To determine if a PV module is affected by PID, it's possible to perform an I-V curve test or an electroluminescence test. Note that the electroluminescence test only indicates if some cells are underperforming without giving any relevant indica. To determine if a PV module is affected by PID, it's possible to perform an I-V curve test or an electroluminescence test. Note that the electroluminescence test only indicates if some cells are underperforming without giving any relevant indication about the causes. The I-V curve test is more appropriate in this case due to the nature of the PID e. PID is related to the negative potential that each PV module can deal with when working in normal operative conditions. PV modules are connected in series to create a string and the overall string voltage is distributed among all the single PV modules. How this voltage distribution happens depends on the inverter type used. For example in case of a. A PV module is made by several components (Figure 1), but the ones that play an important role in this discussion are the solar cell, the encapsulant material (EVA in most of the cases), and the aluminum frame. When a solar cell is polarized with a high negative voltage, there is a relevant voltage difference between the cell itself and the module. Luckily, in most cases, the PID effect is reversible. However, if it has existed for a prolonged time without measures taken to fix the problem, it will permanently affect the cells and the encapsulant intrinsic properties. If PID has taken place, it can be mitigated by grounding the negative DC pole on the inverter in order to avoid negative volta. In the case of new PV plants, it's important to focus attention on the type of materials and the design choice of each module before making any purchases. Design choices that can affect the occurrence of PID are mainly related to PV module choice. For example, choosing a frameless PV module reduces the probability of PID because the region at zero.
