources of electricity, while coal is the worst. Gasoline-fueled cars are powered by oil, which is a major source of heat-trapping pollution.

Read more about Electric Cars Becoming Popular As Grid Gets Greener at Climate Central