1 Hot spot effect
The shaded solar cell modules in the series branch will be used as loads to consume the energy generated by other illuminated solar cell modules, and the shaded solar cell modules will heat up at this time, which is the hot spot effect.
This effect can seriously damage solar cells. Part of the energy produced by a lit solar cell may be consumed by a shaded cell. The hot spot effect may be caused by just a piece of bird droppings.
In order to prevent the solar cell from being damaged due to the hot spot effect, it is better to connect a bypass diode in parallel between the positive and negative poles of the solar cell module to avoid the energy generated by the lighting module being consumed by the shaded module. When the hot spot effect is severe, the bypass diode may be broken down, causing the component to burn out.
2 PID effect
Potential Induced Degradation (PID, Potential Induced Degradation) is that the battery components are exposed to high voltage for a long time, causing leakage current between the glass and packaging materials, and a large amount of charge is slammed on the surface of the battery, which deteriorates the passivation effect of the battery surface, resulting in Component performance is below design criteria. When the PID phenomenon is serious, it will cause the power of a module to decrease by more than 50%, thereby affecting the power output of the entire string. PID phenomenon is most likely to occur in coastal areas with high temperature, high humidity and high salinity.