10-K: ESS Tech Faces Going Concern Doubt Amid Revenue Drop

ESS Tech, a long-duration energy storage company, reported a significant revenue decline and substantial doubt about its ability to continue as a going concern, despite ongoing capital raises and cost-cutting measures.

Summary

• ESS Tech, specializing in iron flow battery technology, reported a net loss of $63.4 million for the year ended December 31, 2025, an improvement from $86.2 million in 2024.
• Revenue significantly decreased by 75% to $1.6 million in 2025, down from $6.3 million in 2024, primarily due to the wind-down of legacy product contracts and a settlement agreement with a customer.
• The company has an accumulated deficit of $845.8 million as of December 31, 2025, and total liquid assets of $22.0 million.
• Management has concluded there is substantial doubt about the company's ability to continue as a going concern for the next 12 months, necessitating additional debt or equity financing.
• Operating expenses decreased by 33% to $29.7 million in 2025, driven by cost-saving initiatives, reduced personnel, and lower production levels.
• A cybersecurity incident occurred on November 1, 2025, involving unauthorized access and system non-availability, but investigation and remediation found no material impact.
• The company received a NYSE notice on March 24, 2025, for failing to meet minimum market capitalization and stockholders' equity standards, and a subsequent notice on June 17, 2025, for market capitalization falling below $15 million. A cure plan was accepted on August 19, 2025.
• ESS Tech is transitioning its product focus to the gigawatt-hour scale Energy Base and core power trains, discontinuing the Energy Warehouse and Energy Center offerings for new sales.
• Manufacturing capacity at the Wilsonville, Oregon facility is expected to increase from 560 MWh to 1.05 GWh annually with the commissioning of a second automated line.

Sentiment

Score: 3

Explanation: StockSavvy.ai views this filing with significant concern due to the substantial doubt about the company's ability to continue as a going concern, the drastic revenue decline, and NYSE delisting risks, despite efforts in cost reduction and capital raising.

Positives

• Net loss improved by 26% to $63.4 million in 2025 from $86.2 million in 2024.
• Gross loss improved by 39% to $27.7 million in 2025 from $45.4 million in 2024, driven by cost-saving initiatives and reduced personnel expenses.
• Operating expenses decreased by 33% to $29.7 million in 2025, reflecting significant cost reduction and cash conservation measures, including a workforce furlough.
• The company's iron flow battery technology is non-flammable, operates in a wide temperature range (-15C to 50C), and is environmentally sustainable and substantially recyclable.
• The proprietary Proton Pump solution enables 20,000 cycle-design life without capacity fade, offering a potential long-term cost advantage over lithium-ion for durations over eight hours.
• Manufacturing capacity is planned to increase from 560 MWh to 1.05 GWh annually, with a long-term goal of 2.0 GWh, indicating scaling potential.
• The company successfully raised approximately $14 million in net proceeds from a Registered Direct Offering in January 2026 and drew a $10 million tranche from a Promissory Note in February 2026.
• The Inflation Reduction Act (IRA) provides significant tax credits (ITCs and PTCs) for energy storage, which are expected to benefit the company's gross margins.

Negatives

• Revenue decreased by 75% to $1.6 million in 2025 from $6.3 million in 2024, indicating a significant decline in sales.
• The company has a history of recurring net losses and negative cash flows from operations, with an accumulated deficit of $845.8 million as of December 31, 2025.
• Management has concluded there is substantial doubt about the company's ability to continue as a going concern for the next 12 months, requiring additional financing.
• The company's common stock and stockholders' equity fell below NYSE continued listing standards, with market capitalization dropping below $15 million, posing a delisting risk.
• A $1.7 million abandonment charge was recognized in Q4 2025 related to the patent portfolio, indicating a reevaluation of certain intellectual property's usefulness.
• The company has experienced supply chain issues, shipping delays, and vendor quality problems, which have affected production ramp-up and ability to deliver products.
• Certain existing customer contracts were based on projected cost reductions that may not be realized, and some shipped systems have not met contractual specifications, leading to additional costs and potential claims.
• The company implemented a furlough for a substantial number of employees as of May 30, 2025, as part of cost reduction measures, which may have unintended consequences like attrition and delays.
• The Promissory Note from Yorkville has a high effective interest rate of 291%.

Risks

• Significant barriers exist in producing energy storage products at commercial scale, with certain products still under development and aspects not fully field-tested.
• Inability to adequately control costs associated with operations and components, or failure to reduce cost structure and scale operations, may impair profitability.
• Dependence on third-party suppliers for key raw materials and components, with risks of quality issues, delays, and increased costs due to supply chain disruptions or price fluctuations.
• Past and potential future delays, disruptions, or quality control problems in manufacturing operations.
• Future success depends on increasing production capacity, which may not be cost-effective, and challenges in constructing/leasing new manufacturing facilities.
• Risk of product recalls or other actions due to defects or non-compliance, which could harm reputation and financial condition.
• If required maintenance is performed incorrectly or maintenance requirements exceed expectations, it could adversely affect reputation, business, and financial results.
• Expectations for future operating and financial results and market growth rely on assumptions that may prove incorrect, leading to actual results differing materially from anticipated.
• No assurance that nonbinding pre-orders or framework agreements will convert into binding orders or that orders will be completed, leading to uncertainty in revenue generation.
• Failure to deliver the benefits offered by the technology, or the emergence of improvements to competing technologies, could reduce demand for energy storage products.
• Dependence on market acceptance of products and long-duration energy storage technology, which is an emerging market.
• Highly competitive energy industries with larger competitors having greater resources.
• Project awards and sales pipeline may not convert to contracts or may be delayed, impacting revenue and cash flows.
• Risk of termination of contracted sales by customers due to unmet conditions, performance failures, or for convenience.
• Inability to accurately estimate future supply and demand for products and services, leading to inefficiencies or delays.
• Failure to manage growth effectively could strain management, operations, and financial infrastructure.
• Warranty obligations may be significant if products do not operate successfully or if estimates of useful life are inaccurate.
• Exposure to product liability claims, even without merit, due to product malfunction, tampering, or misuse.
• Third parties might attempt to gain unauthorized access to networks or compromise products and services, leading to security breaches and operational disruptions.
• Inability to identify or complete transactions with attractive acquisition candidates, or significant expenses and costs from future acquisitions.
• Facilities or operations could be damaged by natural disasters and other catastrophic events, with potential insufficient insurance coverage.
• Changes in the global trade environment, including tariffs, could adversely affect revenues, results, or cash flows.
• Exposure to foreign exchange risk, particularly if the U.S. dollar strengthens, impacting international competitiveness.
• Risk of write-downs or write-offs, restructuring, and impairment charges due to unexpected risks.
• Results of operations could vary due to changes in accounting policies, methods, estimates, and judgments.
• Requirements of being a public company may strain resources and divert management's attention.
• Relationships with related parties (SBE, Honeywell) are subject to risks, including no obligation for firm orders.
• Regulatory challenges or limitations on ability to sell products in certain markets, and risks associated with international expansion.
• Customers may be unable to obtain necessary environmental, health, and safety certifications for product installation.
• Subject to multiple U.S. federal, state, local, and other regulations, with changes potentially increasing costs or negatively impacting business.
• Subject to environmental and safety regulations and remediation matters, with risks of incidents, litigation, and fines.
• Delays, limitations, and risks related to environmental and other operating permits.
• Collection and processing of customer and individual data subjects the company to privacy, data protection, and cybersecurity laws and regulations.
• Exposure to penalties and adverse consequences for violations of FCPA and other anti-bribery/anti-corruption laws.
• Subject to governmental export and import controls and economic sanctions programs.
• Exposure to various risks related to legal proceedings or claims that could exceed insurance coverage.
• Restrictions and obligations on business due to governmental grants and loans, including potential government rights in intellectual property.
• Reduction, elimination, or expiration of government tax credits, subsidies, and economic incentives related to renewable energy solutions.
• Changes in tax laws or their implementation/interpretation may adversely affect business and financial condition.
• Ability to utilize net operating loss carryforwards and certain other tax attributes may be limited by ownership changes.
• As a smaller reporting company, taking advantage of exemptions could make securities less attractive to investors.
• Failure to protect intellectual property or incurring significant costs in defending it.
• Third parties may assert infringement claims, diverting attention and incurring costs.
• Patent applications may not result in issued patents, or patent rights may be contested, circumvented, invalidated, or limited.
• Products contain third-party open-source software, with risks of non-compliance with licenses.
• Debt service obligations may adversely affect financial condition and cash flows.
• Price of common stock may be volatile due to various factors.
• Sale of a significant portion of total outstanding shares could cause market price to drop.
• Warrants outstanding, if exercised, would increase shares eligible for resale and dilute stockholders.
• Terms of warrants may be amended, potentially disadvantageously to holders.
• Company may redeem unexpired warrants prior to exercise, making them worthless.
• No dividends expected in the foreseeable future.
• Inability to satisfy NYSE continued listing standards.
• Reports published by analysts, including projections in those reports that differ from actual results, could adversely affect the price and trading volume of common stock.
• Subject to short selling strategies that may drive down the market price of common stock.
• Provisions in charter documents and Delaware law might discourage, delay, or prevent a change in control of the Company or changes in management and, therefore, depress the market price of common stock.
• Exclusive forum provisions in bylaws could limit stockholders' ability to obtain a favorable judicial forum for disputes with the company or its directors, officers or employees.
• Claims for indemnification by directors and officers may reduce available funds to satisfy successful third-party claims against the company and may reduce the amount of money available to the company.

Future Outlook

Management anticipates continued losses in the near term and requires additional debt or equity financing to meet operating cash flow requirements. The company expects to grow revenues over time, contingent on accelerating pipeline development, fulfilling orders, increasing production capacity, and reducing manufacturing and warranty costs. The full impact of the IRA and OBBB on operations remains uncertain, but the company generally expects to benefit from domestic manufacturing incentives and plans to sell tax credits to third-party buyers. Future growth depends on successfully expanding into new geographic markets and product lines, potentially through strategic partnerships, joint ventures, and licensing arrangements.

Management Comments

• "We believe our business model is positioned for scalability due to the ability to leverage the same core technology in the Energy Base's modularized form for different project size and duration needs across our customer base."
• "We anticipate significant reduction in our cost of goods through our cost reduction initiatives, including design optimization from value engineering, strategic supply chain projects, and further automation of our manufacturing processes."
• "We expect our indirect cost of revenue and operating expenses to increase when we ramp up our manufacturing and sales activities."
• "We believe our unique technology provides a compelling value proposition and an opportunity for favorable margins and unit economics in the energy storage industry in the future."
• "We are closely monitoring macroeconomic developments... and how they may adversely impact our and our customers, contractors, suppliers and partners respective businesses."
• "We are continuing to evaluate the overall impact and applicability of the IRA and OBBB as guidance is issued and further legislative changes are enacted... to our results of operations going forward."
• "We generally expect to sell these credits to third party buyers, which will have a positive impact on our gross margins in the future."
• "Despite the cost reductions and cash conservation measures, we will need additional debt or equity financing in order to meet our near-term operating cash flow requirements, and accordingly substantial doubt exists as to our ability to continue as a going concern for 12 months from the issuance of the consolidated financial statements."

Industry Context

StockSavvy.ai notes that ESS Tech operates in a rapidly evolving and highly competitive long-duration energy storage market, driven by global decarbonization efforts and increasing demand for grid stability. While the company's iron flow battery technology offers distinct advantages like non-flammability, wide temperature tolerance, and environmental sustainability compared to dominant lithium-ion solutions, its early commercialization stage and significant financial losses highlight the challenges of scaling innovative technologies against established players like Contemporary Amperex Technology Co. Limited and Tesla, Inc. The regulatory landscape, particularly U.S. tax incentives from the IRA, provides tailwinds, but the complexity introduced by FEOC rules and the company's ongoing need for substantial capital underscore the high-risk, high-reward nature of this sector.

Comparison to Industry Standards

• ESS Tech's iron flow batteries are designed for 20,000 cycles without capacity fade, which compares favorably to typical lithium-ion battery cycle life, often ranging from 3,000 to 10,000 cycles depending on depth of discharge and chemistry.
• The company expects its batteries to be less expensive than lithium-ion alternatives for storage durations greater than eight hours on a lifetime levelized cost of storage (LCOS) basis, a key differentiator against competitors like LG Chem, Ltd. and Samsung Electronics Co., Ltd.
• ESS Tech's non-flammable technology and wide operating temperature range (-15C to 50C) allow for deployment in sites where lithium-ion batteries, which require more extensive fire suppression and HVAC, cannot be placed, offering a competitive advantage over traditional solutions from companies like Tesla, Inc.
• The company's focus on earth-abundant materials contrasts with the reliance of many competitors, including those in the lithium-ion space, on rare earth metals, positioning ESS Tech as a more environmentally sustainable option.
• Despite these technological advantages, ESS Tech's early commercialization stage and limited deployment of products (e.g., Energy Warehouse and Energy Center) mean it lacks the extensive field-proven track record and market acceptance of larger, more established competitors like Contemporary Amperex Technology Co. Limited.

Management Changes

Corporate Governance

Legal Proceedings

• The company is not currently a party to any material legal proceedings, nor is any material legal proceeding threatened against it.

Related Party Transactions

• Recognized $2.4 million in revenue from related parties in 2025 for sales of energy storage systems, core technology components, reimbursable expenses, and extended warranty services.
• Recorded deferred revenue of $194 thousand for sales of extended warranty services and equipment purchases to related parties as of December 31, 2025.
• Recorded a non-refundable deposit for future equipment purchases by Honeywell (a related party) of $5.3 million as of December 31, 2025.
• Entered into a Sale and Leaseback Agreement with UOP (an affiliate of Honeywell) on July 10, 2025, where UOP purchased the stack assembly line for $10.5 million and leased it back to the company.
• Agreed to reimburse UOP a minimum of $8.0 million for research and development expenses incurred through December 31, 2028, under a Joint Development Agreement.
• Had a framework agreement with SBE (an affiliate of SoftBank Group Corp.) to supply energy storage products, but SBE is under no obligation to place firm orders, and no orders have been placed to date.
• Had a strategic partnership with Energy Storage Industries Asia Pacific (ESI) and delivered systems through early 2025, but agreed to move forward separately in late 2025.
• Delivered systems to Sacramento Municipal Utility District (SMUD) in Q2 2023, but the task authorization expired on December 31, 2024, and future orders are not obligated.

Stakeholder Impact

• Shareholders face significant dilution risk from ongoing equity raises (ATM, SEPA, RDO) and warrant exercises. The substantial doubt about going concern and NYSE delisting risk could lead to a loss of investment. Anti-takeover provisions in corporate governance may limit opportunities for premium acquisition.
• Employees experienced a furlough for a substantial number of employees as part of cost reduction, potentially impacting morale, productivity, and retention. Management changes (new CEO) could bring strategic shifts.
• Customers may experience delays in product delivery due to supply chain issues and site integration problems. Quality issues with earlier generation products and potential future failures could affect confidence. Benefits from government tax incentives (IRA) are subject to new FEOC rules and guidance.
• Suppliers face risks from potential supply chain disruptions and inconsistent quality requirements. Low volume requirements in the near term could strain relationships or result in less favorable pricing.
• Creditors: The company's significant debt obligations (e.g., Promissory Note with Yorkville, Credit Agreement with EXIM) and going concern doubt pose risks to repayment. The high effective interest rate on the Promissory Note indicates high perceived risk.

Next Steps

• Obtain additional debt or equity financing to fund operations and address going concern issues.
• Continue to execute the plan to expand the business, including accelerating pipeline development and fulfilling orders.
• Increase production capacity at the Wilsonville facility to 1.05 GWh annually and eventually to 2.0 GWh.
• Continue cost reduction initiatives, including design optimization, strategic supply chain projects, and further manufacturing automation.
• Expand into new geographic markets and product lines, potentially through strategic partnerships, joint ventures, and licensing arrangements.
• Monitor and comply with NYSE listing requirements to avoid delisting.
• Continue research and development activities to expand the product roadmap and explore alternate chemistries.
• Evaluate the overall impact and applicability of the IRA and OBBB, including FEOC guidance, on business and operations.
• Sell Section 45X Production Tax Credits to third-party buyers to positively impact gross margins.
• Successfully recruit and integrate new leadership team members.

Key Dates

Recommendation

The filing presents a dire financial situation for ESS Tech, Inc. The company explicitly states 'substantial doubt' about its ability to continue as a going concern, a critical red flag for investors. Revenue plummeted by 75% year-over-year, and despite cost-cutting, net losses remain significant. The company is actively engaged in multiple capital raises, indicating a desperate need for funds, which will lead to substantial dilution for existing shareholders. Furthermore, the company has failed to meet NYSE listing standards, with its market capitalization falling below $15 million, signaling a high risk of delisting. While the technology has potential, the current financial instability, operational challenges, and the high effective interest rate on recent debt make the stock a 'strong sell' as the risk of total capital loss is extremely high.

Keywords

Iron Flow Battery, Energy Storage, Long-Duration Storage, Renewable Energy, Grid Stabilization, SEC Filing, 10-K, ESS Tech, GWH, Battery Technology, Clean Energy, Sustainability, Corporate Governance, Financial Performance, Capital Raise, NYSE Listing, Risk Factors, Proton Pump, Energy Base, Warrants, Inflation Reduction Act, OBBB, Supply Chain, Cybersecurity