ESS Reinforces Leadership Position in Long-Duration Energy Storage with Over 20 Additional Patents Awarded

Company now holds 62 patents for innovative energy storage technology with additional 225 filed

WILSONVILLE, Ore.--(BUSINESS WIRE)-- ESS Tech, Inc. (“ESS”) (NYSE:GWH), a leading manufacturer of long-duration energy storage systems for commercial and utility-scale applications, has been awarded over 20 additional patents for the company’s industry-leading iron flow battery (IFB) technology since the beginning of 2022. This brings the total number of patents held by the company to 62 worldwide with a further 225 applications filed.

Founded in 2011, ESS has built an extensive portfolio of patents, proprietary knowledge, and experience in scaling the commercial manufacturing and deployment of iron flow battery systems. ESS’ innovations have addressed the critical advancements needed to facilitate mass adoption of IFB technology including the company’s patented Electrolyte Health Management System (EHMS). Collectively, these innovations have created systems capable of delivering unlimited cycling with zero capacity-fade over their operating life.

“Solving the world’s big energy challenges requires research and innovation,” said Julia Song, CTO of ESS. “We are proud of our team’s work to develop long-duration energy storage solutions and are grateful for the validation of our distinct innovations by U.S. and global officials. We look forward to the continued advancement of our technology and the competitive advantage it creates in the marketplace as we enable the rapid expansion of wind and solar generation and catalyze the clean energy future.”

ESS systems provide up to 12 hours of long-duration energy storage for utility and commercial-scale applications. The company’s technology has been validated by multiple third parties including the U.S. Department of Energy’s ARPA-E program, global insurer Munich Re, and utility and commercial customers worldwide. ESS recently announced a partnership with Coldwell Solar to deploy Energy Warehouse systems to microgrids that will power multiple wineries in California, safely providing power even during wildfire conditions.

The company’s battery modules have been ETL certified to conform to UL 9540A and UL 1973 standards, further affirming ESS modules’ quality, resilience and ability to operate safely.

About ESS

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” 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 ability to execute on orders and the Company’s relationships with customers. 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.

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Investors:

Erik Bylin

Investors@essinc.com

Media:

Morgan Pitts

503.568.0755

morgan.pitts@essinc.com

Source: ESS, Inc.