Is ethanol the answer (part 1)

An article in the business section of today's New York Times on the use of genetically engineered crops to produce ethanol reminded me that my promised post on ethanol is somewhat overdue.

Here in New Jersey, most of the gas stations I frequent are already selling a 10-15% ethanol-gasoline blend. Ethanol blends are also popular in the mid-west corn belt region. There is talk of pushing this much further. The question is whether this is a good idea.

There appear to be two reasons why the use of ethanol in place of gasoline could be a good idea. The first is to reduce the reliance of the United States on foreign oil. The second is to reduce our dependence on non-renewable energy sources in order to slow the growth of greenhouse gases in the atmosphere and, thereby, delay or reverse global warming. Frankly, I believe the second goal is far more important than the first, and, of course, finding good renewable energy sources would almost automatically reduce our dependence on foreign oil.

It turns out that what seem to be the obvious advantages of ethanol may not necessarily exist. The reason is that it requires a significant input of energy to make ethanol from corn, which is the principal crop now in use for the production of ethanol. First, just the process of growing the corn itself requires significant energy/fossil fuel input for fertilizer, tilling, planting, and harvesting. Second, the process of mashing and distilling the corn to produce ethanol also requires significant energy input.

There is an on-going debate among “experts” over whether it takes more energy to produce ethanol than the ethanol contains and over what types of energy must be used. One scientist at Cornell University, David Pimentel, concludes that it takes about 1.3 gallons of oil to produce one gallon of ethanol. Others, including the US Department of Agriculture disagree. It's very difficult to sort out who is correct about this because everyone seems to have an ax to grind. Much of the pro-ethanol literature is sponsored by or associated with the corn and ethanol lobbies – and these are powerful groups, including growers and politicians from the corn-belt states and the ethanol producers. Those on the other side often seem to have ties to the oil industry. Given the Bush administration's tendency to cook its science to fit its ideology, even the USDA studies are questionable.

After a review of many studies and after weighing the merits of each against the apparent biases of the authors, I've come to the conclusion that, while it probably requires slightly less energy to produce ethanol than the ethanol contains, the net energy gain is small, perhaps in the range of 5% - 25%. However, most of the energy now used in the production of corn-ethanol comes from coal and gas, not petroleum. Hence, the use of ethanol does appear to contribute somewhat to the goal of lessening dependence on foreign oil. Unfortunately, it appears that ethanol use contributes little or nothing to the goal of reducing greenhouse gas emissions since the energy used in producing the ethanol is from non-renewable fossil fuel sources.

In the interest of keeping this post from growing too large, I'm going to end it here, but that's not the end of the story. There will be more posts to come.