A good quality solar system that's been properly installed should run smoothly for years. But regular maintenance can help make sure your system is functioning safely and efficiently.
What are signs your solar system may need a little tune up? A significant increase in your energy bill, a red or orange light on your inverter during daylight hours, or panels that are noticeably dirty or obstructed are all signs that your solar output may be reduced and your system could benefit from a service.
But even if you don't have any of these obvious red flags, it's still worth booking a regular service, because poorly maintained panels could cost you much more than just a few dollars on your energy bill.
Solar panel fires have increased five-fold over the past three years. Fire and Rescue NSW data shows firefighters attended 139 solar panel fires last year, well up from 56 fires in 2019, and 22 in 2018.
While many of these fires are caused by incorrect installation or faulty manufacturing of direct current (DC) isolator switches – which are designed to isolate the solar panels from the rest of the house – Fire and Rescue NSW advises that regular servicing is an important factor in preventing fires.
"By ensuring solar panels are installed by a licensed installer, and are well maintained by a professional, you can prevent a tragedy," says superintendent Graham Kingsland from the Fire Investigation and Research Unit.
Annual servicing can get expensive and may not be necessary.
The Clean Energy Council (CEC) recommends setting up an annual maintenance schedule to ensure your system is safe and functioning efficiently. But annual servicing can get expensive, and some experts think this is probably overkill.
CHOICE solar expert Chris Barnes says if you have a good quality, well-installed system, the risk of something going badly wrong is very low.
"In most cases, having your system serviced once every five years or so should be sufficient," he says. "If there's any particular reason you're concerned about your system, it would also be worth getting a one-off check."
In most cases, having your system serviced once every five years or so should be sufficientChris Barnes, CHOICE solar expert
Solar Quotes CEO Finn Peacock agrees: "A well-installed solar system should be inspected every five years. If you're not confident that the system was properly installed, or you have flat solar panels, more frequent inspections are probably a good idea."
He also strongly recommends buying a good quality monitoring system to keep an eye on your system's performance.
"If you get an alert, call your installer and they will let you know if they need to come and check the system or not."
Red flags that should prompt a one-off inspection
The experts agree that in addition to regular servicing, one-off inspections may be required if issues arise.
There are some situations that should prompt a special inspection, according to the CEC:
- A change in the system's production which you may notice through your monitoring system or energy bill.
- Warnings or alerts generated by the system through monitoring software or on the inverter itself.
- Before moving into or buying a property with an existing system.
- To check for a build-up of debris – trees that drop leaves and branches on and around the system.
- To check for fauna that may be damaging your system – rats, pigeons, possums etc.
The purpose of a solar panel service is to check that the system is still in good condition and all elements are functioning as they should be. This will usually include a visual inspection, and an electrical inspection to check the electrical integrity of the panels.
Technicians will likely remove any debris and obvious grime from your panels during a service, but you'll need to pay extra for a full clean of your system.
The Australian Government's Clean Energy Regulator (CER) advises a good service should make sure that:
- solar panels are clean, secure and free of defects
- no parts have deteriorated/corroded
- vents are free of debris
- switches don't have any defects
- wiring hasn't been damaged or hasn't deteriorated
- electricals are checked to make sure all components are operating as intended
- fittings and cables are securely attached
- the inverter display panel for recorded faults is working
- access to the isolator switches hasn't been impeded
- emergency procedures for shutdown and isolation are clearly displayed.
One of the most important things that technicians will be checking for during a service is to see if water has got into your DC isolator. This issue has been identified by the CER as the most common safety risk associated with PV solar systems.
A DC isolator is a manually operated switch which turns off the power flow from the panels to the inverter. It's currently a requirement under the Australian Standard that all solar PV installations include a DC isolator switch as a safety feature to help protect firefighters from electrocution during a house fire.
But it seems these switches may be doing more harm than good. According to Fire NSW, solar panel fires have increased by more than 20% in the past year, with DC isolators identified as the cause of almost half of these blazes.
Solar panel fires have increased by more than 20% in the past year, with DC isolators identified as the cause of almost half of these blazes
A recent report published by the CER analysed fire data provided by states and territories which suggested DC isolator switches, particularly the ones located in an exposed location on the roof, have been the major cause of house fires.
The report also summarised CER inspection data from 28,041 inspections to 20 June 2019 for systems installed 2010–18. It found that 3.3% of all systems inspected have been classified as unsafe or potentially unsafe, the majority due to water getting into DC isolators. The agency notes that while many of these systems don't pose an imminent risk, they'd be likely to become unsafe without maintenance.
A burnt-out DC isolator. Credit: Fire and Rescue NSW.
Should I be worried if I have a DC isolator?
No. Most solar systems in Australia are required to have a DC isolator switch. (Those with a microinverter system are exempt because the system converts energy straight to AC power.) While they're a common cause of rooftop solar system fires, the overall risk is still relatively small, especially if you have a good quality switch installed by a reputable solar installer.
While they're a common cause of rooftop solar system fires, the overall risk is still relatively small
According to the CER, DC isolators generally have a warranty of up to five years, and they're likely to degrade over time, so it's a good idea to have your solar system and DC isolator regularly inspected, especially if you have an older system.
How long should a DC isolator last?
Since 2019 the Australian standard has required that all DC isolator switches have a metallic shroud to protect them from the elements. If you have one of these covers, and it has been well installed, you should expect your isolator to last the lifetime of the solar system.
"If your isolator switch doesn't have a cover I would recommend having it replaced (if it is showing signs of damage) or having a metal cover retrofitted," says Peacock.
A new DC isolator switch is fairly inexpensive, with the hardware costing around $50, plus installation costs.
A standard service by an accredited solar installer costs roughly $200 to $300 depending on the size of the system and the individual provider. If repairs are required, the costs will vary, but many repairs may be covered by your warranty.
A solar panel system is a complex and potentially dangerous piece of technology and it's recommended that any service or maintenance should only be performed by a licensed electrician or a Clean Energy Council-accredited solar panel system installer.
Barnes says if you're looking for somebody to perform the service, the simplest option may be to use the same company that installed your system if you're happy with their work.
"They should know the ins and outs of your system, so it may be easier for them to perform the service," he says.
But he also recommends shopping around and getting quotes from a few companies before committing.
"If you aren't familiar with the company, do a little online research first to make sure they're reputable."
Always ask to see your provider's inspection checklist before booking and make sure they'll provide a written inspection report
You can read our guide on how to find a good solar installer for more information on finding a reputable installer.
Peacock adds that you should always ask to see your provider's inspection checklist before booking and make sure they'll provide a written inspection report.
"This will help to weed out any dodgy providers and give you peace of mind that your system has been checked properly."
A professional clean can cost $10–20 per panel, but for most people rain does the job just fine.
While poorly maintained panels can pose a safety risk, dirty panels aren't usually dangerous – they may just be less efficient. But a professional clean can cost $10–20 per panel and Peacock says for most people, regular cleaning will end up costing you more than it's worth.
"For most people who have angled solar panels, rain does the job just fine. Unless you live in a very dry climate, or have specific issues with animal droppings or overhanging vegetation, you should never need a professional clean," he says.
Give your panels a rinse by hosing them off from the ground ... or follow the manufacturer's cleaning instructions
If your panels are looking a little dirty but you don't want to shell out for a professional clean, it may be tempting to climb up there and clean them yourself. But we don't recommend going up a ladder or on the roof to clean your panels.
If it hasn't rained in a while, you can give your panels a rinse by hosing them off from the ground instead or follow the manufacturer's cleaning instructions. But be careful not to damage them as it may void your warranty.
If you move into a home with solar already installed, your landlord has a responsibility to ensure that the system is appropriately maintained, says Jemima Mowbray, policy and advocacy co-ordinator at the Tenants Union of NSW.
"As a renter, you absolutely have the right to request that your solar system is maintained to make sure your home remains habitable and safe," she says.
If the solar system on your rented home causes a fire, the landlord could be liable to pay you compensation
In fact, if something goes wrong and the solar system on your rented home causes a fire, the landlord could be liable to pay you compensation.
"If the landlord has failed to properly maintain the system and this has led to a fire, you have the right to claim compensation for economic loss," says Mowbray. "I would recommend keeping a note of how well the system is being maintained, as well as the expected lifespan of the system."
She notes that in the rare case that the tenant has bought the solar system themselves, they'd be responsible for maintenance.