1. Solar Panel’s Product Quality

Due to the hidden crack, poor quality, air oxidation, air welding of solar panels, defects of raw materials such as side plates and embrittlement of long-term application, the output power of modules is affected in the whole process of long-term operation, which leads to low power generation of modules.

2. PID Effect

In the outdoor environment, the water vapor seeps into the module through the side plate, resulting in EVA hydrolysis reaction, glacial acetic acid positive ions precipitate metal ions in the laminated glass, resulting in high bias voltage between the internal power circuit and the outer frame of the module, resulting in the electrical performance attenuation coefficient and sudden drop of power generation.

3. Solar Module Installation Method

The basic principle is that the total output of solar radiation on the inclined surface is composed of the immediate solar radiation intensity HBT, the sky transmission amount HDT and the road surface radiation intensity HRT, that is, HT = HBT HDT HRT. In the same location, with the different inclination angle of the module installation, the digestion and absorption of natural light are different, and the accumulation difference of radiation intensity leads to the difference of power generation.

4. Environment Factor

Air temperature is also one of the factors that affect the efficiency of power generation. When the temperature and cloud are thick, the compressive strength of natural light irradiance decreases, the natural light absorbed by solar panels is less, the power generation is reduced, and the dark light response of monocrystalline solar cells under low irradiance is better than that of polycrystalline cells. Under the condition that the conversion efficiency of solar module is fixed, the power generation of solar power generation system is determined by the solar irradiance. The power generation of solar systems is closely related to the solar radiation intensity, and the solar irradiance and spectrometer characteristics change with the meteorological elements.

5. Shading Factor

When the solar panels are operating, based on the amount of shading blocks the panel and the foundation settlement level of dust, and the environmental pollution of gum, all these factors will lead to "hot spot effect". The blocked part of solar panels will not make output power contribution and become energy consumption load inside the components. In addition, the temperature of some modules will rise, and the over temperature area can cause EVA to accelerate embrittlement and yellowing, making the area transparent. As a result, the hot spots become more malignant, resulting in the invalidity of solar panels.

6. Temperature Coefficient

The temperature coefficient of crystalline silicon battery is generally - 0.4% ～ - 0.45% / ℃, and the temperature coefficient of monocrystalline products is lower than that of polycrystalline ones. The change of external working temperature and the amount of heat generated in the whole process of the module will lead to the rise of the module temperature and the decrease of the power output of the module.

7. Cleaning and Maintenance

Dust and snow will land and cover on the tempered glass. The stacked dust or sand will reduce the transmission of natural light. In addition, the surface temperature of the module will rise, which will affect the power generation efficiency of the module. When the dust on the surface of the module is relatively serious, the difference between the power generation before and after cleaning is 5.7%. If the cleaning is not carried out for a long time, the difference of power generation in the area where the surface of the module is polluted is more than 10%.

Summary:

The analysis is only carried out from the solar module itself and related environmental factors. In addition to the factors mentioned above that affect the efficiency and output of power generation, there are also output power attenuation coefficient and power generation reduction in the whole process of components due to circuit system end and other factors, which need to be improved.

Ningbo Raytech New Energy Materials Co., Ltd. is specialized in solar panels manufacturing and system integration. The company has independent product R&D teams, national key laboratory and 1.2GW full-automatic manufacturing line. Raytech’s production scale, product range and manufacturing standards are on a leading position in the industry. Raytech will continuously provide high transparency solar modules, double glass solar modules, and bifacial modules to support the community.