Anaerobic digestion systems can reduce greenhouse gas emissions while turning waste products into energy. Past U.S. economic research on anaerobic digesters has studied dairy farms, but limited economic information is available on anaerobic digestion systems for swine. Net present values (NPVs) were calculated for biodigesters and covered lagoons under different coproduct and policy scenarios. With no government intervention, covered lagoons are more promising for swine operations than more capital-intensive biodigesters. As there is interest in subsidizing anaerobic digestion systems, subsidies equal to a $38/t social cost of carbon would provide positive NPVs.
