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East River Electric Power Cooperative is working with local partners to develop multiple sources of energy in eastern South Dakota. One methane digester is nearly constructed at a local dairy operation, with plans for more at other dairy farms and at a closed landfill in Sioux Falls. Odors resulting from livestock operations can be unpleasant, and managing manure produced at confined animal feeding operations is an environmental challenge. However, methane digesters can effectively turn waste into an energy resource.

Manure collects in an upright metal container or a covered, concrete lagoon and is eaten by an enzyme injected into the sludge. The process creates a gas, which after being scrubbed to remove corrosive particulate matter, enters a generator and is heated to produce electricity. A value-added benefit: the solid by-product from the digestion process can be used as a high-quality bedding product for the dairy cows.

Like wind turbines, methane digesters add economic benefit to the region. Agricultural operations that use digesters can sell power to the cooperative's grid as well as use their own methane-generated power, reducing their farms' operating costs.

Earth Resources, Inc. is redefining recycling for the Georgia Mountains Region. Earth Resources invested $1.13 million to build a model plant in Franklin County that converts chicken manure into a renewable energy source. They also have plans to construct a full-scale energy plant that will employ 35 people.

The Georgia Mountains Regional Development Center provided assistance to Earth Resources in securing funding, including a U.S. Department of Agriculture and Department of Energy joint biomass research and development grant to fund a three-year study on chicken manure-energy conversion. Georgia Mountains RDC's Economic Development Director David Sargent explains, "The plant uses a heated oven to cause pressure on the chicken litter. This extreme pressure releases gases in air and separates it from the solid component. At the same time, the gases ignite and create steam, which turns a turbine and generates electricity."

The model plant contracts with local electric cooperatives to market its energy. It is capable of converting three tons of manure each day into enough power for 25 homes, while the full-scale plant should provide electricity for about 6,000 homes.

Managing chicken litter is a serious concern for the region's environmental quality, as well. Georgia is a leader in U.S. poultry production, and the industry produces 1.5 million tons of manure each year. But heating the chicken manure to create electricity also reduces the manure to ash, and the process burns cleanly, emitting few gases. The solid by-product loses its phosphates and nitrates, which contribute to water pollution and algal blooms when unprocessed manure is applied to land as a fertilizer.

Sargent says, "In Georgia and elsewhere, there is too much phosphate going into the water source. So when the chicken litter is turned into a material that can be used as a fertilizer for fields or lawns, we ultimately address runoff problems that harm our water sources."

East River Electric Power Cooperative 121 SE First St., P.O. Box 227 Madison, SD 57042 Tel: 605.256.8015 Fax: 605.256.8057 http://www.eastriver.coop/

Georgia Mountains Regional Development Center P.O. Box 1720 Gainesville, GA 30503 Tel: 770.538.2626 Fax: 770.538.2625 http://www.gmrdc.org