Though electric vehicles have no tailpipe emissions, in most of the U.S. the electricity recharging their batteries likely includes some portion of coal-generated power. In 2019, coal accounted for more than 23% of the U.S. electricity supply, but its share varies regionally. It's almost 80% in West Virginia, and nearly zero in California.
In states with "relatively low-polluting energy sources," electric vehicles "typically have a well-to-wheel emissions advantage over similar conventional vehicles running on gasoline or diesel," the U.S. Energy Department says. In coal-dependent regions, the advantage may not be significant.
A 2020 study by three European universities found that in 95% of the world, electric vehicles "lead to lower carbon emissions overall, even if electricity generation still relies on fossil fuels."