Japan avoided approximately 1.2 tonnes of carbon dioxide emissions during a two-hour demonstration on September 25, when the tanker Kiko Maru navigated roughly 33 kilometers across Osaka Bay using a four-stroke hydrogen marine engine. The Nippon Foundation, responsible for the program, presented the trial as a way to reduce fossil fuel reliance in coastal shipping by 2050.
How the Hydrogen Propulsion System Operates
The Kiko Maru does not use its hydrogen engine to turn its propellers directly. Yanmar Power Solutions built the system inside a container mounted on the vessel’s deck, where it generates electricity to power two electric motors connected to the ship’s propulsion shafts. The 4,800-deadweight-ton tanker, which has a gross tonnage of around 4,500 tons, also incorporates lithium-ion batteries and a hybrid generator. This setup stabilizes power delivery and compensates for shifting energy demands during navigation.
Japan tests hydrogen supply systems for commercial routes
The project began in 2022 to evaluate hydrogen supply systems, ship modifications, safety protocols, and crew training before introducing the technology to commercial routes. While the Osaka Bay demonstration proved the concept, establishing a broad refueling network remains a challenge for the industry. Developers are exploring floating hydrogen supply stations to service ships without relying on land-based power grids. Meanwhile, the Kiko Maru remains a technology demonstration rather than a direct replacement for conventional vessels as Japan works toward its long-term emission reduction targets.
Frequently Asked Questions About the Hydrogen Tanker Trial
Does the hydrogen engine connect directly to the propeller shafts?
No. The hydrogen engine built by Yanmar Power Solutions functions as a generator on the deck, producing electricity that feeds two electric motors to turn the vessel’s propulsion shafts.
How much carbon dioxide did the Osaka Bay demonstration save?
The Nippon Foundation calculates that the test avoided about 1.2 tonnes of CO2 emissions compared to running the ship on conventional fossil fuels.
What is the deadweight tonnage of the Kiko Maru?
The tanker has a deadweight of approximately 4,800 tonnes and a gross tonnage of around 4,500 tonnes.
When did the maritime decarbonization project start?
The development and testing initiative began in 2022 to prepare for future commercial shipping routes.
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