Solar panel maintenance: an expert guide

When you’re investing in your home’s future by getting solar panels, it makes sense to take proper care of them.

That way, they can produce as much electricity as possible, which will save you even more money on your electricity bills and reduce your carbon footprint by as much as possible.

In this guide, we’ll explain why solar panels need maintenance, how to take care of them, the most common problems that can arise if you don’t, and how much it costs.

If you’re wondering how much a solar & battery system could save you, just answer a few quick questions below and we'll provide you with an estimate.

Do solar panels need maintenance?

Modern solar panels are durable and have no moving parts, but it's a common misconception that they require no maintenance.

Some technical experts in the industry estimate that a solar & battery system will need three maintenance call-outs across a 20-year period - one for the panels, one for the battery, and one for the inverter.

Solar panels also require cleaning every few years in order to get rid of dirt and debris.

Other complications can pop up too, with little warning. Solar panel owners told a Which? survey in 2022 that they’d seen their panels get cracked or broken, suddenly produce less or no electricity, and experience electrical problems.

They also reported generation meters breaking, weak electrical connections, and isolator problems.

According to government research, 55% of people in the UK who don’t want (or aren’t sure about) solar panels see ongoing maintenance as a key concern, and 40% think a guarantee scheme would assuage their concerns.

The Microgeneration Certification Scheme (MCS) recommends having an ‘intermediate maintenance’ inspection of your solar panels from a certified contractor every 10 years, and a ‘full maintenance’ inspection every 15 years.

However, you can avoid the need for external solar inspections by getting yourself a solar panel maintenance support package.

Sunsave Plus is the UK's first solar subscription, and it means you can switch to solar with no upfront cost. Every Sunsave Plus system is protected by the Sunsave Guarantee, which includes 24/7 monitoring and maintenance, free replacement parts, downtime cover, and insurance.

What can go wrong with solar panels?

Like any piece of technology, solar panels will face problems every so often.

The hardware involved can experience wear and tear, electrical connections can break down, and unwanted obstructions can stop your panels from working properly.

Panels can be damaged by falling or windswept detritus, while your battery can overheat if put in a poorly ventilated space.

These problems can be exacerbated or multiplied if your installer doesn’t set up your panels or battery properly, if you don’t keep any eye on your system, and if you buy cheap solar panels.

Some of the most common issues that can occur include:

1. Inverter issues
2. Electrical problems
3. Battery failure
4. Damaged solar panels
5. Build-up of dirt

2. Electrical problems

Any system that creates, converts, exports, and runs on electricity has the potential to experience electrical issues, and it’s important to look out for them.

Electrical problems may indicate that your system includes faulty materials or loose connections, that other electrical systems in your home are affecting your solar array, or poor workmanship on the part of your installer.

This is why it’s crucial to find the best solar company possible, to ensure your system is set up properly.

If water gets into the DC cables between your panels, or if those cables rub up against your roof tiles, they can break down over time, which naturally causes problems.

If you suspect your system may be suffering from electrical problems, look at your inverter to see if it’s providing an error code that you can check online or with the manufacturer.

Don’t try to solve the issue yourself, though – electrical issues should always be handled by a certified professional.

The Sunsave Guarantee comes with 24/7 remote monitoring of your solar & battery system, so we can spot any issues as soon as they occur, troubleshoot them, try to fix them remotely, and – if necessary – pay a visit to fix the issue.

3. Battery failure

Storage batteries can fail for multiple reasons, although a top-class installer will take steps to ensure your battery can work as well as possible for as long as possible.

Lithium-ion batteries, which are the most popular type, can overheat if they’re overcharged, kept in an inadequately ventilated place, paired with a defective charger, or suffer a short circuit.

This can cause a phenomenon called thermal runaway, in which excessive heat heightens the battery’s chemical process, which causes more heat, and on and on in a destructive spiral.

At best, overheating can cause reduced capacity or output. At worst, the battery can shut down and damage the surrounding area.

Your battery can also stop working if it’s left in especially cold temperatures. Most batteries start malfunctioning if they’re made to operate at 0°C or below.

If you don’t cycle lithium-ion batteries for an extended period, or if you regularly undercharge them, they’ll usually deteriorate at a much faster rate than they would otherwise.

If you’re using lead batteries, undercharging can lead to sulfation, which is a build-up of lead sulphate crystals. This can make your battery very slow to load, or stop it working entirely.

And of course, physical damage can massively impact your battery. If it causes a leak of the electrolyte, which transfers the ions between the machine’s electrodes, it can be disastrous for the battery and anyone the electrolyte touches.

If caught early on, damage can sometimes be repaired, but if not, the battery may need to be replaced.

And even if it functions perfectly, batteries last around 12 years, on average – well short of the typical lifespan of solar panels, which is 25-40 years.

The Sunsave Guarantee means any Sunsave Plus customers automatically get a free battery replacement once it performs at less than 70% of its original capacity.

4. Damaged solar panels

When stormy weather blows through, debris such as broken branches can sometimes hit solar panels and crack them.

In these situations, it can be easy for panels to shatter – especially as the best models are designed to do so if they’re struck, just like the tempered glass in phone screens, oven doors, and car windscreens.

Damage like this could impact your solar panel system’s output, and you’ll need a certified engineer to fix it.

But without professional monitoring help, you’ll only know one of your panels has shattered if you find broken glass nearby, fly a drone above your roof, or carefully track your system’s output over a period of weeks.

The Sunsave Guarantee includes 24/7 monitoring of your solar & battery system, troubleshooting of any issues, and it will also be insured by Aviva against damage, fire and theft.

5. Build-up of dirt

A build-up of dust on solar panels can reduce their output by up to 30% a month, according to the Massachusetts Institute of Technology (MIT).

Fortunately, regular rainfall means dust is rarely a problem in the UK, unless you live near a construction site or a mine.

Still, dirt and debris can gather on solar panels if left unchecked for too long, so it’s best to clean your system every couple of years or so, or hire a professional to take care of it for you.

In fact, the MCS recommends that solar panels in the UK only be cleaned once every 10 years, although this is a minimum.

How to maintain your solar panels

Here are the key steps to take to ensure your solar panels are maintained in good working order:

1. Monitor their output
2. Keep them clear of shading 
3. Look after the inverter
4. Keep them clean
5. Get bird protection

1. Monitor their output

Reduced daylight hours means that drops in output during winter months are to be expected, but at any other time of year, a sharp drop in output may be a sign that something isn’t working properly. 

If your output looks wrong, don’t try and fix the issue yourself – it’s easy to get in a mess when dealing with wiring and connections, and it can be dangerous. It’s much safer and more reliable to have the issue looked at by a professional.

You should also check that the recorded amount of electricity being generated is continuing to increase cumulatively.

For more post-installation tips, read our guide on what to do once you're a solar panel system owner.

2. Keep them clear of shading

Trees or buildings that cast shade on your roof can reduce the amount of sunlight that reaches your solar panels, which in turn lowers your system’s output.

Shading is the bane of solar panels, particularly when they’re all on a single inverter string. This setup forces all panels to generate the same level of output – which means the lowest.

In a system like this, the shaded cells’ electrical resistance will increase, which can create hotspots.

The resultant heat can melt or burn the cells, damage the electrical equipment within, or cause cracks in the glass, all of which can permanently degrade your system.

In theory, your array’s bypass diodes should divert the extra current around shaded cells – but bypass diodes can also fail if they get too hot.

So get an installer who’ll wire your panels in the most beneficial way, and make sure you keep an eye on any trees that grow near your panels so you can cut them back before they start to be a problem.

3. Look after the inverter

If any part of your system is going to fail, it’ll most likely be the inverter – and a solar installation can’t function properly without one.

This complicated piece of technology requires care and attention, so make sure you keep it in a well-ventilated area, out of the sun, and wipe it down with a cloth once every six months.

And if your system’s output drops dramatically, look at your inverter first.

Don’t worry if they get hot, though – they convert DC electricity into AC electricity all day long, so it’s normal for them to heat up.

If their temperature rises beyond a safe level, they’ll shut down to protect themselves and their surroundings.

4. Keep them clean

In the UK, solar panels are deliberately installed at angles of 15 degrees or more, partly to ensure they’ll be cleaned by rainfall. This helps to keep panels performing at their best.

Having said that, if you have ground-mounted panels, which are more susceptible to a wider range of dirt due to being at ground level, or the area you live in has a high level of airborne dust, you’ll likely have to clean your solar panels every year or so.

But for rooftop solar panels in most parts of the UK, the recommended frequency for cleaning is once every couple of years. 

You should clean your roof-mounted panels with an extendable clearing brush, as it’s a lot safer than going up on the roof. Use a soft brush in line with the manufacturer's recommendations, to ensure you don’t void the panels’ warranty.

Don’t use a pressure washer, as this may cause more damage, and avoid soap, which is likely to leave a residue.

If you don’t have an extendable brush or your panels aren’t within easy reach, you should hire a professional. Individual costs will vary depending on where you live, but you can expect to pay around £10 per panel.

If it snows where you are, resist the urge to brush it off your panels, as this will likely damage them. Just leave the snow to melt on its own.

5. Get bird protection

If pigeons end up invading your solar panel system and nesting underneath them, they can cause some pretty significant issues, such as disrupting the wiring, damaging the panels, and reducing the panels' efficiency.

The best way to prevent this from happening is to get a barrier installed around the edges of your solar panel array, which usually comes in the form of wire mesh, spikes, or plastic skirting. And it makes financial sense to get bird protection added on the same day your panels are being installed, otherwise you'll have to pay for scaffolding twice.

Bird protection isn't essential in every part of the UK - it all depends if there are a lot of birds in your local area, particularly pigeons.

To learn more, check out our complete guide to solar panel bird protection.

What to do if something goes wrong with your solar & battery system

Waking up and finding that your solar panels have stopped generating electricity is not a fun experience. And nor is discovering that your battery isn't storing electricity properly, either.

If you don't have a maintenance support package already in place, your next steps may involve a fair amount of confusion and stress.

Firstly, you may not be sure if the issue falls under your system's hardware warranty, or your system's workmanship warranty. You might be able to solve this problem by phoning your solar panel installer and seeing what they think, but this assumes that your installer is still trading.

If your installer tells you that it's a manufacturer issue, you'll have to make a claim on your warranty directly to the manufacturer, which tends to involve a lengthy submission process and lots of waiting around. And even then, there's no guarantee that your panel or battery manufacturer will help.

Alternatively, it could be an issue with the way the system was installed, but most workmanship warranties are usually only a couple of years long, which isn't the most extensive cover. Not ideal if you're experiencing system issues in, say, the fifth year.

At this point, you'd have to turn to a different solar panel installer and pay for them to help - if they can.

In contrast, every Sunsave Plus system is protected by the Sunsave Guarantee for the full term, which is designed to give you total peace of mind that you'll have a reliable source of green electricity for 20 years. You can find out more here.

How much does solar panel maintenance cost?

In the specific case of solar panel maintenance, the costs are pretty low because it's rarely required. Technical experts in the industry estimate that a solar & battery system will need three maintenance call-outs in 20 years, but only one of these call-outs would be for the panels.

Although, depending on the nature of the problem and whether you have a maintenance support package in place, this issue could cost a lot of money to fix - especially if scaffolding is required.

The main cost of solar panel maintenance is cleaning, which is generally recommended every two to three years in the UK - or a bit more frequently, if you live a particularly dusty area, or right by the sea.

And solar panel cleaning is very affordable, costing roughly £10 per panel if you pay professionals to do it, or you can spend about £70-£150 on an extendable cleaning pole (that can be re-used).

However, when thinking about solar maintenance costs, it's more important to focus on the battery and the inverter, rather than the panels. Your battery and inverter will both likely need replacing after around 12 years, and this can cost thousands of pounds if you go it alone.

Opting for Sunsave Plus means your system will be protected by the Sunsave Guarantee for 20 years, and this includes free replacement parts. So once your old battery and/or inverter need swapping out for new kit, we'll be there to sort it out.

What to look for in a solar panel maintenance package

If you want to spread out your maintenance costs – and potentially pay less overall than you would otherwise – you should consider getting a subscription package.

As well as looking for a cost-effective offering, it’s worth ensuring that your chosen package keeps your system running, expertly deals with problems as they come up, and generally makes your life easier.

If the company also provides you with free replacement parts, that’s a massive bonus.

These are the main features to look out for:

• Monitoring. Try to find a company that can constantly keep an eye on your solar panel system to see issues as they appear. This way, you don’t have to spend precious hours of your life tracking electricity output.

• Remote troubleshooting. If a maintenance firm can help fix any problems straight away, it’ll allow your system to generate as much electricity as possible, which will maximise your savings – and if a remote check is the first port of call, you won’t have to pay for unnecessary call-outs.

• Processing warranty claims. If any of your equipment performs below the standards laid out in its warranty – or suffers any damage – a maintenance company should be able to handle the complicated, bureaucratic claims procedure for you.

• Free hardware replacements. When your inverter and battery reach the end of their useful life – usually after around 12 years – you’ll have to replace them to continue generating electricity and saving the same amount of money each year. The best packages offer these new models for free.

• Physical on-site visits. Your maintenance company should offer on-site visits to fix any issues that can’t be solved over the phone. This way, you know that if something goes really wrong, it’ll receive professional, in-person attention.

How often do solar panels have to be replaced?

Solar panels usually have to be replaced every 25-40 years.

How long solar panels last depends largely on the type of panel, but most modern rooftop installations are carried out with black, monocrystalline panels that last up to four decades.

If your panels haven't seen a significant drop in efficiency within this time, there's no need to replace them. A maintenance company can track their performance and make recommendations.

However, make sure you factor in replacing the inverter and battery every 12 years or so, which can add thousands of pounds to the overall cost – particularly if your panels last the full 40 years.

What’s the typical warranty of a solar panel?

Solar panels come with two kinds of warranty: product, which includes the physical panel, and power output, which is how long many years can expect a certain amount of power to be generated by the panel. 

Most product warranties for solar panels are around 10-25 years, and most power output warranties are around 25 years.

Does solar panel output decrease over time?

Solar panel output is likely to decrease very slowly, with an expected decrease of around 0.5% each year. 

While this will have a minimal impact initially, it does accumulate, which is why you’re unlikely to find a warranty for solar power lasting beyond 25 years. 

Most warranties will usually guarantee 90% of maximum output for the first 10 years, and 80% by the 25th year.

Next steps

A solar & battery system can require a fair amount of maintenance across its lifetime to ensure it keeps producing as much electricity as possible, such as replacement parts and output tracking.

It’s best to put these obligations in the hands of a maintenance company that knows what signs to look out for, can fix problems quickly, and provides free replacement hardware. It takes all the hassle out of owning solar panels.

If you don't have a maintenance support package from an installer, you should consider arranging for an intermediate maintenance visit from an MCS contractor every 10 years, and a full maintenance visit every 15 years. 

If you would like to see the savings you could get from a solar & battery system, answer a few quick questions and we’ll provide an estimate.

Solar panel maintenance: FAQs