Perth solar maintenance guide: what to check every year

Perth solar systems are often marketed as "set and forget." There's some truth to this — well-installed solar with quality components has very few active maintenance requirements. But completely ignoring your system for years means issues like soiling, shading from tree growth, inverter faults, and DEBS misconfiguration can quietly reduce your savings for months before you notice.

An annual 30-minute check catches these problems early.

Month 1 after installation: set up your baseline

Before anything goes wrong, establish what "normal" looks like for your system. In the first month after installation:

Record your baseline generation: Note your system's daily average generation in kWh. Your monitoring app (Solarweb, SolarmanPRO, Enlighten) will show this. A 10kW Perth system in summer should average 45–55 kWh/day; in winter, 20–30 kWh/day.

Confirm DEBS is active: Check your first Synergy bill after installation for DEBS credit lines (Super Off-Peak exports + Off-Peak exports). If DEBS isn't appearing, call Synergy on 13 13 53 immediately — meter configuration issues are easiest to fix soon after installation.

Save your installation documentation: System specifications, CEC installer details, product warranties, NCN approval, and Western Power commissioning documentation. Keep these in a dedicated folder (physical or digital).

Annual panel inspection (do this yourself)

Visual check from the ground: Once a year, look at your panels from the ground with binoculars or from an upper-floor window if accessible. Check for:

• Cracked or delaminated panels (usually visible as discolouration or broken glass)
• Leaves, branches, or bird nesting material in racking gaps
• Seagull or pigeon fouling accumulation (especially in coastal Perth suburbs — Cottesloe to Joondalup coastal strip)
• Visible racking corrosion (white powdery oxidation on aluminium rails) near the ocean in Fremantle, Cottesloe, North Beach, etc.

Do not walk on the roof to inspect panels unless you have appropriate roof access training and fall protection equipment.

When to call an installer: If you see cracked glass, significant corrosion, or large amounts of soiling you can't safely address, request a professional inspection ($150–$300 from most Perth solar companies).

Panel cleaning: when it matters in Perth

Perth's climate splits into two cleaning seasons:

Pollen and dust season (late winter to spring: August–November): WA's spring pollen season and the onset of easterly dust winds (particularly in the northern and eastern suburbs) deposit fine layers of pollen and limestone dust on panels. This is the period when cleaning provides the most measurable benefit — studies in Perth's climate suggest this type of soiling can reduce output 3–8%.

Seabird fouling (year-round for coastal suburbs): Coastal suburbs from Rockingham to Mindarie deal with seagull fouling. A single fouled panel can drag down a string's output by 20–30% (the weakest-link effect of series-wired strings). If your system includes string inverters (most older and budget systems), regular fouling on one or two panels has an outsized effect on overall generation.

When cleaning is not cost-effective: Rain washes most Perth panels adequately through the winter months. If your panels face north and aren't under trees or near the coast, professional cleaning every 2–3 years is typically sufficient. Self-cleaning with a long-handled soft brush and water (no soap, no pressure washer) once yearly is appropriate for most Perth homeowners.

Professional cleaning cost: $150–$300 for a typical Perth residential system, depending on panel count and roof access complexity.

Annual inverter check

Access your inverter display or app monthly: Your inverter should show today's generation and a running annual total. Compare against previous years (if your app records history). A generation shortfall over a full year — not explainable by weather — suggests a component problem.

Check fault log: All major inverters maintain a fault log. Access it via the display or monitoring app:

• Occasional grid voltage/frequency events: normal (Perth's grid has some voltage variability, particularly in suburbs with high solar penetration)
• Ground fault (GFI) faults: flag for professional inspection — can indicate insulation degradation in panel or wiring
• Communication errors: usually harmless but worth investigating if persistent
• Repeated AC contactor faults or relay errors: precursor to inverter failure; worth a professional diagnosis

Check fan operation: Hold your hand near the inverter's cooling vents during a sunny afternoon — you should feel warm air moving. A silent fan during peak generation is a fault indicator.

Clean ventilation area: The inverter needs clear airflow. If you have a garage inverter with stored items blocking the ventilation path, clear them.

Annual monitoring data review

Once per year, pull up your monitoring app and review the annual generation summary:

Compare year-on-year generation: Solar panels degrade at approximately 0.3–0.5% per year (TOPCon/HJT cells) to 0.5–0.7% per year (older PERC cells). After 5 years, expect 2–4% less generation than year one. A 10–15% drop relative to year one suggests a panel or inverter issue.

Check seasonal pattern: Perth generation should follow a predictable curve — summer peaks in December/January, winter trough in June/July. An anomalous low month (unexpected dip compared to the same month in previous years) is worth investigating.

Cross-check with bills: Compare your annual Synergy bill electricity cost to the previous year. If bills have increased faster than tariff increases, your self-consumption or solar generation may have dropped.

Annual battery check (if you have battery storage)

State of health (SoH): Most battery management systems report state of health — the battery's remaining capacity as a percentage of original. After 5 years, a quality lithium battery should retain 90%+ SoH. Below 80% suggests faster-than-expected degradation (worth a warranty claim if still in warranty).

Cycle count: Batteries have a warranted cycle count (typically 3,000–6,000 cycles depending on brand and chemistry). At one cycle per day, that's 8–16 years of expected life. Your app should show cumulative cycles.

Backup mode test (annually): If your battery has backup capability, test it annually by deliberately triggering manual backup mode (consult your inverter manual). Confirm that backup circuits operate correctly. A battery that's never tested in backup mode may surprise you when you actually need it.

Summary annual checklist

• [ ] Visual panel inspection from ground (cracks, fouling, debris, corrosion)
• [ ] Panel cleaning if accumulated soiling is visible (or schedule professional clean in October before summer)
• [ ] Inverter fault log review via app or display
• [ ] Fan operation check during peak generation hours
• [ ] Annual generation comparison (year on year in monitoring app)
• [ ] Synergy bill DEBS credit check (confirm both Super Off-Peak and Off-Peak lines present)
• [ ] Battery SoH and cycle count check (if applicable)
• [ ] Battery backup mode test (if applicable)

Most Perth solar systems need only 30 minutes of annual attention: check the panels visually, review the monitoring app for generation trends, glance at the inverter fault log, and confirm DEBS credits are appearing correctly on your Synergy bill. Catching a fouled string, a silent fan, or a meter configuration issue early is far cheaper than discovering it 12 months later when you realise your bills haven't come down as expected.