Potential induced degradation (PID) is a phenomenon that has only recently become a concern in the photovoltaic industry. PID impacts the ions of a solar cell and results in the degradation of the output of that cell.

PID can significantly reduce the power output of a photovoltaic (PV) module within the first year of operation, with power losses at the module level as high as 70% in the first 18 months. These module level losses can progress rapidly and become so severe that they affect the performance of an entire system.

 

Factors which causes PID

  • System voltage
  • Temperature
  • Humidity
  • Irradiance

 

PID is the main reason for efficiency losses of solar panels. Therefore it is important to timely detect this phenomenon.

 

Presence of PID can be detected by means of several tests:-

 

Infrared image-forming:- This test is done on a sunny day with an infrared camera. A module affected by PID has a higher temperature than surrounding modules that are unaffected by PID.

Note:-The infrared test is easy to perform because the installation does not need to be turned off.