Water for energy: The bad bet for biofuels

Water Number: 50 gallons of water per mile. This is the water required to produce the ethanol biofuels needed to drive a car ONE mile, using irrigated corn. This number comes from a recent Environmental Science and Technology (ES&T) journal article by R. Dominguez-Faus, Susan E. Powers, Joel G. Burken, and Pedro J. Alvarez.

50 gallons per mile. Wow. This is an average value and varies significantly depending on where and how you grow corn or other potential fuel feedstocks. It can be half this value or more than twice as this value, depending on irrigation technology and, especially, climate. But by any measure, it is huge.

How does this compare to the water required to produce gasoline? According to Professor Michael Webber at the University of Texas at Austin (in a piece he did for Scientific American in 2008), it takes 0.07 to 0.14 gallons of water to make the gasoline to drive a car one mile. Plug-in hybrids are a bit more water intensive, because you have to count the water to make the electricity too – perhaps 0.25 gallons water per mile. But these pale in comparison to water for biofuels.

San Francisco Chronicle

Study: PDF