From 1 October 2026 the Ofgem price cap puts the average electricity unit rate at 26.32p per kWh. Every unit your solar panels generate and you use yourself is one you do not buy. But how much do panels cost, what do they really save, and how long do they take to pay back?
How Much Do Solar Panels Cost?
The Energy Saving Trust says the average home system is around 4.5 kilowatt peak (kWp) — usually about 12 panels covering 20–30m² of roof — and costs around £7,600 to install. Your price depends on the system size, your roof and access, and whether scaffolding is already up for other work.
Installing solar panels and batteries in a home is currently zero-rated for VAT, until 31 March 2027.
How Much Can You Save?
Savings depend on where you live, how much of the electricity you use while it is being generated, and whether you are paid for what you export. The Energy Saving Trust’s estimates for a four-bedroom detached, gas-heated home, based on fuel prices as of July 2026, are:
- London: £900–£930 a year with export payments; £200–£330 without
- Manchester: £740–£810 with export payments; £190–£310 without
- Aberystwyth: £840–£870 with export payments; £190–£320 without
- Stirling: £680–£740 with export payments; £180–£290 without
In each range, the lower figure is for someone out all day and the higher for someone at home all day. The gap between the “with” and “without” figures shows how much export payments matter.
Export Payments: the Smart Export Guarantee
Through the Smart Export Guarantee, electricity suppliers offer tariffs that pay you for electricity you send to the grid. Rates vary between suppliers and tariffs; the Energy Saving Trust says you will typically get around 12p a unit. Because buying electricity costs more than twice that, using your own solar electricity is usually worth more than exporting it. You can choose an export tariff from a different supplier to the one you buy from, so compare them and check what each needs from you.
What Is the Payback Period?
A simple way to estimate payback is to divide the cost by the yearly saving. Using the Energy Saving Trust’s figures — £7,600 and £680–£930 a year with export payments — that gives roughly 8 to 11 years. Treat this as a rough guide: it ignores future energy price changes, the cost of replacing the inverter (usually after around 12 years) and any battery.
Panels themselves should last 25 years or more.
Should You Add a Battery?
A battery stores electricity generated during the day so you can use it in the evening. The Energy Saving Trust puts battery costs at around £5,000 to £8,000. A battery can make more sense if you use a lot of electricity in the evening, or with a time-of-use tariff, heat pump or electric car. Ask installers to quote with and without one so you can compare.
Do Solar Panels Work in the UK?
Yes. Panels generate electricity from daylight, so they still produce some power on cloudy days, although output is much higher in summer than in winter. South-facing roofs generally generate the most, and heavy shading reduces output.
Planning Permission and Registration
Solar panels on houses are usually permitted development and do not need planning permission, but there are exceptions — for example for listed buildings and in conservation areas — so check with your local planning office. Your system must be registered with your Distribution Network Operator, which the installer usually does for you.
Help With the Cost
In England, the Warm Homes: Local Grant can include solar panels for eligible lower-income households, and the government has said it will offer low- and zero-interest loans for solar panels and batteries through its Warm Homes Plan. See our grants guide.
Are Solar Panels Worth It?
For many homes with a suitable, unshaded roof, the numbers can work — especially if you use electricity during the day or sign up for export payments, and plan to stay in the home for a while. Get more than one quote, and check any installer yourself, for example through the MCS installer search.
Sources: Energy Saving Trust, “Solar panels” (updated 27 August 2026; savings based on fuel prices as of July 2026); Ofgem price cap for 1 October to 31 December 2026; HMRC VAT Notice 708/6; GOV.UK Warm Homes Plan. Last reviewed September 2026.