Solar panel calculator: see what solar would save on your home
Answer a few questions about your roof and energy use. You'll see your likely savings, your payback time and whether a battery pays off, before you speak to anyone.
- Free estimate in 2 minutes
- Based on your postcode's sunshine
- No obligation
Prices updated October 2026
- Your home
- Your roof
- Energy use
- Your results
How the solar panel calculator works
The calculator builds your estimate in three parts.
- Sunshine. Your postcode area sets how much energy each kilowatt of panels produces in a year, from about 800 kWh in Scotland to 1040 kWh in Cornwall. Roof direction and shade adjust that figure.
- System size. Your bill gives your yearly electricity use. We size the system to cover it, up to the number of panels that fit a typical roof of your property type.
- Savings. Solar power you use yourself saves 26.32p per kWh at the October 2026 price cap. Power you export earns around 12p per kWh through the Smart Export Guarantee. A battery stores daytime power for the evening and can charge on a cheap overnight tariff in winter.
See every assumption on our how we calculate page.
Solar panel savings by region
The same home earns noticeably different returns depending on where it is. Here is a typical semi-detached house in each part of the UK.
| Region | kWh per kWp | Yearly output | Saving, year 1 | Payback |
|---|---|---|---|---|
| South West England | 1040 | 5,491 kWh | £973 | 7.5 yrs |
| The South coast | 990 | 5,227 kWh | £927 | 7.9 yrs |
| London and the South East | 960 | 5,069 kWh | £899 | 8.1 yrs |
| The Midlands and South Wales | 920 | 4,858 kWh | £861 | 8.4 yrs |
| North Wales and Cheshire | 880 | 4,646 kWh | £824 | 8.7 yrs |
| Northern England | 860 | 4,541 kWh | £805 | 8.9 yrs |
| Scotland | 800 | 4,224 kWh | £749 | 9.5 yrs |
| Northern Ireland and the islands | 830 | 4,382 kWh | £777 | 9.2 yrs |
Semi-detached home, 12 panels (5.3 kWp), south-facing, no shade, £150 monthly bill, solar only. Prices from the October 2026 price cap.
What affects your savings most
How much power you use at home in the day
Every unit you use yourself is worth about twice as much as a unit you export. A household where someone works from home typically uses half of what the panels make. A household that's out all day uses closer to 30%, unless it adds a battery.
Roof direction and shade
South-facing roofs give the most power. East and west roofs produce about 15 to 20% less per panel, but you can often fit panels on both sides. Shade from a chimney or tree on part of the roof can be managed with optimisers.
Your tariff
Pairing solar with a smart tariff changes the maths. With a battery you can charge overnight at around 8.5p per kWh in winter, then use or export solar power in summer. Our solar battery calculator compares battery sizes for your home.
Are solar panels worth it in the UK?
For most homeowners with a suitable roof, yes. Electricity costs 26.32p per kWh at the current price cap, panels last 25 to 30 years, and installation carries 0% VAT until 31 March 2027. A typical system pays for itself in 7 to 10 years and then provides free electricity for the rest of its life.
Solar is less likely to pay off if your roof faces north, is heavily shaded, needs replacing soon, or if you plan to move within a few years. Even then, solar panels can raise a home's EPC rating, which buyers increasingly look at.
Frequently asked questions
How much do solar panels save in the UK?
A typical 3-bed home with 12 panels saves around £750 to £1,100 a year on electricity and export payments at October 2026 prices. Savings are higher if someone is home in the day, if you add a battery, or if you live further south.
How long do solar panels take to pay for themselves?
Most UK homes break even in 7 to 10 years. Panels are warrantied for 25 years or more, so the remaining years are profit. A south-facing roof, high daytime use and a smart tariff all shorten the payback.
Do solar panels work in winter and on cloudy days?
Yes, but output is lower. A UK system makes roughly 75% of its yearly energy between April and September. Panels still generate in daylight under cloud, just less than in direct sun.
Is my roof suitable for solar panels?
South, south-east, south-west, east and west roofs all work well. North-facing roofs produce about 40% less. The roof needs to be in good condition and free from heavy shade. The calculator rates your roof as you answer.
How accurate is this calculator?
It uses regional sunshine data, the current Ofgem price cap and typical 2026 installation prices. Most homes land within 10 to 15% of a surveyed quote. A free survey measures your roof and gives a fixed price.
Do I need planning permission for solar panels?
Usually not. Most homes in England can install roof panels under permitted development. Listed buildings need consent. Read our planning permission guide for the details.
Ready for an exact price?
Run the calculator and book a free, no-obligation survey with a local MCS-certified installer.