US-based independent PV module testing laboratory, PV Evolution Labs (PVEL) has carried out Potential Induced Degradation (PID) testing programs on modules from Yingli Green, SolarWorld, JA Solar, Kyocera, and Trina Solar.
PVEL tested modules at 85˚C at 85% relative humidity for 600 hours that resulted in all manufacturers passing the test. However, the testing house did not provide details on possible PID degradation or which modules from the manufacturers were actually tested.
Although no industry-wide acknowledged test standard for PID currently exists, the IEC 62804 standard includes test conditions of 60 degree Celsius, 85% relative humidity and a negative 1,000V DC charge for a continuous period of 96 hours.
However, modules are considered to have passed the test if they show less than a 5% loss in performance of their nominal power.
Jenya Meydbray, CEO of PVEL said, “Sophisticated module testing and characterization is about realizing the benefits of good design. Our PID Certification provides manufacturers and project investors with detailed intelligence about how PV products withstand a common cause of performance degradation and module failure.”
Extending the testing period is designed to provide further confidence in a module manufacturer’s product quality.