Monday, April 30, 2007

Ethanol and Water Use: Should We Be Worried?

Iogen, a Canadian biotechnology firm, plans to build the first American commercial-scale cellulosic ethanol plant near Idaho Falls, Idaho. This choice of location piqued my curiosity. Corn ethanol production is notoriously water intensive, but what about cellulosic ethanol production? Depending on how much water it takes to make cellulosic ethanol, locations in semi-arid Western states could pose a problem.

I could not readily find any information about water use and cellulosic ethanol, so I called Barry Solomon, a researcher who recently reported on the cost of water use in cellulosic plants. Professor Solomon estimated that cellulosic plants use 4.5 to 5 gallons of water for every gallon of ethanol produced, depending on the pretreatment methods. I hate to say it, but unless these plants become more efficient, a commercial cellulosic ethanol industry could strain our water resources.

Because cellulosic ethanol can be produced from a variety of feedstocks, plants can be located virtually anywhere, whereas corn ethanol plants are concentrated in the Midwest. At first glance, I found this to be troublesome. If locations in places like Idaho, Montana or, God-forbid, Arizona became de regeur, cellulosic ethanol could become a water hog of behemoth proportions. However, there is a flipside to this scenario - their lack of geographic concentration will prevent cellulosic plants from ganging up on the water resources of one region.

Realistically, it might be premature to worry about water use and cellulosic ethanol production. Right now 99% of ethanol comes from corn and politicians are continue to push for more. Corn ethanol production uses about 4 gallons of water for every gallon of ethanol produced, not to mention the water required for irrigation. According to the Energy Information Administration (EIA), current ethanol production capacity is 5.6 billion gallons per year. The EIA expects that capacity to increase to over 11 billion gallons per year if all current projects are completed. This level of production would require over 40 billion gallons of water every year. While the Midwest is normally pretty wet, the U.S. Drought Monitor has reported several Midwestern droughts in the last few years. At least one Minnesota plant, located in Granite Falls, is beginning to run into water problems. After exhausting its groundwater options, it is looking for alternatives such as treated wastewater and Minnesota River water. I imagine that situations like this will become more common as the corn ethanol boom expands.

In my opinion, the government should start investing in efficiency improvements if we are going to continue on our ethanol high. It is also important to methodically investigate environmental impacts when permitting these facilities. I think it is too easy for politicians and administrative agencies to stick their heads in the sand when potential problems delay politically popular ethanol plants.


Anonymous Anonymous said...

Your comments are interesting and timely. I think that ethanol has been touted as the be-all/end-all when it comes to alternative energies. But it seems if you scratch the surface, there's a lot that isn't so energy efficient about ethanol production. As someone who lives in Minnesota, drought conditions in some areas have been moderate to severe in recent seasons. Same with other regions in the midwest. With so much water needed to produce ethanol, is it worth it to bet on ethanol production as the answer to our fuel issues? It really seems almost unpatriotic to raise the issue but if producing ethanol sucks up that much water, then we should rethink the issue.

5/01/2007 12:29 AM  
Anonymous Anonymous said...

This is, from a 'water availability' standpoint, just plain silly. Install national ZONING for an ethanol plant, or for a hundred ethanol plants.

1. Need water. Force the ethanol plants to locate on the shores of the Mississipi River.

2. Need corn. There are barges of corn up and down that river now.

3. Need refineries to mix ethanol with oil. All the refineries are at the end of the Mississippi, or on the Texas gulf coast. The ethanol can travel there by barge.


11/05/2007 3:04 PM  
Anonymous Anonymous said...

One gallon of ethanol on average requires five gallons of water. Not only that, ethanol is an expensive fuel to produce. Currently the U.S. government subsidizes its production at .54 a gallon. That's to drop to .47, due to the 2008 Farm Bill.

Most plants today are 50 million gallons. At five gallons per, that's 2.5 billion gallons of water for one year of ethanol production. That water typically comes from regional aquifers that are quickly drained. While that frequently hurts regional wells, particularly rural residential wells, that's not going to stop these plants.

Energy production is a high priority in our nation. So that even in the Phoenix desert, companies can justify building an ethanol plant.

Great post,

7/19/2008 10:15 PM  
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