Summer is when your solar power system earns its keep. Longer days, higher sun angles and intense UV across Sydney mean your panels should be producing at their peak from November through to March. But after months of autumn rain, winter storms and spring pollen, your system may not be performing as well as it could.
A quick pre-summer solar inspection helps you catch small problems before they cost you real money. Dirty panels, a flickering inverter light, a cracked cell or a tree that has grown just enough to cast a shadow can all drag down your output right when generation should be at its highest. The good news is that most of these checks take minutes, not hours, and a handful can be done from the ground without climbing onto the roof.
Here are eight things every solar system owner in Sydney should inspect before the hot months arrive.
1. Clean Your Solar Panels
This is the single most impactful thing you can do before summer. Over the cooler months, panels accumulate a layer of grime from bird droppings, dust, pollen, tree sap and general atmospheric fallout. Even a thin film of dirt can reduce output by 5 to 15 percent, and stubborn bird droppings sitting on a single cell can cause localised hot spots that affect the performance of an entire panel string.
For most single-storey homes in Sydney, a gentle rinse with a garden hose from the ground is enough to clear light dust and pollen. Avoid using high-pressure washers, abrasive sponges or harsh chemicals, as these can scratch or damage the anti-reflective coating on the glass. For bird droppings or sticky residue that will not shift with water alone, a soft brush with an extension pole and plain soapy water does the job.
If your panels are on a two-storey roof or in a hard-to-reach position, leave the cleaning to a professional. The cost of a professional solar panel clean in Sydney is modest compared to the generation you recover, and it avoids any safety risk from working at height.
2. Inspect for Physical Damage
While your panels are clean (or while the professional cleaner is up there), take the opportunity to look for visible damage. Sydney’s spring storms can send branches, hail and debris onto rooftops, and even minor impacts can crack a cell or chip the glass without being obvious from the ground.
Look for hairline cracks across the panel surface, chips or fractures along the edges, and any discolouration or browning of individual cells. Yellowing or browning patches can indicate delamination, where moisture has penetrated between the glass and the cell layer. If you spot any of these, contact your installer or a qualified solar technician for a closer inspection. A damaged panel will underperform and, in some cases, create a safety risk.
Also check the mounting rails and clamps that hold the panels to the roof. Over time, expansion and contraction from temperature swings can loosen fixings. Anything that looks shifted, raised or rattling in the wind should be tightened or repaired before summer storms test the system’s structural integrity.
3. Check Your Inverter Display and Error Codes
Your solar inverter is the brain of the system. It converts the DC electricity produced by your panels into the AC power your home uses, and it monitors the health of the entire array. Most inverters have a front-panel display or LED indicator that shows whether the system is operating normally.
Take a minute to walk to your inverter (usually mounted on a garage wall, laundry wall or near the switchboard) and check its status. A solid green light on most Fronius and Sungrow models means everything is running as expected. A flashing light, red indicator or error code on the screen signals a fault that needs attention.
Common inverter issues include earth faults, grid voltage fluctuations and isolation errors. Some of these resolve on their own after a system restart (switching the inverter off and back on via the DC and AC isolators), but persistent faults should be investigated by a qualified technician before summer, when you need the system performing at full capacity.
4. Review Your Monitoring App Data
If your solar system came with a monitoring app (most modern inverters from Fronius, Sungrow and other major brands include one), open it up and review the generation data from the past few months. You are looking for any unusual drops in daily output that cannot be explained by cloudy weather.
A sudden decline in production on a clear day often points to a specific issue: a faulty panel, a tripped string, a shading problem or an inverter fault. A gradual decline over several months may indicate soiling buildup or slow degradation of a component.
Compare the current output to the same period last year, if you have that data available. If your system is producing noticeably less than it did at the same time last spring, that is a strong signal to investigate before the high-production summer months. Catching a performance issue now means you get the full benefit of summer’s long, sunny days rather than losing weeks or months of output to an undiagnosed fault.
5. Trim Overhanging Trees and Clear Shading
Trees grow. It sounds obvious, but a branch that was well clear of your panels when the system was installed may now be casting a shadow across part of the array, especially during the morning or late afternoon when the sun sits lower. Even partial shading on a single panel can reduce the output of an entire string in a standard string inverter system.
Walk around your property in the morning and again in the mid-afternoon to see where shadows fall across the roof. If overhanging branches or new growth from neighbouring trees are creating shade on your panels, arrange for trimming before summer. In Sydney, most tree trimming on your own property does not require council approval, but trees protected under a Tree Preservation Order (TPO) may need a permit. Check with your local council if you are unsure.
If shading is an ongoing issue that cannot be fully resolved by trimming, ask your installer about adding panel-level optimisers or switching to micro-inverters, which allow each panel to operate independently and minimise the impact of partial shade on the rest of the array.
6. Inspect Wiring, Conduits and Isolator Switches
This is a visual check you can do from the ground. Look at the DC cabling and conduits that run from the panels down to the inverter. You are checking for any signs of wear, cracking, UV degradation or pest damage. Sydney’s possums and rats are notorious for chewing through exposed solar cabling, and damaged insulation can create a serious electrical hazard.
Check that all conduit clips are secure, that no wiring is hanging loose or rubbing against the roof, and that the conduit itself has not cracked or split from prolonged sun exposure. Also inspect the DC isolator switch (the weatherproof switch usually located on the roof near the panels or on the wall near the inverter). DC isolators can degrade over time, especially cheaper models exposed to heat and moisture. Any signs of discolouration, melting, water ingress or a burning smell mean the isolator should be replaced immediately by a licensed electrician.
Do not open any electrical enclosures yourself. If anything looks suspect, photograph it and contact your installer or a qualified solar electrician for a proper assessment.
7. Test Your Battery Health and Capacity
If your system includes a solar battery, pre-summer is the right time to check that it is still performing as expected. Batteries degrade gradually over their lifespan, and after a few years of cycling you may notice a slight reduction in usable capacity.
Most battery monitoring apps, including those from Tesla Powerwall, Sungrow and BYD, display the current state of health (SoH) as a percentage. A battery at 95 percent SoH after two or three years is perfectly normal. A significant drop, say below 80 percent within the warranty period, is worth raising with your installer or the battery manufacturer.
Also check that the battery’s charge and discharge cycles align with your household’s usage patterns. If you have switched to a time-of-use electricity tariff since the battery was installed, the charge and discharge schedule may need adjusting to ensure the battery releases its stored energy during the most expensive peak window rather than an off-peak period.
8. Book a Professional Solar Health Check
The seven checks above cover what a homeowner can realistically assess on their own. But once every year or two, it pays to bring in a professional for a comprehensive solar system health check. A CEC-accredited technician has the tools and training to test panel-level output, check string voltages, inspect DC isolators internally, verify earth fault protection and assess the inverter’s long-term performance data.
A professional health check is especially worthwhile if your system is more than five years old, has been through a major hailstorm, or if you have noticed a persistent drop in output that you cannot explain. The technician can also advise whether your system would benefit from upgrades such as panel-level optimisers, a newer inverter model with better efficiency, or adding battery storage to capture more of your summer generation.
Booking a health check before summer means any repairs or upgrades can be completed in time for peak production season, so you do not lose weeks of high output to avoidable downtime.
Get Your System Summer-Ready
A pre-summer solar inspection is one of the easiest ways to protect your investment and ensure you get the maximum return from your panels during Sydney’s sunniest months. Most of the checks on this list take just a few minutes, and the ones that need professional attention are straightforward to arrange before the busy season starts.
If your system needs a service, a panel replacement, an inverter upgrade or you are ready to add battery storage to capture more of your summer generation, the team at Solar National can help. As a trusted solar company in Sydney, Solar National offers expert system health checks, quality repairs and new installations backed by industry-leading warranties. Get in touch to book your pre-summer check today.
FAQ:
Can I clean solar panels myself or do I need a professional?
If your panels are accessible from the ground using a garden hose with gentle water pressure, you can safely rinse off light dust and debris yourself. For stubborn grime like bird droppings, a soft brush on an extension pole with plain soapy water works well. For panels on a two-storey roof or in difficult-to-reach locations, a professional cleaner is the safer and more effective option.
What does a flashing red light on my inverter mean?
A red indicator or flashing light on your inverter usually signals a fault such as an earth fault, isolation error or grid voltage issue. Try restarting the system by switching the DC and AC isolators off and back on. If the fault persists, contact your installer or a qualified solar electrician for diagnosis before summer.
How do I know if my solar panels are underperforming?
Check your monitoring app for any unexplained drops in daily output on clear, sunny days. Comparing current production to the same period in previous years is one of the easiest ways to spot a decline. A persistent gap between expected and actual output could indicate dirty panels, shading, a faulty panel or an inverter issue.
Do solar panels overheat in Sydney's summer heat?
Solar panels are rated to operate in high temperatures, but extreme heat does reduce their efficiency slightly. This is normal and accounted for in system design. Keeping panels clean, ensuring adequate airflow between the panels and the roof, and addressing any ventilation obstructions helps minimise heat-related output losses.
How long does a professional solar health check take?
A standard residential solar health check typically takes one to two hours, depending on the system size and whether any issues are found. The technician will inspect panels, wiring, isolators, the inverter and (if applicable) the battery, and provide a report on the system's condition.
Should I add battery storage before summer?
Summer is when your panels produce the most surplus energy, so adding battery storage before the hot months lets you capture and use that extra generation rather than exporting it at a low feed-in tariff. A battery also provides backup power during summer storm blackouts and allows you to shift stored solar into expensive evening peak hours.
