Sumitomo Electric Begins Building 8,000 kWh Vanadium Flow Battery in Kashiwazaki

Sumitomo Electric Industries has received an order from Kashiwazaki IR Energy for a fourth-phase vanadium redox flow battery system in Kashiwazaki City, Niigata Prefecture, and construction has begun. The 8,000 kWh system, rated 1,000 kW for 8 hours, is scheduled to start operation in spring 2027 and will lift cumulative storage at the site to 32,000 kWh. The project is subsidized under the FY2026 Program for Promoting Public Understanding of Advanced Energy Structure and Transformation and will store surplus solar power for use at peak demand.

Key facts

Market context

Vanadium redox flow batteries store electricity in liquid electrolytes held in external tanks, so power and energy capacity can be sized independently. This makes them suited to long-duration grid storage, typically in multi-hour blocks, and they are generally valued for long cycle life and tolerance of frequent charging. Their main demand drivers are utilities and grid operators integrating variable solar and wind output, along with commercial sites that shift power to higher-price peak periods. Vanadium electrolyte is the key material cost, so project activity links directly to vanadium pentoxide and electrolyte supply chains. Each new installation adds incremental demand for electrolyte, membranes, and power conversion equipment, and it can tighten availability of vanadium feedstock when deployments cluster. Japan has been a meaningful market for these systems because of its growing solar base and policy support for storage, which is why projects of this scale attract attention from suppliers and investors.

Source: official release on sumitomoelectric.com. Summary and context written by Market Krystal.