On March 28, the Obama administration unveiled its Strategy to Reduce Methane Emissions, as prescribed by the President’s Climate Action Plan (CAP) released last June. While shorter-lived in the atmosphere, methane is a potent greenhouse gas (GHG), 84 times more effective at trapping heat in the atmosphere than carbon dioxide in a 20-year period. While most of the attention has been focused on the emissions of the booming domestic oil and natural gas industry, agriculture is the largest source of domestic methane emissions, at 23 percent. The plan targets methane emissions from four sectors; landfills, coal mining, agriculture, and oil and gas. Currently, methane accounts for almost 9 percent of domestic GHG emissions, down from 11 percent of total GHG emissions in 1990, despite an uptick in methane producing activities. However, methane emissions are expected to rise by 2030, unless further action is taken.
There is tremendous opportunity in biogas for American farmers. Cow manure is roughly 65 percent methane. Anaerobic digestion can turn a problem into a solution – the process converts manure, food scraps and agriculture waste into biogas and fertilizer, allowing farms to be more self-sustaining, economical and environmentally friendly. The Innovation Center for U.S. Dairy, a non-profit funded by the USDA dairy checkoff program, is working to demonstrate the multiple co-benefits of anaerobic digesters on dairy farms. According to the Innovation Center, the dairy industry could support at least 2,600 biodigesters that could convert manure to biogas, as well as 19.8 million tons of food waste, that is normally sent to landfills. The GHG reductions from these digesters alone would offset as much carbon as removing 3.2 million cars from the road, cut the dairy industry’s carbon footprint by 25 percent, generate enough electricity to power a million homes, and create enough phosphorous to fertilize all U.S. tomato production, as well as producing 813 million bags of potting fiber, to boot! Department of Agriculture Secretary Tom Vilsak commented on the USDA’s support of the methane reduction strategy, stating, “technologies like anaerobic digesters and biogas systems … create jobs and allow producers to tap into a $3 billion market for renewable energy. Since 2009, USDA has provided $62 million in support for 93 methane digester projects across the United States”. The numbers calculated by USDA are a conservative estimate that relates primarily to the dairy industry. According to the American Biogas Council, there is the potential for 12,000 biogas systems across the agricultural sector.
Anaerobic digesters make sense – particularly on dairy farms, yet barriers still exist. According to the EPA AgSTAR program, there are only 239 anaerobic digesters currently operating on the roughly 2.2 million commercial farms in the U.S. The cost-effectiveness and benefit to farmers must be made clear. According to USDA, if there were 2,600 biodigesters on U.S. dairy farms, they would produce an astonishing 11.7 million megawatt hours per year of biogas -- worth $894 million, $467 million dollars worth of nitrogen, $325 million dollars of phosphorous, and $217 million dollars per year of fiber. These numbers would be even higher if calculations included the potential for biogas production at hog, cattle, poultry and produce farms as well as waste from food manufacturers, restaurants and homes. Just one example is Fair Oaks Farms in Fair Oaks, Indiana, a large dairy producer. Manure from the company’s 30,000 cows’ produces enough biogas to power the company’s entire operation, which includes 10 barns and a vehicle fleet. The biodigester's compost-like byproduct is spread as soil enhancer. These types of closed-loop systems can save farmers money, reduce inputs and lighten the environmental footprint of livestock production.
The methane strategy aims to reduce the agricultural sector’s greenhouse gas emissions by 25 percent by 2020. US Department of Agriculture (USDA), EPA and Department of Energy (DOE), with consultation from the dairy industry, will release a Biogas Roadmap in June, outlining voluntary measures that dairy producers can use to increase the use of methane digesters. Financial support will be provided through USDA’s Natural Resources Conservation Service’s (NRCS) Environmental Quality Incentive Program (EQUIP), as well as several programs from the Farm Bill’s Energy Title: the Rural Energy for America Program (REAP), the Bioenergy Program for Advanced Biofuels, and the Biorefinery Assistance Program.