Biogas is a mixture of predominantly carbon dioxide and methane that is formed from the anaerobic decomposition of organic materials. It is also a high-quality fuel that can be used in most natural gas applications such as home heating or electricity generation or scrubbed and sold into the gas grid. In the United States the production of biogas from animal manure alone represents an enormous potential energy resource, on the order of 0.9 quadrillion BTU (quad) annually, or nearly 1% of total US energy consumption. Biogas from the wastewater treatment sector in the US could provide another 1.5 billion kWh (or 5 trillion BTU). Despite the promise of this resource as a renewable, low-carbon source of energy, as of 2007 only 125 functioning biogas operations using manure exist in the US. These facilities produced 290 GWh (0.001 quad) of energy in 2007, which accounts for 0.001% of annual energy consumption in the United States and one thousandth of the nation’s biogas potential. In addition, only 15% of the wastewater treatment flow in the US produces biogas that is used as a source of energy; the rest of the wastewater flows either do not produce biogas at all, or produce biogas that is wastefully flared instead of captured for heat or power. In contrast, Sweden currently produces 0.3% of their annual energy usage from biogas, primarily from the wastewater treatment sector. This report analyzes the policy incentives and barriers that exist for the production and utilization of biogas as well as the policy and institutional factors that have contributed to Sweden’s relative biogas success. Based on this analysis, the authors make recommendations for policy measures that would increase biogas production in the United States. These recommendations include R&D to promote technological advancement with digesters, state and national environmental objectives, state and national renewable energy quotas, financial support for biogas operations, state biogas education and support programs, and infrastructure improvements that facilitate biogas use. Such policy incentives would promote both biogas production and use, and thereby help increase the market penetration of a domestically-produced, renewable, low-carbon fuel.
An overview of biogas production and utilization at full-scale wastewater treatment plants (WWTPs) in the United States: Challenges and opportunities towards energy-neutral WWTPs
