Solution to the phenomenon of photovoltaic panel light attenuation

After the solar PV module is manufactured, the power of the module is normal when the power test is carried out, but the customer receives the module, and finds that the power attenuation is large
when it is installed and operated.
This phenomenon is mostly caused
by photodecay of the cell sheet.

Photoaeration of photovoltaic modules can be divided into two stages: initial photodecay and aging attenuation
.

Initial photoattenuation, i.
e.
the output power of the PV module decreases considerably in the first few days of use, but then stabilizes
.
The main reason for this phenomenon is that the boron-oxygen complex in P-type (boron-doped) crystalline silicon wafers reduces the low birthrate lifetime
.
By changing the P-type dopant, replacing boron with grain can effectively reduce photodecay.
Or pre-illumination treatment of the cell, the initial photoattenuation of the battery occurs before the module is manufactured, and the initial photoaeration of the photovoltaic module can be controlled within a small range, and the output stability
of the module is also improved.

Aging attenuation refers to a very slow power decline in long-term use, and the main reason is related to the slow decay of the battery and the performance degradation of the packaging material
.
Among them, the main reason
for the degradation of the performance of the main material of the module when irradiated with ultraviolet light.
Long-term exposure to ultraviolet rays causes aging yellowing of EVA and backplane (TPE structure), resulting in a decrease in the light transmittance of the module, which in turn causes a decrease
in power.

The early photoattenuation phenomenon of solar cell performance mainly occurs on monocrystalline silicon solar cells, and for polycrystalline silicon solar cells, the early photoattenuation amplitude of its conversion efficiency is very small
.
It can be seen that the properties of the silicon wafer itself determine the early degree of photodecay of solar cell performance
.
Therefore, it is necessary to solve the early photoattenuation problem
of photovoltaic modules.
It is necessary to start by solving the silicon wafer problem
.

Since the early photoatteriscence of photovoltaic modules is caused by the early photoattenuation of the cell, the light pre-attenuation of the cell makes the early photoattenuation of the cell occur before
the module is manufactured.
The early photoattenuation of photovoltaic modules is very small and can be completely controlled within
the measurement error.
At the same time, it also greatly reduces the chance
of hot spots in photovoltaic modules.

Improving the output stability of PV modules can bring more benefits
to our users.
Although pre-attenuation by illumination is a dead solution, before the quality of silicon wafers is effectively improved, this method is an effective measure
to solve the problem of early photoaeration of photovoltaic modules.