The Myth of EV Charging Emissions

One common argument against purchasing an EV is the amount of emissions associated with the electricity used to charge the car. Many consumers believe that the amount of CO2 emissions from a conventional vehicle combusting gasoline is the same as an EV charging on electricity due to the amount of coal and natural gas used in electricity generation. This is actually not the case—charging an EV at almost any location in the US emits less CO2 than fueling your vehicle with gasoline.

On average, a gasoline-only vehicle emits 381 grams of CO2e per mile. The How Clean Is Your Electric Vehicle? tool developed by the Union of Concerned Scientists allows users to see how much CO2e is emitted by BEV and PHEVs charged in any ZIP code in the US. A sample of ZIP codes from the tool is presented in the table below.

How Clean Is Your Electric Vehicle?

(Source: Union of Concerned Scientists)

Even in some of highest coal producing areas of the country, the emissions from charging and driving an EV are lower per mile than driving a gasoline vehicle.

Cleaner Charging Thanks to Alternative Energy Sources

In 2018, fossil fuels made up about 64% of US electricity generation—35% from natural gas, 27% from coal, and 2% from oil and other gases. However, between 2008 and 2018 coal consumption in the electric power sector decreased around 40% from approximately 1,000 million short tons to 600 million short tons. Given that coal emits between 205-228 pounds of CO2/million Btu (depending on the type of coal) and natural gas emits 117 pounds of CO2/million Btu, the shift from coal to natural gas in the electricity sector brings with it fewer CO2 emissions.

The decline in coal consumption and production in the US is fueled by decreasing costs of alternative fuel sources, like natural gas and renewables. Alternative energy sources coming into the generation mix negatively affect coal as it becomes less cost competitive—particularly when considering the cost to upgrade older coal-fired power plants to meet new regulations. Electric utilities have since closed numerous coal-fired power plants as they become increasingly uneconomical and replaced them with primarily natural gas (which has gone down in cost considerably due to new technology innovations and productivity gains).

The changes to the generation mix in the electric power sector means cleaner electricity to power EVs. It is expected that coal will continue to decrease in production and consumption in the US for the next several years and more renewables are set to come online. While the amount of CO2 emissions from electricity could certainly be lower, consumers can rest assured that charging an EV in the US will emit less CO2 per mile than driving with gasoline—not to mention, charging is cheaper than filling up at the pump.