ESS Tech, Inc.

What they do

ESS designs and produces long-duration energy storage batteries, originally iron flow technology, for grid and commercial applications. The company is now accelerating development of U.S.-made sodium-ion battery energy storage systems, including the Bridge modular system, and no longer offers its original Energy Warehouse and Energy Center products. Current product focus includes the gigawatt-hour scale Energy Base and core power trains, with a strategic pivot to sodium-ion for short- and medium-duration applications.

Revenue drivers

• Energy Base and core power trains — Near- and medium-term revenue expected primarily from Energy Base and core technology component sales; the original Energy Warehouse and Energy Center are not currently offered for sale.
• Sodium-ion Bridge modular system — Newly launched modular sodium-ion system with first module completed; early-stage opportunities approaching $1 billion across data centers, critical infrastructure, and utility markets, including a LOI with Juniper Energy for 500+ MWh.
• Iron flow battery platform — Long-duration iron flow batteries cyclable over 20,000 times, using earth-abundant materials; positioned for durations greater than eight hours where cost advantage over lithium-ion increases.

Recent performance

Revenue was $73,000 in Q2 2026, down from $128,000 in Q1 2026 and $2.4M in Q2 2025. Annual revenue declined from $6.3M in 2024 to $1.6M in 2025. Net income was $63.4M in 2025, though diluted EPS was negative at -$4.34. Operating cash flow was -$50.3M in 2025, and cash & equivalents were $10.8M at June 30, 2026.

Strategy

ESS is pivoting to sodium-ion energy storage, with a signed LOI with Alsym Energy for 8.5 GWh of U.S.-made sodium-ion cells and modules. The company is streamlining Wilsonville operations, reducing expenses by 12% in the first half of 2026 and reallocating capital toward high-return sodium-ion opportunities. Management is also pursuing a non-binding LOI for a strategic business combination with a private energy-sector company, implying a $515 million combined enterprise value, with ESS shareholders allocated an estimated 5-10% of the combined entity. The company aims to convert early-stage sodium-ion demand into near-term revenue, targeting data centers, critical infrastructure, and utility markets.

Risks

• Revenue decline and cash burn — Quarterly revenue has fallen sharply to $73K, while operating cash flow is negative and cash reserves are limited at $10.8M.
• Going concern uncertainty — The company has negative shareholder equity of -$2.7M and has flagged an ability to continue as a going concern.
• NYSE listing compliance — The company received delisting notices and is working to regain compliance with NYSE listing requirements.
• Pivot and execution risk — The strategic shift to sodium-ion is new and unproven, with customer acceptance and scale-up still to be demonstrated.

Outlook

Management expects the first operational Bridge sodium-ion product by end of 2026, with a planned 80 MWh California utility project targeted for commercial operation in 2027. Early-stage sodium-ion opportunities are approaching $1 billion, and the company is advancing a potential strategic business combination. Management has noted the need for additional funding and intends to reduce costs and cash burn while scaling production.