The carbon emissions from electricity generation are measured in tones of CO2 emitted per gigawatt hour of electricity produced.
- tCO2e/GWh = 0 for hydroelectric, nuclear and renewable energy
- tCO2e/GWh = 500 to 600 for natural gas power plants
- tCO2e/GWh = 1000 for coal-fired power plants
In countries that generate much of their electricity by burning coal charging EV's battery will significantly boosts carbon emissions. Even in Canadian provinces Alberta, Saskatchewan and Nova Scotia, electric cars generate more carbon pollution over their lifetimes than gas-powered cars. To really contribute to a greener environment you have to buy rather an HEV than EV. Sources