The kit
Buy it in your own name from any installer. We help with the quote and spec, then plug in the Brain. Any battery works if the inverter is supported: FoxESS and Solis hybrids today.
Starting from nothing
| Item | Typical cost |
|---|---|
| FoxESS EP6 battery 5.76kWh, as in our savings example. | £1,344 |
| FoxESS H1 hybrid inverter 5kW H1 5.0 G2, as in our simulation. | £815 |
| The Brain · Pi 5 Runs our optimiser. Yours to keep. | Free |
| Wiring & parts Isolators, breakers, cabling, consumer-unit work. | £315 |
| Installation One to two days, including sign-off. | £1,100 |
| Grid paperwork DNO notification. | £100 |
| Typical total, installed | ~£3,700 |
| With the grant covering half (every member) | ~£1,850 |
This setup saves about £600 a year in our simulation, or £480 after the £10 per month membership.
Already got solar?
We reuse a supported hybrid inverter, so it’s ~£1,450–1,850 with the grant. See the savings with solar.
Already own a battery?
Behind a supported inverter, there’s nothing to buy: the Brain is free. Other models, ask us.
Prices checked July 2026; quotes vary by a few hundred pounds. To join, you’ll need to own your home and use an Octopus half-hourly tariff.