This paper contains a techno-economic feasibility study of implementing an anaerobic digester to supply biogas to a cogeneration system, meeting the electricity and heating demand on a small-scale Norwegian livestock farm. Three configurations, using the same model with different compositions of biowaste, were identified to meet the energy demand on the farm while being financially feasible. Running simulations in ECLIPSE found overall system efficiencies of 86.25%, 90.12% and 87.83% for a combined heat and power (CHP) unit. Annual emissions can be reduced from self-produced energy, carbon sequestration and replacing mineral fertilisers with digestate by up to 2,605, 153,096, and 10,958 kg of CO2eq, respectively. Economic analysis proved that with external funding, the payback period of the project would be between 10 and 19 years for the different options, which is within the 20-year lifetime of the system. Additionally, yearly savings of up to Â£1,406 and Â£2,761 could come from avoiding paying a potential carbon tax and using digestate.
Keywords anaerobic digestion, biogas, CHP system, net- zero energy system, sustainable farming, and techno- economic analysis