Passivated Emitter Rear Contact (PERC) is an advanced mono-crystalline cell that captures more energy by adding an extra layer between the silicon and the back coating. This special layer created an efficient internal reflectivity, while preventing electrons from recombining and blocking free flow of energy.
When the area of a solar cell is cut in half, the amount of electrical current that is carried by each busbar is reduced by half as well.
This decrease in electrical resistance within the busbars results in an overall increase in efficiency, especially during times of high irradiance, driven by significantly higher short-circuit current (Isc) and Fill Factor (FF).
The actual increase in efficiency per manufacturer varies in the range of 1.5-3% efficiency increase, which is significant.
A regular solar panel has 3 cell-strings, each of which can be bypassed with a (red) bypass-diode. One shaded cell will shut down one-third of the panel. Leading to low efficiency.
A half cut solar panel has 6 separate cell-strings (3 bypass diodes), offering better partial-shade tolerance. If half of the panel is shaded the other half can still operate.
Thanks to the inovative cell aligment in the halfcut solar panels, they tend to perform much better in the shade envoriments. Hence the user can enjoy upto 50% performance compare to conventional panels uder shadow envoirment.