Power Cooperative to Produce Renewable Electricity From Anaerobic Digesters

Power Cooperative to Produce Renewable Electricity From Anaerobic Digesters

Sep 24 - BioCycle

Dairyland Power Cooperative based , in La Crosse, Wisconsin provides the wholesale electrical requirements and other services for 25 electric distribution cooperatives and 20 municipal utilities. Together they serve more than half a million people in four states (Wisconsin, Minnesota, Iowa and Illinois).

Dairyland was formed in 1941 and today has five generating stations with 1,066 megawatt capacity. Now Dairyland and Microgy, a subsidiary of Environmental Power, have formed a "green alliance" to produce renewable electricity at dairy and swine farms within the Dairyland system. Energy source will be manure, and the process is anaerobic digestion.

Initially, the partnership is working with these Wisconsin farms: Five Star Dairy (Elk Mound); Wild Rose Dairy (LaFarge); Daley Farm and Bach Farms (Dorchester); and Norswiss Farms (Rice Lake). The first farms should be online in late 2004, and each will generate 750 kilowatts of renewable power. Together they will generate enough energy to power 3,000 homes within the Dairyland system.

"Project goal is to create up to 25 MW of renewable electricity, fulfilling the energy needs of approximately 20,000 homes in our service area," says Katie Thomson of Dairyland. A mini power plant will be sited at each farm. After the manure is collected, it will be heated in the digester tank at 135F for approximately three weeks. "Methane gas that is the by product of that process will be the fuel used to generate electricity. The digester will be owned by the farmer, and the generator will be owned by DPC," adds Thomson.

According to specified arrangements, the farmer buys the digester from Microgy. DPC will purchase the gas from the farmer. Microgy will take care of operation and maintenance. Size of digester operations is approximately one-quarter acre.

Benefits are cited as follows: Clean air and water pollution issues associated with manure disposal are significantly reduced, as is the odor problem; Weed seeds and pathogens are killed during the heating process, and therefore, the fly count is reduced; Heated, dewatered by-product of the digestion process can be used as a natural bedding and fertilizer by the farmer, thus reducing dependence on chemical fertilizers and pesticides; Odor issues, an increasing problem for farmers, are reduced by 95 percent by the manure digesters; Minimizes potential for pollutants from manure in ground and surface water.

A first-hand description of the process and cooperative arrangement will be given at the BioCycle 4th Annual Renewable Energy From Organics Eecycling Conference, November 8-10, 2004 in Des Moines, Iowa. To register for the conference, see pages 15-17 of this issue -which includes complete agenda.