Japan has completed its first on-site proof-of-concept (PoC) test of a hydrogen fuel cell-powered hydraulic excavator at an active construction site, marking a significant step toward decarbonizing heavy construction equipment.
The demonstration was jointly conducted in December 2025 by Obayashi Corporation, Iwatani Corporation and Komatsu Ltd..
The test took place at the Joshin-Etsu Expressway (Rockfall Countermeasure) Kitanomaki (No.2) Construction Project, under contract from East Nippon Expressway Company Limited (Kanto Regional Head Office).
According to Komatsu (as of January 2026), this marks Japan’s first on-site PoC test of a hydrogen fuel cell-equipped excavator operating at a live construction project.
Background: Decarbonizing Construction Sites
Approximately 70% of CO₂ emissions at construction sites originate from diesel fuel consumption. While electrification and biodiesel alternatives are gaining traction, hydrogen-powered construction machinery is emerging as a viable pathway toward carbon neutrality.
Since 2023, Komatsu has been testing a concept medium-sized hydraulic excavator equipped with a hydrogen fuel cell (FC) system. Prior controlled tests confirmed:
- Excavation performance comparable to diesel-powered models
- High operability
- Zero exhaust emissions
- Reduced noise and vibration
Compared to battery-electric systems, hydrogen fuel cells offer higher energy density and output, particularly advantageous for medium-sized excavators operating in energy-intensive applications.
However, real-world validation and hydrogen refueling logistics remained critical hurdles prior to broader commercialization.
On-Site PoC Test: Scope and Execution
The hydrogen fuel cell excavator PoC Japan trial ran from December 10–23, 2025, at a temporary storage yard within the expressway project site.
Objectives:
- Evaluate operational feasibility in real jobsite conditions
- Test on-site hydrogen refueling of onboard tanks
- Identify supply-chain and refueling challenges
Roles of Each Company:
Obayashi Corporation
- Selected the PoC site
- Managed planning, execution and supervision
Iwatani Corporation
- Supplied hydrogen
- Provided technical support using a differential pressure refueling system
Komatsu
- Supplied the concept FC excavator
- Led technical planning and support
Key Results
The PoC confirmed that the hydrogen fuel cell excavator delivered:
- Work performance equivalent to diesel-powered machines
- Reduced operator fatigue
- Lower vibration levels
- Improved situational awareness due to quieter operation
These findings reinforce hydrogen’s technical viability as a substitute for diesel in medium-sized hydraulic excavators.
Commercialization Challenges Identified
Despite positive operational results, several commercialization barriers remain:
- Limited onboard hydrogen storage capacity
- Need for faster hydrogen refueling
- Legal and regulatory constraints governing hydrogen handling
- Site-specific suitability requirements
As the construction project progressed, changing site conditions helped clarify which jobsite environments are most appropriate for hydrogen-powered equipment deployment.
These insights will inform future implementation models and operational criteria.
Future Initiatives
The three companies will build on the hydrogen fuel cell excavator PoC Japan findings through coordinated next-phase actions.
Obayashi Corporation
- Develop criteria for hydrogen refueling station setup at construction sites
- Enhance workforce competency in safe hydrogen handling
Iwatani Corporation
- Explore deployment of a mobile liquefied hydrogen refueling station
- Advance high-capacity, fast-refueling systems supported by the Tokyo Metropolitan Government’s FY2023 Technology Development Assistance Project for New Energy
Komatsu Ltd.
- Continue R&D toward commercial production of medium- and large-sized hydrogen fuel cell construction equipment
Toward Carbon-Neutral Construction
By advancing hydrogen fuel cell-equipped machinery and establishing safe, scalable refueling infrastructure, Obayashi, Iwatani and Komatsu aim to significantly reduce CO₂ emissions from construction sites.
The successful on-site PoC signals that hydrogen-powered heavy equipment is transitioning from conceptual development toward practical deployment — positioning hydrogen as a strategic enabler in Japan’s broader carbon-neutrality ambitions.
