The kit
You buy everything in your own name, fitted by any installer you like. We’ll help you get a good quote, check the spec before you commit, and set up the Brain - a small control unit that plugs into your inverter - once it’s in. Bring whatever battery you want: the Brain talks to the inverter, so it just needs one we support - FoxESS and Solis hybrids today, more coming.
Starting from nothing
| Item | Typical cost |
|---|---|
| FoxESS EP6 battery 5.76 kWh certified LFP, 6,000+ cycles, 10-year warranty. | £1,344 |
| FoxESS H1 hybrid inverter UK grid-certified (G98), built-in export limiting. | £815 |
| The Brain · Pi 5 Runs the club’s open-source optimiser. Yours outright. | Free |
| Wiring & parts Isolators, breakers, cabling, consumer-unit work. | £315 |
| Installation Qualified electrician, one to two days including sign-off. | £1,100 |
| Grid paperwork DNO notification. | £100 |
| Typical total, installed | ~£3,700 |
| With the £750 grant (every member) | ~£2,950 |
Already got solar?
Same kit, and the battery stores your surplus too - your FiT payments are unaffected. A supported hybrid inverter gets reused, dropping the price to ~£2,150–2,950 installed with the grant.
Already own a battery?
If it sits behind a supported inverter there is nothing to buy - the Brain and the compatibility check are free. Anything else with local control, ask us with your model.
Prices checked July 2026, and move a few hundred pounds with quotes, distance and consumer-unit condition. Where the savings come from: our numbers. To join you’ll need to own a house and be happy on an Octopus half-hourly tariff.