From an article by in the Wisconsin Ag Connection:

As the University of Wisconsin-Platteville continues to explore renewable and sustainable energy sources on campus, one opportunity has more to do with the local bovine community than anything else. Tim Zauche, UWP professor and chair of the chemistry and engineering physics department, along with Chris Baxter, UWP assistant professor of agronomy, are leading a project team exploring the possibility of having an anaerobic digester on campus and another in the Platteville community.

An anaerobic digester uses bacteria to break down organic waste to produce methane, much like a cow’s stomach. One by-product of the bacteria digesting this waste is methane, also known as natural gas, which is used to heat homes and generate electricity.

“We need to mix the waste because, like our bodies, the bacteria can’t survive on sugar alone. We need to provide them with a balanced diet, so to speak,” said Zauche. “By using the same bacteria that produces gas in a cow’s stomach, we can turn waste into energy that can provide electricity or heat for homes. The material from four cows can provide the electricity for one home for a year and one digester could provide seven percent of UWP’s annual power consumption.”

Once used, the waste from the digester will be filtered into liquid and solid forms of fertilizer ready for direct field application and other forms of fertilizer use.