Independent research of Solar Tester shows that more than two thirds of solar modules of 10 years or younger is suffering from efficiency losses greater than 20% due to Potential Induced Degradation or PID.
PID occurs on all photovoltaic panels, often without the owner of the installation being aware of it, and implies accelerated efficiency losses. Due to high humidity and temperature differences, certain solar cells become inactive.
As a result, the solar panels degrade faster and therefore don’t achieve the expected return during their lifetime. The degradation process often occurs after 2 or 3 years and after this it will proceed fast.
In the period prior to 2008, PV plants were standardly equipped with inverters with transformers. Today, such types of inverters are no longer available on the market, since transformerless inverters achieve a significantly higher efficiency (in the conversion from DC to AC current).
In particular PV plants with transformerless inverters , typically installed after 2008, appear to be very much affected by PID. After all, their inverters no longer have a transformer, as a result of which there is no galvanic separation between the panels and the AC grid.
Consequently, from 2008 it became impossible to ground the cable that runs from the solar modules to the inverter (negative pole), which encourages yield losses.
In order to offer a solution to the PID phenomenon, iLumen developed the PIDbox. This patented device regenerates and prevents from efficiency losses due to PID. In other words, the PIDbox increases the efficiency of your solar modules and extends their life.
If your inverter with transformer turns out to be defective, you can only replace it with a transformerless inverter as inverters with transformer are no longer available on the market.
As mentioned earlier, PV plants that are equipped with a transformerless inverter are more sensitive to efficiency losses due to PID than PV plants with a transformer-inverter.
That is why PV owners best choose to replace their (defective) inverter with transformer by a transformerless inverter, including a PIDbox integrated between the solar modules and the inverter.
In this way they ensure the highest possible return on their PV plant and extend its lifetime.
N-type and P-type PV modules
Finally, it is also important to mention that today mainly solar modules of the p-type are installed on our houses. However, higher yield can be obtained by n-type panels. In particular Sunpower and BenQ sell this latter type of panels since a long time. Also n-type panels suffer from Potential Induced Degradation.
The PIDbox is compatible with both p-type and n-type solar panels. For this latter type of panels a slightly modified version of the PIDbox needs to be integrated with respect to the more ‘standard’ p-type of solar panels. The PIDbox can also be easily connected to the thin film solar panels.