GWH · ESS Tech, Inc. · Investor Relations

Agreement Supports Advancement and Real-World Evaluation of ESS’s Non-Lithium Long Duration Energy Storage Energy Base Technology Collaboration Expected to Support Utility and Large-Load Sustainability Objectives, and Clean Energy Goals of Project Participants ESS Tech, Inc. (NYSE: GWH) (ESS, or the Company), a leading manufacturer of long-duration energy storage (LDES) systems for commercial and utility-scale today applications, today announced a collaboration framework with Salt River Project (SRP) and Google for Project New Horizon to advance long-duration energy storage innovation at SRP’s Copper Crossing Energy and Research Center in Florence, Arizona. Project New Horizon is a five-megawatt (MW), 50 megawatt hour (MWh) system that will deploy ESS’ iron flow Energy Base technology and represents a significant commercial validation milestone for the Company’s next-generation, utility-scale platform. The pilot is expected to support SRP’s evaluation of emerging non-lithium LDES

Veteran Energy Storage Commercial Leader to Drive Global Commercial Execution as ESS Strengthens Leadership Team and Scales Deployments ESS Tech, Inc. (NYSE: GWH) (“ESS” or the “Company”), a leading innovator in long-duration energy storage solutions, today announced that Randall “Randy” Selesky has joined the company as Chief Commercial Officer (CCO). In this role, Selesky will lead global commercial strategy, sales, marketing, product management, and business development initiatives as ESS advances commercialization and scales deployment of its long-duration energy storage solutions worldwide. Selesky joins ESS with more than 20 years of leadership in the energy sector, including more than a decade in the battery storage industry. Prior to joining ESS, he served as the Chief Commercial Officer at VoltStorage, where he played a central role in shaping commercial strategy, building partnerships, and guiding the company’s market expansion. Throughout his career, Selesky has been