Savings calculator

What it saves – honestly

Most plug-in solar ads exaggerate. We’d rather you know the real numbers. Enter what you pay for electricity and see what a kit could take off your bill.

You'll find this on your latest bill or in your online account.

Electricity only — leave out gas if your bill covers both.

Your estimated saving – around

£111.20

Per month
£9.27
Electricity generated
650 kWh a year

What this is based on

  • We assume around 65% of what you generate is used in your home as it is generated.
  • Yield estimates: Solarfy Duo 910 (2 panels) about 650 kWh a year, Solarfy Solo 455 (1 panel) about 325 kWh a year, for a south-facing position with no shade.
  • Electricity you generate but don't use is not paid for, so it isn't counted here.

This is an estimate, not a guarantee. What you actually save depends on your position, shading, the weather and how much electricity you use during daylight hours. Figures are based on the assumptions above and are not a promise of performance or savings.

What the rules say about plug-in solar in the UK

The honest numbers

In a sunny, unshaded spot the Duo makes around 650 kWh a year (the Solo around 325 kWh). If you use 60–70% of that at home, that’s around £100–£120 a year off your bill with the Duo and around £50–£60 with the Solo, at 26.32p/kWh. The government’s own estimate for plug-in solar is £70–£110 a year – shade, direction and when you use electricity make the difference.

*Savings estimate: south-facing, unshaded, approx. 650 kWh/year, 60–70% used at home, electricity at 26.32p/kWh (Ofgem price cap, 1 Oct–31 Dec 2026). Results depend on location, orientation, shading and usage.

Your home. Your solar power.

Complete kit, delivered by two people, registered in minutes. From £549.

Shop the Duo