Sodium-ion batteries have been making headlines for years as a cheaper, safer alternative to lithium-ion. But until this month, most of those stories were about lab breakthroughs and pilot projects. That changed in July 2026: two companies — California-based UNIGRID and German startup Revolta — have started shipping residential sodium-ion storage systems to real homes, marking the technology's first serious push into the home energy market.
Global demand for home battery storage is accelerating fast. The IEA's Global EV Outlook 2026 projects battery storage deployments will need to grow sixfold by 2030 to meet clean energy targets, and residential systems make up a growing share of that. Most homes today pair storage with rooftop solar, using the battery to absorb midday generation and discharge it during evening peaks when grid electricity is most expensive. Sodium-ion's long cycle life and wide temperature tolerance make it a natural fit for that use case — provided the economics pencil out at scale.
Why Sodium-Ion Matters for Home Energy
Lithium-ion batteries have dominated residential energy storage for over a decade. The Tesla Powerwall, LG Chem RESU, and Enphase IQ Battery all run on lithium chemistry. But lithium carries baggage: prices swing with global supply chains, the raw materials are concentrated in a handful of countries, and thermal runaway — the chain reaction that causes battery fires — remains a concern even in well-engineered systems.
Sodium-ion sidesteps most of that. Sodium is the sixth-most-abundant element on Earth. It's found in seawater and rock salt, available everywhere, and cheap to extract. There's no cobalt, no nickel, and no lithium in the cathode. That means sodium-ion batteries don't depend on the same geopolitically sensitive supply chains that lithium batteries do.
The tradeoff has always been energy density. Sodium ions are larger and heavier than lithium ions, so sodium-ion cells store less energy per kilogram than comparable lithium cells. For electric vehicles, where every kilogram matters, that's a real problem. But for stationary home storage, where a battery sits on a garage wall or in a basement, weight and size matter much less.
UNIGRID's Na+Casa: First Commercial Shipments Land in Europe
UNIGRID, a sodium-ion battery startup based in San Diego, announced on July 8 that it had shipped the first units of its Na+Casa residential energy storage system to homes across Europe. The company says installations are already complete in several European countries, with US availability expected by the end of 2026 after North American certification is finalized.
The Na+Casa system stores 9.25 kilowatt-hours (kWh) of usable electricity — enough to power a typical European home for several hours during an evening peak or overnight. Each battery weighs 240 pounds and measures 18.8 inches wide by 34.1 inches tall by 10.6 inches deep, designed for wall mounting or optional wheeled stands.
UNIGRID says the battery uses its proprietary sodium chromium oxide (NCO) cathode chemistry, which delivers an operational lifespan of 10,000 charge-discharge cycles at 100% depth of discharge. That works out to more than 27 years of daily cycling — roughly the lifespan of a rooftop solar system. Some of the company's commercial products promise over 30,000 cycles.
The company also highlights safety as a differentiator. Unlike lithium-ion cells, which can enter thermal runaway if damaged or overcharged, UNIGRID says its NCO chemistry eliminates the risk of thermal propagation entirely. That means a single failed cell won't cascade into a battery-wide fire.
Price is positioned as competitive with lithium-ion systems today. Darren H. S. Tan, CEO and co-founder of UNIGRID, said in a statement: "With Na+Casa, UNIGRID is moving NCO sodium-ion from just a promising technology to a tangible residential storage product, giving installers and integrators a lucrative alternative to lithium-ion."
The battery operates in temperatures from -40°F to 140°F (-40°C to 60°C), making it suitable for outdoor and unconditioned indoor installations across most climates. It connects to standard hybrid inverters, simplifying retrofits into existing solar setups.
UNIGRID's current production capacity is 200 MWh per year, but the company plans to scale to 2 GWh annually in 2027 through manufacturing partnerships in China, South Korea, and Japan. Tan has also floated a leasing model — zero-money-down installations where UNIGRID retains ownership of the battery and shares the savings with homeowners — a structure the company plans to pilot in California later this year.
Revolta Brings High-Voltage Modular Sodium-Ion to Germany
A week and a half later, on July 24, German startup Revolta announced its own entry into the residential sodium-ion market. The company's high-voltage battery storage system uses a modular architecture: each module stores 2.0 kWh, and up to 10 modules can be connected in parallel for a total capacity of 20 kWh.
Each module measures 284 mm by 186 mm by 260 mm and weighs 19 kilograms. The system runs at a nominal voltage of 450 V DC — high-voltage architecture that pairs efficiently with modern hybrid inverters. Revolta claims efficiency above 95%, an energy density of 105 Wh/kg, and an IP65 protection rating that makes the system dust-tight and resistant to water jets.
One standout claim: Revolta says the battery can remain in standby for more than a year without needing a recharge. Standby losses are described as very low, and noise emissions are specified at below 40 decibels — quieter than a library.
Installation follows a "plug-and-play over-the-air" process managed through Revolta's smartphone app or Bluetooth connection. The company said commissioning can be completed without a technician, although it's targeting the traditional three-tier distribution model — wholesalers to installers to end customers.
Revolta presented the system at The smarter E trade fair in Munich and says the official market launch is scheduled for September 2026, with several pilot projects already planned. The company is receiving daily inquiries from end customers and is in initial discussions with distributors. It plans to focus on the German market first, with expansion into other European countries to follow.
"The system configuration can be freely adapted to scale according to individual requirements," a Revolta spokesperson told pv magazine. As a high-voltage system connected directly to the inverter rather than the grid, there are no major technical obstacles to entering additional European markets.
The Bigger Picture: Sodium-Ion Residential Storage in 2026
UNIGRID and Revolta are not the only players entering the sodium-ion home storage space. Eleven Energy, Biwatt, and Lithium Valley have also launched residential sodium-ion systems, and at least two of them — Biwatt and Lithium Valley — have obtained the UL certifications needed for US market sales.
The timing makes sense. Residential energy storage is growing fast as homeowners pair batteries with rooftop solar to hedge against rising electricity rates and grid instability. Most of those systems still use lithium-ion, but sodium-ion offers a longer lifespan and a simpler supply chain. The 25-year-plus cycle life means a sodium-ion battery installed today could last through the entire life of a solar system, eliminating the need for a mid-life replacement.
There are caveats. Energy density is lower, so a sodium-ion battery that delivers the same usable capacity as a lithium-ion equivalent will be physically larger and heavier. And while UNIGRID and Revolta claim competitive pricing, the real-world cost per kilowatt-hour for sodium-ion at residential scale hasn't been tested at volume yet. The first production batches from both companies are small — UNIGRID's 200 MWh annual capacity is a fraction of what Tesla or LG can produce.
Still, the direction is clear. Sodium-ion has moved from the lab to the warehouse to the garage wall in a matter of months. If UNIGRID's 2 GWh production target for 2027 materializes and Revolta's distribution network comes together, sodium-ion could capture a meaningful slice of the residential storage market within two years.
For homeowners considering solar-plus-storage, that competition is good news. More chemistries in the market mean more choice, more price competition, and more pressure on lithium-ion manufacturers to keep improving. The home battery market has been effectively a lithium-ion monopoly for a decade. That monopoly is ending.
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