Solar, battery and an EV charger in Quainton

A heat pump is planned for next year, so this year's solar and battery were sized with that in mind. The battery had to live outside.

Black solar panels covering both faces of a tiled roof on a newer house in Quainton

Quick facts

System size: 7.44 kWp
Panels: 16 × DMEGC DM465G12RT-G48HBB, 465 W
Mounting: On-roof, Fastensol FTH01 pantile rack
Inverter: Fox ESS KH7, 7 kW hybrid
Battery: Fox ESS EP12 Plus, outdoor IP65 and self-heating — 11.52 kWh nominal, 10.4 kWh usable
Backup: Whole-home backup via the Fox Gateway EPS box
EV charger: myenergi Zappi Glo
Roof: Concrete tiles at 35°, both faces used, 8 panels each
Grid connection: G99, a few weeks
Installed: August 2026
MCS estimated generation: 5,690 kWh a year
Estimated savings: £1,324 a year
Estimated payback: 6 years

Estimated at quote stage based on the customer’s usage and tariff at the time. Actual savings vary.

Why they got in touch

A homeowner in Quainton had been planning a heat pump, but as they put it: “the installer I went with couldn’t do the heat pump due to distance… I’ve decided to do solar and battery this year, and add an air source heat pump next year.”

What we recommended and why

Knowing a heat pump is coming changes the sizing. A heat pump runs on electricity through the winter, so there is no point fitting a system that only just covers today's usage. We max-fitted the roof — eight panels on each face, 16 in total — and specified a battery with room to work alongside the heat pump later.

The battery had to go outside, so we used the EP12 Plus: IP65-rated and self-heating, which matters for an outdoor battery through a British winter. We also added the Fox Gateway EPS box, so the house has whole-home backup rather than nothing in a power cut.

The install

Two things to work around. The property is on a newer development, so written consent from the developer was needed before work could start. And the survey had to be done remotely from photographs rather than in person.

The existing EV charger was swapped for a Zappi Glo at the same time, so the car charging, the solar and the battery all work off the same system.

The result

Both roof faces working, 11.52 kWh of outdoor storage, whole-home backup and a Zappi on the wall — with headroom for the heat pump next year. The MCS certificate puts estimated generation at 5,690 kWh a year.