How Green are Electric Vehicles?


Here’s my confession: I’ve never bought a new car, because my relatives let me buy their used cars for cheap. My first car, which I bought for $500 in 2004, was a 1984 Volkswagen Quantum and it looked very much like a bronze bread box. The car I’m driving right now is a 1995 Honda Civic, so at some point I might need to think about buying a vehicle made in the 21st century.

Which is why I started researching electric vehicles.

There are a lot of different opinions out there on the environmental performance of electric vehicles (EVs). It seems like the perception is that EVs could be worse for the climate than standard gasoline cars if the electricity grid where you get your power is using coal and natural gas.

But EVs are probably greener than you think.

As it turns out, a majority of the time the efficiency of EVs far surpasses standard gasoline cars and even hybrid vehicles.

Recent research by the Union of Concerned Scientists found that, based on the mix of energy sources fueling electricity grid in the U.S., 70 percent of Americans live in places where driving an EV results in fewer emissions (on a miles-per-gallon-equivalent basis) than an efficient 50 mile-per-gallon gasoline vehicle.

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Keep in mind that the average fuel economy of standard 2015 model-year vehicles is just below 25 MPG. So EVs are much more efficient to drive than gasoline cars and even—for the most part—more efficient than hybrids.

And because of state-specific rebates and incentives, more EVs are being bought in places with greener grids. According to David Reichmuth, a senior engineer in the Clean Vehicles Program at UCS, “Based on where EVs have been bought to-date, the average EV in the U.S. now produces emissions equivalent to a hypothetical gasoline car achieving 73 MPG.”

But before you buy a new car, you might wonder: Aren’t the emissions associated with manufacturing a new car pretty high? Wouldn’t it be better, Emily, if you kept driving around in your old Honda Civic?

From the atmosphere’s perspective, EVs make up for manufacturing emissions pretty quickly, usually in a few months. Even in the case of the new Tesla models that have larger batteries, the efficiency gained from driving them pays off those up-front emissions in about a year, according to research at UCS. Over their lifetime, EVs are expected to cut emissions just over 50 percent relative to gasoline cars.

Plus, electricity grids across the U.S. are getting greener every year. About 95 percent of net new electricity capacity installed in 2017 came from renewable wind or solar sources. So driving an EV also allows for a big reduction in transportation-related emissions as grids become greener over time.

Transportation makes up about one-third of the average American’s carbon footprint, so choosing an electric car is the way to go if we want to drastically reduce carbon emissions.

If you’re looking for different ways to help change the energy system, check out PlanetVision’s Action Guide.


Emily Cassidy is Sustainability Science Manager at the California Academy of Sciences.