Clean solar panels are efficient solar panels
Your new solar system requires very little maintenance, but a clean solar panel is much more efficient than a dirty or dusty one.
Your solar power system’s output may be reduced if your panels are covered in dust, dirt or grime. This blocks the sunlight out and reduces its efficiency. To get the full cost-saving benefit of solar power, it’s best to keep your panels relatively clean and free of debris.
Dust, dirt, pollen, bird droppings and leaves can all take their toll on the performance of your solar system. A regular cleaning can do wonders to improve its efficiency.
Often, natural rainfall will wash away particles of dust or dirt, but you may still need to give it a helping hand with your garden hose.
Step-by-step guide to cleaning solar panels
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.
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.
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.
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.
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.
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.
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.
Common questions about cleaning solar panels
How often should I clean my solar panels?
Your solar panels should be cleaned approximately every 6 months.
Late spring and late autumn are great times to clean your solar panels: you could combine this with your semi-annual gutter clearing.
In particularly dry, dusty areas, such as rural farms, or areas where there is more air pollution, including industrial areas or construction sites, your solar panels might need to be cleaned a little more often, but this shouldn’t be more frequent than every 3-4 months. This might also apply if your solar panels are relatively flat and regular rainfall can’t rinse off the dust effectively.
Can I use a pressure cleaner to clean my solar panels?
We suggest not.
A pressure water could do more harm than good – you’d hate to accidentally damage your solar panels while you’re trying to improve their performance. A gentle stream of water will be more than sufficient to wash away the dirt and debris. Leave the pressure washer for your driveway or the caked-on mud on your 4WD!
What can I use to clean my solar panels?
A simple, mild soap and water is enough to wash any accumulated dirt and debris. Check your manufacturer’s instruction or operating manual for any instructions about what cleaning fluids or materials you should or should not use.
If the grime is a little more stubborn, you might want to invest in a soft cloth-covered squeegee or sponge – an extended handle is also great to have handy for those hard-to-reach spots, without the need to climb up a ladder.
Need more advice?
Download your copy of our Solar and Battery Storage Buying Guide for comprehensive information about solar panels and battery storage.
This guide covers:
- how solar panels work;
- what is included in a solar power system;
- ongoing maintenance; and
- how to future-proof your system for maximum payback.