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Solar panels have become increasingly prevalent in recent years, as the cost of the tech and installation falls, and society becomes more conscious of climate change and the importance of renewable energy.

If you’ve switched to solar energy or are considering having solar panels installed, you may have some questions about their maintenance. In this article we answer all your questions about how to clean solar panels to ensure their maximum efficiency and a long lifespan.

What is a solar panel?

Without getting into the finer technical points, solar panels on a building’s roof absorb sunlight, and convert the light into electricity to power appliances in your house.

An average sized house has enough roof area for a grid of solar panels to generate enough electricity to meet the energy needs of the home.

Do solar panels need cleaning?

Solar panels often require less maintenance in the UK compared to other regions in the world, thanks to the level of rainfall we have that regularly washes away grime, dust and debris. However, it may still be the case that there are instances when your solar panels need to be cleaned; for example if there is visible dirt, bird droppings, algae, pollen, or if your solar panels have become generally grimy – especially if they’re on the ground (they become dirty more quickly than panels on a roof). If the tilt on your panels is less than 5 degrees they are also prone to collecting more dirt so it’s worth bearing that in mind.

If you don’t have time or aren’t confident cleaning your solar panels yourself, it is possible to install automated cleaners that work like sprinkler systems. This, however, is an expensive solution and in the UK is generally not necessary. Alternatively, you can arrange for specialists like Cardiff Window Cleaner Ltd to come and clean your solar panels.

How often should I clean my solar panels?

How regularly you clean your solar panels depends on the factors mentioned above, but a good rule of thumb is if the panels become visibly dirty, it is time to consider cleaning them. This can also be signified by a drop in the amount of electricity being generated – a loss in efficiency like this might be due to less sunlight penetrating the panels.

How do you clean solar panels?

If you decide to clean your solar panels yourself instead of hiring a professional, we strongly recommend cleaning them from the ground for safety reasons. Only professionals trained at working at height should clean the panels at roof level.

Equipment needed:

  • Soft brush
  • Squeegee (sponge on one side; plastic blade on the other)
  • Hose

First of all, choose the right time of day for the job. We recommend either early morning or evening, preferably on an overcast day. Morning is great as the air is often damp and can make it easier to soften the debris on the panels.

This next point is crucial: before you start, shut down the system and be wary of the cables. If you see damage to any of the cabling, stop and get it checked.

To clean solar panels from the ground, we recommend first using a soft brush with a long extension. Use this to brush away any loose debris.

Next, apply water to the panels using the hose. Make sure whatever grime or dirt is covering the panels is thoroughly soaked.

Finally, use the squeegee to clean the panels, being careful not to apply too much pressure to the surface. Be sure to finish with the plastic blade as this will reduce the chance of streaks and water deposits remaining on the panels, both of which can reduce their efficiency.

Can you pressure clean solar panels?

Do not use high pressure spray to clean your solar panels. Even if you have stubborn dirt or debris stuck to the panels, pressure washers can damage the panels, at the very least impairing their capacity to convert sunlight to electricity, and could invalidate any warranty.

Do solar panels need cleaning snow off?

Clearly, if your panels are covered in snow they won’t be generating any electricity for your home. One option is, however, to wait until the snow melts and slides off the panels. This will happen more quickly with roofs and panels that are at higher angles.

If you can’t wait for the thaw, it is possible to spray the snow with water from your hose to melt it. This, of course, is dependent on the air temperature being high enough that the water doesn’t simply freeze on the panels. It’s also really important to make sure the water temperature is right for this – if it is too hot there is a risk that it could crack your panels.

In summary, the air temperature needs to be high enough that the water doesn’t freeze, and the water temperature needs to be low enough that it doesn’t crack your cold solar panels when it hits them.

Finally, it’s also possible to use your squeegee to dislodge the snow so it slides off the panels.

In conclusion, it is eminently possible to clean your solar panels yourself. However, if you aren’t confident or don’t have the appropriate tools for the job, it is worth considering hiring a professional for peace of mind and knowledge that the job will be carried out by experienced cleaners.

If you’d like to discuss further or would like a quote for us to clean your solar panels, please do get in touch for an initial discussion. Email us at or contact us on 07971 048 128. You can also send us photos of your set up via WhatsApp.

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