The omnipresent dust accumulates on photocells and reduces their efficiency. This worries both owners of huge photovoltaic power plants and private owners of solar cells.
In extreme conditions (heavy pollution, no precipitation, many months without cleaning), the loss of productivity can reach 20%. Of course, no investor can afford such losses and regularly clears installations. Taking care of the cleanliness of the panels is easier in the case of a power station that has ground installations and related services. For private owners with roof panels, every time you clean a solar installation, you need to hire a professional company or go to the roof yourself, which is associated with danger. In practice, the installation is usually cleaned twice a year. Unfortunately, this is not very accurate, and it is difficult to determine when the optimal time for this operation has come. Why?
Well, the dust depends on the circumstances. In some months the panels get dirty more than others. Some places are also more prone to dirt, while others are less. Emissions are a problem in large cities. In rural areas, dust from the fields, especially during harvest. In turn, the rain to some extent cleans the panel. Therefore, the best solution would be to measure the degree of contamination.
The Dutch company Kipp & Zonen recently developed the DustIQ system, which is designed to accurately measure the pollution of photovoltaic panels.
The system consists of small measuring panels that must be installed in parallel with photovoltaic panels. They consist of a polycrystalline cell and two sensors covered with a glass panel, identical to the one that covers the photovoltaic panels.
When light falls through clear glass, its rays are parallel to each other. Dust, however, scatters light. Sensors measure how much incoming light is scattered, and on this basis calculate the pollution of the installation. The result does not depend on the amount of solar radiation, therefore, according to the manufacturer’s assurances, weather conditions and the position of the sun in the sky do not affect the readings.
Studies show that dirt falling on panels in different parts of the world diffuses light differently and affects the efficiency of panels. Therefore, DustIQ can be calibrated for pollution in a specific area.
So far, the system is primarily interested in large power plants, which, thanks to this system, can concentrate on cleaning panels in more polluted areas of photovoltaic fields. However, it is possible that in a few years this system will become the standard at home.
