How to clean your solar panels

There is no set golden rule to cleaning solar panels. There are some simple rules to follow but it is mostly common sense. You wouldn’t clean your glass splash back with steel wool, and the same principles apply for solar panels.

Solar panel manufacturers may have requirements to make sure that you will not void their warranty policy. For these reasons we suggest that no chemicals are needed to be used.

We have been cleaning solar panels for over 5 years now and have found that most installed can be cleaned using clean tap water (any temperature apart from very cold to avoid any possible glass cracking due to temp mismatch)  but luke warm to hot seems to work well on stubborn dirt and bird droppings.

Treat the panels like your glass splash back or window in your home. A non abrasive cloth is the safest option and elbow grease (hard manual labor) will always give a great result.

After panels have been cleaned, depending on the amount of dirt and debris on the panels, the efficiency of the panels in some instances could be improved by between 3 and 30 %.


Amorphous solar panels before cleaning.


Amorphous solar panels, fully cleaned on right half cleaning on left.


After panels have been cleaned depending on the amount of dirt and debris on the panels the efficiency of the panels in some instances could be improved by between 3 and 30 %.

Do I need a solar professional to clean my panels?

A solar professional, should know the best ways to clean your panels and should have their working at heights certification. If you choose to not use a solar professional to clean your panels then there are a couple of things to take into consideration.

As mentioned please make sure that who ever goes onto the roof has his working at heights certification and works safely as roofs and water are not a great combination if not taking care.  Secondly there is a right way to move around a solar panel. It is best to stay off the solar panels but if there is no other options than certain areas of the panels are better to put weight on than others. Specifically the points of the panels where mid clamps are connected have a better load distribution and support. Again, please consult with us prior to attempting cleaning yourself.

When Solar panels get moss and lichen built up.

This is not a common occurrence but there are specific areas that are prone to moss and lichen build up. They seem to be more likely with the older Amorphous solar cells and roof surfaces that are light in colour. This is a lot harder to clean off your roof and should be done by solar professionals that know what they are doing as specialised equpiment may be needed.

Unfortunately moss and lichen cause large amounts of shading to panels and can have a detrimental effect on system performance.

How often should I clean my solar panels?

This is not a straight forward question. Every site is completely different. Some variations that would alter the timing of cleaning solar panels can be the angle of the panels on the roof. The lower the pitch the harder it is for the panels to self clean. New estates unfortunately usually get more dust build up because of construction work amd in coastal areas salt build up can be an issue. The type of solar cell can also have an impact.

The standard answer to the question is vague but the cleaner you keep your panels the better the solar production. The thing to remember when deciding how often to clean your panels is not only the energy yield but also the expense. If you are paying a tradesman money to complete this service and it greatly exceeds the the increased value received from having cleaner panels, you may need to consider the frequency of your panel cleans. If lichen or moss is present and in large amounts, regular cleaning becomes more warranted, as loss of performance will start to make a significant difference to system production.

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