Feasibility Study of Solid Oxide Fuel Cells in Cogeneration Applications by a Multiobjactive Optimization Approach

Economic, energy-saving and environmental protection feasibilities of solid oxide fuel cell (SOFC) and SOFC/microturbine (MT) hybrid cogeneration systems are investigated based on a multiobjective optimization approach. Equipment capacities and maximum contract demands of utilities such as electricity and natural gas are determined so as to minimize the annual total cost, primary energy consumption and CO2 emission subject to satisfaction of all the energy demand requirements. The Ε-constraint method is adopted as a solution one for the above multiobjective optimization problem. Numerical studies are carried out on the SOFC and SOFC/MT cogeneration systems installed in a hotel by changing the capital unit costs of SOFC and SOFC/MT cogeneration units. Through the studies, the trade-off relationships between the economic, energy-saving and environmental protection properties are clarified, and it is found that the SOFC/MT hybrid cogeneration system is excellent from viewpoints of energy-saving and environmental protection properties.