Scientists and postgraduate students from the SUSU Institute of Engineering and Technology have patented a device preventing the contamination of the surface of solar panels. This device will help improve the efficiency of electric power generation both in privately-owned solar modules and in solar panels at big power plants.
The performance of a solar module can decrease due to its overheating, mechanical damage, or contamination. This leads to its degradation and subsequent disposal, and that is also a problem in the solar power industry.
“There is especially much concern about the problem of dust pollution of solar modules in the regions with frequent dust and sand storms. Even fine dust from around the neighbourhood can affect the operation of solar modules. A fallen leaf on the surface can already give a shading effect in a module section and thus decrease the amount of generated energy,” explains professor of the Department of Power Stations, Grids, and Electric Power Systems Irina Kirpichnikova.
The device developed at the SUSU Department of Power Stations, Grids, and Electric Power Systems is designed to be mounted on a solar module. It consists of a frame made of dielectric material, with thin wires located in it in parallel. One wire has positive potential, and the other – negative one. Using a high-voltage source, 6000 to 12000 V are applied to the wires. To power the frame, practically no energy input is required, as during the generation of a high-voltage pulse the current amounts to just several milliampere.
The wires can be oriented either horizontally or vertically: the efficiency would be approximately the same in both cases. A dust particle has its own natural electric charge. When it enters the electric field of the engineered device, it gets exposed to the physical and electrical forces and gravitates to one of the electrodes. If it is a particle with a positive charge, it is captured by the negative-charge electrode, and vice versa.
“We took a number of parameters into consideration when choosing the design of the device. Thus, for instance, we must take the electric strength of air into account in order to avoid voltage breakdown (like lightning in nature). The wires diameter is selected so that the shading of the solar module does not exceed 6–8%. The electrode spacing was determined by way experimenting,” shares postgraduate of the Department of Power Stations, Grids, and Electric Power Systems Valeriia Shestakova.
Thus, dust particles settle on the device and do not reach the surface of the solar module. Once the protection device gets dirty, it can be dismounted from the solar module and cleaned using running water. After air drying, the “protection frame” is ready for further operation.
The scientists used special software to simulate the processes of dust settlement on the module’s surface. They studied the efficiency of operation of the solar panel protected with the high-voltage device in the conditions of the most optimal location of the solar module, which corresponded to the geographical latitude of our region: at the angle of 55%, on the territory of the city’s industrial enterprise located near a dust source – an unpaved road.
The experimental research showed that the payback period for this dust protection device is up to 8 months per one solar module. The device makes up for the losses in electric power generation caused by the shading of the module and reduces the consumption of clean water for washing of the solar modules.
The developers paid special attention to the possibility of using this device in other sectors of the national economy (for example, in the housing and utility sector, to protect windowpanes from dust). Also the authors of the development provided recommendations both on improving the design of the device, and on determining the operating conditions and the materials used.