Study: Electric Cars Produce 30% More Emissions Than Ethanol Cars
An analysis done by Biofuels Digest has come to the very surprising conclusion that an electric car will produce 30% more carbon dioxide emissions over its lifetime than a car powered by E85 corn ethanol. Not only that, the study also found that the same electric car will produce 21% more carbon dioxide than even a gasoline powered car.
These claims assume that 100% of the electricity for the EV comes from coal-fired power plants and that a comparable car would get 35 mpg—both of which seem like unrealistic assumptions. So I dug around the internet today to try and come up with more realistic numbers.
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I have a lot of respect for Biofuels Digest, and I really hope they don’t take this post the wrong way. I imagine that the study was prompted by several issues, including the fact that public opinion has been steadily shifting to adopt a future filled with electric cars instead of biofuels and the impression within the biofuels industry that biofuels are being shut out of the lion’s share of stimulus funding due to a shift in political opinion from an increasingly EV-hungry public.
Certainly the recent half-billion dollar stimulus loans to Tesla and Fisker did nothing to assuage the biofuel industry’s anxiousness.
Problems With the Study
Biofuels Digest deserves credit for thinking hard about the big picture, but, after all of my research and thinking today, I feel they’ve left out some details that make the study difficult to swallow. Namely the following:
- The future of electric cars is not based on the Tesla Roadster, it is based on sedans that seat 4-5 people. When comparing cars you need to compare apples to apples. Comparing a hypothetical 35 mpg car to an electric car doesn’t seem logical. That 35 mpg car would be a Toyota Yaris or Chevy Aveo. If you want to compare an electric car to a fuel-powered car, compare that EV to a 27 mpg 4 door gasoline sedan (and I’m being generous on mpg there). CAFE standards are fleet-wide standards. It’s not that every car in the US will get 35 mpg when CAFE takes full effect.
- There is nowhere in the country that you can obtain 100% of your electricity from coal (even if you are a crazy, twisted soul and really wanted to). In the US, coal accounts for roughly 51% of all electricity generation. In some areas, such as where I live in the Pacific Northwest, hydropower accounts for 80% of electricity generation. Coal-fired power plants are far and away the largest CO2 emitter in the US. In fact, when just looking at electricity generation in 2007, coal accounted for about 81% of all CO2 emitted by power plants.
- Total CO2 emissions from all kinds of US electricity generation in 2007 was 2,433 teragrams and the total electricity generation was 3,828 billion kWh. When you do the resulting calculations and conversions you find that, on average, the US is emitting 1.4 pounds of CO2 for every kWh of electricity generated—much better than the 2.09 pounds CO2/kWh cited in BD’s study.
- On average, regardless of size or type, electric cars go about 4 miles per kWh (mpkWh) of electricity. BD’s study used a value of 3.12 mpkWh because that is what Tesla used to get some time ago. Newer electric cars will get at least 4 mpkWh, and that number is getting better all the time.
Electric Cars Actually Produce 40% Fewer Emissions Than E85 Powered Cars
If you download Biofuels Digest’s results spreadsheet and plop in some corrected numbers accounting for the above criticisms, you find that electric cars produce 40% fewer CO2 emissions than E85 powered cars and 52% fewer emissions than gasoline powered cars. Even if you don’t change any numbers except for the pounds of CO2 emitted per kWh of electricity generation, electric cars still do better than E85 powered cars. These are much more realistic numbers. And the great thing about electric cars is that, as our electricity becomes cleaner over time, so do all of our cars.
Even so, I’ve always felt that for our country’s security and for the benefit of the environment, it is important to have as diverse an energy/transportation portfolio as possible. There are many reasons to have both electric cars and biofuels. Both improve on the environmental impacts of living and both fulfill different needs. Personally I think electric cars make a lot of sense and they will eventually win out over combustion engines naturally, but it will take some time. In the meantime we need biofuels to increase our energy security and lower the environmental impact of our current fleet.
Great article, very thoughtful conclusion. It’s amazing that investigative journalism is gone from most of the official sources and has been rediscovered in blogs.
I also wouldn’t be surprised if the ethanol study underestimated the CO2 and other negative effects of the inputs in the process of growing corn and producing and distributing ethanol. The CO2 equation for making and moving ethanol is also different in different regions of the country.
You always have to look at who finances a study when interpreting at the results.
I agree. It is important to have a diverse range of energy options for transportation. Better not to put all your eggs in one basket. We’ve been relying solely on petrol for many year and look what that got us.
Even though I like me my combustion engines, this is a damn good analysis. Goes to show you that just about any study can be skewed to give the desirable results.
Why do you think a publication about biofuels would be truthful about electric cars? Don’t they have their own axe to grind here? Maybe they have a lot of credibility, I don’t know that. This just seems akin to asking an MSNBC to have a fair and unbiased opinion of Fox News.
Another consideration you’re ignoring here is land use requirements and other well-wheel sort of issues. The farming activity required to produce the biomass that produces biofuels means huge huge tracts of land. Further farming activities has its own carbon footprint. I recently read a study by Mark Johnson (a researcher at Stanford Univ) saying the land required to grow enough ethanol to power every car in the U.S. is larger than the size of California. The same study showed the land required for wind power to produce enough electricity to power every car (if every car were an EV) is a miniscule fraction.
David,
I know the publisher of Biofuels Digest. He is a smart, deep thinking guy. Certainly they have an audience that cares more about biofuels than EVs and it wouldn’t be right if they didn’t try and defend biofuels… But they are not even in the same ball park as FOX or MSNBC when it comes to bias. All of us are biased in some normal sort of way, and my experience with BD is that their bias is a normal type of bias.
The issues we are talking about are incredibly complex and leave much room for interpretation. Your concern about well-to-wheel issues is good, but if you read through BD’s study, they used a widely accepted government model for well-to-wheel emissions from E85. I don’t think it takes into account land use considerations (that’s something that California has tried to breach, with little success), but it does take into account things such as the environmental impact of growing corn.
I’d give this post 10 points!
That’s what we like to see, some researched FACTS to counter the negative propaganda.
Good job!
Even if you beleive this - we can all sleep easily knowing noone goes hungry because I drive an EV - unlike corn ethonol where poor people’s food is used to drive cars.
Well done. I have no problems with biofuels, just where they tend to come from. Ethanol is great, except that most of it is made from corn. If you factor in the energy used and emissions expended to get the seeds into the ground, grown, harvested, distilled, then burned as fuel, you’re talking about a barely break-even proposal on emissions.
I think electrics are great too, but I don’t see them as the end-all, be-all of our foreseeable vehicular future. I see a mix of things. I see battery, hydrogen fuel-cell, biofuels, etc. all having a place in our transportation future.
Unless EESTOR can truly deliver on their claims and then doesn’t go the way of the pharmaceuticals with their patents, EVs will not be a long-range solution in the next fifty years.
Bio fuels, unless they clean up their image (and stop receiving double and triple subsidies as corn-based ethanol does) will not get much further than it already has. We need more Bio Willie’s and fewer BioUSDAs.
Nice post and analysis Nick…and nice display of diplomacy…if only our politicians would work this hard to build bridges between ideologies.
My 2c would be that you could have subtracted from the EV column the GHGs of trucking fuel to our gas stations. Also, there are several petroleum based fluids that aren’t used in an EV…thus you could subtract out from the EV column 90% of the GHG emissions of the creation, transportation, and usage of these fluids. But like you said, comparison of these systems is very complex…especially when you consider the lifecycle of smaller components. The rabbit hole is very deep.
There’s no contest to me…EVs are way cleaner in every category. Especially when you consider the economy of managing the environmental impact of thousands of power plants vs. hundreds of millions of vehicles.