Patrick Serfass, executive director of the American Biogas Council, said dairies are a desired partner for the more than 260 companies and 3,000 professionals who comprise his organization. The council’s goal is to maximize the production and use of biogas from organic waste.
Serfass said while wastewater facilities remain the largest biogas sector, “agriculture has always been an important piece of the puzzle because of how strong the sustainability story is and how important it is to agriculture.” He describes a “closed loop system” on dairies with digesters.
“You have cows eating feed that’s grown in the fields, they then produce milk and manure,” he said. “That milk needs to be delivered every day and those trucks need to be fueled, so you can fuel those trucks with biogas that comes from manure. The milk processing facilities produce wastewater and that can be sent back to the farm to produce more biogas and then use the digestive (byproduct) material from the biogas system to increase your crop yield. In many cases we have found that the digestive material from the biogas system improves crop yields 10% to 30%. Those numbers are big enough to appeal to any farmer.”
One other benefit of digesters is that farmers can work with their communities to accept food waste. Such is the case with Vermont dairy farmer Chase Goodrich, who never imagined his farm would become a destination for food scraps. However, that all changed when the state passed a law in 2020 banning items such as peels, seeds, pits, bones, tea bags, coffee grounds, eggshells and grease from landfills to reduce GHG emissions. More >>