Covered Lagoon Systems Saving Energy and Farms

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Research is being done all around the world to find a renewable source of energy that can sustain us as a people. Earth has just about seven billion people on it consuming energy. In the not so distant future, non-renewable energy such as fossil fuels will not be available. Renewable energy that is sustainable is the only answer. Energy needs are going up while the supply is going down.

I was intrigued the other day when I saw an advertisement that suggested that maybe the answer to this question was not one large innovation, but many innovations being used simultaneously. Farmers here in North Carolina, and especially hog farmers in southeastern regions, have unique opportunities to help provide renewable energy. Swine waste from lagoons can be stabilized and used for energy production using anaerobic digesters in covered lagoon systems. There are multiple examples of farms using these renewable energy systems here in North Carolina while the process is always improving. This provides our region of North Carolina a unique opportunity to provide renewable energy.

By covering the lagoons, this biogas can be trapped and used to make renewable and sustainable energy. It does this by a process known as anaerobic digestion. This process is where microorganisms act on waste and break them down with an end result of biogas emissions consisting of methane and carbon dioxide mostly. This biogas can be combusted in a micro turbine producing electricity. Electricity produced can be used on the farm and surplus electricity can be sent to the power company and provide additional income for the farmer. Additional benefits for the farm include decreased lagoon odor and gas emissions.

The amount of electricity produced really depends on the size of the lagoon, the amount of biogas produced, and the efficiency of the covered lagoon system. This is a new technology and there are multiple designs with slight variations for harnessing the energy.

 In addition, North Carolina law currently requires that at least 12.5 percent of retail power sales of electric utilities come from renewable energy and energy efficiency programs by 2021. A recent bill (298) was brought forth — that if passed, would repeal the renewable energy law. Recently, growers who have used covered lagoon systems and representatives supporting livestock waste-to-energy spoke out against the bill. Currently the measures taken to repeal the law have been unsuccessful. Livestock producers have invested lots of money in these systems and are providing renewable energy for our state. Please support our producers by not supporting the repeal of the renewable energy law.

Written By

Photo of Max KnowlesMax KnowlesExtension Agent, Agriculture - Livestock (910) 592-7161 max_knowles@ncsu.eduSampson County, North Carolina
Posted on May 16, 2013
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