ESS Tech's Q2 net loss widens 41% to $15.6 million as cash falls to $5.6 million and going concern doubt emerges

ESS Tech, Inc. (NYSE: GWH) reported a net loss of $15.6 million for Q2 2026, up 41% from $11.1 million in the prior-year period, when it released second-quarter financial results on 11 August 2026^[1]. Revenue fell to $73,000, a 97% decline from $2.4 million a year earlier, as the company wound down legacy iron flow battery contracts^[1].

Going concern and liquidity

The financial report carries the most serious disclosure yet on ESS Tech's cash position. Unrestricted cash stood at $10.8 million at 30 June 2026 and had dropped further to approximately $5.6 million by 31 July, triggering a going concern qualification in the company's Form 10-Q^[1]. Stockholders' equity turned negative at $(2.7) million.

The company has been deleveraging in parallel: it has repaid $37 million of the original $40 million principal outstanding under its Yorkville promissory note. First-half 2026 operating expenses fell 12% year-on-year, and net cash used in operating activities improved 27% to $22.4 million.

Business combination LOI

On 6 August 2026, ESS signed a non-binding letter of intent for a strategic business combination with an undisclosed private energy-sector company. The transaction implies a combined enterprise value of approximately $515 million, with ESS shareholders expected to own 5% to 10% of the combined entity at closing^[1]. Management is targeting a definitive agreement by the end of September and a close before year-end, subject to due diligence and required approvals. The prospective partner has not been named publicly.

Sodium-ion pivot and the Alsym supply agreement

ESS has been repositioning around sodium-ion chemistry since signing an LOI with Alsym Energy for 8.5 GWh of U.S.-made sodium-ion cells and modules^[1]. Alsym's technology uses a proprietary sodium iron phosphate pyrophosphate (NFPP+) cathode, which the company claims eliminates thermal runaway risk^[1]. The domestic supply chain is designed to avoid Foreign Entity of Concern restrictions and to qualify for U.S. tax credits.

A separate LOI with California-based Juniper Energy covers deployment of 500 MWh or more of sodium-ion BESS across multiple projects, anchored by a planned 10 MW / 80 MWh system in California^[1]. Management said early-stage opportunities for the sodium-ion platform are approaching $1 billion across data center, critical infrastructure, and utility markets, though these remain unconverted and without a disclosed conversion timeline.

Key risks management flagged in the earnings call:

• The Bridge modular sodium-ion system has not yet been commercially deployed or validated by customers in real-world conditions.
• The Juniper and Alsym LOIs are non-binding and may not result in definitive agreements or revenue.
• The business combination LOI remains subject to due diligence, negotiation, and multiple approvals.
• Liquidity is the most immediate operational constraint.

What to watch

The September deadline for a definitive business combination agreement is the near-term pivot point. If that slips, ESS will need to demonstrate alternative financing with only a few million dollars of runway. The first full-scale Bridge system is targeted for delivery by end of 2026 - commercial validation before that deadline would materially change the risk profile of the sodium-ion pipeline.