PowerSecure Awarded Distributed Energy Award for Unique Hog Farm Microgrid
July 1, 2019 via powermag.com
Power from pig manure is not a public relations stunt, but rather, it’s an innovative solution to several farm challenges. Installing lagoon covers not only reduces odors and eliminates rainwater ingress, but it also allows biogas to be captured and utilized as a renewable energy resource.
The power industry is frequently blasted for the amount of greenhouse gases (GHGs) it emits, but what often goes overlooked is how much CO2, nitrous oxide, and methane the agricultural sector produces. According to the U.S. Environmental Protection Agency’s Inventory of U.S. Greenhouse Gas Emissions and Sinks, the U.S. agriculture industry released 582.18 million metric tons of CO2 equivalents in 2017. That was about one-third of the total emitted by the nation’s fossil-fueled electricity generation sector that year, and U.S. farmers don’t typically burn coal, except in their barbecue grills.
So, you might ask yourself, where are all those agricultural GHGs coming from? Well, according to an article written by Eugene Takle, professor of atmospheric science and professor of agricultural meteorology at Iowa State University (ISU), and Don Hofstrand, retired ISU extension value-added agriculture specialist, a majority of ag-related GHG emissions (about 61%) come from nitrous oxide produced naturally in soils through the microbial processes of nitrification and de-nitrification.
Enteric fermentation, that is, methane produced as part of the normal digestive processes in animals, especially ruminant animals such as cattle, is next on the list (18%). Those gases are exhaled or belched to the atmosphere by animals.
Coming in third on the ag list is manure management, which accounts for 9% of the total GHG emissions. “When manure is handled as a solid or deposited naturally on grassland, it decomposes aerobically (with oxygen) and creates little methane emissions. However, manure stored as a liquid or slurry in lagoons, ponds, tanks or pits, decomposes anaerobically and creates methane emissions,” the ISU authors wrote. Swine and dairy cattle are the two largest contributors to those emissions.