Which conditions influence PV module sensitivity to PID?Ilumen
Potential Induced Degradation (PID) occurs on all photovoltaic modules often without the owner of the installation being aware of it. Because of this phenomenon the solar modules degrade faster and therefore don’t achieve the expected return during their lifetime. But which conditions have a significant impact on the extent to which PID occurs?
PI Berlin developed an overview table with six variables influencing PV module sensitivity to PID.
|Variable parameter||Effect on PID||Conclusion|
|Temperature||The hotter the stronger||Heat is bad|
|Humidity||Water is supporting leakage current||Humidity is bad|
|Soiling||In case of dust on the panel PID is enhanced||Dust is bad|
|Light intensity||The more light intensity the slower PID occurs||Light is good|
|Voltage level||PID only occurs under negative voltage||Negative Voltage is bad|
|Tilt angle||Low tilt angle leads to more accumulation of dust and longer presence of water (at lower edge)||Large tilt angle is good|
In other words, PV power plants are more at risk when:
- located in warm/hot climates
- located in humid environments (at the cost)
- at higher system voltages
Locations that meet these conditions are marked in red on the map below, but of course significant yield losses also occur at PV plants at other locations.
Moreover, researchers of PI Berlin concluded that PID sensitivity can change over time. Therefore preventive measures for power plants are always recommended.