Manure to Electricity Makes Sense

Turning manure into electricity. It's been done. It makes sense.

Sept. 14, 2007

Cow Power: System Could Let Cows Produce Milk AND Electricity

Writer: Edith Chenault, 979-845-2886,EChenaul@ag.tamu.edu
Contact: Dr. Saqib Mukhtar, 979-458-1019,mukhtar@tamu.edu

COLLEGE STATION – Contented cows may be giving more than milk these days. Their manure could help to turn the lights on at farms, thanks to a project being undertaken by the Texas Water Resources Institute and Texas Cooperative Extension.

The Institute received a grant from the Natural Resources Conservation Service to test an on-farm manure-to-energy conversion system for future use on Central Texas dairies.

"This project is a little more than ‘the price of gas is high and we're trying to find an alternative,'" said Dr. Saqib Mukhtar, Extension agricultural engineer and one of the project leaders. "We're trying to find out if we can benefit the environment by diverting some of the manure that is being applied to waste application fields."

The grant is funding the assembly and testing of a portable energy generation unit that's otherwise known as a thermophilic digester and fluidized bed gasifier system. Because the unit will be on skids, it can be taken from farm to farm for educational demonstrations.

"We're trying to find ways to divert excess manure and reduce repeated and excessive application of phosphorus to waste application fields that can potentially become a non-point source of pollution," Mukhtar said.

Presently, many dairy farmers—to meet Texas Commission on Environmental Quality standards—remove excess manure and apply it offsite to nutrient deficient crop and pastureland in an effort to keep excess nutrients out of surface and groundwater, he said.

Repeated applications of manure results in soil levels of phosphorus exceeding quantities needed for plant growth, he said. That excess phosphorus can wash into creeks, rivers and lakes, causing additional problems with excess algal blooms and decreased oxygen in the water.

"Some farmers have contracts with commercial composting outfits," he said. "These composters pick up manure that is scraped from corrals and piled on site. Composted manure is used by home gardeners and commercial nurseries. Some of it is used for fertilizing rights-of-ways by the Texas Department of Transportation.

"Dairies are trying their best to comply with all the rules," he added. "(But) if you apply manure at more than agronomic rates to land again and again, you still face environmental problems."
If the environmental problems aren't solved, he said, "You....(rest of story here)