Find Out if You Live in the Best—or Worst—State for Electric Cars

A new study finds that where you live determines how far you can drive your battery-powered vehicle and how environmentally friendly it is.

(Photo: Robert Galbraith/Reuters)

Mar 11, 2015· 2 MIN READ
Padma Nagappan is a multimedia journalist who writes about the environment, renewable energy, sustainability, agriculture, and biotechnology.

In the market for a new car? Wondering whether to go green with an electric car? Before you make that big and expensive decision, you might want to consider new research that shows that where you live in the United States determines how far you can drive a battery-powered vehicle and whether it’s really an environmentally friendly alternative.

Hot and cold weather, for instance, can zap your battery as more power is needed to run the car’s heater or air conditioner, reducing a vehicle’s range dramatically. In other words, your range anxiety is tied to the thermometer. So if you live in coastal California, you can drive 70 miles on the worst weather day of the day, while in parts of frigid North Dakota, your range will plummet to 45 miles, according to the study.

(Map: CMU Vehicle Electric Group/Twitter)

“Coastal regions are green even on the hottest or coldest day of the year, because the coast maintains milder temperatures,” said Jeremy Michalek, director of the vehicle electrification program at Carnegie Mellon University and a coauthor of the study, which was published in the journal Environmental Science and Technology.

“Phoenix is the worst because it can get so hot, as are the north-central and upper Midwest regions, because it’s very cold,” he added. “Right now, if I’m in San Francisco, I’m not worried, but if I’m in Minnesota, I’d be concerned.”

(Map: CMU Vehicle Electric Group/Twitter)

Michalek said the weather directly affects how effectively a car’s battery functions and how much energy the vehicle consumes per mile.

While your car may emit no planet-warming greenhouse gases, the power plant that generates electricity for your vehicle does. So if you live in a coal-dependent region, your car won’t be nearly as environmentally friendly as those that are powered by renewable energy.

(Map: CMU Vehicle Electric Group/Twitter)

The researchers determined that the electric cars driven on the West Coast, which relies on relatively clean natural-gas-fired power plants, hydropower, and renewable energy, have the lowest emissions. The electricity powering those cars emits 100 grams of carbon dioxide per mile.

Electric vehicles in coal states like North Dakota, South Dakota, and Nebraska, on the other hand, rack up 340 grams per mile.

Even oil-rich Texas is relatively green at 140 grams per mile, thanks to the state’s wind power boom.

“It’s dirtier in the upper Midwest since it relies on older coal plants, and there are also more coal plants in the region,” Michalek said.

He noted that his team looked at which power plants would respond to the additional demand to charge an electric car.

Utilities encourage owners to charge their cars at night, when electricity demand and costs drop. But in some regions, that’s also when cheaper coal-fired power plants are ramped up.

“We found that nighttime charging often resulted in more emissions because of where that energy came from,” Michalek said.

E.V. adoption rates vary across the U.S., driven by state and federal rebates. California leads with about half of all U.S. electric car sales, followed by Washington, Hawaii, Oregon, and Georgia, according to a UC Davis study.

California’s balmy weather surely isn’t hurting sales.