Before anaerobic digestion gained much traction across the dairy industry, Allen Farms had already proven the merits of the manure-handling and power-generating technology.
“Our system was so much of a prototype in the beginning,” says Dave Allen, an Oshkosh, Wisconsin, dairy farmer. “Now that the bugs have been worked out, everything works well.”
Since 2012, Allen has worked in collaboration with the University of Wisconsin Oshkosh (UWO) and BIOFerm Energy Systems (biofermenergy.com) to purchase and set up the anaerobic digester on his 130-cow farm. The running of the digester now depends on Allen’s daily input of manure and other feedstocks, while UWO staff manage the technical aspects of the system.
Holistic efficiency is the hallmark of the digester’s role on the dairy farm. “We’re taking waste and collecting the methane from it,” Allen says. “From that, we’re generating electricity and heat. When it’s all said and done, we have an awesome fertilizer to put back on the land.”
The annual electrical output of the digester is enough “to provide power to about 50 average American homes,” says Brian Langolf, director of the UWO biogas program. “The digester’s 64-kilowatt combined heat and power unit can put out a maximum of 1,536 kilowatt-hours per day, or 560,640 kilowatt-hours per year. We are currently running at 80% to 90% of full output capacity. The electricity is sold to the local power utility.”