Cleaning solar panels: why, when and how you should do it
Step-by-step guide to cleaning solar panels
1. Shut down your system entirely.
Your system should be completely shut down before cleaning as per the shutdown procedure listed in your user manual or your inverter manufacturer’s operating manual. DC Systems will need to be completely shut down. AC Systems should be shut down via the Solar Supply Main Switch.
2. Disconnect or block off any rainwater collections or gutters.
Where rainwater tanks are installed and connected to your guttering system, have them temporarily disconnected or shut off from the gutters to ensure no run-off of dirty water goes into your tank.
3. Choose a cool, mild time of day.
The combination of hot glass on your panels and cool water can increase the chance of cracks from a sudden change in temperature. Additionally, if the hot sun is beating down on the panels, any water you’ve used could quickly evaporate and leave dirty marks – undoing all of your hard work! A cool, early morning is a particularly good time for cleaning. Dew that has settled on the panels overnight could have softened the dirt and grime, meaning you’ll need to use less water and less energy to clean your solar panels. If you can’t manage an early morning, an overcast day or a mild, cool evening are also ideal times to clean your solar panels.
4. Clean your panels from the ground if possible.
For safety reasons, it’s wise to clean your panels from the ground if possible. Use a hose to direct water onto your panels. Use a hose with a suitable nozzle to allow the stream of water to reach the panels.
5. Make sure that you only direct water onto the top of your solar panels.
Whilst it is ok for some water to touch the back of your panels, you should not intentionally direct water onto the back of your panels or into the gap between your panels and your roof.
6. For stubborn grime, use a soft cloth and mild soap.
You don’t need to invest in any fancy cleaning solutions: just water and a mild soap will do the job. A good quality soft brush and squeegee with a plastic blade on one side and a cloth-covered sponge on the other, coupled with a long extension, can make for the perfect tool – and keep you safely on the ground.
7. Don’t attempt to climb on your roof without appropriate safety equipment.
The risk of working on your roof is increased by using water. A roof can become quite slippery when water is used for cleaning. If cleaning your panels from the ground is not possible, do not attempt to access your rooftop unless you have the appropriate safety equipment and training. For your safety, it’s best to hire a suitably qualified professional cleaner instead.