For electric vehicles (EVs), the future is here. No longer just concept models, EVs are being featured in—and rolling out of—showrooms across the country. For example, the all-electric Nissan LEAF, powered solely by batteries, and the plug-in hybrid Chevy Volt, powered both by batteries and an internal combustion engine, debuted in 2011. Automakers are introducing many new models in 2012, including the Ford Focus Electric, Toyota Prius Plug-in Hybrid, and Mitsubishi “i,” with plans for many more EVs over the next several years.

These vehicles will draw some or all of their power from the U.S. electricity grid instead of the gas pump, resulting in significant reductions in the oil consumption, global warming emissions, and fueling costs of driving. However, the global warming emissions of driving an EV depend on how the electricity is generated—given that the sources of power vary among the nation’s regional electricity grids—and the cost to fuel these vehicles is dependent on local utilities’ electricity rates. To compare the global warming emissions and fuel-cost savings of electric vehicles with traditional gasoline -powered vehicles, consumers need access to more localized information, which has not been readily available— until now.

This report’s analysis shows that consumers should feel confident that driving an electric vehicle yields lower global warming emissions than the average new compact gasoline-powered vehicle.