Up to 1.5 GWh of Japanese-made BESS may be supplied for projects in the United States in 2027, under a strategic partnership agreement that PowerX has signed with Energy Vault Japan KK. The products have been designed to meet US FEOC rules, and the two companies also intend to develop BESS and data centre projects together.
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PowerX, a Japan-based manufacturer of grid-scale BESS, has signed a strategic partnership agreement with Energy Vault Japan KK, the Japanese subsidiary of the US power infrastructure company Energy Vault Holdings. Under the agreement, which was announced on 5 November 2026, the two companies will explore the supply of up to 1.5 GWh of PowerX's Mega Power series products for deployment in the United States in 2027.
The supply would be drawn from the three product lines of the Mega Power series. Mega Power is a containerised BESS, while Grid Connector is an all-in-one grid connection package that combines a power conversion system, a transformer and switchgear. The third line, Mega Power DC, is a scalable modular data centre with a large-scale BESS built into it. All of the products would be manufactured at PowerX's factory in Japan, and they have been designed to meet the Foreign Entity of Concern (FEOC) requirements of US federal law, which apply to storage projects that seek federal clean energy tax credits.
Those requirements have given the Japanese origin of the products a commercial weight in the US market. FEOC rules have made the source of a supply chain a key factor when buyers select their equipment, and PowerX has said that its in-house manufacturing and vertically integrated range place it to meet the growing demand. Data centres and new renewable capacity have been lifting that demand, and the U.S. Energy Information Administration has forecast a record 24 GW of utility-scale battery storage for 2026, some 60% above the 2025 figure.
Beyond the US supply, PowerX and Energy Vault intend to work together on the development, financing, construction and operation of BESS and data centre projects in Japan, Australia, the United States and other markets, with the scope of each settled case by case. PowerX has described the agreement as a step in taking its business beyond Japan through Energy Vault's global commercial platform.
The agreement is, however, non-binding, and the volume that it names is indicative. Both the supply and the projects remain subject to the signing of definitive agreements, and PowerX has stated that they may not materialise.
Each company has already been active in the markets that the agreement names. In Japan, PowerX has been ordered to supply 40 Mega Power 2700A units, totalling 109.7 MWh, for a 50 MW ENEOS Power project in Shizuoka, and four Mega Power 2500 units of 10 MWh for Tokai Rika in Aichi Prefecture. Energy Vault, for its part, has acquired 15 US BESS development projects of more than 2.3 GW from Goshe Energy Storage, and in Australia it has bought the land for its 125 MW/1 GWh Stoney Creek BESS in New South Wales.