Bioenergy

Wisconsin Farmers Receive Grants for Anaerobic Digestion Technology

Focus on Energy, Wisconsin’s energy efficiency and renewable energy initiative, has awarded eight grants totaling more than $1.5 million to Wisconsin dairy farms to help them install anaerobic digesters.

Anaerobic digestion is the bacterial decomposition of organic matter that occurs in the absence of oxygen. An anaerobic digester system is an enclosed tank that excludes oxygen and through which organic matter is passed and broken down by naturally occurring bacteria, producing biogas. This biogas is composed of approximately 55 percent to 70 percent methane. The methane produced in the process can be used in an engine-generator to produce electricity. Anaerobic digesters can also be used to provide heat.

“When completed, the anaerobic digesters will generate approximately 3 megawatts and 22,886,000 kilowatt-hours of electricity per year,” said Larry Krom, project manager for Focus. “That is enough energy to power 2,298 average Wisconsin homes or over 75 percent of the electricity use of a city the size of Waupun.”