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.
Ben Q produces monocrystalline solar panels in its SunForte series. The company claims that their Sun Forte solar panels are PID-free, as shown in this datasheet.
iLumen performed an electroluminescence test (EL-test) on the Ben Q Sun Forte 327 model after receiving a complaint from a customer. This test was done at night with a charge-coupled device camera, while the solar panel was energized by a power source and without sunlight.
A solar panel that is subjected to an EL-test, shows a pattern in which the cells all have the same brightness. This is clearly not the case for the Ben Q Sun Forte 327 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. As opposed to the declarations of Ben Q, their Sun Forte solar panels are in fact affected by PID and therefore suffer from efficiency losses. The efficiency of the worst solar panel investigated equals 81,3% of its initial value, only after 1,5 years.