1. The quality of solar panels
Due to factors such as cell cracks, black cores, oxidation, virtual welding, material defects such as the backplane, and long-term use aging, the power of the modules will be affected during long-term operation, resulting in low power generation of the modules. It is worth noting that the crystal structure of the single crystal determines its better performance in anti-cracking.
2. PID effect
During the long-term operation of the module in the outside world, because the water vapor penetrates into the module through the backplane, the EVA is hydrolyzed, and the acetate ion causes metal ions to be precipitated in the glass, resulting in a high bias voltage between the internal circuit of the module and the frame, resulting in electrical performance degradation. Power generation has dropped sharply.
3. Component installation method
From the total amount of solar radiation on the inclined plane and the principle of direct-scattering separation of solar radiation, it can be obtained that the total amount of solar radiation Ht on the inclined plane is composed of the direct solar radiation amount Hbt sky scattering amount Hdt and the ground reflected radiation amount Hrt, namely: Ht=Hbt+Hdt+Hrt. In the same geographical location, due to the different installation inclinations of the modules, the cumulative amount of sunlight absorbed is different, and the cumulative difference in radiation amount causes the difference in power generation.
4. Weather factors
Weather is also one of the factors that affect the power generation efficiency of modules. In cloudy and rainy weather and when the cloud layer is thick, the solar radiation intensity decreases, the solar cells absorb less sunlight, and the power generation decreases. The weak light response of single crystal is better than that of polycrystalline under low radiation. When the conversion efficiency of the solar cell module is constant, the power generation of the photovoltaic system is determined by the radiation intensity of the sun. The power generation of photovoltaic power plants is directly related to the amount of solar radiation, and the solar radiation intensity and spectral characteristics change with the meteorological conditions.
5. Shadow occlusion
During the working process of the module, due to the partial occlusion of the shadow, the different degrees of dust settlement, and the pollution of bird droppings, the "hot spot effect" will be caused. The local temperature of the module increases, and the overheated area can cause the EVA to accelerate aging and turn yellow, which reduces the light transmittance in this area, which further deteriorates the hot spot and leads to aggravated failure of the solar cell module.
6. Temperature coefficient
The temperature coefficient of crystalline silicon cells is generally -0.4% to -0.45%/℃, and the temperature coefficient of single crystal is smaller than that of polycrystalline. The change of the external ambient temperature and the heat generated by the components during the working process will cause the temperature of the components to rise, which will also cause the power generation of the components to decrease.
7. Clean and maintain
When the module is in the field for a long time, dust and other sundries will fall on the glass, and a large amount of dust or sand will settle for a long time, which will weaken the penetration of sunlight, and at the same time cause the surface temperature of the module to rise, which will affect the power generation efficiency of the module. When the dust on the surface of the module is serious, the difference between the power generation before and after cleaning is 5.7%.
The above analysis only affects the power generation of the module from the aspects of the module itself and external environmental factors. In addition to the factors mentioned above that affect the power generation efficiency and power generation, there are also problems caused by the electrical system end and other factors during the working process of the module. Power attenuation, power generation reduction, etc., follow-up process improvement, technology improvement, material research and development and more related research are needed to solve and improve the factors affecting the power generation of components.