About
ESS Tech, Inc. (NYSE: GWH) is the leading manufacturer of long-duration iron flow energy storage (LDES) systems, founded in 2011 with a mission to accelerate global decarbonization safely and sustainably. Using abundant, non-toxic materials—iron, salt, and water—ESS's patented iron flow chemistry delivers scalable energy storage with up to 22 hours of capacity and zero capacity degradation across a 25-year design life with unlimited cycling. ESS's product portfolio includes the Energy Base™, Energy Center™, and Energy Warehouse®, offering flexible and rapidly deployable solutions available in months rather than years. These systems address a wide range of real-world applications: AI data centers facing a projected 165% electricity demand increase by 2030, utility-scale distributed energy resources (DER), green baseload energy, industrial microgrids, and transport electrification hubs. With 8 TW of long-duration storage needed globally by 2040, ESS positions itself as critical grid infrastructure. American-made and backed by major industry partners including Honeywell, ESS has earned recognition from Forbes, The New York Times, and S&P Global for its innovation. ESS is purpose-built for utilities, energy developers, data center operators, and industrial enterprises seeking a long-duration, cost-effective, and environmentally responsible alternative to lithium-based storage systems.
Key Features
- Iron Flow Chemistry: Uses iron, salt, and water as electrolyte materials for safe, non-toxic, and sustainable energy storage with unlimited charge-discharge cycling.
- Up to 22 Hours of Energy Storage: The Energy Base™ product line removes electrolyte volume constraints, enabling extended multi-hour storage to support baseload renewable energy dispatch.
- Zero Capacity Degradation Over 25 Years: Iron flow technology delivers consistent performance across a 25-year design life with no capacity loss, ensuring long-term ROI.
- Scalable & Rapidly Deployable Products: Multiple product lines (Energy Base™, Energy Center™, Energy Warehouse®) are American-made and deployable in months rather than years.
- AI Data Center & Grid Applications: Purpose-designed for high-demand applications including AI data centers, utility-scale DER, industrial microgrids, and transport electrification.
Use Cases
- Providing long-duration energy storage for AI data centers to ensure uninterrupted, reliable power amid projected 165% demand growth by 2030.
- Enabling utilities to capture excess renewable energy and dispatch it as stable baseload power during periods of low generation.
- Supporting industrial microgrids with resilient behind-the-meter storage to reduce outage risk and energy cost volatility.
- Helping energy developers meet utility-scale DER requirements with scalable, rapidly deployable iron flow storage systems.
- Electrifying transport infrastructure by delivering sustained, reliable energy storage at EV charging hubs, depots, and fleet facilities.
Pros
- Safe & Sustainable Materials: Iron flow chemistry uses abundant, non-toxic inputs—iron, salt, and water—eliminating fire risk and environmental concerns associated with lithium-based batteries.
- No Capacity Degradation: Unlimited cycling with zero degradation over 25 years ensures predictable, long-term energy output and strong return on capital investment.
- Industry-Leading Storage Duration: Up to 22 hours of storage far exceeds typical 4-hour lithium battery systems, enabling true renewable baseload power delivery.
- Strong Industry Validation: Backed by global partners like Honeywell and recognized by Forbes, The New York Times, and S&P Global as a leader in the long-duration storage category.
Cons
- Capital-Intensive Hardware Investment: As a physical infrastructure product, ESS systems require significant upfront capital, site preparation, permitting, and grid interconnection work.
- Maturing Deployment Ecosystem: Long-duration energy storage is still gaining commercial traction at scale, meaning financing models and installer ecosystems are still developing.
- Not a Software or Digital Tool: ESS products are physical energy storage systems requiring on-site installation and commissioning, unlike software-based infrastructure solutions.
Frequently Asked Questions
What is iron flow battery technology?
Iron flow batteries store energy in a liquid electrolyte solution composed of iron, salt, and water. Unlike lithium-ion batteries, they use abundant and non-toxic materials, support unlimited charge-discharge cycles, and maintain consistent capacity over decades without degradation.
How long can ESS systems store energy?
ESS's Energy Base™ product line supports up to 22 hours of continuous energy storage, making it suitable for overnight renewable dispatch, multi-period grid balancing, and sustained power delivery to AI data centers.
What applications are ESS products designed for?
ESS systems serve AI data centers, utility-scale distributed energy resources (DER), green baseload energy projects, industrial microgrids, and transport electrification hubs requiring resilient, long-duration storage.
How quickly can ESS systems be deployed?
ESS American-made solutions are engineered for rapid deployment, typically available in months rather than the multi-year lead times associated with competing large-scale storage technologies.
Is ESS a publicly traded company?
Yes, ESS Tech, Inc. trades on the New York Stock Exchange under the ticker symbol GWH.
