Electric Cars May Pollute More than Gas Models: Study

Electric Cars May Pollute More than Gas Models: Study

Electric vehicles probably seem to have a tiny carbon footprint at the surface, but a recent study suggests environmental impact varies in gravity according to where the vehicle is charged.

Automakers tout EVs as zero-emission transportation but that doesn’t mean they don’t have an environmental impact. The issue is that charging creates green house gases, and those emissions aren’t necessarily constant. According to the Union of Concerned Scientists, which uses the electric power requirements of the Nissan Leaf as a basis for comparison, there is a significant disparity in greenhouse gases released into the environment depending on the source of the electricity itself.

The study that will be officially released on Monday states that a full cycle of energy production, also known as well-to-wheel analysis, must be taken into account. Findings from the U.C.S. report demonstrate that electric utilities that rely on natural gas, nuclear, hydroelectric, or renewable sources to power their generators serve a far greater potential of reducing carbon dioxide emissions than coal-burning electric plants. According to U.C.S., greenhouse gases from coal plants negatively affect the well-to-wheel figure for electric vehicles enough that it suffers a greater carbon footprint than that of subcompact vehicles featuring the latest gasoline engines.

A geographical breakdown of electricity generation is also included in the report to identify the dirtier coal power plants in question. The findings show that only the 45 percent of the U.S. population living along the coasts have sources of electricity capable of using a Nissan Leaf EV at lower greenhouse gas levels than gasoline engine vehicles capable of 50 mpg in combined driving.

In fact, 37 percent of Americans reside in regions where a Nissan Leaf’s impact would only match gasoline vehicles rated at 41 to 50 mpg. Finally, 18 percent of Americans live in regions that are worse, where greenhouse gas emissions from the Leaf only match gasoline vehicle rated from a combined 31 to 40 mpg, which measures up to emissions from the Ford Focus, or Hyundai Elantra.

At its core, U.C.S. hopes the study will encourage modernized power plants. Senior U.C.S. engineer, Don Anair, said the dirtiest electric-grid regions account for between two and a half to four times the global-warming emissions than those of the cleanest regions. Still, it seems there’s hope.

“A number of old coal-fired power plants are now being retired. Given emission standards recently introduced by the current administration, any new coal-fired plants will be far cleaner than their predecessors,” he said.

[Source: New York Times]

  • The study says that 82% of people in the US live where emissions for EVs are lower than a 41-50 mpg car.  Sounds pretty good to me! My next car will be an EV because I choose to purchase my fuel from a local source, not from Venezuela or Iran or who knows from where else, that would just as soon bomb us with weapons bought with OUR money!

  • RedmondChad

    The study hasn’t been released yet, so I can’t see what they did or didn’t include.  But I can say that this study seems notably more pessimistic than most full-cycle studies, and there have been a lot of them.  Here’s an overview of a few dozen earlier studies: http://www.sherryboschert.com/Downloads/Emissions.pdf.  Despite the fact that coal was 52% of generation in 2007 (the center of most of these studies) and it’s now down to 42%, the general consensus of these studies (they don’t all conclude exactly the same thing; some of the more pessimistic are missing some obvious things) was that almost everybody is better off with an EV.  The only exception is where electricity comes from 100% coal; then you might be slightly better off with the best of hybrids, like a Prius.

    Of course, that’s only considering the environmental reasons to buy them.  Even if the EV is no cleaner today (it could be in the future–the gas car won’t be!), it’s still domestic energy, and it’s still a lot cheaper, and you still get a smoother, quieter car with much nicer throttle response and great low-end torque.

  • SteveEV

    When I say my carbon footprint is zero, I mean zero. I installed solar collectors on my garage to power my house and car. Half the other LEAF drivers I know have done the same. If a car buyer is concerned about fuel costs, look at an electric vehicle. If a car buyer is concerned about pollution, look at an electric vehicle. If a car buyer is concerned about long-term maintenance costs, look at an electric vehicle. If a car buyer is concerned about improving the local economy, look at an electric vehicle. If a car buyer is concerned about national security and oil shortages, look at an electric vehicle.

  • PaulScott58

    It’s time the media got on the right side of this issue. This whole “which is cleaner, the EV or the gas burner” issue has been viewed from the wrong end of the binoculars. 

    You assume stasis in a given utility’s grid mix, when a cursory study of the electrical grid would indicate otherwise. The direction energy providers are going is clearly toward renewables. Since Obama became President, we’ve reduced coal’s percentage of the national grid mix from 53% to today’s 39%. All it took was for the EPA to be told to enforce laws already on the books. That, and a severe recession that reduced demand.

    Since Steven Chu has been in charge of the Energy Dept., there has been a rapid growth in renewables. In the past 3 years we’ve installed over 27 GW of wind and 3 GW of solar on the U.S. grid. That’s enough renewable energy to power 25 million EVs! The adoption of plug-in cars will be vastly outpaced by the renewable energy being added to the grid.

    The extraction and refining of oil uses more electricity and natural gas than any industry in California with the exception of pumping vast quantities of water hundreds of miles and over mountains. Once enough plug-in cars replace gas burners, we’ll start seeing refineries close. These are the most polluting industrial complexes in the U.S. They are directly responsible for thousands of deaths from the pollution they generate. The faster we transition to EVs, the faster we close refineries.

    Going back to the original story line of whether an EV was more polluting than an internal combustion car, in essence, this is a question of how aware the customer is. If anyone is truly concerned about pollution from coal generated electricity, all you need to do is enroll in your utility’s renewable energy program, or install solar panels. That choice is, and has been, yours to make for a long time. If you don’t think cars should run on dirty energy, then your house shouldn’t either.

  • Patrick Connor

    With an EV, you can choose how you fuel it. Clean or not, it is up to you, either way it is American made fuel. Guess what, oil refineries use electricity, a lot of it. EVs just cut out this middle man. The grid is getting cleaner as more wind turbines are put up. Oil is only getting dirtier as heavier crude is pumped from deeper sources.

  • InigoMontoya6

    I wish they would stop with the pessimistic slant on these types of reviews.  I know its for ratings but as others have pointed out, its not accurate and IMHO only serves to generate negative talk on what passes for “news” these days.  EVs should be evaluated from pump to wheel rather than well to wheel…and everyone should get panels on their roof to distribute/localize energy production.  Separate studies can be done to evaluate well to pump which is a separate (yet related) issue.  And most importantly, as some others have mentioned, even if EVs were only equal to current gas solutions, they shift reliance to domestically created energy rather than imported.

  • The Cat

    If you took the time to actually read the studies from the UCS, you’d see that your headline is completely wrong, and does NOT agree with the UCS reports at all. Bad reporting, boys and girls. As we get better and better at producing clean energy, EVs will also get cleaner and cleaner. Check out



  • Michael Heffron

    My Chevy Volt is 100% solar powered. The Nissan Leaf can be solar powered just as easily. I don’t think it takes a genius to figure out that solution. Are there any real scientists in the Union of Concerned Scientists?

  • An Electric car does not pollute.!!! Electric power plant pollutes more or less. From which pervert conception does a non emiting car emits something ??

  • Atr72_captain

    sorry but your wrong, the batteries you have in your leaf took energy to produce and they are gonna take energy to dispose of their toxic chemicals when their service life is complete  so you only lie to yourself

  • ATR72_captain

    you have no idea where the oil comes from that you buy. the fueling stations get their fuel all from the same place. then they add their own additives in to make it the product they advertise.

  • SteveEV

    Hardly. Those batteries are far too valuable to throw away. I expect to use them far a home backup power system or sell them to a recycler when thy have finished serving my transportation needs. Meanwhile I have already stopped burning gas. The money I save supports our local economy. The air is cleaner in my driveway. Since I generate my own electricity the air is cleaner towards the power plant as well. Every car requires energy to manufacture. Most require even more to operate. That generally translates into a significant toxic contribution to the air we breathe. I prefer a different arrangement.

  • Falco

    You don’t fart? watch out since South Park shows people will blow up if they hold their farts.

  • SteveEV

    I installed solar collectors on my garage roof that now generate my transportation fuel. Can’t get more local than that.