ESS Tech, Inc. (“ESS,” “ESS, Inc.” or the “Company”) (NYSE:GWH), a leading manufacturer of iron flow long-duration energy storage (“LDES”) systems for commercial and utility-scale applications, today announced financial results for its fourth quarter and full year ended December 31, 2025.
“The fourth quarter of 2025 and 2026 to date has seen the Company make continued progress in advancing our proprietary LDES and strengthening ESS for the next phase of execution,” said Drew Buckley, Chief Executive Officer of ESS. “We have taken decisive steps to reinforce leadership, governance, and financial discipline in support of long-term value creation, including a leadership and organizational reset that more closely aligns management and board oversight around execution and capital allocation. We also expanded our commercial capabilities through the acquisition of VoltStorage GmbH’s intellectual property and asset base, an iron-salt battery company, adding experienced personnel and strengthening our ability to execute our go-to-market priorities. We are also seeing a supportive macro backdrop for LDES, as rising electricity demand and increasing grid reliability requirements are driving greater urgency for resilient, long-duration solutions. Commercial momentum was highlighted by a $9.9 million award supporting deployment of up to 27 MWh of American-made LDES at U.S. military installations, and by Google’s recently announced participation in Project New Horizon as we advance the project toward manufacturing in 2026. With three tier 1 foundational projects expected to begin delivery in 2027, we are focused on executing across our pipeline as projects move to delivery and commissioning.”
2026 Outlook
- 2025 and 2026 to date have been a period of change, focused on strengthening leadership, governance, and financial discipline and aligning the organization for the next phase of execution.
- Expect an increasing pace of commercial activity over the next several years as projects progress from contracting to delivery and commissioning, supported by an active pipeline across targeted end markets.
- Recent commercial progress reinforces demand for resilient, domestically produced LDES in critical applications, including defense and data infrastructure.
- Improved liquidity position with additional capital raised after year end provides enhanced financial flexibility to support execution and sustain momentum.
Fiscal Year 2025 and Subsequent Highlights
- Following the Company’s agreement to deploy the 5-megawatt (“MW”), 50 megawatt-hour (“MWH”) battery system at Salt River Project’s (“SRP”) Copper Crossing Energy and Research Center under a 10-year energy storage agreement, recently announced an updated collaboration with Google for Project New Horizon that includes cost sharing and multi-year operational testing. Manufacturing is expected to begin in 2026 with delivery targeted for December 2027.
- Acquired the intellectual property and assets of VoltStorage GmbH, a pioneer in iron-salt battery technology, adding VoltStorage’s portfolio of patents and technical development work to the Company’s existing intellectual property base.
- Appointed Randall Selesky, former Chief Commercial Officer of VoltStorage, as Chief Commercial Officer of ESS Tech.
- Awarded a $9.9 million contract from Concurrent Technologies Corporation (“CTC”) and the United States Air Force Research Laboratory (“AFRL”) for a large capacity energy storage (“LCES”) system at the U.S. Clear Space Force Station in Alaska.
- Appointed Drew Buckley as Chief Executive Officer, succeeding Interim CEO Kelly Goodman; appointed Kelly Goodman as Chief Strategy Officer and General Counsel; and appointed Kate Suhadolnik as Chief Financial Officer from her role as Interim CFO.
- In October 2025, closed a $40 million financing transaction with YA II PN, Ltd., an investment fund managed by Yorkville Advisors Global, L.P. (“Yorkville”).
- In November 2025, launched an at-the-market (“ATM”) equity offering program and raised approximately $8.6 million in gross proceeds.
- As of March 1, 2026, repaid approximately $28.5 million, or 95%, of the first $30 million tranche under the promissory note with YA II PN, leaving approximately $1.5 million outstanding, and drew the second $10 million tranche on February 27, 2026.
Fiscal Year 2025 Financial Highlights
- Revenue was $1.6 million for the year ended December 31, 2025. The company’s business has been focused on the development and commercialization of its LDES systems.
- ESS delivered and recognized revenue from completed and in-process Energy Warehouses and Energy Centers (plus related equipment), engineering services for a site deployment, and extended warranty services, primarily offset by revenue reductions tied to settling and winding down legacy contracts as the Company shifted to the Energy Base offering and by lower overall sales volumes year over year.
- Net loss for the year ended December 31, 2025, was $63.4 million, as compared with $86.2 million for the year ended December 31, 2024.
- Adjusted EBITDA improved 38% year-over-year to $(44.3) million for the year ended December 31, 2025, compared to $(71.3) million for the year ended December 31, 2024.
- Total operating expenses decreased 33% to $29.7 million for the year ended December 31, 2025, compared to $44.4 million for the year ended December 31, 2024. The decrease was primarily due to a decrease in research and development expenses of $3.5 million, a decrease in sales and marketing expenses of $5.3 million, and a decrease in general and administrative expenses of $5.9 million.
- Unrestricted cash and cash equivalents was $14.5 million as of December 31, 2025, and short-term investments were $7.5 million. Subsequently closed a $15 million registered direct offering priced at a premium to the market for general corporate purposes and working capital in January 2026.
- As of December 31, 2025, working capital was approximately $1.0 million, compared to $15.8 million as of December 31, 2024.
Kate Suhadolnik, ESS’ Chief Financial Officer, commented, “We have prioritized balance sheet improvements, with financing initiatives that strengthen liquidity, enable meaningful debt repayment, and provide flexibility to support operations. These steps contributed to improved operating performance and a meaningful year-over-year improvement in adjusted EBITDA. We ended 2025 with $14.5 million in cash and cash equivalents and $7.5 million in short term investments, and we completed a $15 million registered direct offering after year end.”
