Catalyst Winter 2016

Electric Vehicles: Just How Green Are They?

By Pamela Worth

You’re a savvy consumer, concerned with your carbon footprint. If you’re considering buying an electric vehicle, you’re faced with a lot of misinformation. “Your electric vehicle might not be as green as you think,” reads one headline. “There are places where electric cars pollute more than gas-powered cars,” cautions another. Will your electric car suck up electricity generated by coal-fired power plants, negating any benefit to the environment? Is the process required to manufacture an electric car’s powerful battery just as bad as burning gasoline? Should you just throw in the towel and get a gas guzzler?

Not So Fast!

Recent research by the Union of Concerned Scientists found that driving and charging an electric vehicle anywhere in the United States produces fewer global warming emissions than driving an average new gas-powered vehicle. Furthermore, the research shows that more than two-thirds of Americans live in areas where driving an average electric vehicle is better for the planet than even the most efficient hybrid vehicle on the market. (Learn more about these results.)


Photo: © Dreamstime.com/Mopic

Using the latest data about how electricity is generated around the country, as well as crunching the numbers on the energy and materials required to build the batteries that power electric cars, UCS analysts examined all global warming emissions created during an electric car’s lifetime—from its production and years of driving to its eventual retirement. The research considered emissions based on models similar to the two most popular electric cars available to American drivers: the midsize Nissan Leaf and the full-size Tesla Model S.

From the Factory to the Road

UCS researchers found that, although the production of lithium-ion batteries leads to more global warming emissions from the manufacturing of an electric car than a gas-powered car, these manufacturing emissions are rapidly offset by reduced emissions from driving: after 4,900 miles, or about six months, of driving the midsize electric car, and within 19,000 miles, or about 16 months, of driving the full-size model.

Of course, while electric cars produce no tailpipe emissions, that doesn’t mean there are no emissions associated with driving them. Just how green they are ultimately depends on how the electricity used to charge the car’s battery is generated. To offer the most accurate assessment possible, UCS analysts rated 26 regions of the United States using power plant data from the Environmental Protection Agency (EPA). A region that relies more heavily on coal-powered electricity generation, for example, rated worse for global warming emissions than a region using more renewable sources of energy.

The results? Even for U.S. regions with the least renewable electricity generation, the analysis showed that:

  • Driving the average electric vehicle in any region of the country produces lower global warming emissions than the average new gas-powered car getting 29 miles per gallon.
  • More than 66 percent of Americans now live in regions where powering an electric car on the regional electricity grid produces lower global warming emissions than a gas-powered or hybrid car getting 50 miles per gallon.

Thanks to the Clean Power Plan released by the EPA this year, and to improved state renewable energy standards, regional grids are using more and more renewable energy—meaning the environmental benefits of driving electric cars will almost surely improve.

Across the Country, Electric Vehicles Are a Cleaner Choice

The mpg (miles per gallon) values listed represent the equivalent combined city/highway fuel economy rating for an electric vehicle in that region. Two-thirds of the nation’s residents live in regions where an EV is cleaner than the most efficient hybrid (50 miles per gallon).
Note: Regional global warming emissions ratings are based on 2012 power plant data from the Environmental Protection Agency.

How Does Your State Rate?

Electric cars are clean and getting cleaner and their popularity is steadily increasing among consumers. Even so, gas-powered cars remain the norm for American drivers. Cutting oil use and moving toward cleaner electricity worldwide are both vital to avoiding the worst impacts of climate change, and electric vehicles are part of the solution—as are stronger fuel economy and global warming emissions standards for gas-powered cars.

Before you give in to misinformation, get the facts on how your state rates for global warming emissions from electric versus gas-powered cars. Visit our EV Tool and enter your zip code to see how different types of vehicles compare where you live.