ESS Inc. has entered into a multi-year agreement with Alsym Energy to supply at least 8.5 GWh of non-lithium energy storage systems. Under the partnership, Alsym Energy will integrate ESS’s iron flow battery technology into utility-scale, commercial and industrial projects across North America, Europe and Asia. Beginning in the third quarter of 2026, ESS will deliver containerized Energy Warehouse units capable of discharging continuously at full power for ten hours per cycle and designed for a service life exceeding 25 years.
This transaction represents one of the largest non-lithium battery supply awards to date and underscores growing demand for long-duration storage solutions that complement renewable generation. Iron flow batteries use abundant, non-flammable materials and can be cycled daily without degradation of energy capacity, offering a pathway to more resilient grid operations and extended renewable integration.
Under the agreement, Alsym Energy will handle project development and deployment, leveraging its global network and engineering expertise to install ESS systems at distributed generation sites, microgrids and behind-the-meter applications. ESS will retain responsibility for manufacturing, quality control and ongoing system performance monitoring through its digital Battery Management System platform. Together, the companies aim to accelerate project timelines and reduce balance-of-system costs by co-locating manufacturing and installation resources.
“Sodium-ion and iron flow are complementary technologies,” said Drew Buckley, Chief Executive Officer of ESS. “Alsym’s sodium-ion Na-Series is an ideal solution for ESS’s short- and medium-duration applications where high power, fast cycling, and rapid response are paramount. ESS’s existing Energy Base® iron flow platform is engineered for the 8–24 hour long-duration segment, where deep daily cycling, 25-year asset life, and zero capacity degradation deliver the lowest levelized cost of storage.”
“Together, the two chemistries form a unified, non-lithium platform that enables ESS to meet customers’ full storage needs from a single trusted provider, whether the application calls for firming renewables over a few hours, shifting energy across a full day, or pairing both within a single project to optimize economics across the full duration curve.”
Randall Selesky, Chief Commercial Officer at ESS, added, “This partnership represents a major milestone in our strategy to become a full-spectrum, non-lithium solutions provider for the entire energy storage market with safer, more sustainable technologies. By combining Alsym’s high performance, non-flammable sodium‑ion technology with ESS’ systems expertise and Energy Base® long‑duration solutions, we are giving customers a clear pathway beyond lithium‑ion — without compromising performance or economics.
Source: Business Wire
