How Long Do Solar Panels Last?
Solar panels last 25 to 30 years or more, and many keep working well beyond that. Quality panels lose around 0.4% to 0.5% of their output each year, so after 25 years they still produce roughly 85% to 90% of what they did when new. The inverter usually needs replacing once, after 10 to 15 years, and a home battery typically lasts 10 to 15 years.
In this guide we’ll explain how long each part of a solar system lasts, how much output panels lose over time, what your warranties really cover, what can shorten or extend their life, and what happens when they finally reach the end of the road.
How long do solar panels last in the UK?
Solar panels last 25 to 30 years or more in the UK, with many older panels still producing useful electricity after 35 or even 40 years. They don’t suddenly stop working. Instead, they slowly produce a little less each year.
The rest of your system has its own lifespan, so it helps to think about each part separately:
| Part of the system | Typical lifespan | Typical warranty |
|---|---|---|
| Solar panels | 25 to 30+ years | 25 to 30 year performance warranty |
| String or hybrid inverter | 10 to 15 years | 5 to 12 years |
| Microinverters | 20 to 25 years | 20 to 25 years |
| Panel optimisers | 20 to 25 years | 20 to 25 years |
| Home battery (LFP) | 10 to 15+ years | 10 years |
| Mounting rails and roof hooks | 25+ years | 10 to 25 years |
| Cables and connectors | 25+ years if installed correctly | Covered by installer workmanship warranty |
Why the UK climate is kind to solar panels
Heat is one of the main things that ages solar panels. The UK’s cool, mild weather means panels run at lower temperatures than in hot countries, which helps them last. Rain also washes off most dirt naturally. The biggest risks here tend to be storms, salty coastal air and poor installation, rather than the weather itself.
Panels that have already proved it
Some of the earliest home solar panels installed in Europe in the 1980s and 1990s are still working today. Modern panels are built to much higher standards, so a system fitted now should comfortably last into the 2050s.
Want a system built to last for decades? EE Renewables provides expert solar panel installation across Southern England, Greater London, South West England, and South Wales, including areas like London, Brighton, Oxford, Southampton, Bristol, and Cardiff. Use our online tool and get a free solar panel quote tailored to your location today.
How much do solar panels degrade each year?
Solar panels degrade by around 0.4% to 0.5% a year for most quality panels today, after a slightly bigger drop of 1% to 2% in the first year. Premium panels can lose as little as 0.3% a year, while older or budget panels may lose 0.7% or more.
Output remaining over time
Here’s roughly how much of their original output quality panels keep over the years:
| Years in use | At 0.5% loss a year | At 0.4% loss a year |
|---|---|---|
| 1 year | 98% | 98% |
| 10 years | 93.5% | 94.4% |
| 20 years | 88.5% | 90.4% |
| 25 years | 86% | 88.4% |
| 30 years | 83.5% | 86.4% |
What that means in real terms
Take a 4kW system in the South that produces about 3,900 kWh in its first year. After 25 years, it will still be making roughly 3,400 to 3,500 kWh a year. That’s a small drop, and it’s easily outweighed by rising electricity prices over the same period.
Why panels lose output
Panels lose output because of tiny changes in the cells from years of sunlight, heating and cooling, and moisture. The first-year drop happens as the cells settle in after their first exposure to sunlight. Better quality panels use tougher materials and newer cell designs that slow this down.
Newer panel technologies
Many panels now use newer cell designs, often described as N-type, which tend to degrade more slowly than older panels. When comparing quotes, look for the yearly degradation rate on the panel’s data sheet, not just its wattage.
How long do the other parts of a solar system last?
The other parts of a solar system last between 10 and 25+ years, depending on what they are. The inverter is usually the first thing to need replacing, while the mounting system and cables should last as long as the panels.
Inverters
A standard string or hybrid inverter usually lasts 10 to 15 years. It works hard every day, converting the electricity from your panels, and contains electronics that wear out over time. Most homeowners should expect to replace it once during the life of their panels.
Microinverters and optimisers
Microinverters and optimisers sit behind each panel and typically last 20 to 25 years, often with warranties to match. They’re common on shaded roofs and systems where panels face different directions. Because they’re on the roof, replacing one can mean putting up scaffolding or a ladder system again.
Home batteries
Most home batteries now use lithium iron phosphate (LFP) cells, which typically last 10 to 15 years or more. They gradually hold less charge rather than failing suddenly, and warranties usually guarantee around 70% of the original capacity after 10 years.
Read our in-depth guide on how long solar batteries last.
Mounting systems
The rails, clamps and roof hooks are usually made from aluminium and stainless steel, which don’t rust. They should last 25 years or more, as long as they were fitted correctly and the roof underneath stays in good condition.
Cables, connectors and isolators
Cables and connectors are designed to last the life of the system. Problems usually come from poor installation, such as loose connectors or cables left rubbing against the roof. The rooftop and inverter isolator switches should be checked from time to time, as they’re exposed to weather.
What do solar panel warranties cover?
Solar panel warranties cover two different things: faults in the panels themselves, and how much electricity they’ll still produce over time. On top of that, your inverter, battery and the installation work each have their own separate warranties.
| Warranty type | What it covers | Typical length |
|---|---|---|
| Product warranty | Manufacturing faults, such as failed cells or broken frames | 12 to 25 years, sometimes 30 |
| Performance warranty | A minimum level of output as the panels age | 25 to 30 years |
| Inverter warranty | Faults in the inverter | 5 to 12 years, often extendable |
| Battery warranty | Faults and a minimum storage capacity | Usually 10 years |
| Installer workmanship warranty | Problems caused by how the system was fitted | Often 2 to 10 years |
| Insurance-backed warranty | Protects your workmanship cover if the installer stops trading | Usually matches the workmanship warranty |
Product vs performance warranties
This is where people often get confused. A 25 or 30-year performance warranty doesn’t mean the panels are covered against every fault for that long. It guarantees they’ll still produce a set amount, often around 85% to 90% of their original output, by the end. Faults are covered by the product warranty, which may be shorter.
Workmanship and insurance-backed warranties
Your installer should guarantee their own work, covering things like leaks around fixings or wiring faults. Choosing an MCS certified installer who’s a member of a consumer code such as RECC or HIES means that cover is usually backed by insurance, so it still holds if the company closes.
Keeping your warranties valid
Keep your paperwork, register your panels and inverter with the manufacturers if asked, and avoid DIY repairs. Some battery and inverter warranties also require the system to stay connected to the internet so the manufacturer can monitor it.
What affects how long solar panels last?
How long solar panels last is affected mainly by the quality of the panels, how well they were installed, and the conditions they face on your roof. The good news is that most of these are within your control when you choose an installer.
Panel quality
Well-made panels from established manufacturers use stronger glass, better seals and higher quality cells. They lose output more slowly and are less likely to develop faults. Very cheap panels can look similar on paper but may degrade faster.
Read our guide on the best solar panels in the UK.
Installation quality
Poor installation is one of the most common causes of early problems. Loose connectors, cables rubbing on tiles, badly sealed fixings and panels fitted too close to roof edges can all shorten a system’s life. An MCS certified installer has to follow set standards for design and fitting.
Wind and storms
Panels are tested to cope with strong winds and heavy snow, but the mounting system has to be designed for your roof’s exposure. Homes on high ground, near the coast or in open countryside across Devon, Cornwall and South Wales need fixings designed for stronger winds.
Salty coastal air
Sea air can slowly corrode frames and connectors. If you live near the coast, such as in Brighton, Southampton, Bournemouth, Cornwall or along the South Wales coast, ask for panels certified for salt mist resistance.
Shading and hot spots
When part of a panel is shaded for long periods, that area can heat up, creating what’s called a hot spot. Over many years, this can damage the cells. Good system design and optimisers reduce the risk on shaded roofs.
Birds and pests
Pigeons love nesting under panels, especially in towns and cities like London and Bristol. Their nests and droppings can damage cables and block drainage. Bird mesh fitted around the edges stops this from happening.
Roof condition
Panels can outlast a roof covering that was already near the end of its life. If your roof needs work within the next few years, it’s cheaper to do it before the panels go on than to remove and refit them later.
How panels are cleaned
Pressure washers, harsh chemicals and walking on panels can damage the glass, seals and cells. If panels need cleaning, soft brushes and clean water are all that’s needed, ideally done by a professional.
How can you make your solar panels last longer?
You can make your solar panels last longer by choosing a quality kit and a certified installer, keeping an eye on your system’s output, and arranging the occasional professional check. Solar panels need very little care, but a few simple habits help.
Start with the right installation
The choices made on day one matter most. Choose an MCS certified installer, good quality panels with a low degradation rate, and a mounting system designed for your roof and location. Ask for bird mesh if you’re in a town or city.
Check your monitoring app
Most systems come with an app showing how much electricity you’re producing. Glance at it every month or so and compare it with the same month last year. A sudden or steady drop is often the first sign that something needs attention.
Keep panels reasonably clean
In most of the UK, rain keeps panels clean enough. Homes near busy roads, farmland, trees or the coast may benefit from a professional clean every year or two. Never use a pressure washer, and don’t climb onto the roof yourself.
Book a periodic check
A professional inspection every four to five years is a sensible habit. An installer can check the fixings, cables, connectors and isolator switches, test the inverter, and spot early signs of wear before they become costly.
Look after your inverter
Keep the inverter somewhere cool, dry and well ventilated, and don’t cover it or stack things around it. Many manufacturers offer extended warranties, which can be worth considering when the standard cover runs out.
Deal with problems quickly
If you notice damage after a storm, a warning light on the inverter or a big drop in output, get it checked promptly. Small issues, like a loose connector or a nesting pigeon, are much cheaper to fix early.
What are the signs your solar panels need attention?
The signs your solar panels need attention include a noticeable drop in output, warning lights or error codes on the inverter, and visible damage on the panels themselves. Spotting these early usually keeps repair costs down.
A drop in output
Compare this year’s generation with the same month last year. Weather varies, so small differences are normal, but a fall of 10% or more, or one panel producing far less than the others on an optimiser system, is worth investigating.
Inverter warning lights and error codes
A red or orange light, an error code, or an inverter that keeps switching off are common signs of trouble. Sometimes it’s a simple reset or a grid issue, but repeated faults often mean the inverter is nearing the end of its life.
Cracks and broken glass
Cracked glass lets moisture in, which can damage the cells underneath. This can be caused by falling branches, very large hailstones or someone walking on the panels.
Discolouration, bubbles and burn marks
Brown or yellow patches, bubbling under the surface, or small burn marks can point to moisture getting in, a failing seal or a hot spot. Panels showing these signs should be checked, as they may be covered by the product warranty.
Loose fixings or cables
Cables hanging loose, rattling panels in the wind or gaps around roof fixings suggest the mounting system needs attention. Left alone, these can lead to leaks or storm damage.
Nesting birds
Regular pigeon noise, feathers or droppings around your panels are a sure sign birds have moved in underneath. Getting them cleared and fitting bird mesh protects your cables and roof.
How much does it cost to repair or replace solar panels?
It costs around £800 to £1,500 to replace a standard inverter, which is the most common repair over a system’s life. Replacing a single panel usually costs £200 to £500, plus access costs if scaffolding is needed. Many faults in the early years are covered by warranty.
| Repair or replacement | Typical cost |
|---|---|
| Replacing a string inverter | £800 to £1,500 |
| Replacing a hybrid inverter | £1,000 to £2,000 |
| Replacing a single panel | £200 to £500, plus access |
| Replacing a microinverter or optimiser | £150 to £400 each, plus access |
| Fitting bird mesh | £300 to £600 |
| Professional clean | £100 to £250 |
| Health check and inspection | £100 to £250 |
| Scaffolding for roof-level repairs | £400 to £1,200 |
| Full replacement of a 4kW system at end of life | £5,500 to £7,500 at today’s prices |
These are approximate costs based on typical jobs in our region.
Budgeting for the inverter
It’s worth setting aside £800 to £1,500 for a new inverter somewhere between years 10 and 15. When the time comes, you may choose to upgrade to a hybrid inverter, which makes it easy to add a battery.
When repair beats replacement
Most problems, such as a faulty connector, a failed optimiser or a single damaged panel, can be fixed without replacing the whole system. A full replacement usually only makes sense once panels are 25 to 30 years old, or if you want to upgrade to more powerful modern panels.
How does solar panel lifespan affect payback?
Solar panel lifespan affects payback by deciding how many years of savings you enjoy after the system has paid for itself. Most home systems in the South pay back in 8 to 15 years, leaving 10 to 20 years or more of low-cost electricity afterwards.
| System size | Typical cost | Rough payback | Est. savings over 25 years |
|---|---|---|---|
| 3kW | £5,400 | 9 to 15 years | £8,000 to £14,000 |
| 4kW | £6,500 | 8 to 14 years | £10,000 to £19,000 |
| 5kW | £7,500 | 8 to 14 years | £12,000 to £22,000 |
These figures are at today’s energy prices, after allowing for panel degradation and one replacement inverter. If electricity prices rise, you’ll save more.
Why degradation barely dents the maths
Losing 0.4% to 0.5% of output a year sounds worrying, but over 25 years it adds up to only around 10% to 14%. Electricity prices have tended to rise faster than that over the long term, so the value of each unit your panels produce often goes up even as output dips slightly.
Years beyond the warranty
Panels don’t stop at 25 or 30 years. If they’re still producing 80% or more of their original output, they can keep saving you money for years, with no extra cost beyond occasional maintenance. For many homeowners, those extra years are pure bonus.
What should you do with an older solar panel system?
With an older solar panel system, the best thing to do is check its output, get the inverter looked at if it’s more than 10 years old, and consider whether adding a battery would help. Most panels from the 2010s still have plenty of life left.
Systems from the Feed-in Tariff years
Hundreds of thousands of UK homes had panels fitted between 2010 and 2019 under the Feed-in Tariff. Many of these systems are now 10 to 15 years old. The panels themselves are usually fine, but the original inverter is often nearing the end of its life. Feed-in Tariff payments typically last 20 or 25 years from installation, depending on when the system was registered.
Replacing the inverter
If your inverter is showing faults, a like-for-like replacement is usually straightforward. Let your Feed-in Tariff supplier know about the change and keep the paperwork. It can also be a good moment to switch to a hybrid inverter if you’re thinking about a battery.
Adding a battery
You can usually add a battery to an older system, which lets you store more of your own solar for the evening. It needs to be installed so that your Feed-in Tariff generation meter still records only what the panels produce. A good installer will set this up correctly and tell your supplier.
Upgrading or repowering
Older panels were often rated at 250W or less, while modern ones are 430W or more. Replacing old panels with new ones can boost output from the same roof, but it can affect Feed-in Tariff payments if the system’s size changes. Always check with your supplier before making major changes.
Getting a health check
If your system is over 10 years old and you’ve never had it inspected, a health check is worthwhile. It can confirm that the panels, cables, connectors and inverter are still safe and performing as they should.
What happens to solar panels at the end of their life?
At the end of their life, solar panels are removed and recycled, rather than sent to landfill. In the UK, they’re covered by waste electrical and electronic equipment (WEEE) rules, which require producers to fund their collection and recycling.
How solar panels are recycled
By weight, a solar panel is mostly glass and aluminium, both of which are easy to recycle. Specialist recyclers separate the frame, glass, cells and wiring, and recover materials such as silver, copper and silicon. A large share of each panel’s materials can be reused.
Who takes them away
When your system is replaced, your installer should arrange for the old panels to be collected and sent to an approved recycler. Panels must not go in household waste or to a general tip. The same applies to old inverters and batteries, which also have their own recycling routes.
Second life for older panels
Panels that still work but are being replaced for an upgrade don’t always need recycling straight away. Some find a second life powering sheds, garden buildings or off-grid projects, although they should always be checked for safety first.
The environmental payback
Making a solar panel uses energy, but a panel in the UK typically generates that energy back within its first few years. Across a 25 to 30-year life, it produces many times more clean electricity than it took to make.
Ready to get a long-lasting solar panel system from EE Renewables?
Getting a long-lasting solar panel system starts with a free quote from EE Renewables. We’ll survey your roof, recommend quality panels with low degradation rates and strong warranties, and design a mounting system suited to your home’s exposure, whether you’re in central London or on the Cornish coast.
Use our online tool to get your free solar panel installation quote today.
Frequently Asked Questions
Can hail, snow or frost damage solar panels?
Hail, snow and frost rarely damage solar panels in the UK. Panels are tested to survive hailstones around 25mm across hitting them at high speed, and to carry heavy snow loads. Frost doesn’t harm the cells, and snow usually slides off quickly once the sun comes out.
Can you mix new panels with older ones?
You can sometimes mix new panels with older ones, but it needs care. Panels with different ratings can hold back the whole string if they’re wired together. Installers often solve this with optimisers or a separate inverter input for the new panels, so each set works at its best.
What happens to solar panels if you need a new roof?
If you need a new roof, your panels can be taken down, stored safely and refitted afterwards. This typically costs £800 to £2,000 for a home system, plus scaffolding, depending on the number of panels. It’s worth using a solar installer for this, so the electrical work and warranties stay intact.
What should you check when buying a house with old solar panels?
When buying a house with old solar panels, ask for the MCS certificate, the installation date, warranties and recent generation figures. Check whether the panels are owned outright or leased, and whether any Feed-in Tariff payments transfer with the property. A quick health check can confirm the inverter’s condition.
Do in-roof solar panels last as long as on-roof panels?
In-roof solar panels last about as long as standard on-roof panels, usually 25 to 30 years or more. They can run slightly warmer because there’s less airflow behind them, but the difference is small. The key is a well-fitted flashing kit, so the roof stays watertight for the panels’ whole life.
