36 Gallons of Water Per Mile: Corn Ethanol Uses More Water Than Any Other Biofuel
by Matthew McDermott, New York, NY on 10.21.08
photo: Jenny
Another nail has been hammered into the corn ethanol coffin. According to researchers at the University of Texas at Austin, the water requirements to produce corn ethanol are significantly higher than producing non-irrigated biofuels, hydrogen generated from renewable energy, or petroleum or diesel fuel.
The researchers compared the amount of water withdrawn (used and returned to the source) and the water consumed (water not returned to the source) per mile traveled in a typical car when powered by gasoline, diesel, corn ethanol, soy-derived biofuels, hydrogen and electricity and obtained the following results:
Irrigation, Not Biofuels Themselves, The Problem
Petrol and diesel, non-irrigated biofuels, hydrogen and electricity from renewable resources: <0.15 gal water/mile consumed water and <1 gal water/mile withdrawn water;Hydrogen and electricity derived direct from the US grid (currently mainly fossil fuel and nuclear power): 2-5 times more consumed water and 5-20 times more withdrawn water;
Irrigated biofuels (corn ethanol): 28 gal water/mile consumed water and 36 gal water/mile withdrawn water;
Soy-derived biofuels: 8 gal H2O/mile consumed water and 10 gal H2O/mile withdrawn water.
Evaluation of Biofuel’s Impact on Water Supply Crucial
In their recommendations, report authors Carey King and Michael Webber write (apologies to the authors for this abbreviated excerpt),
Transportation is yet another area where the nexus between water and energy can potentially create conflicts where they did not exist before. [...] The historical use of petroleum-based fuels has had a small overall impact on US water resources, and the most plausible alternatives have higher water intensities. [...] The difference in water intensity between irrigated and non-irrigated biofuel feedstocks (up to 3 orders of magnitude in gallons per mile) shows the tremendous amount of need to properly plan for their incorporation. Due to water resource limitations at aquifers that are already being used intensively for food crop production, using those same aquifers for fuel production may exceed existing limits.
Full original journal article (here be academia...): Water Intensity of Transportation
Corn Ethanol
Corn Ethanol Worsens Gulf of Mexico Dead Zone
Common BioFuels Myth: Corn-Based Ethanol To Blame for Global Food Shortages
Midwest Flooding Brings to Light the Vulnerability of Corn Ethanol
Ethanol Mandates: The Single Most Misguided Agricultural Program in Modern American History
Thirsty for more? Check out these related articles:
- Corn Ethanol Is Stupid: 13 Year Old Weighs In On Renewable Energy
- Big Food’s War on Biofuels
- Future Biofuels Could Be Created Out of Thin Air: Craig Venter & Synthetic Genomics
- Wind Power Beats Nuclear & Clean Coal, Other Renewables As US’s Best Energy Option
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Big Corn, just like Big Oil, has tremendous lobbying power in Washington. Plus, 'supporting farmers' through subsidies has a nicer ring to taxpayers, so this has gone through smoothly. We need more articles like the above to expose all this. We really need to move to mass transit, and away from the car - ever sit in rush hour traffic and think 'yeah, this is the way it's supposed to be!'
For those interested in water conservation for the home, (after all, it's all related!) I just ran across a good article: http://eartheasy.com/live_water_saving.htm
Not all corn is irrigated. It's ridiculous to imply that all corn-derived ethanol uses 36 gallons per mile (withdrawn).
While the article is informative, and some ethanol does use that much water, the headline is misleadingly skewed to Treehugger's interests.
Do you assume all corn is irrigated because you have never been in a cornfield?
Perhaps someone that's not from Brooklyn could write about the happenings of middle America?
While this particular piece may not be the nail in the coffin of corn biofuel, the elimination of a 54 cent tarriff on Brazilian cane based biofuel would be...and both candidates have promised that repeal.
And that really doesn't change if someone from Iowa is writing it...
Start diversifying your crop my Midwestern friend...
Biodiversity; it's not just for rainforests...
HG
I think ethanol should only be used as filler for gasoline when corn is in surplus, and thus cheap enough to be mixed in with the oil. It's not greener than gasoline when corn is being used as a replacement. It's just better to use the corn for fuel when it's not better suited to something else, since letting corn rot releases methane, and methane is worse for the atmosphere than CO2 released from burned ethanol.
Corn Ethanol isn't a great idea... unless you're a corn farmer in which case you'll be loving those subsidies.
@ Garrett - I am fairly certain the University of Texas at Austin is not located in Brooklyn.
Everything produced uses some water to make it. Plastics, chemicals, food, machinery, steel products, etc. The water argument is irrelevant. If you count all the water used to irrigate fields to grow crops, then that usage should be argued for all uses of the crop. If you use the crop to make corn flakes or bread then it takes 1700 gallons of water to make them. ("Pimentel" from Cornell - you have to take into account the rain that falls) But if you take if from the production side then it is a different look. Gasoline takes about 66 gallons of water to make a gallon of gas. Ethanol uses about three. You don't have to trust me. Look it up.
As for subsidies: There are two basic ethanol subsidies that are available in producing ethanol. There is a blenders credit of $.51 cents per gallon. This is available to whomever blends the ethanol with gas to make it available to market. Most times it is the distributor or oil company that gets this. Not the farmer or ethanol producer. The second is a small ethanol producer credit which is available only on the first 15 million gallons of ethanol a company produces up to $1.5 million. This goes away when the plant exceeds 60 million gallons of production. A lot of plants make more then this.
Corn farmers are caught in the middle. They still need to plant the corn, grow it and harvest it. Regardless of how much diesel, fertilizer or equipment costs. Regardless of how much rain falls or how early winter comes.
If you read the research report, you learn the TRUTH about this issue:
"Ethanol processed from corn grain from non-irrigated fields results in water consumption and withdrawal intensities of 0.15-0.35 gal H2O/mile and 0.33-0.56 gal H2O/mile,"
Considering a vast majority of corn in this country is produced by non-irrigated corn, a vast majority of ethanol fits into that picture.
Most of the new ethanol plants also use less water than estimated in the study.
So yes, the headline of this post is designed to draw attention and mislead, and the text in the post isn't much better.
@ Tim:
Corn farmers don't get subsidies for ethanol production. Fuel blenders do (the oil companies). In fact, if corn prices were $2 again, farmers would be receiving subsidies from the government to offset the low prices. Not sure which is worse, but I'd rather see higher corn prices and a strong rural economy even if fuel blenders get a subsidy to help them build infrastructure to support current renewable fuels - and those coming down the pipe.
This data is deceiving.
Unless the water is PERMANENTLY TOXIFIED, like the tailings ponds at the Alberta tar sands, it is not consumed. It is just part of the water cycle.
This is like saying that because organisms use x amount of oxygen per day, we will soon suffocate from the disappearance of atmospheric oxygen.