How solar panels save you money
Solar panels save you money in two ways:
- Lower bills. Every unit you use from your panels is one you don’t buy. At the price cap, that’s worth 26.32p a unit.
- Selling what you don’t use. Your supplier pays you for electricity you send to the grid, often 12p a unit or more.
Using your own electricity is worth about twice as much as selling it. So the more you use in the day, the faster the panels pay off.
0% VAT ends on 31 March 2027
| Installed up to 31 March 2027 | 0% VAT |
|---|---|
| Installed from 1 April 2027 | 5% VAT |
This covers solar panels and batteries fitted to homes. On a £7,100 system, 5% VAT would add about £355.
Typical prices
| Small, 3 kW | £5,300 |
|---|---|
| Medium, 4 kW | £7,100 |
| Large, 6 kW | £10,500 |
| Add a battery | About £5,000 more |
These are typical prices from government figures on hundreds of thousands of home installations, so your quote may be higher or lower. Scaffolding, a tricky roof or a bigger battery all add to the price.
Ready to get quotes?
Use an MCS-certified installer. You need MCS certification to be paid for the electricity you sell.
Find an installerWorked example
Sam gets a 4 kW system for £7,100, with no battery. Someone is at home some days.
| Electricity made in a year | 3,520 kWh |
|---|---|
| Used at home (1,350 kWh × 26.32p) | £355 |
| Sold to the grid (2,170 kWh × 12p) | £260 |
| Saving in the first year | £616 |
The panels pay for themselves in about 12 years. Over 25 years, Sam is about £7,560 better off, and more if electricity prices rise.
Questions
Is a battery worth it?
A battery lets you use more of your own electricity in the evening, so your yearly saving goes up. But it adds about £5,000, so the panels usually take longer to pay for themselves. It makes more sense if you’re out all day or use a lot of electricity in the evening.
Do I need planning permission?
Most homes in England don’t need it for panels on the roof. Listed buildings and some other homes may. Your installer or local council can tell you.
Can I sell to a different supplier?
Yes. Your export tariff doesn’t have to be with the company you buy electricity from, although some pay more to their own customers. You need a smart meter that records what you export.
What does this calculator leave out?
Changes in electricity prices, replacing the inverter, shading, which way your roof faces, and time-of-use tariffs. It’s a guide, not a quote.