Does an electric car make sense for you? Well, it may depend on where you live. If the smokestack from your local power plant is emitting coal fumes, chances are the planet would be happier if you were in a hybrid. That’s according to a new Climate Central report that analyzes the grid across the U.S. and provides a map of states where plug-in cars will work best.


“In 36 states,” the report says, “the hybrid electric Toyota Prius produces less greenhouse gas pollution than the all-electric Nissan Leaf, because when you plug in a Leaf to recharge, you are tapping into electricity generated largely by burning coal and natural gas in those states.”


According to the report, “Coal is the largest contributor to the high carbon footprint of our electrical grid today.” In high coal states, “driving a Leaf is responsible for much more greenhouse gas emissions per mile (about 0.9 pounds) than a Prius (about 0.5 pounds)….The Leaf does best in states that rely heavily on nuclear, like Connecticut (0.3 pounds), or on hydropower, like Idaho or Washington (0.1 pounds). It isn’t only the Prius that out-performs the Leaf. In the 10 states with the most carbon-polluting electricity generation, there are 20 cars that are better for the climate than the Leaf; 13 of them are gas-powered vehicles with conventional engines. The rest are gas-powered hybrids.”


The Prius does better than the Leaf in 36 states, the report says. Even the conventionally powered Hyundai Accent beats the Leaf in 12 states.


It’s important to note that not all fossil fuel grids are the same. Coal is the dirtiest fossil fuel, but natural gas — on a considerable growth curve now that it costs about $2 per gallon equivalent — is vastly cleaner. It’s true that “zero emission” cars aren’t pollution-free when plugged into a fossil fuel grid. There’s surprisingly little analysis of how EVs fare when the charge comes primarily from coal.


In my book "High Voltage," I talked to Eladio Knipping of the Electric Power Research Institute (EPRI), who spent a few minutes with a calculator and came up with a tentative evaluation: on the U.S. grid as it is now, a battery EV will have about the same global warming impact as a hybrid like the Prius. On average, they’re 30 to 40 percent cleaner than average gas cars in terms of greenhouse gas. That’s not too shabby.


I identified the states with the cleanest grids as Washington, Oregon and Idaho — all stars on the Climate Central map, too — and the dirtiest as big coal states North Dakota and Wyoming. California, a mega-car state, is also very clean, 25 percent better than the national average.


I talked to John Voelcker of Green Car Reports, and he pointed to a 2007 study from EPRI and the Natural Resources Defense Council which concluded, in alliance with Climate Central, that “in a few states with the dirtiest grids, the wells-to-wheels carbon profile for one mile driven was better in a 50-mpg car (e.g. Prius) than for the same mile driven electrically.”


Voelcker added these three crucial points:

  • The grid will get cleaner over time, state by state, with newer natural-gas plants replacing older, dirtier coal plants, not to mention renewable-fuel mandates in a number of states — whereas the gasoline car will never get any cleaner;
  • The conclusions are fine you want to drive a 50-mpg Prius, but many people don’t like the way hybrids drive. Electric cars are NICER and more pleasant to drive;  
  • California will buy more plug-in cars than the next five states combined, and its grid is quite clean, so this is not a worry in the biggest market for electric cars.

Jay Friedland of Plug in America adds that "30 states have renewable portfolio standards (RPS) which will dramatically improve the grid over time with the larger impact of renewable electricity." He also complains that the report authors' well-to-wheels analysis was more rigorous for EVs than for the conventional cars under study.


My own view, not enshrined in a scholarly report, is that people should consider an electric car, no matter where they live. If you’re resident in the coal-dependent Midwest, with no public charging grid anywhere near, maybe it’s not your best choice right now, but as Voelcker points out, the situation is likely to change for the better relatively soon. So although the Climate Central report is probably accurate, it’s only a snapshot of where we are right now. For EVs, the good news keeps becoming better news.


As to the critical question of whether an EV will save you money, check out this video:


MNN tease photos of electric car and EV illustration: Shutterstock

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

Should I buy an electric car?
It depends on where you live, says a new report, because some states force you to charge up from a dirty coal grid. But that's just a snapshot, and the long-ter