Japanese utility Tokyo Gas has entered into a long-term offtake agreement for a 49.7MW/202.1MWh battery storage project in Fukushima Prefecture.
Announced last week (28 July) by offtake partner Hexa Energy Services, Tokyo Gas will acquire operating rights and play the asset’s stored energy into electricity markets over the 20-year term of the agreement.
Hexa Energy Services will develop, own and maintain the facility, which is scheduled to go into commercial operation in 2029.
Further details of the project were not given in Hexa’s announcement, including whether the project has any long-term contracted revenue streams.
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Tokyo Gas, as the name implies, is a major provider of natural gas to Tokyo and surrounding regions, but it is also an electricity producer and supplier.
In a three-year plan for 2026 to 2028, published last October, the utility said that of a total \1.1 trillion to \1.3 trillion of planned investments, it will invest \430 billion in its energy business line, including maintenance and investment in its gas infrastructure and constructing electricity storage facilities.
In April, as it signed a similar offtake deal for two projects with Hongde Energy Technology Japan, an arm of Taiwanese developer HD Renewable Energy (HDRE), Tokyo Gas said it had increased its BESS investment target.
It had aimed to invest in 1GW of operational BESS capacity by 2030 but had already almost reached this point in the two years since it entered the market. Tokyo Gas upped its target instead to 2GW “in the early 2030s”. This would include a mix of Tokyo Gas-owned projects with offtake deals for third party-owned assets and optimisation services.
“By combining Tokyo Gas’s use and operation of this battery storage facility with our accumulated project development and management capabilities, we aim to maximize asset value through a stable grid-based battery storage business,” Hexa Energy Services said.
Developer-investor Hexa claimed earlier this year that it put the first BESS project with a Long-Term Decarbonisation Power Source Auction (LTDA) capacity market contract into operation in Japan.
Hexa Energy Services held a completion ceremony on 24 March for the 30MW/120MWh Tagawa BESS project in Kyushu, southern Japan. The company had bid successfully in the first annual staging of the LTDA, held in the 2023 financial year.
Eku Energy project with ‘first-of-a-kind’ Tokyo Gas tolling deal
Macquarie-backed energy storage developer Eku Energy’s first project in Japan has moved into the commissioning phase.
The company said yesterday (4 August) that all major project equipment has been installed at its 30MW/120MWh Hirohara BESS in Miyazaki Prefecture, Kyushu. That includes 32 Tesla Megapack 2 XL BESS units.
Hirohara BESS now moves into the integration and commissioning phase of construction, with system testing and regulatory inspections also ahead. Eku Energy said the project is on track to meet its scheduled COD in January 2027.
The developer has since announced a further three large-scale BESS projects in Japan. The company announced Hirohara BESS in April 2024, when it too signed a long-term offtake deal for the project with Tokyo Gas.
As with the Hexa Energy Services deal for the Fukushima project, Eku will own the project, and Tokyo Gas has full operating rights for the 20-year term of the agreement. Eku Energy closed financing on the project a few months after the offtake deal signing, which it described as a “first-of-a-kind” agreement for Japan. MUFG participated in financing, marking the Japanese bank’s first BESS investment within Japan.
In other Eku Energy news, the company has just acquired a 300MW/600MWh development project in Oxfordshire, UK, and in June acquired its first 400MW/1,600MWh project in Germany.
Shortly before that, the developer acquired land on which to build the 30MW/120MWh Naganohara BESS, its fourth project in Japan, from the local government of Gunma Prefecture.
ESN Premium spoke with Eku Energy’s managing director for Japan, Kentaro Ono, and investment and origination head Hirofumi Sho in a two-part deep-dive series into the Japanese market published in mid-2025:
Japan: Large-scale battery storage opportunities in an evolving market
Japan: Strong fundamentals for energy storage drive expectations despite challenges
