Lithium-ion has long dominated home battery storage, but sodium-ion is starting to make its move. Sodium-ion battery startup UNIGRID has shipped the first units of its Na+Casa residential battery, with the first systems now installed in homes across Europe.
The California-based company says US installations are expected by the end of 2026, pending North American certification requirements for sodium-ion batteries.
Home battery storage is becoming more popular as homeowners pair batteries with rooftop solar for backup power, lower electricity bills, and more energy independence. Most of those home systems use lithium-ion batteries, but companies like UNIGRID are betting that sodium-ion can offer a safer, longer-lasting alternative while avoiding the supply chain challenges that come with lithium, cobalt, and nickel.
UNIGRID says its Na+Casa battery is designed to last 25 years – roughly the lifespan of a rooftop solar system. If it performs as promised, that could eliminate the need to replace the battery halfway through the life of a solar installation.
The company also says the battery’s sodium-ion chemistry eliminates the risk of thermal propagation, the chain reaction that allows battery fires to spread from cell to cell. While modern lithium-ion home batteries already include multiple layers of safety protection, reducing fire risk remains a major focus for battery developers.
