How to clean and maintain solar panels

Solar panels generally require very little maintenance, and in many cases, rainfall will wash away most dirt and debris. However, an occasional clean can help ensure they’re generating as much electricity as possible. This is especially the case if dust, pollen, leaves or bird droppings have built up on the surface.

As a guide, it’s worth checking your panels every 12 to 18 months and cleaning them if there’s visible dirt. You may need to do this more often if:

• you live in a dry, dusty area
• your panels are close to trees, grow lichen or are regularly affected by bird droppings

Rooftop solar panels are often kept relatively clean by rainfall because of their angle. Ground-mounted panels may collect more dirt and could require more frequent cleaning.

If your panels are near trees, keep branches trimmed to reduce shading and prevent leaves from accumulating on the panels.

Your solar panel installer can advise on whether cleaning is recommended for your system and provide guidance on any other maintenance requirements.

Professional solar panel cleaning costs typically start at around £60 to £100 for a standard system. However, the price can be higher for larger installations or roofs that are difficult to access.

The final cost will depend on factors such as:

• the number of panels
• their location
• whether specialist access equipment is needed

Before booking the job, it’s worth getting a few quotes from local providers.

For most homes, professional cleaning is an occasional expense rather than a routine requirement. This is because rainfall naturally removes much of the dirt that builds up on solar panels.

If you only need to remove dust from the panels, you might be able to wash this off with water using a hose pipe. If you can reach the panels with a jet of water from the ground, this is a quick and easy process. 

Occasionally you might need to do a deeper clean to get rid of more stubborn dirt. In that case, use a soft, long-handled brush or sponge to lightly wipe the surface of the panels.

You’ll need safe access to the solar panels themselves, and you’ll need to know how to turn off your solar panel system too.

It’s best to use just water and a soft brush or sponge. Washing up liquid and other cleaning products can leave a residue on the panels, which may affect their performance.

If water alone isn’t enough to remove stubborn dirt, check the manufacturer’s guidance or ask your installer for advice before using any cleaning products.

No, you shouldn’t stand on solar panels when you’re cleaning them. Solar panels aren’t designed to support the weight of a person and could crack or break completely.

Panels can also have slippery coatings on them, which is dangerous especially if you’re working at a height. 

No, you should avoid using a high-pressure power washer to clean your solar panels. Power washers can interfere with seals and wiring on your solar panels, which can lead to water damage.

A soft spray from a garden hosepipe should be enough to clean your solar panels effectively.

To clean solar panels from the ground, you’ll need a hosepipe with a jet that can reach the panels. For a thorough clean, you’ll also need a long-handled brush to reach them. Make sure you’re standing on even ground and be careful with objects surrounding you. 

If you’re struggling or straining to reach your solar panels, it may be best to ask a professional to clean them. 

Solar panels don’t cost much to maintain. If you’re able to clean them yourself, you can simply use water from the tap. If you get a professional clean, expect to pay at least £60 to £100.

Solar inverters, which convert the energy produced by the solar panels into electricity typically need to be replaced every 10 to 15 years. This usually costs around £800. 

Many parts of a solar panel system will be covered by a warranty from your installer, so keep your warranty documents safe.

With proper maintenance, your solar panels should work effectively for many years. Follow this checklist to see what steps you should take to keep your solar panel system working smoothly.

Every one to two years

• Inspect your solar panels, mounting system and any visible wiring, or have a professional do so.
• Check for signs of wear and tear, damage, water ingress, dirt build-up, bird droppings or lichen growth.
• Arrange repairs if any issues are identified, and clean the panels if needed.
• You should consider cleaning more frequently or as required if they are particularly dirty due to local environment conditions such as dust, bird activity or lichen growth.

Every three to five years

• Have a full professional service to inspect for small cracks or inverter issues.
• Check your warranty policy from your installer. Some installers require a full service within a specific period to keep the warranty valid.

Do solar panels clean themselves in the rain?

Rain does clean solar panels, but cleaning them with water from your garden hose and a light brush or sponge can help improve performance.

When’s the best time of year to clean solar panels?

There’s no “best” time to clean solar panels. It depends on what’s causing them to get dirty. For example:

• more dust during dry weather
• more bird droppings at certain times of year
• more pollen in the spring
• more leaves in the autumn

Check your panels occasionally and clean them if dirt or debris is starting to build up.

What is the best time of day to clear solar panels?

• Check with manufacturer instructions or with your installer as its best to have the water within a specific temperature range.
• Morning or late afternoon is usually recommended.
• If you can, avoid very hot days. Solar panels can become much hotter than the surrounding air, and cleaning them when they’re hot can cause water to evaporate quickly and leave streaks behind.
• If you can, wait for a cooler, overcast day or clean them early in the morning before the panels have heated up.

Does cleaning solar panels improve performance?

Yes. Dirty solar panels can reduce how much electricity solar panels generate as it affects how much sunlight reaches the panels.

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