ESS Tech has signed a Letter of Intent (LoI) with Juniper Energy to deploy 500 MWh or more of sodium-ion battery energy storage systems, marking a significant expansion of its business. The agreement establishes a framework for a long-term partnership focused on deploying ESS's sodium-based battery solutions across multiple projects in the coming years.

As part of the agreement, the companies plan to collaborate on an initial 10 MW / 80 MWh energy storage project located in California. This project is expected to utilize ESS's recently announced modular sodium-ion AC solution, Bridge™, along with an ESS Energy Management System (EMS). The commercial operation for this initial project is targeted for 2027.

Project Details

The LoI outlines a strategic roadmap for the deployment of energy storage systems, beginning with the California project. The following table summarizes the key specifications of the initial phase:

Strategic Implications

The partnership with Juniper Energy represents a major milestone for ESS as it continues to scale its operations. The LoI provides a structured approach to deploying ESS's innovative battery solutions, starting with the specific project in California and expanding to a broader portfolio totaling at least 500 MWh.

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.

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.