Monday, January 14, 2008

Electrical Switchgrass?

Although most of my posts are centered directly around the production of biofuels, a slight foray into a closely related topic never hurts. Recently I was asked about an energy company's goal of co-firing their electricity generating plant with coal and switchgrass. After a little digging, I found that the Chariton Valley Energy Cooperative -- a locally owned utility in Eastern Iowa, was testing out how replacing 10% of the coal with switchgrass would have on electricity production and emissions of gases. For a little more background, Chariton Valley is running this project under the control of Alliant Energy, which serves most of the Eastern Iowa area.
Chariton Valley ran its tests at its plant in Chillicothe, Iowa with continuous biomass (switchgrass) burn for 1,675 hours to collect data (approximately 2 months). In this amount of time 15,647 tons of switchgrass was burned, eliminating the need for 12,060 tons of coal. The reason that these two numbers differ reflects the lower energy density of switchgrass (approximately 23% that of coal). In other words, according to Heller et. al, adding 10% biomass to cofire with coal will only result in an increase of 8.9% in total energy delivered. However, there was some good news from the study. The Department of Energy, which monitored the pilot-project, recorded that the power station had a drop of 62 tons of sulfur dioxide and 50,800 tons of carbon dioxide from the plant when using 10% biomass, which is a drop of approximately 10% in both emissions categories.
That was the good news, here's the bad news. According to Chariton Valley's own website, electrical companies might be able to pay farmers $45 per ton of switchgrass produced (emphasis on might be able). One acre of land will produce approximately 11.5 tons of switchgrass (or a $517.5 value). Keep in mind that the ability for Chariton Valley to purchase switchgrass at $45 per ton is in part due to the ability to produce 'renewable energy credits' that can be used to sell to other companies as a carbon-offset program. (This test run produced 19,600 credits for the company). But back to switchgrass... if you are a farmer making $517.5 per acre on switchgrass and corn, let's say is $4.00 per bushel, (even though it is more like $4.80 per bushel right now), you might want to go over the economics real quick. If a farmer can get 180 bushels of corn per acre in a good year, that would be a value of $864 per acre shattering the $517.5 per acre price for switchgrass.
I regret that the value of an agricultural product rarely if ever reflects the intangible benefits it provides -- such as a better habitat for the environment, less soil runoff, or a decreased need for nitrogen fertilizer inputs. If these categories were factored into the price, switchgrass would probably win hands down, but they don't. And because of this, switchgrass is definitely a losing proposition for farmers in the very fertile region of Eastern Iowa. Hopefully this technology can be used in states where switchgrass might be the only option for sustained plant growth such as Western Nebraska, but until prices can go above $45 per ton for switchgrass, the farmer will be losing money by switching entire fields to the tall prairie grass.

To review my sources or get more information, follow the links below:
1)
"Corn Prices." Chicago Board of Trade. 14 Jan. 2008. 14 Jan. 2008 .
2)
"Economic Benefits." Chariton Valley Biomass Project. 14 Jan. 2008 .

3)
Heller, Martin C., and Timothy A. Volk. "Life Cycle Energy and Environmental Benefits of Generating Electricity From Willow Biomass." Journal of Renewable Energy (2003). 14 Jan. 2008 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V4S-4BM6BJ4-1&_user=716796&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000040078&_version=1&_urlVersion=0&_userid=716796&md5=5dcd72e55f02e8ffd504ef5d13b5a873.

4)
"State Energy Program: Iowa Utility Mixes Switchgrass with Coal in Cofiring Test." Department of Energy. 7 June 2007. 14 Jan. 2008 .

1 comment:

mus302 said...

Interesting post. In some cases switchgrass may make better sense for a farmer than what your economics show. Since fertilizer cost is up once the differences in the cost of fertilizing an acre of swithcgrass compared to an acre of corn is considered the net income should be closer. And the equipment to harvest is less and at least in my area of eastern Tennessee in much greater supply. Anybody that can bale hay for their cattle could grow and harvest switchgrass.

One other thing to consider, it takes two to three years for switchgrass to achieve it's maximum yield so it isn't a crop that can be raised for just one year then switch to something else the next year.