The Golden State could soon become home to one of the largest non-flammable sodium-ion battery storage systems, after two US companies announced plans to deploy a 500 megawatt-hour (MWh) project in the Mojave Desert.

Alsym Energy, a Massachusetts-based battery manufacturer, and Juniper Energy, a renewable energy developer based in California, signed a strategic partnership to deploy 500 MWh of high-performance Battery Energy Storage Systems (BESS) across the state.

The initiative will predominantly focus on regions with extreme heat conditions, such as the Mojave Desert. The 54,000-square-mile arid region stretches across southeastern California and southern Nevada, with smaller portions extending into Arizona and Utah.

Known for its extreme temperatures, the area often forces traditional lithium-ion batteries to rely on costly HVAC cooling systems to operate safely. The two firms noted that the system’s deployment cut fire risks, simplify operations, and lower long-term costs for renewable energy projects.

A lithium-free energy future

Alsym’s Na-Series technology eliminates thermal runaway, which is a dangerous chain reaction, where rising temperatures can trigger fires or explosions. It is one of lithium-ion batteries’ primary risks. Instead, the company’s design relies on passive cooling, which significantly reduces energy consumption and costs.

“After several years of evaluating the non-lithium landscape, it became clear that sodium-ion – and specifically Alsym’s Na-Series – is the premier solution for the next generation of California’s grid,” Keith McDaniels, Juniper Energy’s founder and managing partner, said.

Meanwhile, California is significantly expanding solar and renewable power. The state added a record 7,000 megawatts (MW) of clean energy in 2024. It is further targeting 100 percent clean energy by 2045.

This is why utilities are increasingly seeking energy storage systems that can run for long periods in harsh climates. Because of this, the partnership will focus on deploying sodium-ion batteries in regions where high ambient temperatures can strain lithium-ion systems.

“Alsym’s ability to provide a safe, US-produced battery allows us to maximize tax credits and improve project IRRs while providing our off-takers with a more flexible, reliable, and cost-effective storage asset,” McDaniels continued.

Safer battery storage

According to Alsym, the batteries support high charge and discharge rates. This, in turn, enables multiple cycles daily for applications such as solar shifting and frequency regulation. They can also charge in approximately 30 minutes.

The technology was developed using a proprietary, physics-informed AI platform. It enables the discovery of commercially viable chemistries that are up to 10 times faster than traditional trial-and-error methods. The batteries are built with earth-abundant materials, and are designed for large-scale energy storage applications, like utility grids, data centers, industrial facilities and even military installations.

Mukesh Chatter, Alsym Energy CEO and co-founder, praised Juniper Energy for recognizing lithium’s challenges in extreme heat. “Our Na-Series technology was built for exactly this: providing high-performance, fast-charging storage that doesn’t require complex cooling or risk community safety,” Chatter explained.

The initial phase of the collaboration will focus on multi-megawatt deployments across California. However, the companies said their longer-term goal is to scale sodium-ion battery systems across Juniper Energy’s entire development pipeline. “By manufacturing here in the US, we are ensuring that partners like Juniper can deploy projects faster and more profitably,” Chatter concluded in a press release.