MHI started developing the SOFC-MGT combined-cycle power generation system in 2004 at MHI’s Nagasaki Shipyard and Machinery Works under consignment by the New Energy and Industrial Technology Development Organization (NEDO).
In 2007, the system marked a maximum power generation capacity of 229kW, and confirmed 52.1% power generation efficiency. The company has now achieved the 3,000-hour milestone.
MHI will pursue further reliability enhancement and system downsizing. The company is also working toward a business/industrial-use hybrid system combining SOFCs and an MGT in joint development with Toyota Motor. MHI further plans to develop a system for use by power generation companies, the company said.
SOFCs are ceramic-based fuel cells that operate at a high temperature above 900 degrees Celsius and produce electricity directly by chemical reaction between the hydrogen and carbon oxide removed from city gas and oxygen in the air.
The SOFC-MGT combined-cycle power generation system utilizes the unreacted portion of city gas exhausted from the SOFC module and hot air likewise discharged from the SOFC module.
The gas and air from the SOFC module are used to drive an MGT to generate electricity. This two-stage power generation system is able to achieve power generation efficiency than conventional fossil-fuel power generation systems, and will contribute to the realization of a high-efficiency power generation system, MHI said.
As higher power generation efficiency is expected by combining SOFCs with other power generation systems – ranging from small-scale (under one MW) to large (several hundreds of MW) – MHI views the development of large-scale combined cycle power generation systems using SOFCs.
As to business/industrial-use hybrid power generation system combining SOFCs and an MGT for under one MW, MHI has been conducting joint development with Toyota Motor since 2008.
