Detecting the Cause of Energy Production Drops

Case Overview

A 10 MW photovoltaic installation was seeing underperformance issues. However, the causes and how serious the issues were remained unclear. At this point, the goal was to reveal the true condition of the plant along with the reasons for production efficiency drops. With this in mind, Solar Spy was asked to help.

What is PID?

PID (potential induced degradation) is triggered by current leakages and is invisible to the naked eye. PID can cause substantially lower production. If not detected early, it brings further degradation to the PV installation over time.

Case Facts

  • 10 MW solar installation
  • Site operating for more than 6 years
  • Thermal and RGB images collected within a 4-hour flight
  • Drone inspection performed in line with IEC TS 62446-3:2017 standards


Solar Spy performed a professional inspection with the use of proprietary AI – fault detection algorithms. The collected data was analyzed to provide the location and classification of defects, along with exact insights on productivity drops, and with maintenance & operations priority recommendations. In this case, an additional electroluminescence inspection and IV measurements provided further confirmation of the site’s issues. 


  • The PV site’s condition was verified with confirmed production drops.
  • The report provided a precise list of located and classified defects with recommendations on O&M repairs – enabling decisions based on data.
  • PID was identified in multiple modules accounting for 17% site underperformance – the units were categorized as needed to be replaced.
  • The predictive maintenance helped extend the installation’s lifespan, preventing further module degradation