US-based energy storage developer Energy Vault has entered the Japanese energy market through a binding agreement to acquire an 850 MW pipeline of BESS projects (Energy Vault press release, 09/04/2026).
“The transaction includes the integration of an established team of local energy experts and the acquisition of a high-quality, 850 MW BESS development portfolio, positioning Energy Vault to capitalize on one of the fastest growing and structurally-advantaged energy storage markets among developed economies”, according to the company’s press release.
The acquired portfolio comprises 350 MW of advanced-stage BESS projects planned to begin construction in H2 2027 and reach commercial operations in H2 2028. The portfolio also includes 500 MW of early-stage BESS projects.
Japan’s grid faces challenges integrating high levels of renewable energy due to limited regional interconnections and a fragmented frequency system (50Hz/60Hz). Solar curtailment, particularly in regions such as Kyushu, has become common, creating both a need and an opportunity for the flexibility that batteries can provide (ESS news, 10/04/2026).