Solar Panel Maintenance and Cleaning: How to Keep Your System Performing
Solar panels are built to sit outdoors for decades, and for most homeowners they need very little attention. But dust, bird droppings, leaves and the occasional wasp nest can all build up over time, and a little regular care can help your system keep performing as it should.
The good news is that solar panel maintenance and cleaning is usually simple. The important part is knowing what is worth doing, how often, and what is best left to a professional.
This guide explains whether your panels really need cleaning, how to clean them safely, and which simple checks can help you spot problems early.
Do Solar Panels Actually Need Cleaning?
In many parts of Australia, rain does a good job of washing loose dust off panels, particularly when they are tilted at an angle. Most panels are installed on a tilt, so rain can run across them and carry dirt away.
That does not mean cleaning is never needed. Rain does not remove everything, and some types of build-up stay put and can bake onto the glass in the sun.
Anything that sits on the surface of a panel blocks some sunlight from reaching the cells. A light layer of dust usually has a small effect, while heavy build-up can reduce output more noticeably. Panels that are already reasonably clean will not gain much from a wash, so cleaning "just in case" often makes little difference.
What Makes Solar Panels Dirty?
The most common causes of build-up on Australian roofs include:
Dust and dirt, especially in dry areas or near unsealed roads
Bird droppings
Pollen and tree sap
Leaves and other debris
Salt spray near the coast
Smoke and ash residue after bushfires
Moss or lichen in damp, shaded areas
Why Bird Droppings Matter Most
Bird droppings are usually worse than a general film of dust. They can completely cover part of a panel, and because solar cells are wired together, a blocked section can drag down the output of the whole panel. Rain rarely shifts them, so they tend to stay until someone removes them.
How Often Should You Clean Your Solar Panels?
There is no single answer, because it depends on where you live and how your panels are installed. As a general guide:
Panels on an angled roof in an area with regular rain often only need a wash when they look dirty. A visual check once or twice a year is a good habit.
Flat or low-angle panels do not self-clean as well, so they may need cleaning more often.
Panels in dry, dusty areas, near busy roads or on the coast can build up grime faster.
Panels near trees, or in areas with lots of birds, may need more frequent attention because of sap, leaves and droppings.
After pollen season or a bushfire, an extra check is worthwhile.
If your solar production has dropped and nothing else has changed, a visual check is a good first step.
Solar Panel Maintenance and Cleaning: How to Do It Safely
Safety Comes First
Do not climb onto your roof to clean your panels. Falls from roofs are a serious risk, panels can become extremely hot in the sun, and solar systems carry high voltages. If you cannot reach your panels safely from the ground, leave the job to a professional.
A Simple Ground-Level Method
Check your panel manufacturer's cleaning recommendations first, as they may affect your warranty.
Choose a cool time of day, such as early morning or late afternoon, and avoid cleaning hot panels.
Rinse loose dust off gently with a garden hose, if you can reach the panels safely from the ground.
Use a soft brush or non-abrasive sponge on a long, extendable pole with clean water. For stubborn marks, a small amount of mild, non-abrasive soap may help.
Rinse thoroughly with clean water so no soap residue is left behind.
What to Avoid
Do not use a pressure washer or high-pressure hose, which can damage the panels or the seals.
Do not use harsh chemicals, abrasive pads or stiff brushes, which can scratch the glass or coating.
Do not stand or lean on the panels.
Do not clean in the middle of a hot day, when cold water on a hot panel is not ideal and the panels are too hot to work around safely.
Do not touch or move any wiring.
When to Call a Professional
It is worth calling a professional if your roof is high or steep, if the build-up is baked on and will not shift with a soft brush, or if you notice damage. Many window cleaners and specialist solar cleaners are trained to clean panels safely and have the right equipment.
Beyond Cleaning: Simple Maintenance Checks
Cleaning is only one part of looking after a solar system. A few regular checks can help you catch problems early:
Look at your panels from the ground. Check for cracks, discolouration, loose or damaged parts and anything sitting on the surface.
Watch for shading. Growing trees and new structures can start to shade panels over time and reduce output.
Check for nests. Birds, possums and wasps sometimes nest under or around panels, so keep an eye out.
Check your monitoring app. Compare your production on similar sunny days, so you can spot a genuine drop.
Check your inverter. Look at the display or indicator lights, and take note of any error messages or warnings.
Keep the area around your inverter and battery clear. Do not store items against them or block ventilation.
Signs Your System May Need Attention
Contact your installer if you notice:
A sudden or unexplained drop in solar production
Production that is consistently lower than usual on similar sunny days
Error messages, fault lights or alerts on your inverter or battery
Cracked or damaged panels
Damaged or exposed cables
Signs of animals or nests around your panels
Do not try to repair or modify your solar or battery system yourself. Electrical work and system checks should be carried out by a qualified professional.
Frequently Asked Questions
Does rain clean solar panels?
Often, yes, especially if they are tilted. Rain can wash away loose dust, but it will not remove bird droppings, baked-on grime or salt film.
Can dirty solar panels reduce my power output?
Yes. Dust, droppings and debris block sunlight from reaching the cells. Light dust has a small effect, but heavy build-up can reduce output more noticeably.
Can I clean my solar panels myself?
Only if you can do it safely from the ground. Never climb onto the roof, and use a soft brush or sponge with clean water. If you are unsure, use a professional.
Can I use a pressure washer on solar panels?
No. High-pressure water can damage panels and seals. Use gentle pressure and clean water.
How often should my solar system be checked by a professional?
There is no single rule, but many homeowners find it useful to have the system checked every so often, or if production drops or alerts appear. Your installer can advise what suits your system.
Keep Your Solar System Performing
A little regular care goes a long way. Keeping your panels reasonably clean, checking them from the ground and keeping an eye on your production can help your system keep delivering for years.
If you have noticed a drop in performance, or you would like your system checked or upgraded, DSW Energy can help you understand what is going on and what options make sense for your home.
DSW Energy provides solar, battery and energy solutions across South Australia, Queensland, New South Wales and Victoria.
Call DSW Energy on 1300 958 778 to discuss your options.
