Ethanol - the challenges with too much of a good thing

The ethanol industry faces a challenge: under the federal Energy Act, passed last December, the industry is required to produce 30 billion gallons of ethanol a year by 2020. Today it produces about 7 billion gallons. And once that much fuel is produced, there is the challenge in ensuring consumers can use it all.

But if ethanol were blended into every gallon of gasoline sold, in the standard 10 percent ratio, it would consume only about half of the 30-billion-gallon requirement.

So far, the Department of Energy (DOE) has proposed two potential solutions:

• Sell more E85 ethanol, though it is a niche market today.
• Raise the standard blend from 10 to 15 or 20 percent.

Unlike the standard blend, called E10, which all cars can use, only specially equipped cars can run on E85 ethanol. About five million of those cars are on the road today. According to DOE estimates, it would take 100 million E85 cars to provide a big enough market to absorb the additional 15 million gallons of ethanol in E85. Currently, automakers (mostly those based in Detroit) are building about 1 million new E85-capable cars every year. And they have promised to raise that to about 3.5 million a year by 2012. Still, getting to 100 million E85 cars by 2020 is a tall order. It would also take between 30,000 and 60,000 million gas pumps capable of dispensing E85. Today, there are only about 1,500.

So the DOE, along with some automakers, is testing the potential to raise the standard ethanol blend to 15 or 20 percent, and making that blend universal for all gasoline sold in the United States. In Brazil, all gasoline sold in the country contains at least 25 percent ethanol.

But there are some problems with increasing ethanol blends. Ethanol contains less energy than gasoline, so increasing the amount of ethanol in gasoline will likely result in lower fuel economy. Increasing standard fuel blends from zero to 10 percent ethanol, as is happening today, has little or no impact on fuel economy. In tests, the differences occur within the margin of error, about 0.5 percent. Further increasing ethanol levels to 20 percent reduces fuel economy between 1 and 3 percent, according to testing by the DOE and General Motors. Evaluations are underway to determine if E20 will burn effectively in today's engines without impacting reliability and longevity, and also assessing potential impact on fuel economy.

In our own tests at Consumer Reports, we found that E85 reduced fuel economy by about 27 percent overall in a Chevrolet Tahoe. Interestingly, this is a lower reduction than the fuel's lower energy density would theoretically suggest. General Motors research fellow Kevin Cullen suggests that E85's higher octane rating is allowing the engine's computer control system to advance ignition timing to compensate for the lower energy density in the fuel and making up a little bit of the energy loss.

Andy Karsner, undersecretary for energy efficiency and renewable energy at the federal Department of Energy, says the department is testing to learn whether there is an ideal ethanol blend for fuel economy. Some cars actually returned higher fuel economy on certain midrange ethanol blends ranging from E20 to E40, according to a fuel economy study conducted in November by the ethanol industry and the DOE.

The second problem with raising ethanol blends is evaporative emissions—not the kind comes from the tailpipe, but the kind you smell when filling up your car at a gas station. In engines, ethanol burns cleaner than gasoline does. But low-blend ethanol mixes such as E20 have higher evaporative emissions than either gasoline or E85. So far researchers don't know at what ethanol blend evaporative emissions begin to diminish. And systems to control these emissions have not been developed.

If ethanol is going to play a significant role in reducing U.S. oil dependence, it looks likely that E15 or E20 will become more common. This would mean consumers won't have to buy special cars and look for special pumps for ethanol, meaning every gasoline-engine passenger vehicle would be able to join the effort to reduce dependency on imported oil.

—Eric Evarts

Learn more about alternative fuels in our fuel economy special section.

Comments

[J]

If you use sugar as in Brazil, okay, or switchgrass maybe, but use of corn is stupid. Food prices are going up. Plus you cannot transport it in pipelines!! Let's get serious about alternative energy sources and not political!!!!

[Nathan Schock]

Eric,

You're right on the money as far as the options for increasing use of ethanol. However, going to a mid-level blend like E20 does not necessarily mean loss of fuel economy. According to a recent study from the University of North Dakota and Minnesota State Mankato, three out of four cars got better gas mileage on E20 or E30 than they did on straight unleaded gasoline.

[Cale]

There seems to be a unquenchable thirst in this country for burning fuel in cars. I wonder about the cost to society should be turn our appetite for energy to the consumption of ethanol. Even if ethanol puts a dent in tailpipe emissions and imports of foreign oil there will be real consequences for the poor in the form of expensive fuel and food. The nation, as a whole, is not equally vested in the benefits of energy independence.

[Coleman Jones]

I work on Biofuels Implementation for GM Powertrain and am very interested in this topic and am glad you are writing about it. GM is constantly supporting the production and distribution of ethanol and we feel it's the best, most cost-effective solution for our energy needs right now. E20 may be a viable alternative in the future, but we do need to make sure E20 has been thoroughly tested. It's a relatively new option in ethanol, and more long-term research is still needed to measure things like driveability, tailpipe emissions and the emissions control systems this article mentions.

You may have read about a couple studies released by the State of Minnesota that suggest E20 vehicles have similar performance to those that run on E85. However, the Minnesota studies only tested the cars for 3000 hours, which is a lot less than what an OEM requires. I encourage them to keep testing and keep learning more about ethanol.

I wrote a blog on GMnext.com that address the issues with E20. You can check it out here: http://blog.gmnext.com/?p=93

Coleman Jones
Manger of Biofuels Implementation, GM Powertrain

[Mike Johnson]

is it good for our enviroment and our economy? someone please answer!!!

[Charlie Bakken]

Remove the $0.54/gallon U.S. tariff on Brazilian ethanol and corn is no longer considered viable (economically and environmentally) for ethanol production. Brazil has more sugar cane than it knows what to do with.