Eos Energy Receives $87 Million DOE Loan Advance for Thorn Hill
Eos Energy received an $87 million DOE loan advance on September 14, 2026, bringing draws under its $303.5 million facility to $178 million.
Photo by Mark Stebnicki on Pexels
Eos Energy Enterprises announced on September 14, 2026, that it received an $87 million advance under the second tranche of its loan agreement with the US Department of Energy’s Office of Energy Dominance Financing. The advance, which reimburses 80% of eligible costs tied to the company’s Thorn Hill manufacturing facility in Warrendale, Pennsylvania, brings Eos’s total draws under the DOE facility to approximately $178 million since 2024, according to the company’s press release.
The funding supports Line 2 at Thorn Hill, which entered commercial production in June 2026 and is being ramped toward its designed annual capacity of about 2 GWh. Eos said that once a planned relocation of Line 1 to Thorn Hill is complete, subject to lender approval, the facility is expected to support approximately 4 GWh of combined annual manufacturing capacity across both lines.
A $303.5 million facility, drawn in stages
The DOE loan backing Eos’s expansion was finalized in November 2024 at $303.5 million, made up of $277.5 million in principal and $26 million in capitalized interest, to support what the company calls “Project AMAZE” (American Made Zinc Energy). The facility, which matures on June 15, 2034, allows up to four draws tied to production milestones and covers 80% of eligible capital and project-related operating costs. Eos received a first funding of $68.3 million from the facility, and the $87 million advance announced September 14, 2026, is the first draw under the loan’s second tranche.
“Loan funding from the Office of Energy Dominance Financing has been critical in scaling Eos,” said Alessandro Lagi, the company’s chief financial officer, in the press release. “This advance reimburses a significant portion of the investment we have already made in Line 2 and returns that capital to the balance sheet, giving us more room to invest in the business while maintaining a disciplined approach to growth.” John Mahaz, Eos’s chief operating officer, said running two lines under one roof “drives more efficient use of our engineering, support resources, and labor.”
DOE facility at a glance
| Detail | Figure |
|---|---|
| Total DOE loan facility | $303.5 million ($277.5M principal + $26M capitalized interest) |
| Facility closed | November 2024 |
| Facility matures | June 15, 2034 |
| First funding drawn | $68.3 million |
| Latest advance (Sept. 14, 2026) | $87 million |
| Total drawn to date | Approximately $178 million |
| Reimbursement rate | 80% of eligible Thorn Hill costs |
| Line 2 capacity | Approximately 2 GWh/year |
| Combined Line 1 + Line 2 capacity (planned) | Approximately 4 GWh/year |
Source: Eos Energy Enterprises press releases, November 2024 and September 14, 2026.
The advance is the latest in a string of DOE-backed moves in battery manufacturing that Winss Solutions has covered, including a $500 million DOE award split across seven critical-minerals and battery projects in August 2026, and NeoVolta’s $30 million credit facility to expand battery storage manufacturing in Georgia. Eos itself was also part of a separate West Virginia deal covered by Winss Solutions, in which Google backed zinc battery storage at a former coal mine site using Eos’s technology.
About Eos Energy Enterprises
Eos Energy Enterprises (Nasdaq: EOSE) is a US manufacturer of zinc-based, non-flammable long-duration battery energy storage systems (BESS), built around its proprietary Znyth technology and, more recently, its Z3 battery module. The company positions its zinc chemistry as a domestically manufactured alternative to lithium-ion for utility-scale, microgrid, and commercial and industrial applications requiring 3 to 12 or more hours of discharge duration. Eos closed its $303.5 million DOE loan guarantee in November 2024 to fund manufacturing expansion at its Turtle Creek and Thorn Hill, Pennsylvania sites, and announced on August 27, 2026, that it would consolidate battery manufacturing at the Thorn Hill location. The company has continued to expand its commercial footprint through 2026, including a September 2, 2026, clean-energy storage partnership with MN8 Energy and Google in West Virginia, alongside the DOE-funded buildout of Thorn Hill toward roughly 4 GWh of combined annual manufacturing capacity.
Sources: Eos Energy Enterprises (GlobeNewswire); Energy-Storage.News; Eos Energy Enterprises
Featured image: photo by Mark Stebnicki on Pexels (free Pexels license).
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I specialize in sustainability education, curriculum co-creation, and early-stage project strategy. At WINSS, I craft articles on sustainability, transformative AI, and related topics. When I’m not writing, you’ll find me chasing the perfect sushi roll, exploring cities around the globe, or unwinding with my dog Puffy — the world’s most loyal sidekick.
