Methane Digesters

Another source of renewable energy can be found on the farms and ranches of eastern South Dakota and western Minnesota. Animal waste is being processed through Methane Digesters to fuel electric generators. In addition to reducing odor, these renewable energy projects generate heat and byproducts that the farmer can use for serving his agricultural operations.

How it works

Naturally-occurring microorganisms break down the waste products and produce methane and other biogasses. The gas is used to fire a boiler to maintain a constant 96 degree temperature so that the bacteria continue to breakdown the waste and produce gas. A large generator, located in an auxiliary equipment building adjacent to the digester, is powered by the surplus methane. The 375-kilowatt generator is capable of supplying electricity for 250 average homes.

The leftover solids and liquids from the waste solution can also be used or sold. The sterilized solids make good bedding for the stalls and the liquids can be used as fertilizer. The boiler also provides hot water for heating the barn floors and washing facilities from a renewable resource. Touchstone Energy Cooperative members are currently working with methane digester projects at several dairy, hog-confinement and livestock facilities.