In fiscal 2010, just before the March 2012 disaster at Tokyo Electric Power Company Holding’s Fukushima No. 1 nuclear power plant, the national average CO2 emission was 416 grams per kilowatt-hour. In fiscal 2013, after all nuclear power plants were idled, the figure rose to 570 grams.
Fuel economy is about 10 km per liter for gasoline-powered passenger cars and a little over 20 km per liter for hybrid cars. The comparable figure for EVs is some 10 km per kilowatt-hour. Even with all nuclear power plants idled, an EV emits only about half as much CO2 as hybrid vehicles. Even if all power stations used coal, the CO2 emission per kilowatt-hour would be 864 grams, making CO2 emissions from an EV less than from a hybrid car.