Peak Energy announces operation of first large-scale sodium ion battery in US
Source：www.ess-news.com
Denver-based Peak Energy claims its sodium-ion battery system offers the lowest operating cost of any energy storage technology on the market today.
By Marija Maisch,Sep 26, 2025
Peak Energy, a U.S.-based company developing low-cost, giga-scale energy storage technology for the grid, today announced the deployment and operation of its passively cooled sodium-ion storage system at SolarTAC in Colorado. | Image: Peak Energy
Peak Energy announced on Friday the successful deployment and operation of the first grid-scale sodium-ion battery system in the US.
First unveiled in July, Peak Energy’s 3.5 MWh sodium-ion storage system is now operating at solar and renewable energy test facility SolarTAC in Watkins, Colorado. The grid-ready installation is being run in collaboration with nine utilities and independent power producers (IPPs), making it the largest sodium-ion energy storage deployment of its kind in the country.
Peak Energy will collect and distribute operational and modeling data from the real-world operation of its system to the project’s participants. The company expects to launch commercial-scale projects starting in 2027.
According to the company, its passively cooled sodium-ion system delievrs significant economi advantages: a 20% reduction in lifetime cost and a 33% lower degradation over 20 years – translating to more than $100 million in potential savings over a project’s lifetime. The company positions its technology as a cost-effective alternative amid projections that U.S. household energy bills could rise by up to 18% in the coming years, driven largely by increased demand and transmission infrastructure costs.
“Storage is critical to solving America’s dual energy crises of affordability and availability,” said Landon Mossburg, CEO and co-founder of Peak Energy. “With the lowest operating cost of any storage system in the market today, Peak Energy is proud to have developed a ready-to-deploy answer to energy affordability.”
In an interview with ESS News earlier this year, Cameron Dales, the president and CCO at Peak Energy said: “If you look at the total cost of ownership over 20 years, these passive system innovations… allow us to deliver savings of up to $75/kWh on a net present value basis. That’s more than the cost of the cells themselves.”
Peak Energy emerged from stealth in 2023 with a $10 million seed round, followed by a $55 million Series A funding round in 2024 to scale production of grid-scale sodium-ion batteries. The company aims to break ground on its first domestic giga-scale manufacturing facility in 2027.
These bold ambitions mirror those of California-based startup Natron Energy, which had announced plans to invest nearly $1.4 billion in a sodium-ion battery gigafactory in North Carolina – but ultimately disclosed it would cease all operations effective September 3.
Peak Energy’s latest announcement follows the launch of Europe’s largest sodium-ion installation earlier this week, as Switzerland’s Phenogy commissioned a nearly 1 MWh system at a commercial site near Bremen Airport in northern Germany. Backed by ambitions to establish vertically integrated local manufacturing, Phenogy marked its formal entry into the European energy storage market.
Despite growing interest, sodium-ion technology still faces several hurdles before reaching mass-market viability. While it is widely viewed as a cheaper and more sustainable alternative to lithium-based chemistries – due to the abundance and low extraction cost of sodium – sodium-ion still trails lithium iron phosphate (LFP) in cost-efficiency and performance, particularly as LFP prices continue to fall.
While the US and Europe are beginning to pilot single-digit MWh-scale deployments, China remains the global leader in both technological development and deployment. Companies such as CATL, BYD, and Huawei are driving innovation, with 100 MW-scale sodium-ion projects already operational. Some of these also incorporate hybrid systems that blend sodium-ion with lithium-ion chemistries, alongside grid-forming inverter integration for enhanced flexibility.