There are about 35 anaerobic digesters in operation on Wisconsin farms, but most are on farms with 800 or more cows. Brian Langolf, director of biogas systems and research development at UW-Oshkosh, thinks there is opportunity for digesters on small farms.
Langolf said there are about 1.5 million cows and almost 1,000 registered dairy farms. The average herd size is about 117 cows.
“Even though there are some very large (concentrated animal feeding operations) and more CAFOs being developed, there is still a tremendous opportunity for small farms in Wisconsin,” Langolf said. “Anaerobic digestion provides the opportunity to better manage that manure and other opportunities for other revenue streams for farms through electric generation.”
Langolf was a presenter March 10 in Stevens Point at one of four organic waste stream management programs planned around the state in March.
Over the past decade, the face of the UW-Oshkosh campus has changed considerably with the addition of geothermal heating systems for campus buildings, green rooftops, photovoltaic arrays, solar heat and energy efficient certified building projects, so it is a natural step to move into anaerobic digestions projects, Langolf said.