Anaerobic digestion technology may help to address two congressional concerns that have some measure of interdependence: development of clean energy sources and reduction of greenhouse gas emissions. Anaerobic digestion technology breaks down a feedstock, usually manure from livestock operations, to produce a variety of outputs including methane. An anaerobic digestion system may reduce greenhouse gas emissions because it captures the methane from manure that might otherwise be released into the atmosphere as a potent greenhouse gas. This book provides information on anaerobic digestion systems, technology adoption, challenges to widespread implementation, and policy interventions that could affect adoption of the technology.