ESS Tech Evaluates Iron Flow Battery with Burbank Water and Power
ESS Tech highlighted the findings of a final report issued in connection with Burbank Water and Power for the American Public Power Association to evaluate the application of ESS' Iron Flow Battery technology in a real-world utility environment. The report, prepared under the APPA's Demonstration of Energy & Efficiency Developments program, documented the installation, operation, and evaluation of an ESS Energy Warehouse system. According to the report, the system was successfully installed, energized, and operated through the 21-month project evaluation period co-located with a solar resource, with Burbank Water and Power concluding that ESS' Iron Flow Battery technology works and there is a place for this battery in a utility's overall energy storage strategy. "This project provides another example of how ESS iron flow technology can perform in an operating utility environment," said Drew Buckley, Chief Executive Officer of ESS. "Third-party demonstration projects like this are important because they show how the technology performs in real-world utility applications. The project helps validate the underlying strengths of our core technology, which carry through to our next generation Energy Base product: long-duration performance, a safe and non-flammable chemistry based on iron, salt and water, and the value of a solution manufactured in America as utilities look for durable energy storage alternatives to lithium-ion." The Burbank Water and Power final report noted several attributes of the system and underlying chemistry, including the use of iron, salt, and water, non-flammable and sustainable, easily sourced components, domestic manufacturing, and a projected long operating life. The report also stated that utility personnel were successfully trained on operation and maintenance of the system and that the project supported broader education and engagement around iron flow battery technology.
Trade with 70% Backtested Accuracy
Analyst Views on GWH
About GWH
About the author

- Surge in Customer Demand: Following its letter of intent with Alsym Energy, ESS Tech has generated nearly $1 billion in early-stage customer opportunities for its U.S.-made sodium-ion battery energy storage system (BESS) within seven weeks, exceeding expectations and highlighting strong market demand for non-lithium battery solutions.
- Accelerated Technology Transition: The company is fast-tracking the development of its sodium-ion BESS platform to meet the increasing demand for safe, domestically sourced energy storage solutions, particularly in data centers and critical infrastructure, ensuring customers can avoid the fire risks associated with lithium batteries.
- Operational Optimization and Resource Reallocation: ESS will continue to develop its iron flow battery technology while streamlining operations in Wilsonville to reduce expenses and reallocate capital towards sodium-ion solutions, aiming for quicker revenue generation.
- Market Opportunities and Long-term Commitment: The company plans to announce sodium-ion containers, racks, and hardware solutions, along with digital software to optimize battery and system health, aiming to seize high-growth market opportunities while maintaining a commitment to long-term innovation.
- Financial Overview: Revenue for Q1 2026 was $128,000, down 78% from $599,000 in the prior year due to fewer customer equipment deliveries, indicating challenges in market demand for the company.
- Cost Control Success: Total operating expenses decreased by $3.3 million, or 33%, to $6.7 million, while net loss was $15.9 million and adjusted EBITDA loss was $10.3 million, reflecting some progress in cost management despite ongoing financial losses.
- Strategic Partnership: ESS signed a letter of intent with Alsym Energy to jointly develop next-generation battery solutions, marking the company's entry into the short- and medium-duration battery storage market, which significantly expands its market potential.
- Project New Horizon: The 5-megawatt/50-megawatt hour pilot project with Salt River Project and Google is expected to begin manufacturing in 2026, with delivery targeted for December 2027, indicating a long-term strategic positioning in the energy storage sector.
- Earnings Miss: ESS Tech reported a Q1 GAAP EPS of -$0.54, missing estimates by $0.25, indicating significant challenges in profitability that could undermine investor confidence.
- Revenue Decline: The company generated $0.13M in revenue, a staggering 78.3% year-over-year drop, falling short of expectations by $0.27M, reflecting weak market demand and inadequate sales strategies that may strain future cash flow.
- Stock Reaction: Following the earnings report, ESS Tech's shares fell by 8%, demonstrating a negative market reaction to the company's financial performance, which could impact its ability to secure financing and future investment plans.
- Future Outlook: Despite short-term challenges, ESS Tech is actively pursuing a $9.9M contract with the U.S. Air Force and a partnership with Google, aiming to ramp up energy infrastructure by 2027, showcasing the company's commitment to long-term growth.
- Successful Technology Validation: ESS's iron flow battery system was successfully installed and operated at Burbank Water and Power, demonstrating its effectiveness in a utility environment over a 21-month evaluation period, highlighting its strategic importance in energy storage solutions.
- Safety and Sustainability: The system utilizes iron, salt, and water, ensuring non-flammability and sustainability, which aligns with future energy safety standards while promoting American-made solutions, thereby enhancing market competitiveness.
- Training and Education: Utility personnel received successful training on the operation and maintenance of the system, and the project fostered broader education and engagement around iron flow battery technology, increasing industry awareness of long-duration energy storage solutions.
- Commercialization Momentum: ESS's collaborations with Salt River Project and the U.S. Air Force Research Laboratory demonstrate its commercial momentum in the long-duration energy storage market, further solidifying its strategic position in renewable energy integration and grid reliability.
- Strategic Partnership: ESS has signed a letter of intent with Alsym Energy to incorporate 8.5 GWh of sodium-ion cells and modules into its portfolio, marking its entry into the short- and medium-duration battery energy storage system market and significantly expanding its market reach.
- Technological Advantages: Alsym's sodium-ion batteries are non-flammable and thermally stable, reducing system complexity and total cost of ownership while eliminating the need for complex HVAC systems, thereby enhancing customer safety and economic viability.
- Market Potential: By combining sodium-ion and iron flow technologies, ESS is positioned to offer flexible energy storage solutions to utilities, independent power producers, and commercial customers, addressing the growing demand for renewable energy and driving comprehensive growth in the energy storage market.
- Sustainability Commitment: The integration of ESS's long-duration iron flow storage solutions with Alsym's high-performance sodium-ion technology underscores the company's commitment to advancing sustainable energy transitions, providing safe and economical alternatives that help customers move beyond the limitations of lithium-ion batteries.
- Conference Call Announcement: ESS Tech has announced a conference call scheduled for May 7, 2026, at 5:00 p.m. EDT to discuss its Q1 2026 financial results, with updates on commercial progress, customer deployments, and anticipated technology milestones expected to be shared.
- Executive Hosts: The call will be hosted by CEO Drew Buckley and CFO Kate Suhadolnik, followed by a Q&A session, enhancing interaction between investors and management, thereby increasing transparency and investor confidence.
- Webcast and Replay: The call will be available via webcast, with participants able to access presentation materials on the company's investor relations website, and a replay link will be provided to ensure that investors who cannot attend live can still obtain key information.
- Company Background: Founded in 2011, ESS Tech focuses on long-duration iron flow energy storage solutions, aiming to accelerate decarbonization through sustainable energy storage, utilizing easily sourced iron, salt, and water to build flexible storage solutions that meet increasing energy demands.







