I check my solar monitoring app at least twice a day. My partner thinks I’m obsessive. She’s right. But being obsessive about monitoring has helped me spot a wiring issue that was costing me 8% of my production, so I’d argue the obsession pays for itself.

Most solar system owners install panels, see the savings on their bill, and never look at the monitoring data again. That’s like buying a car and never checking the fuel gauge. Your system is talking to you — here’s how to listen.

Understanding the production curve

Open your monitoring app or portal (most inverter brands have one — Fronius, Huawei, SolarEdge, Enphase all offer free monitoring). You’ll see a daily production curve that looks like a bell shape: low in the morning, peaking around midday, dropping in the afternoon.

What a healthy curve looks like: Smooth, symmetrical (roughly), peaking between 11am and 1pm for north-facing panels. On a clear day, the peak should be close to your system’s rated capacity. My 13.2kW system peaks at about 10-11kW in summer (systems rarely hit nameplate capacity in real-world conditions due to temperature, angle, and other factors).

Red flags in the curve:

• Sudden drops or notches: These indicate shading. A tree shadow passing over your panels creates a visible dip in the curve. If the dip happens at the same time daily, it’s a physical obstruction. If it’s intermittent, it’s likely clouds.

• Flat-topped curve: If your production hits a ceiling and stays flat rather than peaking naturally, your inverter might be clipping. This happens when your panel capacity significantly exceeds your inverter capacity. A small amount of clipping is normal and even desirable (it means your panels are well-sized). Excessive clipping means you’re losing production.

• Asymmetric curve: If your morning production is much better than afternoon (or vice versa), and your panels aren’t split east-west, something may be affecting production on one side. This could be partial shading, a failing panel, or a wiring issue.

• Much lower than expected: If your daily production is consistently 20% or more below what similar systems in your area produce, investigate. Compare with the SolarEdge or Enphase community data, or check PVOutput.org for nearby systems.

Consumption vs production graphs

The best monitoring systems overlay your consumption on top of your production. This shows you:

Self-consumption: The overlap between production and consumption. Bigger overlap = better economics, because you’re using your own solar instead of exporting.

Export: Production that exceeds consumption. This is power going to the grid at your feed-in tariff rate.

Grid import: Consumption that exceeds production. This is power you’re buying from the grid.

The goal is to maximise self-consumption and minimise grid import, especially during peak tariff periods.

Spotting degradation

Solar panels degrade slowly — about 0.5-0.7% per year is normal. You won’t notice this in daily or weekly data, but if you compare year-on-year production for the same month, you should see a gradual decline.

If production drops more than 2-3% year on year (after accounting for weather differences), something’s wrong. Common causes include:

• A failing panel (micro-cracks, delamination, or hot spots)
• Inverter degradation or a failing MPPT channel
• New shading from tree growth or nearby construction
• Accumulated soiling (rare in areas with regular rainfall)

What to do when something looks wrong

Step 1: Check the obvious. Is it cloudy? Has a tree grown? Is your inverter displaying any error codes?

Step 2: Compare with nearby systems. PVOutput.org lets you see production from systems near you. If everyone’s production is down, it’s weather. If only yours is down, it’s your system.

Step 3: Check your inverter’s event log. Most inverters record faults, isolation warnings, and grid events. Look for recurring errors, especially earth fault or isolation fault warnings, which can indicate wiring degradation.

Step 4: Contact your installer. If you’ve identified a genuine performance issue, your installer should investigate under your warranty. Bring data — production curves, error logs, and year-on-year comparisons. Installers respond better to evidence than vague complaints.

Pro tips for monitoring nerds

Track your daily yield in kWh per kW of installed capacity. This normalises for system size and lets you compare with any other system. In Brisbane, you should be getting about 4.0-4.5 kWh/kW/day annually. In Melbourne, more like 3.5-4.0.

Watch your inverter efficiency. Most monitoring apps show this. A healthy inverter runs at 95-98% efficiency. If you see efficiency consistently below 93%, the inverter may need attention.

Set up alerts. Most platforms let you configure email alerts for production anomalies, zero-production days, or error events. Set them up and let the system tell you when something’s wrong.

Your panels are up there working every day. The least you can do is check in on them occasionally.