Rethinking Ethanol

60 Minutes ran a story last night on ethanol as a fuel for automobiles. There now exists a proven fuel blend called E85 that is 15% traditional petroleum, 85% ethanol. The ethanol can be produced from corn which can be grown in abundance in the United States. Automobile engines using an advanced fuel injection system capable of sensing and adapting to different fuel mixtures (“flex-fuel engines”) can use both E85 and regular gasoline. Flex-fuel engines are not significantly more expensive than standard fuel injection engines.
For years, conventional wisdom held that ethanol was not the solution to America’s energy problems. The belief was that more energy was needed to produce a gallon of ethanol-based fuel than was released when burning one. A growing number of studies are casting doubts on this assertion. A recent study done by study done by Hosein Shapouri and James Duffield of the USDA and Michael Wang of Argonne National Laboratory concluded that corn-based ethanol contains 1.34 times the non-renewable energy needed to produce it.
This Department of Energy summary of Shapouri, Duffield and Wang’s work explains two reasons for the new thinking. One is technical. Modern farming techniques and fertilizers have reduced the amount energy that goes into harvesting a bushel of corn. The other reason involves energy accounting. The DOE summary argues that the solar energy needed to produce a bushel of corn shouldn’t be counted against the cost of ethanol production because solar energy is “free, renewable and environmentally benign”.
To expand on the second point, the laws of physics (thermodynamics, to be exact) state that there is no process that can produce more energy than it uses. This is true even of fossil fuels. The energy released in burning a fossil fuel is less than the sum of the energy required to extract and refine it plus the energy from whatever geologic processes produced it. However, the geologic energy — energy that’s already been stored whether we use it or not — is not counted in fossil fuel efficiency calculations. In the same sense, the solar energy that goes into crop farming should not be counted against the cost of producing ethanol; the energy is there whether we use it or not.
According to a USA Today article, E85 is not as efficient as traditional gasoline — you’d have to burn more E85 than traditional gasoline (albeit at a cheaper price) to go the same distance. But unless there are problems bigger than this with the analysis of the viability of ethanol, it is long past time to consider what needs to be done to take the next step towards increasing the nationwide usage of ethanol-based fuels.

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17 years ago

Good post! Ethanol certainly may serve as a valuable alternative energy source in the near future. However, I tend to view an enthanol-economy as a short-term “bridge” solution, which, in addition to increased oil and gas exploration, could have a significant impact on our economy. That is, while ethanol may enable us to reduce our dependency on foreign oil (a term which is used far too often), it is not a long-term answer to our energy needs nor is it a remedy for our environmental concerns.
I would like to see some posts on AR concerning two additional promising alternative energy solutions — one, which like ethanol would provide for near-term relief from runaway energy prices, and the other which I believe rivals hydrogen in its long-term promise. The former is clean and liquified coal technology, which is readily available in the US, and China is currently utilizing, and the latter is Methanol – a highly innovative energy source that can be pumped in the same way as gasoline and either converted from natural gas, or more interestingly, from a combination of CO2 and Water!
Just think: actually harvesting the CO2 in the atmosphere to power our cars!

17 years ago

Corn-based ethanol isn’t a solution to high gas prices, because corn-based ethanol is more expensive than gasoline, even with massive subsidies. (Here’s a price tracker website: Because 1.5 gallons of ethanol yields the energy equivalent of 1 gallon of gasoline, these wholesale prices — which as of this post are higher than gasoline prices — need to be multiplied by 1.5.
The root cause is the low energy yield achieved by producing corn-based ethanol. Getting 1.3 times the energy put into the process is actually quite a pitiful result — petroleum yields about 10-11 times the energy input (depending on production conditions) and ethanol’s energy yield is lower than other options, such as shale oil. (See
It’s not clear to me why we should respond to high energy prices by switching to more expensive sources of energy.

Marc Comtois
17 years ago

Some of those ideas and a few others are discussed in this Popular Mechanics piece. A good read. There is also a handy comparison chart [PDF].

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