Recent Progress of SOFC Combined Cycle System with Segmented-in-Series Tubular Type Cell Stack at MHPS

Solid oxide fuel cell (SOFC) triple combined cycle system, integrated with gas turbine (GT) and steam turbine (ST), is an ultimate fossil fuel electric power generation system with very high efficiency. Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has been developing for commercialization of an SOFC-micro gas turbine (MGT) system from several hundred kW to several MW class. Recently prototype of a 250 kW class SOFC-MGT hybrid system was operated at Tokyo Gas Senju Techno Station. This system was stable without voltage degradation under operating 4,100 hours. At the same time, we have started the development of fundamental technologies for realization of SOFC-Gas Turbine (GT)-Steam Turbine (ST) triple combined cycle system that aims to achieve more than 70% of power generation efficiency. In this paper, recent progress of the SOFC-micro gas turbine (MGT) hybrid system and development of triple combined cycle system are described.