Add a battery to your existing solar panels
If your panels are sending most of their power to the grid while you buy it back in the evening, a battery fixes that. And yes, you can keep your Feed-in Tariff.
Why people add a battery
Your panels stay as they are
We don’t touch your existing array. The battery is added alongside it, so nothing on the roof changes.
Keep your old inverter, or swap it
If your inverter is working well, the battery can go in alongside it. If it’s getting on, we can replace it at the same time. Done properly, either way is fine for the Feed-in Tariff.
Use your own sunshine
Store what your panels make in the day and run the house on it in the evening.
Your Feed-in Tariff, kept safe
We agree the set-up with your FIT supplier before we start, so your FIT payments carry on. If we replace your inverter, we fit a new generation meter that counts only what your panels make.
Backup when the grid drops
Add a backup gateway and the house keeps running in a power cut.
Cheap overnight top-ups
In winter, charge the battery on a cheap night-time rate and avoid the expensive peak.
Keeping your Feed-in Tariff safe
Most older systems are on the Feed-in Tariff, and adding storage the wrong way can put those payments at risk. If the battery goes in alongside your existing inverter, your original array and its generation meter stay as they are. If we replace the inverter at the same time, we fit a new generation meter that counts in both directions, so you are only paid for what your panels make.
We handle the application to the local electricity network operator (the DNO) and notify your FIT supplier in line with Ofgem's guidance, so you don't have to.
What happens, start to finish
1Free survey
Send us a photo of your inverter and a recent bill, or we’ll come and look. We check what you have and how you use power.
2Your proposal
A battery sized to your evening use and your array, with honest figures and a fixed price. Your deposit is protected by IWA.
3Installation
We fit the battery, and a new inverter if yours needs replacing. Your panels stay as they are, and we fit a new generation meter where the set-up needs one.
4Handover
DNO paperwork done, your FIT supplier notified, the app on your phone and a proper walk-through.
Retrofit in Quorn
What was there
A 4 kWp solar array on the Feed-in Tariff, with its original inverter. The owner wanted to use more of that power at home in the evenings and make the most of dynamic battery tariffs, without putting the FIT payments at risk.
What we did
In September 2026 we replaced the original inverter with a new Sigenergy one and added an 18 kWh SigenStor battery in the garage. We agreed the set-up with the FIT supplier before we started, and swapped the generation meter for one that counts in both directions, so only the panels' own generation is paid for. We handled the DNO application too.
How it's doing
The numbers below come straight from the system's own app. The homeowner watches the same thing live on their phone.
see more of our work →Figures cover the system's first two weeks in the app, 18 September to 2 October 2026: 166 kWh generated and 133 kWh used. Winter will look different, with less sun and more overnight top-ups on a cheap rate. We'll update these figures here every quarter.
Nice things people have said
“Excellent work from Matt, he explained what needed to be done to fit an extra solar battery and all the work was carried out with a minimum of disruption. The system works brilliantly.”
Questions people ask us
Will adding a battery affect my Feed-in Tariff?
Not if it's done properly. We agree the set-up with your FIT supplier before we start. If the battery goes in beside your existing inverter, your generation meter stays as it is. If we replace the inverter, we fit a new generation meter that counts in both directions, so you are only paid for what your panels make, and we send your supplier the paperwork.
Does my old inverter need replacing?
Not always. If it's working well, the battery can work alongside it. If it's old or failing, we can replace it as part of the job, and that's fine for the Feed-in Tariff.
How big a battery do I need?
It depends on your evening usage and your array size. We look at your bills and generation data and size it to suit, not to the biggest box.
Can I add more batteries later?
Yes. With a modular battery, capacity can be added in steps.
Got panels? Let's have a look.
Send us a photo of your inverter and a recent bill, and we'll tell you honestly whether a battery makes sense.
★★★★★ 5.0 from over 120 Google reviews →