Japan to build first gas-only, battery-powered hybrid ship
A consortium of Japanese companies are working together to build a next-generation hybrid propulsion system, which will be installed on a limestone transporter operating on the Japanese coast. The Global Environment Bureau of the Japanese Ministry of Environment and the Maritime Bureau of the Japanese Ministry of Land, Infrastructure, Transport and Tourism are supporting the project to promote the introduction of advanced technologies that will simultaneously enable the social innovation and decarbonization.
The ship’s hybrid propulsion, which will be owned by NS United Naiko Kaiun Kaisha, will consist of Japan’s first gasoline engine combined with a 2,847 kWh lithium-ion battery. The propulsive power and the on-board electrical energy during navigation will be generated by the gasoline engine only developed by Kawasaki Heavy Industries. Natural gas will only be used for electricity during long-distance and long-term navigation. Propulsion power and on-board power during entry, exit and docking at port will be supplied by the battery to achieve zero emission operation.
The companies said CO2 emissions would be reduced by almost a quarter (around 30% under normal load operation) thanks to the introduction of the propulsion system compared to conventional ships of the same type. Using LNG as the sole fuel, the ship’s exhaust will contain almost no SOx and NOx, with overall emissions well below Tier III standards.
Another unique feature in the design of the vessel will be its LNG tank. They plan to use nickel steel plates developed by Nippon Steel Corporation as a marine tank for the first time.
Construction of the new vessel will be carried out by Japanese shipbuilding Tsuneishi and is expected to begin operations in February 2024. She will weigh 5,560 dwt and 308 feet in length. Once in service, it will be chartered jointly by Nippon Steel Corporation and Nippon Steel Cement to transport limestone, which is the auxiliary raw material for steelmaking and the main raw material for cement, between Shiriyamisaki and Muroran, in Japan. Like previous NSU vessels, the new vessel will be equipped with a self-unloading system.
The ship will replace the Shimokita Maru, built in 1994 with a conventional fuel propulsion system.