When people have solar panels installed they often think ‘that’s it, job done, nothing else to do’. It is true to say that solar panels don’t require much maintenance but, there is one job you must do – keep them clean.

So, why do we need to keep solar panels clean? Well, it isn’t anything to do with their appearance, but, it’s to make sure they work well and are efficient. When solar panels are kept clean they operate to full capacity, if the simple task of cleaning is not carried out regularly, then you may see a significant drop in output.

How dirt affects solar energy production

To maximise the output solar panels are usually installed at an upward angle to ensure they catch the maximum amount of light, while this helps to achieve the primary objective of the panels it does, unfortunately, make them more prone to bird droppings, dust, dirt and general debris.

 If this dirt builds up and you don’t have your panels cleaned regularly, you’ll soon realise that the panels will not be performing at full capacity. The more panels you have, the higher the energy loss overall.

Installing solar panels is a significant investment whether that be for a household or indeed a business so make sure you get the most out of your investment and keep your panels clean.

How do you clean solar panels?

It all depends on how many panels you actually have, for example for homeowners with just a few solar panels, there are a couple of simple options for cleaning. You could clean them yourself, if you have a head for heights, a (very) tall ladder and a way to keep yourself safe but, to minimise risk, avoid potential injury and get a better finish, leave it to the experts.

It is safer and easier to use a specialist window cleaner with experience of cleaning solar panels

Most solar panels installed in the UK are self-cleaning, but that doesn’t mean that they never need to be cleaned! There are many factors to consider, e.g. if your panels are only slightly tilted then the rain may not ‘wash’ off all dirt and dust, and dirty water can pool on the surface, leaving residue behind.

If your panels are working efficiently and generating the power you expect then your panels probably don’t need to be cleaned.

As a general rule of thumb, if your generation figures are running at optimum, then you don’t need to do anything about solar panel cleaning. Checking every year is a good idea. For industrial or commercial buildings with large numbers of panels, regular solar panel cleaning is recommended for maximum efficiency.

Essential advice for effective solar panel cleaning

If you have a roof mounted solar panel system, cleaning is clearly a job for the professionals. Solar panel cleaning crews have the right equipment and expert knowledge to clean panels properly and work safely at height, and they can complete the job a lot quicker than you ever could.

For ground-mounted panels, there’s no reason why you can’t clean them yourself. Shut down the system temporarily before starting, and don’t proceed if you spot any damaged cables. You’ll need:

  • A good quality soft brush
  • A squeegee with a plastic blade on one side and a cloth covered sponge on the other – preferably with a long extension if your panels are large, or there’s a lot of them
  • A good supply of soft water, harvested rainwater can be used if there is hard water in your area.

Start cleaning in the early morning, as the panels are cool and the dew can make cleaning easier. Make sure to squeegee the panels immediately after washing to avoid any residue being left behind.

before an after clean image