Spring cleaning: Looking after solar systems

Solar panels wash up pretty well in the rain, provided they’re installed on a decent angle. Find out what you do and don’t have to do to look after your solar PV system, and when to call in the experts.

14/10/19 0.56am

Spring is a good time to check that your solar panels are clean and your system maintained for the peak solar months ahead. Some households will be wondering whether it’s necessary to wash their panels or not, or to get in a professional solar panel cleaner.

Do what you can, up to a point

Solar expert Lance Turner from Renew magazine says it’s important to look at the source of dirt, and to know what you can do yourself and when to call in the professionals.

Debris such as leaves and bird poo can block light, so anything that covers even a tiny part of a panel can reduce output. “Bird droppings can be particularly problematic,” he says. “Brush away anything that you can with a long-handled broom, if the house is single-storey.”

Solar panels can tolerate moderate amounts of grime without too much lost generation, and if your solar panels are mounted at a slope of more than about 10 degrees, then most dirt and the debris you can’t reach with a broom, should wash off naturally when it rains.

Lance says the angle of your panels can make a difference to how well they wash in the rain. “Angled panels have the rain running across them so they get a decent wash. If your panels are installed on a flat roof with no tilt frame then they might need a more frequent hose down. The rain can pool on a flat panel and leave a muddy mark when it evaporates. Even on panels that have a shallow tilt, the dirt can pool at the bottom edge of each panel, partially blocking the bottom row of cells on each panel”.

If there hasn’t been much rain of late, or you can’t reach any debris with a broom, give the panels a light spray of water with a hose, while keeping your feet on the ground. Never use a pressure hose as it could damage your solar panels.

If the panels are particularly dirty then professional cleaning is recommended. “Some areas are dustier than others, especially near farmland or next to a main road. These panels can get much dirtier and might need to be cleaned more often,” says Lance.

Professional panel cleaning

Your installer might offer a cleaning service, done at the same time as other checks on the system. Getting your panels professionally cleaned is a good chance to get a visual inspection for defects such as cracks, chips and discoloration. Any issues can be logged, monitored for further deterioration and their effect on the efficiency of the system recorded. This information could lead to a warranty claim on the panels, if needed down the track.

Or your installer might recommend someone just for the cleaning aspect instead. There are plenty of specialist solar panel cleaning companies so get someone with a track record cleaning panels. Anyone cleaning your system should use full safety gear, and not stand on or place anything on top of the panels. They should also avoid using harsh soap or chemicals – usually water is enough.

“Remember that a bit of dust and grime on the surface of the panels is normal, and cleaning them too often is probably not worth the cost or the risk,” says Lance.

What other checks do I need on my system?

Your solar retailer or installer will provide a maintenance schedule for your system. Here’s what it’s likely to include.

Anti-islanding check

This is also referred to as a PV inverter test, and is to check that the inverter connects and disconnects to the broader electricity grid safely. Electricity distributors want to make sure that your system will not feed electricity into the electricity network in a blackout, to protect those who may be working on a local part of the grid.

Some distributors request that an anti-islanding test of the inverter be carried out once a year, so check the timing with your distributor. The test can be done by a Clean Energy Council accredited solar installer, although some householders can confidently do the test themselves, but only if shown how to do so by an accredited installer.

Professional system check

Talk to your installer about performing a thorough check on your system every five years. If they’re not available then there are a number of businesses around that service and support solar PV systems, although check that they have Clean Energy Council Solar Accreditation.

The Clean Energy Regulator lists what should be looked at in a professional system check, including confirming that no parts have corroded, that switches are free of defects, that the wiring hasn’t been damaged, and that the inverter hasn’t recorded any faults, amongst other checks.

Some installers might recommend this type of check be done once a year and combine it with a detailed clean of the system. Whether or not you want this level of service, and peace of mind, is up to you.

Regular inverter check

Your inverter will be inspected during a professional system check to see that it’s operating correctly and that the heatsinks and ventilation grills are clean. Anything that impedes normal air flow through the unit might cause it to overheat in hot weather and reduce the life of the inverter.

However, you can also do some of this maintenance yourself, by making sure the inverter is free of dirt, dust, spider webs and even vermin. Check that the inverter is running normally, and talk to your installer about what error lights, or warning codes to look for on the display.

Whether your system is brand new or you’re looking to invest in a solar PV system soon, remember that a bit of care goes a long way to making sure your system saves you money on your energy bills for years to come. Do what you can yourself, and make a schedule in your calendar so the essentials don’t get forgotten.

As well as helping system performance, regular checks mean the system is safe for everyone at home as well any electrical workers on the distribution network.


System maintenance advice from Clean Energy Council

Reviewed 14 October 2019

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