ESS Moves Closer to Delivering Green Baseload Power

ESS Tech, Inc. (“ESS” or the “Company”) (NYSE:GWH), a leading manufacturer of iron flow long-duration energy storage (LDES) systems for commercial- and utility-scale applications, achieved significant technical milestones in June far ahead of schedule. These milestones include dramatic improvements from a new material substitution within the core ESS stack technology. The results demonstrate 12.2 hour duration at rated power and 17.8 hour duration at reduced power. The results also demonstrate higher round trip efficiency (RTE), cycling durability, and iron plating robustness, representing an 18-month product roadmap acceleration. This improvement not only increases the value of the iron flow battery faster than expected, but also reduces material costs, accelerating the Company’s cost down objectives. For customers, the RTE increase translates to more energy and lower operating costs with a 6.7% charge time improvement and 6.3% additional input energy per day at standard conditions. Moreover, the increased energy capacity aligns with the market on maximizing clean energy captured and consumed, moving ESS closer to delivering green baseload power, everyday.

These advancements directly support the Company’s strategic pivot to execute on a rigorous and accelerated timeline utilizing agile build principles. “We are in a position where we have to do things better, faster, cheaper. I am pleased to report that our shift in strategy is yielding operational efficiencies with significantly reduced cash requirements and technical results that align with the voice of our customers. We continue to make progress on key customer contracts for our U.S. manufactured, scalable Energy BaseTM solution, which further supports ongoing discussions with potential capital providers and available financing options to execute on our business plan,” said Kelly Goodman, Interim CEO of ESS.

ESS Tech | www.essinc.com