30-01-02 Power companies and animal farmers have recently begun looking at animal manure as an untapped energy source for the new century, a way to generate energy while preserving the environment. Waste products from chicken, pigs and cows can be processed through a "methane digester," heated and mixed with bacteria to create a biogas. The gas is then turned from mechanical energy into electrical energy. The remaining by-products, such as fibre, can be sold as nursery fertilizer.
If the manure is not processed into renewable energy, farmers use it for fertilizer; however, they risk damaging nearby streams as the phosphorous-rich waste may seep into the water, said Jeff Corbin, senior scientist with the Chesapeake Bay Foundation.

Although the US EPA has known about this technology since the 1970s, the US has not fully embraced the process. The process is costly, said Dina Kruger, who leads the methane and sequestration program at Agstar -- the voluntary effort sponsored by the EPA and the US departments of Agriculture and Energy to promote the recovery and reuse of methane. One methane digester can cost between $ 100,000 and $ 500,000, Kruger said.
Besides expensive equipment costs, Barry Kintzer, a national environmental engineer with the USDA said it costs twice as much to generate electricity with manure as opposed to the conventional means. The process is also not completely clean. Smokestacks may emit nutrients and the ash by-product created is high in phosphorous, he said.

Another way farmers are treating manure is through gasification. Tyson Foods turns chicken manure and sludge from its wastewater treatment plants in Temperanceville, Virginia, and Berlin, Maryland, into gas, which in turn produces 120,000 pounds of steam per hour to power one of its protein conversion plants. The gasification process "provides independent farms with an alternative use for their litter," said Ed Nicholson, Tyson spokesman.