How much CO2 do you assume for electricity used to charge EVs and PHEVs?

AutoEcoRating uses an estimate of 638 gCO2e/kWh (grams of CO2-equivalent greenhouse gas emissions per kilowatt hour) of electricity delivered to an EV charging device. This estimate is a national average derived using the latest available statistics from the Department of Energy (DOE) Electric Power Annual report supplemented by data from the Environmental Protection Agency (EPA) eGrid system, and includes the CO2-equivalent global warming impact of methane (CH4) and nitrous oxide (N2O) emissions that are also emitted from power plants. It includes average electric grid transmission and distribution (T&D) losses, but does not include any losses that occur on the electric car itself or inĀ its battery charger.