Japan’s first on-site PoC test of a hydrogen fuel cell-powered hydraulic excavator at a construction site

Japan's first on-site PoC test of a hydrogen fuel cell-powered hydraulic excavator at a construction site

Feb. 16, 2026

Obayashi Corporation (Head Office: Minato-ku, Tokyo; President: Toshimi Sato), Iwatani Corporation (Head Offices: Osaka and Tokyo; President: Hiroshi Majima) and Komatsu Ltd. (hereafter "Komatsu", Head Office: Minato-ku, Tokyo; President and CEO: Takuya Imayoshi) jointly conducted Japan's first*1 on-site proof-of-concept (PoC) test using a medium-sized hydraulic excavator equipped with a hydrogen fuel cell system (hereafter "FC excavator") in December 2025. The PoC test was carried out at the construction site of the Joshin-Etsu Expressway (Rockfall Countermeasure) Kitanomaki (No.2) Construction Project, under contract from the East Nippon Expressway Company Limited Kanto Regional Head Office.

[On-site PoC test at the Joshin-Etsu Expressway (Rockfall Countermeasure) Kitanomaki (No.2) Construction Project]

1. Background
Approximately 70% of CO₂ emissions at construction sites originate from diesel fuel. In efforts to reduce these emissions, the introduction of hydrogen-powered construction equipment, 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 its FC excavator*2, confirming powerful excavation performance and high operability, comparable to diesel engine-powered models, along with the added benefits of zero exhaust emissions and reduced noise and 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 recognized the need to validate performance in actual operations and to establish practical hydrogen refueling methods to move toward broader social implementation.

2. 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 the FC excavator for relocating surplus soil and refueling of the onboard hydrogen tanks on-site. The aim was to assess the practical feasibility of the FC excavator on an actual construction site and to identify potential areas for improvement in hydrogen supply and refueling methods.

Roles of each company:
● Obayashi Corporation:
Selection of the construction site (PoC field), planning, execution and overall supervision of the PoC test
● Iwatani Corporation:
Hydrogen supply and technical support (differential pressure refueling system)
● Komatsu:
Provision of the FC excavator (concept machine), test planning, and technical support

Based on the results of this PoC, the FC excavator demonstrated work performance equivalent to that of conventional diesel-powered models. The test also confirmed additional benefits, including reduced operator fatigue, reduced engine-induced vibration, as well as improved situational awareness due to lower noise levels.

On the other hand, the PoC also reaffirmed several challenges to commercialization, including the need for an increased onboard hydrogen supply and faster hydrogen refueling. 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 on hydrogen refueling. These insights will be instrumental in shaping future implementation models and establishing criteria for site selection.

3. 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 system, explore mobile hydrogen refueling systems, identify suitable jobsites for implementation, and establish operational standards, while verifying hydrogen refueling methods for construction equipment under various site conditions.

Scope of each company's initiatives:
● Obayashi Corporation will study to define criteria for a refueling station setup within construction sites to support on-site deployment of FC excavators. It will also work to improve awareness and competency among employees and partner company workers regarding the safe handling of hydrogen.
● Iwatani Corporation will explore the use of a mobile hydrogen refueling station equipped with liquefied hydrogen. This high-capacity, fast-refueling system is currently under development with support from the Tokyo Metropolitan Government※3.
● Komatsu will continue its efforts toward the commercial production of medium- and large-sized construction machinery equipped with hydrogen fuel cells in the near future by conducting research and development.


By promoting the practical application of hydrogen fuel cell-equipped construction equipment and working with relevant authorities to establish a safe and efficient operational environment for hydrogen use, the three companies aim to reduce CO₂ emissions at construction sites and contribute to the realization of a carbon-neutral society.

※1 According to Komatsu research (as of January 2026), this is the first proof-of-concept test in Japan using a hydrogen fuel cell-equipped excavator at a construction site.

※2 See Komatsu's May 12, 2023 press release:
"Developed a concept machine for a medium-sized hydraulic excavator equipped with a hydrogen fuel cell, and began PoC tests"

※3 Selected for support under Tokyo Metropolitan Government's FY2023 Technology Development Assistance Project for the Promotion of New Energy (in Japanese only)


Media contacts
Obayashi Corporation
Corporate Communications Department, Public Relations Section
Email: [email protected]

Iwatani Corporation Public Relations Department
Tel: 06(7637)3468

Komatsu Ltd.
Corporate Communications Department, Sustainability Promotion Division
Tel: 03-6849-9703
Email: [email protected]

No : 0087（3403）
Corporate Communications Department
Sustainability Promotion Division
Komatsu Ltd.
tel: +81-(0)3-6849-9703
mail: [email protected]

*The information may be subject to change without notice.