Senator Ron Wyden and Senior Officials Join ESS to Celebrate a Year of Achievement in American Clean Tech Manufacturing

ESS Tech, Inc. ("ESS") (NYSE: GWH), a leading manufacturer of long-duration energy storage systems (LDES) for commercial and utility-scale applications, hosted Senator Ron Wyden (D-Ore.), Dr. Christopher Saldaña, Director of the Advanced Materials & Manufacturing Office at the U.S. Department of Energy, and Andrew Reagan, Executive Director of Clean Energy for America yesterday at the company's headquarters and U.S. manufacturing facility in Wilsonville, Oregon for an event commemorating the one year anniversary of the Inflation Reduction Act's passage and the growth of the clean energy industry in Oregon. The event, in partnership with Clean Energy for America (CE4A), convened local and Federal government officials and industry stakeholders for a tour of ESS' first fully automated manufacturing line, where ESS is expanding production of its iron flow battery technology to meet growing demand for LDES and enable clean, reliable and resilient grids powered by renewable energy 24/7.

ESS CEO Eric Dresselhuys, Senator Wyden and Dr. Saldaña delivered remarks on the IRA's contributions to the state's and nation's clean energy economy and ESS' leadership in scaling domestic production of innovative energy storage technology. The Wilsonville manufacturing line currently has a nameplate production capacity of 800 MWh of battery modules per year, which the company plans to scale to over 2 GWh in coming years.

"What I saw here at ESS only reinforced the importance of the clean energy provisions that I fought to get passed in the Inflation Reduction Act ? strengthening domestic supply chains and supporting clean technology innovation," said Senator Wyden. "I will continue to fight so that companies like ESS can keep building a robust domestic clean energy economy and supporting jobs for Oregon families."

"Over the past year, the prospects for the clean energy future have improved tremendously thanks in large part to climate and clean energy provisions in the Inflation Reduction Act. This legislation is driving demand for American-made clean energy technologies, such as the long-duration energy storage systems that we manufacture right here in Oregon and deliver for clean energy projects worldwide," said Eric Dresselhuys, CEO of ESS. "The IRA is delivering broad benefits to Americans. In 2022, ESS drove $170.4 million in economic activity nationwide and supported over 530 direct and indirect jobs and this will only grow as we continue to scale our operations to meet global demand for clean energy technology."

ESS iron flow technology provides cost-effective long-duration energy storage and is ideal for applications that require up to twelve hours of flexible energy capacity. ESS systems provide resilient, sustainable energy storage well-suited for multiple use cases including utility-scale renewable energy installations, remote solar + storage microgrids, solar load-shifting and peak shaving, and other ancillary grid services. Leveraging an ethically sourced and primarily domestic supply chain, ESS technology is safe, sustainable and has a 25-year design life without capacity fade.

"Expanding the domestic manufacturing and global deployment of innovative new clean energy technologies, such as iron flow batteries, were key goals of the Inflation Reduction Act," said Dr. Christopher Saldaña, director of the Energy Department's Advanced Materials and Manufacturing Technologies Office. "American clean technology manufacturers are already delivering against these goals, creating jobs and secure supply chains here in the U.S. to build the global clean energy future."

"This facility, this company and this technology, they're proof of what America's clean energy workforce can achieve, especially when we invest in them as a country. ESS's battery technology is safe, sustainable, resilient, domestically produced and vital for America's 100% clean energy future. And so, this is the perfect place for Oregon to celebrate the first anniversary of the Inflation Reduction Act because ESS's battery plant is what clean energy success looks like," said Andrew Reagan, Executive Director, Clean Energy for America.

Video and photography captured at the event can be downloaded here.

About ESS Tech, Inc.

At ESS (NYSE: GWH), our mission is to accelerate global decarbonization by providing safe, sustainable, long-duration energy storage that powers people, communities and businesses with clean, renewable energy anytime and anywhere it's needed. As more renewable energy is added to the grid, long-duration energy storage is essential to providing the reliability and resiliency we need when the sun is not shining, and the wind is not blowing.

Our technology uses earth-abundant iron, salt and water to deliver environmentally safe solutions capable of providing up to 12 hours of flexible energy capacity for commercial and utility-scale energy storage applications. Established in 2011, ESS Inc. enables project developers, independent power producers, utilities and other large energy users to deploy reliable, sustainable long-duration energy storage solutions. For more information visit www.essinc.com.

Forward-Looking Statements

This communication contains certain forward-looking statements regarding ESS and its management team's expectations, hopes, beliefs, or intentions regarding the future. The words "estimate", "expect", "will," "plan" and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Examples of forward-looking statements include, among others, statements regarding the Company's manufacturing plans and facility expansion. These forward-looking statements are based on ESS' current expectations and beliefs concerning future developments. Many factors could cause actual future events to differ materially. Except as required by law, ESS is not undertaking any obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise.