What is a sodium-ion battery, and why is everyone talking about it?

A new type of home battery is getting attention as an alternative to the lithium batteries typically paired with solar panels: sodium-ion. Sodium is cheap and abundant, and these batteries are not flammable or explosive, so they don't need the heating, cooling, and fire-safety equipment that lithium battery systems require. That could make them cheaper and more compact. They also can be drained fully to zero without damage and work across a wide range of temperatures.

There are a few sodium battery types. One version, called NFPP, is the one most likely to matter for home use — it's the safest and longest-lasting of the sodium options, though it stores somewhat less energy for its size than the lithium batteries (LFP) commonly used in home storage today. Companies working on this technology include Alsym, Peak Energy, and Unigrid, the last of which is specifically targeting homeowners with sodium batteries meant to compete with lithium home storage.

None of these products are widely available for homes yet. Most manufacturing is still happening in China, though a few U.S. companies are building or planning American factories, with one large facility expected to open in Sacramento in 2027. If sodium batteries do reach the residential market in the next few years, they could offer homeowners a cheaper, safer storage option to pair with solar — but for now, this is still an emerging technology to watch rather than something you can install today.