Major Contracts in Texas and Scotland Drive Growth: Eos Energy Scales Up Flow Battery Production

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U.S. manufacturer Eos Energy Enterprises has launched a second production line at its Thorn Hill facility in Marshall Township. The new line manufactures innovative zinc-based flow batteries using a water-based electrolyte. The investment is expected to enable the company to reach annual production capacity of 4 GWh by the end of 2026 and is a direct response to its rapidly growing order backlog in the United States and the United Kingdom.

Zinc Technology for Long-Duration Energy Storage

The company’s flagship product, the Eos Z3 module, is a flow battery designed for long-duration energy storage (LDES) applications. The technology is optimized for continuous discharge periods ranging from 4 to as much as 16 hours, while the manufacturer estimates an operational lifetime of at least 25 years.

The Z3 module is built around three patented components:

  • Sustainable, non-degrading bipolar electrodes,
  • A high-performance water-based electrolyte (eliminating the fire risks commonly associated with lithium batteries),
  • A hermetically sealed polymer enclosure.

In this system, electricity is stored through a process in which zinc is deposited onto the electrodes during charging and dissolved back into the electrolyte during discharge.

Multi-Billion-Dollar Orders in Texas and Scotland

Scaling up production in the United States is essential to fulfilling contracts, including those with Frontier Power USA, which has already secured a 2 GWh capacity reservation. In May 2026, FPUSA acquired a portfolio of 480 MWh battery projects in Texas from Bimergen Energy and subsequently entered into a strategic partnership with Stella Energy Solutions to develop additional projects totaling 2 GWh based on Eos technology.

At the same time, the American technology is making its way into Europe. Frontier Power UK has acquired two long-duration energy storage projects in Scotland—Ayr and Busby. Under previously announced agreements, these projects are expected to deploy Eos Z3 Idensity battery systems with a combined storage capacity of approximately 2.8 GWh.

The Scottish projects are currently seeking support through the UK government’s cap-and-floor regulatory mechanism, which guarantees minimum and maximum revenue thresholds for energy storage operators. A final decision by the British government regarding subsidy support for the Ayr and Busby projects is expected in the summer of 2026.

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