Coupling Dairy Manure Anaerobic Digesters with Commercial Greenhouses - An Assessment of Technical and Economic Feasibility
Through the support of a USDA Hatch and Smith Lever grant, Cornell PRO-DAIRY has undertaken a project to examine both the technical and economic feasibility of coupling Dairy Anaerobic Digesters (AD) with commercial greenhouses. The synergy of digesters and greenhouses is of particular interest as dairy digesters typically produce considerable waste heat. In addition, surplus electricity from biogas powered generators is sold to the utility at the avoided cost of production rate which is typically only on the order of $0.03 to $0.05 per kWhr, which provides little incentive to a digester operator to optimize the operation of their digester. Greenhouses are an ideal user of both the waste heat, and the surplus electricity which typically represent 30% of the cost of production in the Northeastern US.