ESS Tech shares surge after Bridge sodium-ion launch
ESS Tech, Inc. shares rose significantly in after-hours trading after the company launched the ESS Bridge, a modular sodium-ion battery energy storage system designed for utilities and data centers. The system offers 1.2 MWh capacity per unit, scalable to 4.8 MWh, and features a 20-year design life with enhanced safety. Despite the product launch and over $1 billion in early-stage opportunities, the stock remains near its 52-week low of $0.57 with a negative price trend.

*this image is generated using AI for illustrative purposes only.
ESS Tech, Inc. (NYSE: GWH) shares soared 15.01% to $1 in after-hours trading on Tuesday, following the launch of its ESS Bridge modular sodium-ion battery energy storage system. In the regular session, the stock climbed 7.88% to $0.87. The rally comes as the company targets utilities, AI-driven data centers, and industrial customers with its non-lithium platform, which has generated more than $1 billion in early-stage customer opportunities since ESS Tech announced its entry into the sodium-ion market.
The Bridge system is a 1.2 MWh building-block AC battery unit housed in a 10-foot container. It combines advanced sodium-ion technology with system integration, controls, and energy management. The plug-and-play unit includes battery cells, modules, racking, power conversion, cabling, and battery management system hardware and software. These modular blocks are stackable, delivering up to 4.8 MWh of storage capacity in the same footprint as a traditional 20-foot battery container.
Technical Specifications and Features
The Bridge system is engineered to eliminate the risk of fire from thermal runaway and requires no complex HVAC or liquid cooling systems. It operates with simple air cooling and can function in environments ranging from -40° C to 50° C with a 20-year operating design life. The system supports a wide range of charge and discharge profiles, from 1 to 16 hours or more depending on configuration.
| Feature | Specification |
|---|---|
| Capacity | 1.2 MWh per unit |
| Scalability | Up to 4.8 MWh in 20-foot footprint |
| Operating Temperature | -40° C to 50° C |
| Design Life | 20 years |
| Cooling | Simple air cooling |
Strategic Market Position
Drew Buckley, CEO of ESS Tech, stated that the Bridge system is designed to meet the specific power needs of AI workloads and data centers more effectively than conventional technologies. The platform leverages abundant materials to support an alternative supply chain, reducing exposure to constrained critical minerals and geopolitical sourcing risks. This approach helps customers manage exposure to Foreign Entities of Concern (FEOC) while supporting the development of a domestic energy storage supply chain.
Randall Selesky, Chief Commercial Officer of ESS Tech, emphasized that asset owners are seeking solutions that improve safety, simplify operations, and provide flexibility. The Bridge platform is positioned to deliver these benefits across commercial and utility-scale applications.
Financial Metrics and Trading Data
ESS Tech has a market capitalization of $25.43 million. The stock has a 52-week high of $13.87 and a 52-week low of $0.57. Over the past 12 months, GWH has dropped 32.07%. The stock currently has a Relative Strength Index (RSI) of 50.40 and is trading close to its annual low. Benzinga’s Edge Stock Rankings indicate GWH stock has a negative price trend across all time frames.
What is the timeline for converting the $1 billion in early-stage opportunities into firm, binding contracts?
How will ESS Tech secure the necessary capital to scale production given its current market capitalization of $25.43 million?
What are the specific cost comparisons between the Bridge system and traditional lithium-ion solutions for long-duration storage?




























