Peak Energy to Deploy MISO's First Low-Cost Sodium-Ion Grid Storage Battery

Got story updates? Submit your updates here. ›

Peak Energy, a U.S. company developing low-cost, large-scale energy storage technology, has announced an agreement with RWE Americas to pilot Peak Energy's proprietary passively cooled sodium-ion grid storage battery technology. The pilot project will be deployed in Eastern Wisconsin at the RWE lab, making RWE Americas the first to bring this next-generation, capital-efficient energy storage solution to the grid.

Why it matters

Energy storage is crucial for providing reliable, on-demand energy. Peak Energy's innovations using sodium-ion batteries can dramatically reduce the cost of energy storage, helping to address the energy cost crisis in America. Deploying this technology in the MISO region, which is facing growing energy demand and limited storage capacity, could lead to significant system cost savings.

The details

Peak Energy's battery storage system is designed to maximize the stability and thermal advantages of sodium-ion technology. This eliminates the need for costly cooling systems, reduces maintenance, and lowers the overall lifetime cost of energy storage by an average of $70/kWh compared to conventional lithium-ion solutions. The pilot project with RWE Americas will deploy Peak Energy's GS1.1 system, which can reduce total storage system costs by more than 25% relative to lithium-ion.

• The pilot project will be deployed in Eastern Wisconsin at the RWE lab.
• The agreement between Peak Energy and RWE Americas was announced on March 12, 2026.

What they’re saying

What’s next

The pilot project with RWE Americas will be deployed in Eastern Wisconsin at the RWE lab, marking the first deployment of Peak Energy's sodium-ion grid storage battery technology.