MHIET's 500kW-Class Hydrogen Engine Generator Set Achieves Technology Readiness Level for Commercialization
TOKYO, June 24, 2026 - (JCN Newswire) - Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. (MHIET), a part of Mitsubishi Heavy Industries (MHI) Group, previously achieved rated operation (435kW/1,500min-1) of a 500kW-class hydrogen engine generator set(1) at its demonstration facility using 100% hydrogen fuel. Recently, the company has established operational capabilities and completed reliability verification for commercialization, indicating that the generator set has reached a level of technological maturity suitable to support practical applications. MHIET will further accumulate operating hours and conduct tests to accelerate the process toward full commercialization.
The demonstration tests were conducted at its Sagamihara Plant. Through more than 100 hours of operation, the following have been completed to support practical application.
- Year-round operation was conducted to evaluate performance under various atmospheric conditions, including electrical output, generation efficiency, and emissions performance.
- Operation strategies were established for abnormal combustion, a major challenge due to the characteristics of hydrogen.(2)
- Using the prototype generator set representative of a near-commercial product, the ability to handle sudden fluctuations in power demand that may occur during actual operation was verified.
- Various measurements including engine vibration and combustion chamber temperature were taken to confirm that there are no issues with reliability.
- The process from receipt of green hydrogen produced in Yamanashi Prefecture(3) at the Sagamihara Plant to using it for power generation was confirmed.
With these achievements, all evaluations have been completed except for a long-term durability assessment, which is difficult to conduct at present because of hydrogen supply constraints. This demonstrates that the generator set has reached commercially viable technology readiness.
Reciprocating engines, due to their ability to run on various fuels, are expected to play an important role in the energy transition towards a carbon-free society. Among these, 100% hydrogen engine generator sets, which use pure hydrogen as fuel and emit no CO2 during combustion, contribute substantially to the decarbonization of distributed power systems.
MHIET has established a development cycle at its Sagamihara Plant that integrates design, manufacturing, and demonstration testing for hydrogen engine generator sets, enabling immediate incorporation of findings from successive demonstration tests into final products. Going forward, MHIET will continue to pursue product development with the aim of realizing a decarbonized society through widespread use of hydrogen.
(1) A set of equipment required to generate electricity using a hydrogen engine, including a generator mounted on the engine's output shaft, auxiliary equipment (piping systems for fuel gas, lubricating oil, cooling water, intake and exhaust gas, and a generator control panel) required to operate the generator set, and enclosures that house and protect the engine, generator, and auxiliary equipment.
(2) Compared to natural gas, hydrogen is highly combustible, can be ignited with energy comparable to static electricity, and has a wide combustion range. Further, because hydrogen molecules are small and prone to leakage, hydrogen engine generator sets require strict safety measures such as redundant leak prevention, detecting and safely stopping any leaks that do occur, and measures to prevent accumulation of gas in upper areas in the event of leaks.
(3) Yamanashi Prefecture has a Power-to-Gas (P2G) system at its Komekurayama Electric Power Storage Technology Research Site in Kofu to produce green hydrogen from renewable energy and water. Green hydrogen does not emit CO2 during the production process or when used for demonstration testing.
About MHI Group
Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit www.mhi.com or follow our insights and stories on spectra.mhi.com
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