How long solar panels last, and what looking after them involves

The short answer

A modern solar panel is warranted to keep working for 25 to 30 years, and to still be producing 87% to 92% of its original output at the end of that term. There is no service interval, no annual check you are obliged to book and no consumable to replace. Rain does most of the cleaning on a pitched roof. The only two things that need any thought are the inverter, which is the component most likely to be replaced within the panels' lifetime, and the paperwork: knowing which warranty covers which failure, and who you ring.

What degradation actually looks like

Panels lose a little output every year. On current N-type modules the published pattern is a drop of 1% or less in the first year, then around 0.4% a year after that, guaranteed on a straight line to the end of the term. Note what that promise is: a floor the manufacturer will not go below, not a prediction of what your roof will do.

Based on a typical 30 year linear performance warranty of 1% first year degradation then 0.4% a year, applied to 6,289 kWh, the UK average annual generation for a 14 panel 6.3 kWp array. Panels commonly beat these floors.

Read the table the right way round. Twenty five years after handover, a system on those terms is still contracted to deliver around nine tenths of what it produced in its first summer, and the gap between a sunny year and a dull one will be wider than everything ageing takes off across a decade. Every unit you generate and use replaces one bought at the capped average rate of 26.11p per kWh for 1 July to 30 September 2026, and the rest is exported. Export rates, unlike a performance warranty, are not locked for the life of the system, which our guide to the Smart Export Guarantee explains.

What maintenance actually involves

• Rain and a pitched roof handle routine dirt. Panels are sheets of tempered glass set at an angle, and water runs off them.
• Watch the lower edge of the array. Leaf litter, moss washing down from the tiles above and bird fouling collect there, and that is the strip worth a look from the ground each autumn.
• Use your monitoring rather than your eyes. If one part of the array drops away from the rest on a clear day, that shows in the app long before anything is visible from the garden.
• Keep growth off the roof. A branch that was clear of the panels at survey is not necessarily clear of them five summers later.
• Leave the roof to people with proper access. Nothing on a solar system is worth a ladder.

Work on the roof after handover also means access all over again. Scaffolding on a solar job typically runs £300 to £1,000 or more and accounts for around 13% of a typical install cost, which is the argument for doing the roof properly the first time rather than in stages. The solar panel cost guide breaks down where the rest of the money goes.

The inverter ages faster than the panels

Panels have no moving parts. An inverter is power electronics working every daylight hour, and it carries a shorter manufacturer warranty than the array it serves. Across the market it is the component most likely to need replacing at some point inside the panels' life. Module level electronics behave differently, and some microinverters and DC optimisers are warranted for 25 years, matching the panels rather than the string inverter. None of that is a reason to worry on day one. It is a reason to know the warranty term on the specific inverter in your quote, in writing, before you sign anything.

Where the 10 year workmanship warranty fits

The manufacturer warranties cover the equipment. They do not cover how it was fitted, and that is a separate layer. It matters most in the first decade, because early problems on a solar system are far more often installation problems than product failures. Installations are carried out by the regional partner business holding the exclusive OVO partnership for your area, and the workmanship warranty is backed by OVO rather than by that individual business. Sixteen installer businesses are Powered by OVO, selected from around 200 assessed, and between them they completed over 1,000 OVO solar and battery installs in the last 12 months. The coverage page shows who covers your postcode.

Every OVO installation carries the OVO guaranteed 10 year workmanship warranty. Ask your local OVO expert for the written terms of all three layers on your design call.

A warranty is only as good as the company behind it

This stopped being theoretical in 2026. GivEnergy, at one point one of the larger UK residential battery suppliers, entered administration on 9 April 2026 and ceased trading. Installed hardware kept running, because it does not depend on the manufacturer's servers, but hardware warranties and software support were no longer honoured by the company and owners were directed back to their installer. The lesson is not to fear one brand. It is that a paper warranty needs somebody still there in year 12 to answer it, so the strength of the business behind the installation counts for as much as the number of years printed on a datasheet.

OVO SEG Install Exclusive pays 20p per kWh where OVO installs both solar and battery, or 15p per kWh for solar only. The exclusive rates require you to take your electricity supply from OVO and are subject to system size limits. OVO's standard SEG rate of 4p per kWh is open to customers of any supplier. Rates correct at July 2026 and subject to change.