ESS Tech begins Bridge sodium-ion rollout backed by 8.5 GWh Alsym supply LOI and 500 MWh Juniper deployment agreement

ESS Tech (NYSE: GWH) began the market rollout of its Bridge modular sodium-ion battery energy storage system after the close of Q2 2026, with module-level hardware built and initial charge-discharge testing under way^[1]. The company disclosed the milestone alongside its 11 August financial results, which showed a net loss of US$15.6 million for the quarter ended 30 June 2026, up 41% from US$11.1 million in the prior-year period^[1].

The supply agreement: 8.5 GWh of U.S.-made cells

The technology underpinning Bridge comes from Alsym Energy, a U.S. sodium-ion startup. ESS signed a letter of intent with Alsym to add 8.5 GWh of U.S.-made sodium-ion cells and modules to its portfolio, extending its non-lithium platform into short- and medium-duration applications historically served by lithium-ion systems.

Alsym's chemistry is the differentiating claim. Alsym employs a proprietary sodium iron phosphate pyrophosphate (NFPP) cathode material called NFPP+, which the company claims offers best-in-class energy density with no risk of thermal runaway. The chemistry uses earth-abundant materials - sodium, iron, and hard carbon - with no cobalt, nickel, or manganese required, and operates from -40°C to 60°C with passive cooling only.

That operating range is central to ESS's market pitch. Management positioned sodium-ion as a critical solution for AI data centers due to its wide operating temperature range, which it says handles GPU-driven power spikes better than lithium-ion chemistries.

The FEOC angle matters for U.S. procurement. The Alsym LOI gives ESS the opportunity to supply a fully U.S.-manufactured system free of Foreign Entity of Concern concerns and able to take advantage of U.S. tax credits for itself and its customers.

The deployment LOI: 10 MW/80 MWh in California as the anchor

On 22 July 2026, ESS signed a separate letter of intent with Juniper Energy, a California-based renewables developer. The agreement covers the deployment of 500 MWh or more of sodium-ion battery energy storage systems. The arrangement has two layers:

• An initial 10 MW / 80 MWh project in California, targeted for commercial operation in 2027, which would deploy the Bridge system alongside an ESS energy management system^[1]
• A longer-term procurement framework under which Juniper has expressed intent to procure 500 MWh or more of ESS BESS across multiple projects

ESS identified early-stage commercial opportunities approaching $1 billion within roughly seven weeks of signing the Alsym LOI. The Juniper agreement is the first of those opportunities converting into a signed commercial framework with defined projects and deployment timelines.

Revenue collapse and the financial gap to bridge

The strategic pivot is happening against a stark financial backdrop. Revenue fell to just US$73,000 in Q2 2026, down from US$2.4 million in the prior-year period - a 97% decline, reflecting the wind-down of legacy iron flow battery contracts. First-half 2026 operating expenses fell 12% year-over-year and operating cash burn dropped 27%. ESS also repaid $37 million of a $40 million promissory note with Yorkville during the quarter, reducing near-term debt pressure.

The Bridge system has not yet been deployed commercially or validated by customers in real-world conditions, and the letters of intent with Juniper and Alsym are non-binding and may not result in definitive agreements or revenue. Management acknowledged the opportunities are early-stage and unconverted.

What to watch

The first operational Bridge system is targeted for the end of 2026^[1]. Whether ESS can convert the Juniper 10 MW/80 MWh California project into a signed contract - and begin cell deliveries from Alsym - will be the clearest near-term test of whether the sodium-ion pivot translates into revenue. The company also disclosed a non-binding letter of intent for a business combination with an undisclosed private energy company, with a definitive agreement targeted for September 2026 and close by year-end, at an implied combined enterprise value of approximately $515 million.