Home energy guide
Solar panels in the UK: cost, savings and payback
A typical home solar system costs about £7,600 and pays for itself in roughly 9 to 12 years. The biggest factor? How much of the power you use yourself.
Last updated:
Work out your own numbers with the solar calculator →
What it costs
A typical home system (about 4.5 kWp, around 12 panels, 20–30 m² of roof) costs about £7,600 fitted, says the Energy Saving Trust (EST). Scaffolding, tricky roof access, in-roof panels and roof repairs push quotes up.
As one supplier example, Octopus Energy lists panel-only installations from £6,663, and 12 panels with a 10 kWh battery at £11,115 (April 2026 prices, on its Outgoing page). There's no dedicated government solar grant in Great Britain at the moment (EST).
How much sunshine you'll catch
The south of England does best: a typical system makes about 5,050 kWh a year in Plymouth, 4,585 in London and 3,865 in Glasgow. East- or west-facing roofs get about 15–20% less than south-facing ones (EST), and shade from trees or chimneys cuts output further.
See the numbers
We ran the EU Joint Research Centre's PVGIS tool for a 1 kWp south-facing system at a 35° tilt with 14% system losses.
| Location | kWh per kWp | 4.5 kWp system |
|---|---|---|
| Plymouth | 1,122 | 5,050 kWh |
| Cardiff | 1,042 | 4,690 kWh |
| Norwich | 1,030 | 4,630 kWh |
| London | 1,019 | 4,585 kWh |
| Birmingham | 968 | 4,355 kWh |
| Newcastle | 949 | 4,270 kWh |
| Belfast | 919 | 4,135 kWh |
| Aberdeen | 887 | 3,995 kWh |
| Manchester | 886 | 3,985 kWh |
| Glasgow | 859 | 3,865 kWh |
Where the savings come from
- Power you use yourself saves the full import price: 26.32p/kWh at the Ofgem cap average for October to December 2026.
- Power you export earns a Smart Export Guarantee rate set by each supplier. Outgoing Octopus pays a flat 12p/kWh, and EST says about 12p is typical.
So every unit you use at home is worth more than twice one you export. Running appliances in the day, heating hot water with spare solar or adding a battery is what speeds up payback.
An example
A typical system in London, using 40% of its power at home and charging an EV with some of the rest, earns about £884 a year. That pays back £7,600 in about 9 years.
See the numbers
4.5 kWp in London generating 4,585 kWh, with 500 kWh going to an EV you'd otherwise charge at the capped rate:
- Home use: 1,834 kWh × 26.32p = £483
- EV charging: 500 kWh × 26.32p = £132
- Export: 2,251 kWh × 12p = £270
- Total ≈ £884 a year; payback about 9 years, even after a £1,000 inverter replacement in year 12 and 0.5% a year panel ageing.
In Glasgow the same system makes about 16% less, so payback stretches to about 10–11 years. EST's own figures, based on July 2026 fuel prices, range from 9 years (London) to 11–12 years (Stirling).
Charging an EV from solar: does it pay?
Solar going into your car isn't exported, so its real value is what you'd otherwise pay to charge, minus the export rate.
- On a standard tariff (26.32p), each solar unit in the car is worth about 14p more than exporting it.
- On an overnight EV tariff like Intelligent Octopus Go (from 6.5p, checked 31 Oct 2026), it's actually about 5.5p a unit better to export at 12p and charge at night.
Solar charging also needs the car at home and plugged in when it's sunny, plus a charger that can follow spare solar. It makes most sense if you work from home or don't have an off-peak tariff. See our off-peak EV tariff guide.
Before you buy
- Get at least three quotes from MCS-certified installers. You normally need MCS certification to get Smart Export Guarantee payments.
- Panels last 25 years or more, but inverters usually need replacing after about 12 years (EST).
- Rooftop solar is usually permitted development, but check first if you're in a listed building, conservation area or national park.
- Thinking about a battery? Try the home battery calculator too.
Sources (checked 27 October 2026 unless stated)
- Energy Saving Trust: Solar panels: cost £7,600, 4.5 kWp, east/west 15–20% less, inverter ~12 years, payback table (fuel prices as of July 2026)
- EU JRC PVGIS 5.3: yearly kWh per kWp for 10 UK cities, queried 27 Oct 2026
- Ofgem price cap, 1 Oct–31 Dec 2026 (published 26 Aug 2026): 26.32p/kWh, 54.83p/day
- Octopus Energy: Outgoing Octopus: 12p/kWh flat export; installation prices (April 2026)
- Octopus Energy: Intelligent Octopus Go: smart charging from 6.5p/kWh (checked 31 Oct 2026)