1. pn binding degree
the degree of pn combination and the purity of the silicon wafer determine the strength of the solar panel to generate electricity under the same light. as time goes by, the pn junction will continue to rupture, so the efficiency will continue to decline, and the conversion efficiency will be more than 90% after 15 years. , it will drop to about 85% in 25 years. this has led to a continuous decrease in luminous efficiency, and the loss of luminous efficiency is its service life, so the service life of photovoltaic modules is basically more than 20 years.
2. working environment
as time goes by, the solar panel will also be covered with a lot of dust, so the conversion efficiency of electric energy will also decrease. because the solar panel accumulates a large amount of dust, the charging capacity of the battery will also decrease, which leads to the lighting time getting shorter.
3. wafer quality
in the early days, the poor quality of the encapsulating materials of the solar panels used led to unqualified silicon wafers. unqualified silicon wafers would directly affect the service life of solar panels. therefore, solar panel repairs should be carried out in time.
4. photovoltaic module output power
in the early stage, the output power of the photovoltaic module will reduce the life of the solar panel, mainly because the output power will be greatly reduced during the first few days of use, and the later period due to the stable use of light and current injection into the silicon wafer will also cause the life to be reduced.
5. hot spot effect
during the use of solar street lamp panels, under the sunlight, some parts of the solar panels are blocked and cannot obtain solar energy, which causes the temperature of the parts to be too high to burn out and dark spots appear. this kind of heat the fatal thing of the spot is to directly damage the entire solar cell module, so the solar cell panel must be maintained and cleaned frequently.