To meet ship power demand, using a steam turbine‐driven generator by way of a waste gas economizer as the main diesel engine's waste heat recovery equipment is an existing technology. At the same time, Mitsubishi Heavy Industries, Ltd. (MHI) has recently developed a combined power generation system (Steam turbine + power turbine) to drive a power turbine (gas turbine) with the waste gas and to assist steam turbine in line, and has already delivered this system to 38 in‐service ships. This paper provides an overview of the practicalization of a hybrid system where this combined power generator has been expanded and a shaft motor, added as a new application not only to meet ship power demand, but also to assist the main engine and help improve its fuel efficiency by sending the excess power generated back to the shaft motor. Meanwhile, this system has completed shop tests and coupling tests (to verify controllability), waiting for expected future sea trials.
