Sparks of 2026 #3: Eleven Energy and Sodium Batteries
Eleven Energy: The Sodium-Ion Salt Battery That Could Rewrite UK Retrofit Storage
Batteries are very much the 2nd child of the energy industry. So it's interesting to have a solution that feels like it's a candidate for prime position in our race to decarbonise - and sodium batteries are definitely arriving.
The most interesting challenger so far is the new salt battery from Eleven Energy, a Cambridge-based start-up already turning heads thanks to a feature on Artisan Electrics and a rapidly building installer buzz.
Eleven Energy confirmed to Refurb and Retrofit that they expect to sell around 1,000 units in 2026.
Quietly, I think that figure is conservative.
Every installer I’ve spoken to is looking for batteries that are safer, simpler to site and less volatile on price. Sodium-ion lands exactly in that sweet spot.
Even in spite of the problems with batteries cause by the DESNZ freeze, the Eleven Energy units are flying out the door.
Right now, all UK imports and installs are being handled through Midsomer Energy, the wholesaler that has carved out an early exclusive relationship. Eleven Energy say they are preparing warranty structures and aftercare pathways that match or exceed lithium norms. For a new chemistry, that matters.
What makes this product a standout for 2026
- Sodium-ion chemistry removes the cobalt, nickel and mining-heavy materials that dominate lithium systems
- Outdoor-rated performance without requiring complex thermal management
- Lower fire risk profile and inherently stable electrochemistry
- Competitive price point expected to drop with scale
- Perfectly aligned with UK retrofit realities where internal battery space is limited
At EfiXX they did a verbal knockabout to debate the power of Sodium batteries
CEO insight
Here is the statement Eleven Energy provided when we contacted them for our Christmas Countdown review:
“Most UK homes weren’t designed with battery storage in mind, so retrofit solutions must be robust, safe and easy to install. That’s why we’re bringing sodium-ion to the market, a chemistry that performs reliably outdoors and uses abundant, low-impact materials. Our aim is to make retrofit battery installations simpler, safer and more sustainable for both installers and homeowners.”
Yichen Shi PhD, CEO
This is exactly the kind of pragmatic innovation that fits the moment. Simple to install. Safer by design. Transparent about materials. Not trying to win a spec-sheet war, just trying to fix a retrofit bottleneck.
And crucially, it gives installers another option in a market that has been crying out for them.
If sodium-ion is going to break through in 2026, this might well be the battery that does it.
Remember the only place you can get this battery is here;
Midsummer Wholesale
Todays article was sponsored by Becker and Wolf
Becker & Wolf specializes in cutting-edge technology solutions. Their range of all-in-one heat pumps provides a simpler and more efficient alternative to traditional split units. With everything in one unit, installation is quicker and cost-effective. Perfect for properties where exterior modifications are limited.