An increase in the number of power generation facilities with gas engines is expected with the development of shale gas, as well as the utilization of gas pipe lines in addition to the expanding need for the effective operation of power generation facilities such as the distributed generation system and smart grid. Mitsubishi Heavy Industries, Ltd. (MHI) covers a wide power range of lean‐burn gas engines, from the high‐speed GSR model to the mid‐speed KU30GSI model. This report will mainly describe the efficiency improving technology of the KU30GSI‐PLUS engine, which has achieved a generation efficiency of 48.8%, placing it at the top level in the world among the engines in the same class. Technological development to utilize this energy in a co‐generation system, as well as the application technology, will also be introduced.
