ESS Tech, Inc. (“ESS,” “ESS Inc.”) (NYSE:GWH), a U.S. manufacturer of long-duration batteries for utility-scale and commercial energy storage applications, announced today that it will hold a conference call on Thursday, May 12, 2022 at 5:00 p.m. EDT to discuss financial results for its first quarter 2022 ended March 31, 2022.

The news release announcing the first quarter 2022 financial results will be disseminated on May 12, 2022 after the market closes.

Interested parties may join the conference call beginning at 5:00 p.m. EDT on Thursday, May 12, 2022 via telephone by calling (844) 200-6205 in the U.S., or for international callers, by calling (646) 904-5544 and entering conference ID 675891. A telephone replay will be available until May 19, 2022, by dialing (866) 813-9403 in the U.S., or for international callers, (929) 458-6194 with conference ID 679229. A live webcast of the conference call will be available on ESS’ Investor Relations website at http://investors.essinc.com/.

A replay of the call will be available via the web at http://investors.essinc.com/.

About ESS Inc.

ESS Inc. (NYSE: GWH) designs, builds and deploys environmentally sustainable, low-cost, iron flow batteries for long-duration commercial and utility-scale energy storage applications requiring from 4 to 12 hours of flexible energy capacity. The Energy Warehouse™ and Energy Center™ use earth-abundant iron, salt, and water for the electrolyte, resulting in an environmentally benign, long-life energy storage solution for the world’s renewable energy infrastructure. Established in 2011, ESS Inc. enables project developers, utilities, and commercial and industrial facility owners to make the transition to more flexible non-lithium-ion storage that is better suited for the grid and the environment. For more information, visit www.essinc.com.