ESS Tech, Inc.
ESS Tech, Inc. develops and manufactures long-duration iron flow batteries and energy storage systems for utilities, independent power providers, and commercial and industrial customers. Its batteries use an electrolyte based primarily on salt, iron, and water, with power and storage capacity configured independently… From the company’s description.
In fiscal 2025, ESS Tech, Inc. reported revenue of $1.58M, down 74.9% from fiscal 2024, and a net loss of $63.44M. Operations used $50.28M in cash.
Margins and return on equity change in ; everything else in percent. Fewer shares and less debt are shown plainly, not as bad news — it depends what you make of buybacks. Dotted labels explain each measure. is shown separately from the annual figures.
What ESS Tech, Inc. does
In the company’s own words
ESS Tech, Inc. develops and manufactures long-duration iron flow batteries and energy storage systems for utilities, independent power providers, and commercial and industrial customers. Its batteries use an electrolyte based primarily on salt, iron, and water, with power and storage capacity configured independently to support applications ranging from on-site energy resilience to grid stabilization and renewable energy integration. The company’s current product focus is its configurable, gigawatt-hour-scale Energy Base and core power trains that customers can assemble into complete systems; it also maintains warranty and maintenance obligations for its earlier Energy Warehouse and Energy Center products, which are no longer offered for sale. Founded in 2011, ESS became publicly traded through a business combination and completed a legal-entity merger in 2024. It employed 62 full-time employees as of December 31, 2025. Its website is https://investors.essinc.com/.
Company details
- Sector
- Industrials
- Industry (SIC)
- Electronic Equipment
- Headquarters
- WILSONVILLE, OR
- Fiscal year end
- December
- CIK
- 1819438
- SIC
- 3690
Financial performance, year by year
Fiscal 2021–2025 · USDThe full income statement, balance sheet and cash flow for each of these years — every figure traceable to its filing — is on the Financials tab with a free account.
Who owns ESS Tech, Inc. — and what changed
Funds as of 2026Q2 · superinvestors as of 2026-06-30
Largest fund holders · ESS Tech, Inc.’s weight in each
Fund ownership is a floor, not a census — pensions, insurers and people holding shares directly are not visible here.
Could not be determined for this company: bond issues.
Every fund and institutional holder, quarter by quarter, is on the Ownership tab with a free account.
Recent filings
All filings →Each filing opens into its own statements and disclosures here.
Put this business in context.
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