David Pimentel is at it again. The poster boy for the anti-ethanol movement has a figure of 1,700 gallons of water required to produce one gallon of ethanol. He was quoted — again– last week on “Fast Money” on CNBC.
Problem is, like a lot of his other “statistics,” this one is pretty far off base. To arrive at 1,700 gallons he makes the whopping assumption that all ethanol is made from corn and all the corn used is grown under irrigation.
The fact is, only 4 to 5 percent of the corn used to make ethanol is grown under irrigation and the other 95 percent uses the water that falls from the sky, the stuff us folks in farm country call “rain.” Presumably that water is “consumed” if it falls on corn fields but somehow “saved” if falls on a shopping mall.
The correct number is four gallons of water per gallon of ethanol, down 26 percent from 2001 according to Argonne National Laboratory. And growing corn, like all other vegetation, gives off water vapor — about 4,000 gallons of water per acre, per day.
Crude oil, by the way, requires 1,851 gallons of water per barrel in refining. That’s about 44 gallons water for one gallon of crude. Its evaporation rate, in return? Um, that would be zero.
More fun facts on water — these from the EPA.