This study presents a techno-economic analysis of a biogas-fed SOFC system for combined heat and power generation, with a focus on system sizes of 0.5 and 5 MW. A complete biomass-to-electricity pathway was developed, incorporating an anaerobic digester, desulfurization unit, water scrubber, SMR, WGSR, PSA, SOFC, carbon dioxide storage and hydrogen storage. A detailed process flow model was constructed to determine mass flow rates across all streams and to size each unit operation. The SOFC operating conditions were optimized using an electrochemical model to maximize efficiency and minimize fuel consumption, resulting in an optimal hydrogen molar content of 99% in the fuel and an operating temperature of 760°C. Under these conditions, the system achieved an electrical efficiency of 44.54%. An energy integration analysis is also performed to minimize thermal losses and improve overall system performance. The economic assessment considered capital costs, costs of raw materials, utilities, labor, maintenance, revenues, depreciation and inflation. Results indicate that the 0.5 MW configuration is economically unfeasible under all evaluated conditions, while the 5 MW system is financially viable across all sensitivity scenarios, exhibiting a postivie NPV, high IRR, a payback period of 6.57 years and an LCOE of 0.111 €/kWh. Labor cost was identified as the most influential parameter affecting profitability, whereas district heating selling price exhibited the least impact. From a sustainability perspective, the system can achieve net-negative emissions when equipped with CO2 capture and storage.
Vasiliki Korovesi (Wed,) studied this question.