How to check if your solar system is working properly in Perth

Most Perth solar systems operate quietly in the background for years without needing attention. But "no visible fault" doesn't always mean the system is performing correctly. Gradual underperformance — a shading issue, a faulty string, or an aging inverter — can cost hundreds of dollars per year in missed savings without triggering any obvious alarm.

Here's how to confirm your system is performing as it should.

Your inverter app: the starting point

Every modern solar inverter comes with a monitoring app or web portal. Manufacturers have their own platforms:

• Fronius: SolarWeb
• SMA: Sunny Portal / SMA Energy app
• Sungrow: iSolarCloud
• Growatt: ShinePhone / ShineMonitor
• Enphase: Enlighten app (also shows per-panel data)
• Goodwe: SEMS Portal

If your inverter is more than 5 years old and predates app monitoring, it may have a display screen only — or you can add a monitoring datalogger device (Modbus-compatible loggers exist for most inverters).

What the app shows:

• Today's generation in kWh
• Current power output in kW (real-time)
• Lifetime generation total
• Generation history (daily, monthly, annual)
• Grid export and self-consumption (on some systems)
• Fault codes or alerts

Download the app, connect your inverter to your home Wi-Fi (if it isn't already), and check the daily generation.

What should your system be generating?

In Perth, a well-installed north-facing system typically generates:

| Season | Expected output per kW of installed capacity | |---|---| | Summer (Dec–Feb) | 5.5–6.5 kWh/kW/day | | Autumn/spring (Mar–May, Sep–Nov) | 4.0–5.5 kWh/kW/day | | Winter (Jun–Aug) | 2.5–3.5 kWh/kW/day |

For a 6.6kW system, that's approximately:

• Summer: 36–43 kWh/day
• Autumn/spring: 26–36 kWh/day
• Winter: 16–23 kWh/day

These ranges account for normal variation in cloud cover. A single cloudy day generating half the clear-sky estimate is normal. Consistently generating at the bottom of these ranges on mostly-clear days, or significantly below them on good days, is worth investigating.

Perth weather context: Perth has low cloud cover year-round relative to other Australian capitals — meaning actual generation should track fairly close to the theoretical output most of the time. If you're seeing consistent underperformance on days that appear clear, the issue is likely with the system rather than the weather.

Monthly and annual benchmarks

A simpler annual check: look at your Synergy bill or My Synergy usage history for your imported (received) electricity.

If your solar system is working correctly, your imported electricity should be meaningfully lower than before solar — particularly during daylight hours and in summer.

For a 6.6kW system with typical Perth usage (5,000–8,000 kWh household), annual solar generation should be around 10,000–12,000 kWh. If your Synergy bills show your annual import has barely changed since installation, something is wrong.

You can also check your inverter's lifetime generation counter against installation date. For a 6.6kW system installed 12 months ago, you'd expect approximately 10,000–12,000 kWh total. If the lifetime counter shows 7,000 kWh in 12 months, investigate.

Common causes of underperformance

Inverter fault: Inverters can fail partially — still showing as "running" while clipping output significantly. Some fault conditions cause intermittent operation (the inverter restarts itself repeatedly). Fault codes in the app help diagnose this.

String fault: In a string inverter system, panels connect in series strings. If one panel or connection in a string has a fault (failed bypass diode, damaged junction box, loose connection), the entire string performs at the level of the weakest panel. A single bad panel can halve the output of a 10-panel string.

Shading: New shading since installation — a tree that's grown, a new structure, a neighbour's extension — can significantly reduce output from affected panels. Shading in the morning or evening is usually minor; shading over the midday hours (when output is highest) is more impactful.

Soiling: Heavy dust or bird droppings on panels. Perth's dry summers mean dust accumulation is normal — but particularly heavy soiling (after a storm, or in dusty areas near construction) can reduce output 10–20%. See our solar panel cleaning guide for frequency recommendations.

Failed panel: A physically damaged panel (impact, delamination, cell cracking) reduces output from that panel. In a string inverter system, the effect propagates to the whole string. In a micro-inverter or DC optimiser system, only that individual panel is affected.

Incorrect inverter configuration: Occasionally, an inverter is misconfigured after installation or a firmware update — for example, an export limit set incorrectly, or a string configuration that doesn't match the actual physical installation.

How to spot a fault using the app

Check daily generation on a clear day: On a day with no cloud cover, your system should reach close to its rated capacity at solar noon (roughly 12:30–1pm Perth time in summer, 1:00–1:30pm in winter with DST). A 6.6kW system should show close to 5–6kW of real-time output on a clear summer day.

Look for generation plateaus or gaps: In the daily generation graph, a normal generation profile is a smooth bell curve peaking around noon. Gaps (the system went offline mid-day), flat plateaus at a lower-than-expected level, or sharp drops could indicate a fault.

Compare panels (if you have Enphase): Enphase's per-panel monitoring lets you see if any individual panel is producing significantly less than its neighbours. A panel consistently generating 30–50% less than others is worth flagging.

Check fault codes: If the app shows a fault code, record it and search the inverter manufacturer's support resources or contact your installer with the specific code.

When to call your installer

Contact your installer or a solar service company if:

• The inverter shows an error or fault code that persists after a restart
• Daily generation consistently falls below 50% of what similar Perth systems produce on clear days
• The system doesn't appear to be running at all (inverter screen dark or showing error during daylight hours)
• Your electricity bills haven't decreased after installation as expected
• You notice physical damage to panels (cracks, discolouration, burn marks, delamination visible from ground level)

System warranty coverage: Most Perth solar installations include:

• Panel performance warranty: 25 years (manufacturer guarantee of minimum output — typically 85% of rated output by year 25)
• Panel product warranty: 10–25 years (defect coverage)
• Inverter warranty: 5–10 years (manufacturer, some extended to 10yr)
• Installation workmanship warranty: typically 5 years under installer's obligation

If your system is within warranty, fault investigation and repair are typically covered. Outside warranty, service calls typically cost $100–$300 for a site visit + diagnosis, with repairs additional.

A simple monthly habit

Once per month, spend 30 seconds in your inverter app:

1. Check last month's generation total against the previous year's same month (if available)
2. Check the current power output on a clear day around noon — it should be close to inverter rated capacity
3. Look for any new fault notifications

This takes less than a minute and catches most significant underperformance before it costs you a year's savings.

Your Synergy bill is a secondary check: if annual imported electricity is higher than expected given your solar system size, upload it to BillWise for a generation efficiency estimate — it compares your actual grid import against modelled consumption to flag whether solar performance looks normal.

Generation benchmarks are estimates for Perth metro conditions with north-facing panels. East/west or south-facing systems generate less. Actual performance varies with specific installation, shading, soiling, and equipment condition. Always contact a licensed solar installer or electrician for fault investigation and repair.