Issue Overview: Water Use in Ethanol Production

Issue Overview: Water use in Ethanol Production (Source: Nebraska Ethanol Board)

Context & Perspective: Water Usage Comparisons

According to the EPA

1. 62,600 gallons to produce a ton of steel 2. 39,090 gallons are needed to manufacture a new car, including tires 3. 28,100 gallons to process a ton of beet sugar to make processed sugar 4. 1,500 gallons to process a barrel of beer

According to the U.S. Geological Survey (USGS)

1. An acre of corn gives off 3,000-4,000 gallons of water each day through transpiration. 2. It takes 684,000 gallons of water per acre per year to irrigate a golf course. 3. 21,600 gallons to water the average lawn. 4. 150 gallons of water to produce one copy of a newspaper 5. 1,850 gallons of water to refine one barrel of crude oil, yielding 20 gallons of gas 6. Estimates on water requirements for oil production vary widely

According to the National Renewable Energy Laboratory

1. It takes an estimated 65 to 90 gallons of water for each barrel of oil 2. Conservative estimates show the water requirement for a gallon of gasoline (2 to 2.5 gallons [NREL]) is similar to that of ethanol (3 gallons)

Water Use in Ethanol Production

1. 3 to 5 gallons of water required per gallon of ethanol produced 2. Average water use declined from 5.8:1 in 1998 to 4.2:1 in 2005 (Institute for Agriculture & Trade Policy, 10/06) 3. 1/3 of water is used for process water 4. Remaining 2/3 used in utility systems with 90% of that used in the cooling tower 5. Ethanol process improvements indicate water use can be reduced to 1.5 to 1. 6. Water recycling and purification technologies continue to reduce the amount of water used for ethanol production.

Water and Corn Used to produce feed grains (i.e., feed corn) based-ethanol

1. With an estimated 9 billion gallons of capacity, and an average yield of 2.75 bushels per gallon, the ethanol industry processes 3.27 billion bushels of feed grains into fuel. An estimated 66% of those bushel are returned as the animal feed to the feed market. Therefore, only 1.12 billion bushels of animal feed grains are directly used for ethanol production. 2. Nationwide, 86 percent of corn is not irrigated. Irrigation efficiency has improved dramatically in the past 20 years. 3. Irrigated corn may use around 325,000 gallons per acre per year. 4. Nearly 40 percent of the corn acres in Nebraska are nonirrigated, relying solely on rainwater. Reduced-tillage practices help to conserve moisture. 5. Center-pivot systems more efficient than flood irrigation and Low-pressure nozzles more efficient. 6. Natural Resource Districts monitor water usage by irrigators. NRDs monitor water tables, and many districts have implemented agricultural water use limitations. As rainfall returns to normal, water supplies will be replenished.

Water Usage for Corn and Ethanol Production Page 1 FUEL FOR THOUGHT: American Coalition for Ethanol, May 29, 2008

RE: FRANKEN-STAT

It's the monster stat that will never die: 1,700 gallons of water to produce a gallon of ethanol. It was bandied most recently on the CNBC show "Fast Money" earlier this week. The source, of course, is Cornell University entomologist David Pimentel, the fountainhead of quasi-scholarship for the anti-ethanol movement. He gets the number by adding in the water needed to grow corn -- never mind the fact that as little as 4 percent of the corn used for ethanol production in the United States requires irrigation.

Rainfall is enough for the other 96 percent. Is rain a bad thing? Perhaps it would be better if it fell on a parking lot?

The actual ethanol production process takes less than four gallons of water per gallon of ethanol. In fact, water use in dry mill ethanol plants dropped more than 26 percent between 2001 and 2006, according to Argonne National Laboratory.

By comparison, it takes 1,851 gallons of water to refine a barrel of crude oil. That's 44 gallons of water per gallon of crude.

Have a look at the EPA link below for more fun facts on water.

(Special note to Pimentel: See fact number 10. One acre of corn gives off 4,000 gallons of water per day in evaporation.)

Reference Materials for the Issue Overview

1. Argonne National Laboratory. "Analysis of the Efficiency of the U.S. Ethanol Industry 2007." March 27, 2008.

2. Ethanol Production Efficiency’s http://www.ethanolrfa.org/objects/documents/1652/2007_analysis_of_the_efficiency_of_the_us_ethanol _industry.pdf

3. EPA. "Water Trivia Facts." April 1995. 4. http://media.mgbg.com/wkrg/photos/weather/downloads/Water_Facts.pdf

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