Solar Power System Performance Monitoring and Fault Detection

Australia has one of the highest residential solar PV installations in the world with over 1 million systems installed. They’re¬†installed by home owners with the goal of reducing their electricity bill, saving money or getting a good return on their investment. How well this works is totally dependent on how well the solar power system is performing.

Any of the following this can go wrong which reduce output of a solar system:

  • Build up of dirt and grime on panels
  • Faults with individual panels (either prior to or any time after installation)
  • Faults with the inverter
  • Wiring faults
  • Switches or circuit breakers inadvertently being turned off
  • Shading by plants and trees

A typical solar pv installation is expected to operate over a 20 year life, that’s a long time that someone needs to constantly be keeping watch on performance.

To get maximum rated performance out of solar panels they need to be facing magnetic north and set an angle based on their location (depending on how far north or south they are). As most systems are installed on existing roofs they’re almost never optimal. Therefore¬†there’s no easy way of accurately knowing what you ideal output should be.

Small gradual reductions in performance can easily go un-noticed. Major faults such as inverters breaking or switches being accidentally left off can easily be missed until the next power bill arrives showing a lower than expected solar power production. By this time it’s too late, the money is lost.

Even without the occurrence of a fault, simply knowing when sufficient dirt has built up on panels that warrants cleaning will help you avoid lost output.

PerformanCE Monitoring Systems

We’ve previously covered home energy monitoring systems are available that will give you information about usage and production and often in real time. These systems don’t help you detect faults though.

The following three systems can help you do this, all will without doubt pay for themselves in avoiding lost production.


Solar Analytics

  • Automatically collects data and stores in the cloud
  • Detects major faults and minor / gradual performance degradation
  • Their data suggests the average system is under performing by around 20%


  • Automatically collects data and stores in the cloud
  • Detects major faults
  • Unclear if performance degradation is detected




  • Relies on readings taken by system owner from their meter
  • Operated by french based company Reuniwatt

See also

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