Electroluminescence test shows PID on Yingli Panda solar panelIlumen
Because of Potential Induced Degradation (PID), solar panels can suffer from yield losses up to 70%. iLumen developed the PIDbox, a device that increases the efficiency of solar panels affected by PID and extends their life.
On many European rooftops, monocrystalline Yingli Panda YL275C-30b solar panels are installed. Just like Ben Q and Scheuten Solar solar panels, these panels are subjected to efficiency losses due to Potential Induced Degradation.
iLumen performed an electroluminescence (EL) test on some monocrystalline Yingli Panda YL270C-30b solar panels of 270Wp, which were put in operation 2,5 years ago. Solar panels that are free from PID, show a pattern in which all cells have the same brightness. This is clearly not the case for the Yingli Panda model that was tested by iLumen (Figure 1). Some cells are no longer or not completely illuminated, which is a clear sign of the presence of PID.
The Yingli Panda YL270C-30b solar panels are affected by PID and therefore suffer from significant efficiency losses. The efficiency of the worst solar panel investigated equals 86,3% of its initial value, only after 1,5 years.
Figure 1: Yingli Panda solar panel with PID
Figure 2 shows the results of the EL-test that was performed four weeks after the installation of the PIDbox of iLumen. As can bee seen, all cells are completely illuminated and almost equally bright. After installing the PIDbox, the efficiency of the Yingli Panda solar panel increased to 98,7% of the initial value.
Figuur 2: Yingli Panda panel after PIDbox installation