The U.S.’s continued reliance on coal and natural gas to generate electricity makes efficient gasoline-powered vehicles a lower-carbon alternative to electric vehicles in most states, according to a new report by Climate Central. In an analysis of life-cycle emissions from vehicles, based on how electricity is generated in each state, researchers found that the hybrid Toyota Prius remains a more fuel-efficient option than the all-electric Nissan Leaf in 36 states because the electricity used to charge the Leaf in most states comes largely from the burning of fossil fuels. In fact, the Climate Central study said that in the 10 states where electricity generation is most heavily reliant on coal, 20 hybrid and fuel-efficient gas-powered cars produce fewer CO2 emissions than the Leaf. While the Leaf produces considerably lower CO2 emissions in states that are heavily reliant on nuclear or hydroelectric power — including Connecticut and Idaho, respectively — the report’s authors say the findings suggest the importance of “fuel-efficient, gasoline-powered vehicles as a practical, immediate, and technologically viable” strategy to reduce carbon emissions. “This is a technology we understand and that consumers want,” said Alyson Kenward, a scientist at Climate Central and co-author of the report.