ESS Tech Q4 Earnings Call Highlights

ESS Tech (NYSE:GWH) used its fourth-quarter and full-year 2025 earnings call to outline a year of restructuring and a strategic pivot toward its Energy Base long-duration iron flow storage product, while also detailing improved cost metrics and recent financing activity aimed at strengthening liquidity.

Strategic shift to Energy Base and “deliberate transformation” in 2025

Chief Executive Officer Drew Buckley said 2025 was “a year of deliberate transformation,” emphasizing restructuring actions, commercial progress, and balance sheet improvement as the year’s main themes. He described ESS as a manufacturer of long-duration iron flow energy storage systems that use iron, salt, and water, and positioned the company’s Energy Base product as designed for 10 to 22 hours of storage for utility-scale grids, data centers, industrial microgrids, and defense installations.

Buckley said the company has moved away from legacy products—Energy Warehouse and Energy Center—to refocus on Energy Base. He also highlighted domestic manufacturing in Wilsonville, Oregon, and stated ESS has “over 98% domestic content,” framing the product as an American-made, American-sourced long-duration storage option.

Commercial updates: defense award and Project New Horizon with SRP and Google

Management pointed to two key commercial developments discussed on the call:

• $9.9 million defense-related award: Buckley said ESS was awarded a $9.9 million contract from Concurrent Technologies Corporation and the U.S. Air Force Research Laboratory for a long-duration energy storage system to be deployed at U.S. Clear Space Force Station in Alaska. He characterized it as a landmark win for mission-critical defense applications.
• Project New Horizon: ESS announced Project New Horizon, a 5 MW/50 MWh system planned for Salt River Project’s Copper Crossing Energy and Research Center in Florence, Arizona. Buckley said Google has been confirmed as an offtaker and will provide cost sharing and multi-year operational testing.

On timing for Project New Horizon, Buckley said manufacturing is expected to begin in 2026, with delivery targeted for December 2027.

Leadership changes and VoltStorage IP acquisition

Buckley also reviewed leadership changes and a technology-focused acquisition. He said Kelly Goodman transitioned to Chief Strategy Officer and General Counsel, and Kate Suhadolnik was appointed permanent Chief Financial Officer.

In February 2026, the company acquired the intellectual property and assets of VoltStorage, which Buckley described as a pioneer in iron salt battery technology. He said the acquisition “deepens” ESS’s patent coverage and adds human capital.

Following that acquisition, ESS appointed Randall Selesky, former Chief Commercial Officer of VoltStorage, as Chief Commercial Officer. Buckley also said Chief Operating Officer Jigish Trivedi will depart the company, and that Chief Information Officer Brian Lasecki will serve as interim COO while ESS conducts a formal search.

Financial results: lower revenue, improved losses and expense reductions

CFO Kate Suhadolnik reported full-year 2025 revenue of $1.6 million, down from $6.3 million in 2024. She attributed the decrease to the company’s transition away from legacy product lines and the refocus on Energy Base. She said revenue recognized during 2025 included deliveries of legacy units (primarily to related parties), engineering services, and extended warranty revenue, partially offset by the wind-down of active contracts tied to legacy activities.

Despite the revenue decline, Suhadolnik said profitability metrics improved year over year:

• Gross loss: $27.7 million, an improvement of 39% versus a $45.4 million loss in 2024.
• Total operating expenses: $29.7 million, down 33% from $44.4 million in 2024.
• Net loss: $63.4 million, compared with $86.2 million in 2024.
• Adjusted EBITDA: loss of $44.3 million, improved from a loss of $71.3 million in 2024 (management described this as a 38% improvement year over year).

She said expense reductions reflected an “organizational reset,” with research and development down $3.5 million, sales and marketing down $5.3 million, and general and administrative expenses down $5.9 million. Suhadolnik added that ESS made the “smallest cut” to R&D in order to prioritize product development.

Looking ahead, Suhadolnik said the company believes it is on a path to positive EBITDA as Energy Base revenue ramps “in 2027 and beyond,” and she characterized the reductions as “structural, not temporary.”

Liquidity and capital plan; revenue timing skewed to 2027–2028

On the balance sheet, Suhadolnik said ESS ended 2025 with $14.5 million in unrestricted cash and cash equivalents and $7.5 million in other liquid assets, for combined liquidity of $22 million. She also said accounts receivable was “essentially 0,” and inventory was $0.1 million, which she linked to the wind-down of legacy product lines.

Both Buckley and Suhadolnik reviewed financing transactions discussed on the call, including a $40 million Yorkville Advisors financing and an at-the-market (ATM) equity program that raised approximately $8.6 million in gross proceeds. Buckley said the company had repaid approximately $28.5 million, or 95%, of the first $30 million tranche under the Yorkville promissory note. Suhadolnik, referencing the period “as of March first, 2026,” said ESS had repaid approximately $20.5 million, or 95%, of the first $30 million tranche. Management also noted a $15 million registered direct offering that closed in January 2026 and said the second $10 million tranche under the Yorkville note was drawn in early 2026.

During Q&A, Buckley told analysts that the company’s 2026 focus is commercialization of Energy Base to support deliveries to “tier one customers” in 2027 and 2028. He said he expects most revenues associated with key projects to be recognized in 2027 and 2028 rather than 2026. He also addressed the structure of the SRP project, saying it is currently a 10-year power purchase agreement and that ESS is exploring options—potentially including structuring it more like an equipment sale—while indicating revenue recognition under the existing structure would start in 2028.

Asked about liquidity and potential additional capital raises, Buckley said the company’s financial runway has improved since the prior conference call, acknowledged further capital needs to support plans in 2027 and beyond, and said ESS intends to be “thoughtful and strategic” about accessing capital. He added that the company is not looking to tap the ATM immediately.

About ESS Tech (NYSE:GWH)

ESS Tech, Inc (NYSE: GWH) is a Portland, Oregon‐based company specializing in long‐duration iron flow battery energy storage solutions. The company’s core business centers on the design, manufacture and deployment of modular battery systems that store electricity using an iron‐chloride electrochemical process. These systems are engineered to support grid operators, utilities, commercial and industrial customers in integrating renewable power, managing peak loads and ensuring reliable back‐up power.

At the heart of ESS Tech’s offering is its “Energy Warehouse,” a containerized flow battery system featuring non‐toxic, fully recyclable materials and a simple architecture that separates energy storage capacity from power output.