Although both ET Solar and China Sunergy failed to mention which of its modules actually passed recent PID (Potential Induce Degradation) test, both companies achieved Class A-PID free status.
Photovoltaic Institute Berlin (PI Berlin), undertook tests on behalf of ET Solar, which entailed 1000 volt frame grounding at 85°C temperature, 85% relative humidity over a 96-hour period.
TUV Rheinland Group undertook PID testing on behalf of China Sunergy that entailed its modules being exposed to 1,000 volts of bias voltage for 96-hours at a temperature of 60°C and relative humidity of 85%.
The outcome for China Sunergy meant that the modules maximum degradation of power output between initial and final measurement was only 0.1%, compared to the required pass achieving no more than 5% degradation. ET Solar said it had achieved a power degradation of only 0.3%.