Mitsubishi Hitachi Power Systems, Ltd. (MHPS; Yokohama, Japan; www.mhps.com/en) commenced demonstration testing of a pressurized, hybrid power-generation system integrating a solid oxide fuel cell (SOFC) stack and a micro gas turbine (MGT), aiming toward commercial launching in the near future. Under a program supported by the New Energy and Industrial Technology Development Organization (NEDO), a national research and development agency, a system intended for both business and industrial uses was installed at the Senju Techno Station of Tokyo Gas Co., and a ceremony was held to mark the demonstration unit’s start-up. Going forward, the number of demonstration sites will be progressively expanded to four, with commercial launching targeted for fiscal 2017.
The demonstration system start-up ceremony was attended by a number of guests including representations from NEDO and from the Ministry of Economy, Trade and Industry’s Agency for Natural Resources and Energy. During the demonstration testing, the SOFC-MGT hybrid system will be technically evaluated as a cogeneration system that generates power and also makes effective use of waste heat.
SOFCs are ceramic fuel cells that operate at a high temperature of 900°C (1,650°F). In a pressurized hybrid system, power is generated directly by chemical reaction between oxygen in the air and hydrogen and carbon monoxide extracted from reformed city gas; residual fuel is then used to drive an MGT. This two-stage system achieves significantly higher power generation efficiency and, as a result, saves substantial energy. Air pressurized in the MGT’s compressor is supplied to the SOFCs for use in generating power, and then high-temperature exhaust is fed to the MGT and the heat and pressure, together with the residual fuel, are used to generate power. The pressurized SOFCs, having substantially increased voltage as a result of pressurization, lead to enhanced power generation efficiency.
The demonstration system is in the 250-kW class and delivers generation efficiency of 55%. It is a follow-up to the prototype (Model 15) system that has been undergoing demonstration testing at Kyushu University since spring 2015.
Going forward, three more demonstration sites are to be added: a factory of Toyota Motor Corp., which is jointly developing the hybrid system; a plant of NGK Spark Plug Co., (NTK), with which MHPS is forming a tie-up for mass-producing the cell stacks; and a facility of Taisei Corp. At the various venues, demonstration testing will focus on the hybrid system’s operating efficiency, operability and durability in diverse environments, and knowhow will be accumulated toward reducing costs and achieving mass production as a run-up to commercial marketing.
Through this demonstration testing targeting the market launch of a hybrid system for business and industrial uses, MHPS will move forward toward practical application of SOFCs as a strong choice beneficial for alleviating energy and environmental issues, thereby contributing to their widespread adoption in the years ahead.