US energy storage company ESS has launched a modular sodium-ion battery energy storage system aimed at utilities, data centers, critical infrastructure operators and commercial customers looking for an alternative to lithium-ion batteries.
Called Bridge, the battery system is designed to meet growing electricity demand from autonomous computing workloads while reducing dependence on critical minerals used in conventional lithium-ion batteries. The launch expands ESS’ portfolio of U.S.-made, non-lithium energy storage products across short-, medium- and long-duration applications.
The announcement comes weeks after ESS said it had generated more than $1 billion in early-stage customer opportunities following its entry into the sodium-ion battery market, highlighting rising interest in alternative battery chemistries for large-scale energy storage.
Bridge is built as a modular 1.2 MWh AC battery system housed inside a 10-foot container. Multiple units can be stacked to deliver up to 4.8 MWh of storage in the footprint of a conventional 20-foot battery container, allowing customers to increase capacity without requiring additional space.
Beyond lithium batteries
The company said Bridge combines sodium-ion battery cells with integrated power conversion, battery management software, cabling and an energy management system for plant-level monitoring and control. The plug-and-play design can be installed using a heavy-duty forklift and relies on simple air cooling instead of more complex liquid cooling systems.
Unlike lithium-ion batteries, the sodium-ion system is designed to eliminate the risk of thermal runaway, reducing fire hazards while lowering maintenance requirements and overall operating costs. It also supports charging and discharging durations ranging from one hour to more than 16 hours, depending on system configuration.
Engineered for harsh operating conditions, the battery is designed to function in temperatures ranging from -40°F to 122°F and has a projected operating life of 20 years, reducing the need for battery replacements over the lifetime of an installation.
“Bridge is how we meet the demand we’re already seeing,” said Drew Buckley, CEO of ESS. “AI workloads are reshaping what data centers need from energy storage, and sodium-ion handles those power needs more effectively than conventional technologies.”
Built for resilience
ESS said the system is built using abundant and widely available materials, helping reduce dependence on constrained critical minerals while supporting the development of a domestic supply chain for energy storage. The company also said the platform can help customers reduce exposure to Foreign Entities of Concern by relying on an alternative battery supply chain.
“Today’s battery asset owners are looking for solutions that improve upon the conventional model,” said Randall Selesky, Chief Commercial Officer at ESS. “They want systems that improve safety, simplify operations, provide flexibility and support long-term energy security objectives.”
The company believes demand for sodium-ion batteries will continue to grow as utilities and data center operators seek safer, longer-lasting storage systems capable of supporting expanding electricity consumption. With Bridge, ESS is positioning sodium-ion technology as a domestic alternative to conventional lithium-ion systems for grid-scale energy storage.