YAMANASHI, Nov 16, 2025 (News On Japan) - Japan aims to achieve carbon neutrality by reducing emissions of carbon dioxide and other greenhouse gases to net zero by 2050, and in this context, municipalities and companies across the country are accelerating the use of green hydrogen, which is increasingly viewed as the key to realizing a decarbonized society.
About a 30-minute drive from central Kofu City in Yamanashi Prefecture lies Mt. Yumesakayama, where roughly 80,000 solar panels line the mountainside as part of a mega-solar power plant jointly operated by Yamanashi Prefecture and Tokyo Electric Power. The facility generates around 12 million kWh annually, but electricity produced in excess of demand had gone to waste. Beginning in 2021, that surplus power has been used to produce green hydrogen.
When electricity is sent into the system, positive and negative currents are applied and purified tap water from Kofu is supplied into the device, triggering electrolysis and separating the water into hydrogen and oxygen, which are then sent onward to the next stage. Hydrogen produced by electrolyzing water using renewable energy such as solar or wind power is known as green hydrogen, and because it emits no greenhouse gases not only during use but also during production, it is expected to become a powerful tool for achieving decarbonization.
Yamanashi Prefecture hopes the technology related to transporting hydrogen and developing fuel cells will spread to manufacturers within the prefecture and help stimulate the regional economy. The prefecture is also promoting the everyday use of green hydrogen through initiatives such as demonstration tests of electric-assist bicycles equipped with hydrogen fuel cells, and has already begun commercial sales.
Hydrogen produced at Yumesakayama is stored in cylinders and delivered by truck. Valve manufacturer Kids has introduced fuel-cell forklifts at its factory in Yamanashi and has switched the hydrogen used for fuel cells from conventionally produced hydrogen made with fossil fuels to green hydrogen from Yumesakayama. The company says hydrogen is the only domestically producible energy source that can be locally produced and consumed without relying on imports, and believes it will become increasingly important in the future.
Green hydrogen from Yumesakayama is also used at Tokyo Big Sight in Koto Ward, where it powers electricity generation for the facility. The Tokyo Metropolitan Government, working in partnership with Yamanashi Prefecture, provides subsidies to companies purchasing green hydrogen to help stimulate demand.
Storage technology, which will be essential for the widespread adoption of green hydrogen, is also advancing. At Shimizu Corporation’s innovation center in Tokyo’s Koto Ward, the company has introduced a proprietary hydrogen-storage alloy tank. The alloy absorbs and releases hydrogen by raising or lowering its temperature, and finely crushed pieces of the alloy are packed inside the tank. Co-developed with the National Institute for Materials Science, the alloy does not ignite even when exposed to flame while in a hydrogen-absorbed state, eliminating the need for special qualifications to handle it and significantly lowering the barrier to adoption. The alloy uses iron as its main component and does not rely on rare earths, reducing production costs.
In addition to its storage technology, Shimizu has developed Hydro-Cubic, a system that integrates green hydrogen production and fuel-cell power generation. The system has been selected as a model for the hydrogen supply chain at the Osaka-Kansai Expo. Although Hydro-Cubic was originally conceived as a project looking ahead to 2040, the company says technological development is progressing faster than expected and that preparations must now accelerate toward 2030.
The use of green hydrogen continues to expand. In August, Shimizu’s hydrogen-storage alloy tank was delivered to the TBS Broadcasting Center in Akasaka, Minato Ward. Its ability to be safely installed even in an underground urban environment is a major advantage. Akasaka District Heating, which supplies chilled water and electricity to the TBS Broadcasting Center, nearby commercial facilities, and housing complexes, plans to begin using green hydrogen produced at Yumesakayama in its local heating-and-cooling system starting in January next year.
The system’s boiler will mix natural gas and green hydrogen at a ratio of 50–50, significantly reducing CO2 emissions. It will be the first attempt in Japan to use green hydrogen in combination with a district heating-and-cooling system in a major urban area. The company says introducing such systems in cities is challenging, but given long-term national and metropolitan policies requiring the reduction of fossil-fuel use, hydrogen may be the optimal solution.
Fuel-cell equipment is also installed at the site, enabling the plant to use green hydrogen to generate electricity during disasters. While cost challenges remain, efforts to produce, transport, store, and utilize green hydrogen continue to expand among companies and local governments as Japan moves toward a decarbonized society.
Source: TBS
