How to clean solar panels

By BWS

Can you pressure wash solar panels?

Solar panels do not usually require frequent cleaning. A heavy rainfall is usually enough to clean off dust or dirt. In most normal residential situations, your solar panels will rarely need cleaning.

Over time, however, particularly in areas of low rainfall and where the panels are set onto a flatter surface, grime can accumulate. Bird droppings, sand and gritty dust can gather and eventually impact on the amount of power that the panels are generating.

Here are possible scenarios that might warrant your checking your solar panels to ensure they remain clean:

- A colony of fruit bats has moved into the neighbourhood
- A large flock of galahs has taken up residence in the nearby park
- Swarming insects have left many marks and smudges on your walls or windows
- Thick spiderwebs can be seen under the eaves or behind the facia boards
- Leaves are still stuck to your windowpanes after the last storm
- Possums, rodents or nesting birds have been on your roof or near the panels

You get the picture :)

Roof cleaning professionals are usually trained and experienced in correct procedure around solar panels. When you book your roof cleaners you can speak to them about this and you can specify whether or not you wish the panels to be included in the cleaning.

If you decide to DIY, here are some steps to follow.

1. Close down the solar panel system before you begin cleaning it. For this, follow the steps in the instruction booklet that goes with your particular system.

2. The procedure is then similar to that of washing windows that are high up. You do not need a high pressure power wash to clean the panels.

3. If you are able to access the panels from the ground, using an extension pole attached to your pressure washer, then this is a good way to go. It is preferable to standing on the roof while operating the pressure washer.

4. Depending on the roof surface area covered by your panels, the most useful pressure washer attachment for this job is usually a soft bristle, rotating brush.

5. Do not use: too high a water pressure; any metal object for cleaning; any strong abrasive cleaning liquid; anything at all that would risk scratching or marking the surface of the panels. If the surface of the panels becomes scratched this affects their ability to generate power. Using even 'normal' detergents can result in smears or streaks appearing on the panels, affecting their performance. Plain water is probably best.

Jun 01 '22

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