Revealed: the three most common solar panel problems (and what to do about them)

On the whole, solar panel systems tend to be pretty low maintenance. As one owner explained, you simply 'fit and forget'. 

But if your solar PV system does have problems, it can mean it stops producing electricity and needs urgent maintenance. 

That can be costly when you're used to using free solar power and have to use pricey grid electricity instead. Plus, you'll lose out on any payments you get for exporting electricity.

We surveyed more than 2,000 Which? members with solar panels in April 2024 to find out which issues are most likely to occur and which are most serious.

Find out how to solve solar panel problems, or see the best solar panel brands, according to their owners. 

Will my solar panels have problems?

Thankfully, the rate of problems arising from solar panels is fairly low. Some 68% of solar panel owners told us they'd had no technical issues with their solar pv systems since they were installed.

And nearly half of owners had done no maintenance at all on their solar panel system since it was fitted.

Here are the most common issues that did come up and what to do about them:

1. Inverter problems

By far the most common solar panel problem – 15% of owners told us they'd had problems with their solar inverter.

Inverters aren't expected to last as long as the solar PV panels themselves, so you're likely to have to replace yours at least once over the course of your solar panels' lifetime.

If your inverter breaks, you won't be able to use the electricity that your solar panels are producing. That's because it converts the direct current (DC) electricity that your solar panels generate into the alternating current (AC) electricity which your home needs. 

So it's important to get it fixed quickly. 

If your solar panel system is new, you might be able to get your inverter replaced under warranty. If you have the skills needed, you might be among the 2% of those who'd needed a replacement who were able to carry out the job themselves. But the majority (82%) hired a professional.

Find out how to fix solar panel inverter problems, including how much it costs.

2. Faulty electrical connections or wiring

Electrical problems with solar panels are far less likely than inverter problems. Just 3% of the people in our survey reported them.

But it's important not to interfere with electrical connections or wiring (unless you're qualified) because there's a serious risk of electric shock. 

Instead – if it's safe – turn off the AC and DC isolators while you call an electrician.

Find out what causes solar panel electrical problems and whether they're likely to be covered by your warranty.

3=. Solar panels producing no electricity

Shading, misty mornings and cloudy conditions can all cause your solar panels to produce less electricity than usual. Solar panels also become slightly less efficient over time.

But it indicates a more serious problem if they stop producing electricity completely. It could be caused by:

• a fault with the inverter
• a problem with the wiring
• the generation meter failing (see below).

There are a few things you can do quickly to help work out what might be causing the problem. Get this fixed as soon as possible - you'll be relying on pricey grid electricity until then.

Find out what to do if your solar panels stop working.

3=. Solar PV generation meter not working

If there's a problem with the generation meter only, then your panels will still be producing electricity which you can use in your home. It just won't be measured.

This is a bigger issue if you're paid for the energy your solar panels produce (for example, if you get paid the feed-in tariff).

You can check quickly whether this is the problem by comparing the real-time and cumulative generation on your inverter.

Find out what to do next if you have a broken solar PV generation meter. 

What solar panel maintenance should I do?

Solar panel systems don't need huge amounts of maintenance. A third of solar panel owners we asked who had had their panels for more than 10 years said they hadn't needed to do any maintenance.

Rain can wash away much of the dirt and debris unless they're very heavily soiled.

The most common maintenance tasks owners do are:

• Visual checks to look for dirt, debris and damage - 26% do this
• Monitoring day-to-day performance - 22% do this
• Regular cleaning - 16% do this.

To keep your solar panel system in good shape, it's also worth:

• Checking for shade on your panels - trees and shrubs that grow and block the sun from your panels will affect the amount of electricity they produce. So it's good practice to prune them back.
• Keeping an eye out for birds or squirrels nesting under your panels. They can cause damage, as well as soiling your panels. 

Read how to make the most of your solar panels with tips from owners. Or find a reputable solar panel technician using Which? Trusted Traders.