‘Safer’ and ‘longer-lasting’ sodium battery on its way to households

• The Na+Casa battery is made out of sodium, which makes it more eco-friendly than lithium-ion batteries
• It marks a “major step in bringing safe, reliable, affordable, and lithium-free battery storage” to Europe
• It’s 9.25kWh capacity makes it competitive with lithium-ion batteries

There could soon be a new lithium-free home storage battery on the market for households in the UK and Europe after US company UNIGRID announced the release of Na+Casa, a sodium-ion residential energy storage system (RESS).

The new RESS can work in temperatures from -40C to 60C and keep systems working in volatile weather and has a lifespan of more than 30,000 cycles.

This means it can last as long as the average solar panel system of 25 years and can be “part of a home’s long-term energy infrastructure” instead of “a short-term add on”.

The Na+Casa battery is made out of sodium, not lithium as most batteries are. This is positive for the eco-friendliness of the storage battery’s supply chain because sodium is much more common and easier to extract than lithium, cobalt, nickel, which are often sourced to build batteries.

It has a 9.25kWh capacity, the average capacity of a small or medium-sized lithium-ion battery being anywhere from 5kWh to 13kWh, meaning it stands up well against conventional systems as well as being more eco-friendly.

Darren H. S. Tan, CEO and co-founder of UNIGRID, said rising energy bills shows that homeowners need storage that is “safe, reliable, and financially sound”.

“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,” Tan said.

The company, based in San Diego, said that the Na+Casa battery had already been installed in some homes in Europe. It didn’t reveal a price, but it has said that it will be “competitive” with lithium-ion batteries. The average solar storage battery costs around £5,000.

Written By

Maximilian Schwerdtfeger Deputy editor

Max joined The Eco Experts as content manager in February 2024 and became deputy editor in 2025. He has written about sustainability issues across numerous industries, including maritime, supply chain, finance, mining, and retail. He has also written extensively for consumer titles like City AM, The Morning Star, and The Daily Express.

He has represented The Eco Experts on national television several times, including the BBC’s Sunday Morning Live and ITV Tonight .

In 2020, he covered in detail the International Maritime Organisation’s (IMO) legislation on sulphur emissions and its effects on the global container shipping market as online editor of Port Technology International.

He also explored the initiatives major container ports and terminals have launched in order to ship vital goods across the world without polluting the environment.

Since then, he has reported heavily on the impact made by environmental, social, and governance (ESG) practices on the supply chain of minerals, with a particular focus on rare earth mining in Africa.

As part of this, in 2022 Max visited mines and ports in Angola to hone in on the challenges being faced by one of the world’s biggest producers of rare earth minerals.

His most recent sustainability-related work came much closer to home, as he investigated the eco-challenges faced by independent retailers in the UK, specifically looking at how they can cut emissions and continue to thrive.

Max lives in South London and is an avid reader of books on modern history. He has also recently learned to play the game Mahjong and takes every opportunity to do so. He is also yet to find a sport he doesn’t enjoy watching.

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