The dust falling on the surface of the photovoltaic module will block the sunlight on the one hand, reduce the transmittance of the surface glass of the photovoltaic module, and reduce the amount of solar radiation irradiated on the surface of the solar panel; It absorbs solar radiation and converts it into its own heat energy, and at the same time blocks the external heat dissipation of the photovoltaic module cover glass. In a word, dust is one of the main problems affecting the performance ratio of photovoltaic power plants, and the specific performance is as follows:
The effect of dust on the amount of solar radiation
The dust on the glass surface will not only seriously affect the solar radiation transmittance, but also cause a large diffuse reflection of the solar radiation irradiated on the surface of the photovoltaic module due to the surface dust. According to the experimental measurement, the dust accumulated on the glass surface will lead to a loss of 5%-30% of solar radiation, and the loss is mainly caused by the absorption, reflection, and scattering of solar radiation by the dust attached to the glass surface.
Influence of dust calcification deposition on light transmission
Dust contains a large amount of calcium and magnesium oxides. When the dust on the surface of photovoltaic modules encounters rainfall, a small amount of calcium and magnesium ions will be dissolved into the rainwater, and will be attached to the glass surface of photovoltaic modules again. If it is not cleaned in time, a thick and hard layer of calcium and magnesium scale will form on the surface of photovoltaic modules over time. Once the scale is formed, it is not easy to remove, which will seriously affect the power generation effect of photovoltaic modules, and even cause some photovoltaic cells to generate hot spots and other problems.
The effect of dust on the temperature of photovoltaic modules
The dust attached to the surface of the tempered glass will cause a part of the solar radiation to be absorbed by the dust and converted into heat energy, thereby increasing the working temperature of the photovoltaic module. At the same time, the dust on the surface of the module will also have a covering and thermal insulation effect on the surface of the photovoltaic module, affecting the heat dissipation of the photovoltaic module, further increasing the thermal temperature effect of the photovoltaic module and affecting the photovoltaic power generation effect.
As the power generation components of the photovoltaic power generation system, photovoltaic modules are the core unit of the entire photovoltaic system. The photoelectric conversion efficiency of photovoltaic modules is inversely proportional to temperature, and the photovoltaic efficiency of modules will decrease as the temperature increases. Since the dust attached to the surface of the modules absorbs part of the thermal energy, the internal temperature of the solar panel can easily increase due to heat transfer, the photovoltaic efficiency will decrease accordingly.
Summarize
In the photovoltaic power generation system, the dust on the surface of the components will not only affect the solar radiation irradiating the surface of the photovoltaic cells, but also increase the temperature rise of the photovoltaic components. If the dust on the glass surface is not cleaned in time, it will greatly affect the power generation performance of the photovoltaic components. And in the case of a certain thickness of ash accumulation, the larger the incident angle of sunlight, the longer the sunlight path in the ash deposition layer, and more prone to reflection, scattering, absorption and other phenomena. Therefore, in the process of photovoltaic operation and maintenance, special attention should be paid to the impact of photovoltaic surface dust on photovoltaic power generation, and timely cleaning should be carried out to keep the surface of photovoltaic modules clean, so that the power station can operate efficiently.