ESS to Accelerate Sodium-Ion Battery Energy Storage System Development Following Surging Customer Interest

ESS Tech, Inc. (NYSE: GWH) (“ESS” or the “company”), a leading provider of non-lithium energy storage solutions, announced strong early customer engagement for its planned U.S.-made sodium-ion battery energy storage system (BESS) offering, focused on short- and medium-duration applications that have historically been served by lithium-ion systems. Since announcing its letter of intent with Alsym Energy seven weeks ago, ESS has generated significant customer interest for sodium-ion solutions across data centers, critical infrastructure, and utility markets, exceeding demand expectations with limited outbound marketing.

The company has now developed early-stage opportunities approaching $1 billion for its sodium-ion solutions and is accelerating development of its sodium-ion BESS platform to meet growing near-term demand for safer, domestically sourced energy storage solutions.

"The demand we're seeing for sodium-ion is unlike anything in our company's history," said Drew Buckley, Chief Executive Officer of ESS. "Energy demand is changing faster than the market can respond, and it's clear the solutions of the past won't fill the gap. We're moving decisively to meet that need, accelerating our path towards near-term revenue while establishing the foundation to deliver at the scale and speed the market needs."

Across the power sector, including hyperscalers and fast-growing data centers, customers are racing to secure storage that is safe, fast to deploy, and free of supply chain risk. They need systems that avoid the fire and insurance exposure of lithium-ion, meet aggressive delivery timelines, and eliminate Foreign Entity of Concern exposure. Sodium-ion is uniquely suited to fill that gap: it virtually eliminates thermal runaway risk and uses abundant, domestically available materials rather than constrained lithium supply chains.

The company will continue development of its iron flow battery technology for long-duration applications while streamlining its Wilsonville operations, reducing expenses and cash burn, to reallocate capital toward the sodium-ion and related solutions with greater near-term revenue potential.

ESS soon plans to announce sodium-ion container, rack, and hardware solutions, as well as digital software offerings to optimize battery and system health, to support the customer opportunities.

"This transition enables ESS to pursue attractive market opportunities while maintaining our commitment to long-term innovation," added Buckley. " We believe ESS is well-positioned to create value for customers and shareholders by focusing our organization on high-growth markets with a differentiated technology, leveraging our proven execution capabilities, and continuing to deliver American-made energy storage solutions."

ESS | www.essinc.com