Komatsu tests PoC fuel cell excavator
Komatsu, in partnership with Obayashi Corporation and Iwatami Corporation, have jointly conducted Japan’s first on-site proof-of-concept (PoC) test using a medium-sized hydraulic excavator equipped with a hydrogen fuel cell power system. The PoC test was carried out at the construction site of the Joshin-Etsu Expressway Construction Project, under contract from the East Nippon Expressway Company Limited, Kanto Regional Head Office.
Background
With approximately 70 per cent of CO₂ emissions at construction sites originating from the exhaust systems of diesel-powered equipment, the introduction of hydrogen-powered equipment (whose only emissions are water), alongside the adoption of biodiesel fuels and electrification technologies, is considered to be one effective approach.
Since 2023, Komatsu has been conducting PoC tests of a fuel-cell-powered excavator, confirming excavation performance and operability that’s comparable to diesel-engined models, with the added benefits of zero exhaust emissions, reduced noise and reduced vibration.
Compared to battery-powered models, hydrogen-powered systems offer higher energy density and output, making them a promising power source option for achieving carbon neutrality at jobsites that use medium-sized hydraulic excavators.
At the same time, Komatsu recognised the need to validate performance in actual operations and to establish practical hydrogen refuelling methods.
Overview and results of the on-site PoC test
Against this backdrop, with support from the Nagano Construction Office, Kanto Regional Head Office, East Nippon Expressway Company Limited, the three companies carried out an on-site PoC test from December 10 to 23, 2025, at the Joshin-Etsu Expressway (Rockfall Countermeasure) Kitanomaki (No.2) Construction Project site (a temporary storage yard).
The test involved using a medium-sized Komatsu hydraulic excavator equipped with a hydrogen fuel cell system (FC excavator) for relocating surplus soil and refuelling of the onboard hydrogen tanks on-site. The aim was to assess the feasibility of an FC excavator on an actual construction site and to identify potential areas for improvement in hydrogen supply and refuelling methods.
Roles of each company:
● Obayashi Corporation:
Selection of the construction site, planning, execution and overall supervision of the PoC test
● Iwatani Corporation:
Hydrogen supply and technical support (differential pressure refuelling system)
● Komatsu:
Provision of the FC excavator (concept machine), test planning and technical support
Positives to come from this PoC test of the FC excavator was a level of work performance equivalent to that of a conventional diesel-powered model. The test also confirmed additional benefits, like reduced operator fatigue and reduced engine-induced vibration, as well as improved situational awareness due to lower noise levels.
Negatives from the PoC included the need for an increased onboard hydrogen supply and faster hydrogen refuelling. In addition, as the conditions of the construction site evolved along with project progress, the test clarified what kind of jobsite environments are suitable for the safe and efficient use of hydrogen-powered equipment, taking into account the legal regulations (in Japan) on hydrogen refuelling.
These insights reaffirmed that several challenges still remain for the commercialisation of fuel cell heavy equipment and will be instrumental in shaping future implementation models and establishing criteria for site selection.
Future initiatives
Obayashi Corporation, Iwatani Corporation and Komatsu will use the insights gained from this PoC test to further develop construction equipment outfitted with hydrogen fuel cell systems, explore mobile hydrogen refuelling systems, identify suitable jobsites for implementation, and establish operational standards, while verifying hydrogen refuelling methods for construction equipment under various site conditions.
Komatsu adds that they will continue efforts toward the commercial production of medium- and large-sized construction machinery equipped with hydrogen fuel cells in the near future by conducting further research and development.
The ultimate goal is to reduce CO₂ emissions at construction sites and contribute to the realisation of a carbon-neutral society.
