Juniper Energy has entered a new strategic partnership with Alsym Energy to deploy 500 MWh of sodium-ion battery energy storage systems (BESS), mostly located in California, with plans to include deployments in the Mojave Desert.

High-temperature areas like the Mojave Desert impose higher cooling requirements on energy storage assets, and both partners consider sodium-ion technology a better technical fit than lithium-ion BESS. Alsym Energy, a US-based firm headquartered in Massachusetts, noted that its Na-Series sodium-ion chemistry is designed to avoid thermal runaway and operate efficiently with passive cooling instead of active cooling, which simplifies balance of plant requirements and reduces upfront capital costs.

Officially launched in October 2025, Alsym’s Na-Series is non-flammable, non-toxic, and uses materials not sourced from foreign entities of concern (FEOC), avoiding potential customs-related friction. Mukesh Chatter, CEO and co-founder of Alsym Energy, praised Juniper as a forward-thinking developer and emphasized that the Na-Series is built to provide high-performance, fast-charging storage without complex cooling or safety risks, while US manufacturing enables faster and more profitable project deployment.

Keith McDaniels, founder and managing partner of Juniper Energy, stated that sodium-ion technology is the premier solution for California’s grid. He added that Alsym’s US-based status allows Juniper to leverage clean energy tax credits, maximizing returns and providing off-takers with flexible, reliable, and cost-effective storage assets.

The Juniper-Alsym deal comes shortly after Alsym announced an 8.5 GWh partnership with ESS Tech, Inc. ESS Tech, historically focused on iron flow battery technology, has signed a letter of intent with Alsym to add 8.5 GWh of sodium-ion cells and modules to its portfolio.