Gas from manure: Big plant to open

Microgy starts filling its first thermophilic digesters, which use microbes to turn smelly waste into biogas. Photos: Barnyard energy

Michael Kanellos Staff Writer, CNET News.com
Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas.
Michael Kanellos
2 min read
A plan to convert large quantities of manure into natural gas and sell it over pipelines is materializing.

Microgy plans to start operating its first two thermophilic digesters--large, heated vats in which microbes turn manure into fuel--in its Huckabay, Texas, facility next month, according to a company representative.

Barnyard energy

The digesters extract biogas, a mixture of carbon dioxide and methane, from manure. Biogas can be used locally to run generators and farm equipment, but by burning off the carbon dioxide (about a third of the overall gas content), natural gas is created that can be shipped through a pipeline.

The company has already installed digesters at farms in Wisconsin, but the majority of gas created there gets consumed by local farmers. The coming Huckabay Ridge plant is another beast entirely.

When complete, the eight digesters--each of which hold 916,000 gallons--will be able to process the manure of 10,000 cows. That's enough to produce a billion cubic feet of biogas a year. A year's worth of biogas can sell for about $4.6 million. The plant itself costs $11.2 million.

Microgy, a division of Portsmouth, N.H.-based Environmental Power, believes that it could build several digesters throughout the country. Meat giant Swift & Co., for one, is looking at the feasibility of installing thermophilic digesters.

Microgy's first two digesters will likely start producing biogas in October, a little later than the anticipated third-quarter start date. They are being filled up now.

"There is (about) a 20-day digestion process," the company representative said.

Turning manure into gas has environmental benefits. Traditional manure composting can lead to algae blooms and chemical runoffs.

The Five Star Dairy farm in Elk Mound, Wis., which has a Microgy digester, uses the leftover grass and solid bits from gas production--which doesn't smell anymore--for cow beds.