Renewable Biogas: Too Valuable to Waste

Today, most biogas is released to the atmosphere. According to the most recent EPA data, in 2008, methane from landfills accounted for 126 million metric tons carbon dioxide equivalent (MMTCO2e) of methane (22% of all U.S. methane emissions due to human activities); livestock manure management accounted for 45 MMTCO2e (8%); and sewage wastewater treatment systems accounted for 24 MMTCO2e (4%). In terms of reducing greenhouse gas emissions, capturing all of this methane would be the equivalent of removing millions of vehicles from the roads. As a renewable energy source, it could provide heat and power for hundreds of thousands of homes or provide the energy equivalent of billions of gallons of gasoline as a low-carbon, renewable transportation fuel. Since our farms and cities already collect and concentrate so much organic waste, why not use it as a renewable energy resource and turn a waste stream into a revenue stream for dairy and livestock producers and waste management agencies?

 

Related Media Coverage

On June 16, 2010, the Environmental and Energy Study Institute (EESI) held a briefing on capturing and using renewable biogas from urban and agricultural waste streams to help address our nation’s climate, energy, and resource management challenges. Renewable biogas is generated from the natural, anaerobic decomposition of organic matter in landfills, livestock manure, and wastewater treatment plants. The methane in biogas is a potent greenhouse gas that contributes to climate change, but it is also a potential renewable energy source for heat, power, and transportation fuel.

• Using Waste, Swedish City Cuts Its Fossil Fuel Use by Elisabeth Rosenthal, New York Times
• Biogas Growth by Lisa Gibson, Biomass Magazine

• Methane is a highly potent greenhouse gas, with a global warming potential 21 times higher than carbon dioxide over a 100 year period, and an even larger impact on the climate in the near term. Because of its relatively short residence time in the atmosphere (12 years), increasing the capture and use of methane-rich biogas now could help reduce U.S. greenhouse gas emissions significantly in the near term.
• The methane in renewable biogas could displace as much as 10-15 percent of current fossil natural gas use by 2025-2035.
• Most biogas that is captured and used in the United States today is from landfills. However, much of the methane still escapes from landfills. There are more efficient and effective ways to capture and generate biogas, such as through organic waste diversion systems with anaerobic digesters.
• There are now 151 anaerobic digesters are operating in the United States today – all using livestock manure. Most of the largest wastewater treatment plants capture and burn off biogas, but relatively few use the biogas to produce heat and power. There are no large scale urban anaerobic digestion systems operating in the United States using organic matter from the solid waste stream yet.
• As a renewable energy source, biogas has the advantage over renewable electricity because it can be stored indefinitely until it is needed.
• The California Air Resources Board has certified that renewable biogas used as a transportation fuel has the lowest life cycle carbon emissions of any biofuel available today.
• Renewable biogas must be cleaned and refined if it is to be distributed in the existing natural gas pipeline system.
• Pacific Gas and Electric Company currently buys pipeline quality renewable biogas from a Texas producer and uses it to produce renewable electricity.
• In livestock operations, processing manure through an anaerobic digester to produce biogas, also produces high value fertilizer and bedding material, provides odor control, and reduces nutrient run-off.
• In urban settings, organic waste diversion facilities and anaerobic digesters can and must be operated successfully in densely populated areas. In addition to producing biogas, these systems can produce high value compost material and soil amendments.
• In Germany, a carbon tax, carbon cap and trade system, and a renewable energy feed-in tariff have created the incentives for the biogas industry to flourish, creating tens of thousands of jobs in the biomass energy industry. Germany now has more than 5,000 biogas production plants of various sizes in both rural and urban areas.
• Current U.S. policies favor renewable electricity over renewable biogas production for distribution on the gas grid. This drives the market to burn biogas to produce electricity instead of using it for other potentially higher value thermal and transportation applications.
• To increase the capture, generation, and use of biogas, Congress needs to enact policies such as setting a price on greenhouse gas emissions; providing equal incentives for producing biogas to those provided for wind and solar electricity; and providing equal investment tax credits and grants.