• Tesla for iron-flow grid batteries. (Highlights their battery focus for the grid, differentiating their unique iron-flow chemistry from Tesla's lithium-ion.)
• Intel for grid-scale energy storage. (Positions them as a provider of fundamental, enabling technology for the future electrical grid, much like Intel does for computing.)

• Energy Warehouse™ (EW): A large-scale, containerized iron-flow battery system designed for utility-scale applications, renewable energy integration, and grid services requiring long-duration energy storage.
• Energy Center™ (EC): A modular, smaller-scale iron-flow battery system primarily for commercial and industrial customers, microgrids, and localized grid support applications.

ESS Tech (GWH) sells primarily to other companies (B2B) in the energy sector, including utilities, independent power producers, and commercial & industrial clients. Its major customers include:

• Pacific Gas and Electric Company (PG&E) (Symbol: PCG)
• Enel Green Power España (a subsidiary of Enel S.p.A., Symbol: ENLAY)
• SB Energy Global LLC (a subsidiary of SoftBank Group, Symbol: SFTBY)
• TC Energy (Symbol: TRP)
• U.S. Department of Defense (a government entity)

Kelly Goodman Interim Chief Executive Officer

Ms. Goodman was appointed interim CEO in February 2025 and previously served as the Vice President of Legal and Corporate Secretary at ESS Tech, Inc. She possesses nearly 20 years of experience in the clean energy legal sector, both domestically and internationally. Her expertise spans project development, technology agreements (including wind, solar, hydrogen, and storage), and project and corporate financing. Prior to joining ESS Tech, she served as VP-Commercial Transactions & Special Legal Counsel at Summit Power Group LLC, a private company that develops and manages energy projects. Ms. Goodman holds a Bachelor of Arts from the University of Santa Clara and a law degree from the University of Washington.

Kate Suhadolnik Interim Chief Financial Officer

Ms. Suhadolnik was appointed interim Chief Financial Officer of ESS Tech, Inc. effective August 1, 2025. She joined ESS Tech, Inc. in September 2021 and held the position of the company's Controller since April 2023. Ms. Suhadolnik brings 14 years of experience in the financial and accounting sector. Before her tenure at ESS, she was the Corporate Accounting & Reporting Manager at The Standard, an insurance and financial services company, from July 2020 to September 2021. She also held various positions of increasing responsibility at Deloitte & Touche LLP from September 2011 to June 2020. Ms. Suhadolnik earned her bachelor's degree in accounting and business administration from Gonzaga University and is a Certified Public Accountant.

Dr. Julia Song Chief Technology Officer and Co-founder

Dr. Song is a co-founder of ESS Inc. and its Chief Technology Officer. She has been instrumental in transitioning the iron flow battery technology into a commercial energy storage system. Before co-founding ESS Inc. in 2011, Dr. Song was the Vice President of Research and Development at ClearEdge Power Inc., where she led a team of over 20 scientists and engineers in corporate R&D projects and the commercialization of a 5 kW Combined Heat and Power Fuel Cell system. She began her career as an Industrial Research Chemist at Milliken & Co. Dr. Song holds a B.S. in Chemistry from Peking University and a Ph.D. in Chemistry from the University of North Carolina-Chapel Hill.

Craig Evans President and Co-founder

Mr. Evans is a co-founder of ESS Tech, Inc. Along with Dr. Julia Song, he launched the startup in 2011, initially working from a garage to develop the iron-based battery technology. He previously served as CEO and now holds the position of President, where he leads key functional areas including engineering, R&D, and manufacturing. He has deep experience in fuel cells, electrochemistry, advanced material science, and renewable energy.

Dr. Benjamin Heng Executive Vice President of Engineering

Dr. Heng serves as the Executive Vice President of Engineering at ESS Inc. He has a strong background in technology startups, holding key executive and advisory roles. Dr. Heng has successfully guided two solar companies to acquisition and several startups to subsequent funding rounds. As COO of Caelux Solar, he was responsible for taking a perovskite-based solar product from prototype to pilot production. He also headed Solar Product Engineering & Operations at Tesla/SolarCity, where he oversaw the design, development, and manufacturing transition of products, including the solar roof. Prior to that, he was part of Intel’s Device Integration and Process Engineering groups. Dr. Heng holds a Ph.D. in electrical engineering with a focus on device physics and nanobiotechnology from the University of Illinois at Urbana-Champaign and has over 72 patents.

The emergence and scaling of Form Energy's iron-air battery technology presents a clear emerging threat. Form Energy directly competes with ESS Tech in the long-duration energy storage market, specifically targeting multi-hour to multi-day applications. Their iron-air chemistry leverages abundant, low-cost materials and aims to provide high performance and scalability for utility-scale deployments. With significant funding, high-profile partnerships with major utilities, and announced plans for large-scale manufacturing, Form Energy is rapidly establishing a competitive presence in the same strategic market segment ESS Tech is pursuing.

The addressable market for ESS Tech's main products, which are iron flow batteries for commercial and utility-scale long-duration energy storage (LDES) applications, is the Long Duration Energy Storage market. These products include the Energy Warehouse, Energy Center, and Energy Base solutions.

The global market for Long Duration Energy Storage was valued at approximately USD 5.91 billion in 2024 and is projected to reach USD 12.34 billion by 2030, growing at a Compound Annual Growth Rate (CAGR) of 12.89%. Other estimates suggest the global LDES market is expected to increase from USD 4.84 billion in 2024 to USD 10.43 billion by 2030, at a CAGR of 13.6%. Another report values the global LDES market at USD 4.90 billion in 2024 and forecasts it to reach nearly USD 13.88 billion by 2032, with a CAGR of 13.9% from 2025 to 2032. The market was also estimated at USD 3.64 billion in 2024, with a forecast to reach USD 8.61 billion by 2030 at a CAGR of 15.4%.

For the North America region, the Long Duration Energy Storage market was valued at USD 1,495.65 million (approximately USD 1.5 billion) in 2023 and is anticipated to grow to USD 4,535.81 million (approximately USD 4.5 billion) by 2032, at a CAGR of 13.1% during the forecast period (2023-2032). North America held the largest market share in the global LDES market in 2024 and is expected to continue leading due to extensive integration of renewable energy sources and grid modernization efforts.

ESS Tech (NYSE: GWH) is expected to drive future revenue growth over the next 2-3 years through several key initiatives and market trends:

1. Ramp-up and Commercialization of the Energy Base Product: ESS Tech has strategically pivoted its focus towards its new "Energy Base" product, designed for non-containerized scalability and longer-duration energy storage. The company secured its first Energy Base sale and is actively engaged in a growing pipeline of commercial opportunities, including an 8-megawatt hour order anticipated for delivery in 2026. This product is central to their strategy to meet the increasing demand for long-duration solutions, especially as data center build-outs accelerate and electrification efforts expand.
2. Securing and Executing Large-Scale Projects: A significant driver is the company's ability to secure and deliver on large-scale projects. For example, ESS Tech was awarded a 50 MWh Power Purchase Agreement (PPA) project in Arizona, which is highlighted as a considerable market opportunity with potential for much larger follow-on projects. Project-level capital and monthly payment structures like PPAs or tolling agreements are expected to create a smoother and more baseline revenue stream.
3. Leveraging Production Tax Credits (PTCs) and Legislative Tailwinds: ESS Tech anticipates realizing benefits from Production Tax Credits (PTCs), which are part of recent federal legislation like the One Big Beautiful Bill Act. These incentives, along with tariffs on lithium-ion batteries and state-led clean energy initiatives, enhance the competitiveness and attractiveness of ESS Tech's domestically manufactured long-duration energy storage solutions.
4. Growth in Demand for Long-Duration Energy Storage (LDES): The overall market for long-duration energy storage is a crucial driver. ESS Tech is positioning its non-lithium-ion technology to cater to the significant and emerging demand for such solutions, especially for applications requiring storage beyond eight hours, with a stated aim towards 12-plus hour durations by 2027. The increasing electricity demands from hyperscale AI data centers are specifically identified as a major opportunity.
5. Cost Reductions and Manufacturing Efficiency: While not a direct revenue generator, significant progress on cost reduction initiatives and improved manufacturing efficiency for their Energy Base and Energy Center products are expected to lead to improved unit profitability. This allows ESS Tech to offer a more cost-competitive product, which can indirectly drive revenue growth by increasing market adoption and order volumes.

Share Repurchases

• ESS Tech repurchased shares from employees for income tax withholding purposes, amounting to $27 million in Q2 2025 and $178 million in Q1 2025.

Share Issuance

• The company became publicly listed in 2021 through a merger with ACON S2 Acquisition Corp., which provided approximately $465 million in net proceeds, including a $250 million Private Investment in Public Equity (PIPE).
• In September 2024, ESS Tech raised $130 million in a PIPE funding round.
• Stockholders approved in October 2025 the issuance of common stock exceeding 19.99% of outstanding shares, which covers up to $25 million of securities under a standby equity purchase agreement and up to 129,312 shares upon warrant exercise.

Inbound Investments

• ESS Tech secured approximately $465 million in net proceeds from its 2021 SPAC merger, which included a $250 million PIPE investment from institutional investors such as Fidelity, Koch Industries, Tortoise Capital, SB Energy, Breakthrough Energy Ventures, and BASF Venture Capital.
• In October 2025, ESS Tech closed a $40 million financing transaction with YA II PN, Ltd., managed by Yorkville Advisors Global, L.P., structured as a one-year promissory note providing $30 million of immediate capital.
• In July 2025, the company secured a $31 million insider-led funding package, which included a $25 million standby equity purchase agreement with Yorkville Advisors Global LP, $0.9 million in short-term loans, a $0.8 million production tax credit transaction, and a $4 million equipment sale-leaseback deal.

Capital Expenditures

• Capital expenditures were $4.72 million in 2024, $6.51 million in 2023, $1.52 million in 2022, $0.57 million in 2021, and $0.44 million in 2020.
• The $250 million PIPE investment from the 2021 SPAC merger was primarily allocated to fund manufacturing expansion to 16 GWh across three continents.
• ESS Tech is expanding its manufacturing capacity at its Wilsonville facility by commissioning a second automated battery manufacturing line ("Line 2") to improve capital efficiency and focus on higher-margin components, aiming to achieve 6.4 GWh of annual battery production capacity by the end of 2024.