ESS Inc acquires intellectual property and assets of VoltStorage GmbH, an iron-salt battery developer

ESS Inc’s acquisition of intellectual property and assets from Germany-based VoltStorage GmbH, announced on 2026-03-13, strategically diversifies the Oregon company's long-duration energy storage technology base. This targeted purchase focuses on VoltStorage’s iron-salt battery patents and technical development resources, providing ESS Inc with a distinct expansion beyond its established iron flow battery solutions. The deal specifically integrates expertise from VoltStorage GmbH staff in electrochemistry and materials science, directly bolstering ESS Inc's internal R&D capabilities. While the transaction value remains undisclosed, this asset-centric acquisition allows ESS Inc to efficiently absorb critical technological advancements and specialized human capital without a full corporate merger. This approach demonstrates ESS Inc's intent to rapidly enhance its competitive offering within the utility-scale energy storage market. VoltStorage GmbH, a German developer known for intelligent redox flow energy storage systems for private households and commercial applications, is effectively divesting its iron-salt battery intellectual property and related assets. This move allows ESS Inc, a Wilsonville, Oregon-based technology company specializing in utility-scale iron flow batteries, to integrate a complementary iron-salt chemistry into its existing long-duration portfolio. The acquisition of VoltStorage's technical development resources and staff expertise enables ESS Inc to expand its overall market presence in long-duration energy storage. For VoltStorage GmbH, the transaction suggests a potential refocus on its core redox flow technology or a strategic divestment of non-core assets. This transaction illustrates the ongoing technology diversification within the global energy storage sector as companies like ESS Inc optimize their offerings for various applications.