Komatsu reports that a proof-of-concept test of a hydrogen fuel cell medium-sized excavator delivered similar performance to a diesel-fueled model without the emissions.
The company, which performed the test in its home country of Japan, said it also saw “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 test reaffirmed the need for increased commercial hydrogen supply and for faster refueling methods.
Komatsu revealed in 2023 that it had developed a concept excavator in collaboration with Toyota Motor Corporation that runs on a hydrogen fuel cell system and hydrogen tank instead of diesel fuel. Hydrogen fuel cells produce electricity, which powers the machine’s drive system. The main emission is water.
Komatsu and other manufacturers view hydrogen fuel cells as a potential alternative to diesel for larger equipment for which an all-electric battery system would not be practical.
“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,” the company says. It also notes that about 70% of carbon-dioxide emissions from construction sites are from diesel engines.
Komatsu’s test, conducted December 10-23, involved the excavator relocating surplus soil and refueling its onboard hydrogen tanks on-site. The company was joined by Obayashi Corporation, which planned, executed and supervised the test, and Iwatani Corporation, which supplied the hydrogen and provided refueling technical support.
The three companies plan to further develop hydrogen fuel cell technology for construction equipment:
- Komatsu says it will continue research and development on the commercial production of hydrogen-fuel-cell midsize and large construction machinery.
- Obayashi will study refueling options and the safe handling of hydrogen on construction sites.
- Iwatani will explore the use of a mobile hydrogen refueling station equipped with liquefied hydrogen for high-capacity, fast refueling.
Komatsu has also been testing a 92-metric-ton HD785 rigid-frame dump truck equipped with a hydrogen combustion engine.
The engine differs from hydrogen fuel-cell technology, instead operating like other internal combustion engines but with hydrogen as the fuel.
