en.Wedoany.com Reported - US sodium-ion battery developer Unigrid has launched its first residential energy storage system, Na+Casa, which has already completed its initial installations in multi-family homes across Europe.
The system utilizes battery cells based on Unigrid's proprietary sodium chromium oxide (NaCrO₂, abbreviated as NCO) cathode technology. The company claims that this chemistry not only enables a long service life but also mitigates the fire risks associated with traditional lithium-ion batteries.
The Na+Casa battery is rated for 10,000 cycles at 100% depth of discharge, equivalent to over 27 years of operation with one cycle per day. Some of Unigrid's commercial battery products have already exceeded 30,000 rated cycles. The system's wide operating temperature range is also highlighted: the battery can be charged between -20°C and 60°C and discharged between -40°C and 60°C.
Unigrid CEO Darren H. S. Tan stated that as residential energy bills continue to rise, especially against the backdrop of frequent extreme weather events, homeowners need safe, reliable, and affordable energy storage solutions. With Na+Casa, the company has transformed NCO sodium-ion technology from the lab into a residential product, offering installers and integrators an alternative to lithium-ion.
The Na+Casa battery module supports wall-mounted installation or optional wheels. A single battery weighs 108.9 kg, with dimensions of 477 mm × 869 mm × 269 mm, usable energy of 9.25 kWh, a rated voltage of 46.4 V, and a standard charge/discharge current of 50 A. According to the company, the system can also withstand discharge pulses of up to 200 A.
These batteries have already obtained UN 38.3 transport certification. Unigrid stated that it expects to complete CE marking as well as UL 9540 and UL 1973 certifications in the near future. The Na+Casa system is compatible with most hybrid inverters on the market, designed to simplify residential solar retrofits while remaining cost-competitive with lithium-ion energy storage products. The company plans to launch the product in the US market by the end of 2026.
Na+Casa enters an increasingly saturated global sodium-ion residential energy storage market. Other players in this space include Eleven Energy, Biwatt, and Lithium Valley, the latter two having already obtained the UL certifications required for sale in the US.
Unigrid previously set a target of achieving an annual production capacity of 1 GWh of battery cells by 2026. Tan has also been promoting the technology's long-life characteristics, arguing that it is well-suited for third-party ownership and leasing models. The company plans to test this business model in a commercial energy storage project in California later this year, with the residential product complementing its larger commercial battery systems.
In an interview with pv magazine USA, Tan explained that this long-term asset will be offered with zero down payment, allowing the company and users to benefit monthly together, rather than requiring users to invest a large sum upfront and hoping the equipment lasts 25 years. He stated that this approach shifts the risk away from the user.
