Are ‘Zero-emission’ Cars Really Zero Emission?

I am in the market for a new car, and friends are encouraging me to buy an electric vehicle because it will be “zero emission” and help fight climate change. I don’t understand the “zero emission.” The electricity has to come from somewhere, and power plants emit carbon. Am I really being a better steward buying an electric vehicle than an efficient gas-powered vehicle?

A thoughtful question, and one that is not simple to answer. You are correct that electric vehicles are not entirely zero emission. They might be while operating on batteries, but carbon was emitted in producing the electricity if the electricity came from a fossil-fuel-fired power plant. Even if the electricity came from solar panels or wind turbines, there were emissions related to the manufacture of the panels or turbines.

Even if your environmentally conscious friends urged you to switch entirely to bicycle transportation, there would be carbon emissions. When you bike, you breathe. Carbon dioxide comes out. Horrors!

The question, of course, is how much carbon dioxide comes out. A gas-powered car that averages 20 miles per gallon puts 1 pound of CO2 into the atmosphere for every mile it is driven. An electric vehicle averages significantly less, but how much less depends on how the electricity is generated. If electricity comes from coal-fired power plants, the pollution and carbon emissions will be significant, while electricity generated by a mix of natural-gas-fired plants and renewable energy sources will emit much less.

How much less will vary from state to state. Michigan, for example, used to get 60% of its electricity from coal, but that percentage is dropping quickly as power plants are replaced or converted. Michigan utilities have indicated that they plan to build no more coal-fired power plants. By contrast, the state of Washington gets only 7% of its power from coal, with a much higher reliance on renewables. As states and provinces move to a higher percentage of renewable sources, the environmental benefit of electrical vehicles in terms of carbon emissions will increase.

About the Author

Rolf Bouma is an ordained pastor in the Christian Reformed Church who teaches religion, ethics, and ecology in the Program in the Environment at the University of Michigan.

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