Why do we use our food to fuel our cars? A lesson in trade-offs

Ethanol has always been a mystery to me. Why do we voluntarily pay more for a less effective fuel that depletes our resources and is harmful to the environment (consumes a LOT of water, requires more energy to produce and ship)? It is the classic example of politics trumping logic, common sense, and science.

As if we needed more proof, check out this blog post from the Congressional Budget Office Director's Blog (I guess it's official, we should ALL be blogging now!).
http://cboblog.cbo.gov/?p=1161

"The costs to taxpayers of using a biofuel to reduce gasoline consumption by one gallon are $1.78 for ethanol and $3.00 for cellulosic ethanol."

That is just insane. It's not worth it, people! And we wonder why our government is going bankrupt...


There are actually a number of trade-offs that we must consider. EVERYTHING has a trade-off. As Heinlen said in his classic book, The Moon is a Harsh Mistress, TANSTAAFL.

Gasoline use is regarded as a bad thing by so-called environmentalists. But when we look at some of the trade-offs, it doesn't look so bad. Cost is one obvious trade-off as mentioned above. There are others. What about water consumption?

Consider this excellent special report from IEEE Spectrum magazine:
IEEE Spectrum Special Report - Water vs. Energy

In this special report, IEEE Spectrum presents a series of articles in which they consider many of the trade-offs between power production and water consumption. This is a real problem that we are facing NOW in many parts of the world, and right here in our country--in the Colorado River basin, for example.

In this article, Biofuel's Water Problem, we see that gasoline consumes 0.26 liters of water per kilometer driven. E85 ethanol from irrigated corn consumes 26 liters of water per kilometer driven. That's right, ethanol consumes 100 times as much water as gasoline. Biodiesel from soybeans is even worse, at 28 liters per kilometer driven.

Another short article in IEEE Spectrum, CO2 vs. H2O in Power Production, shows the trade-off between water consumption and carbon emissions. They sum it up this way, "The trade-off between water and energy is tough, but the trade-off between carbon emissions and water is even tougher."