October 6, 2025: Peak Energy has announced the startup of a sodium ion-based demonstration BESS in the US.

Peak said on September 25 that the passively cooled 3.1MWh NFPP — or sodium ferric pyrophosphate system — is now operating at the Solar Technology Acceleration Center (SolarTAC), operated in partnership with nine utilities and independent power producers.

Located near Denver International Airport, SolarTAC is a 74-acre facility that includes facilities for testing both photovoltaic and concentrated solar power technologies, including access to the grid.

First unveiled in July, the BESS will collect and distribute operational and modelling data from the real-world operation of the unit, ahead of the anticipated launch of commercial-scale projects starting in 2027.

Peak claims its proprietary design system eliminates active cooling, reduces moving parts, and extends battery life, cutting lifetime costs by more than $100 million for a typical project deployment.

The BESS also allows IPPs to deliver the fastest-to-market energy capacity solution with the lowest cost of ownership, Peak said.