IHI Power Systems (Niigata)

IHI Power Systems Co., Ltd. is the engine and power systems company of Japan's IHI Corporation, headquartered in Tokyo with plants in Niigata and Ota. It was formed in 2019 by integrating the IHI group's power systems business and traces its roots to Niigata Engineering, founded in 1910, which built Japan's first marine diesel engine in 1919. Marine engines are sold under the Niigata brand.

The marine range covers medium-speed diesel engines such as the AHX series (17AHX from 500 kW, 28AHX up to 6,660 kW) and the HX series (19HX to 41HX), dual-fuel and gas engines, high-speed diesels, Z-Peller azimuth thrusters, gas turbines and generator sets. Customers include tugs, coastal ships, ferries, government vessels and naval ships. The company also builds Everllence four-stroke engines under licence.

In 2024 IHI Power Systems developed the ammonia dual-fuel 28ADF engine, and its ammonia engine work won a top award at the CIMAC Congress 2025, the first for a Japanese entity.