Investigation of fly ash soiling effects on solar modules performances

Abstract The increase of solar modules installation worldwide has led to an increase in the investigation of the phenomena that may cause adverse effects on the performance of solar modules, such as soiling. Soiling of solar modules surface leads to a reduction in their performance due to reduced quantity of solar radiation reaching solar cells. Having in mind that (in Serbia) solar modules on the roofs are often located near chimneys, and that for heating fossil fuels are mostly used, during the heating season fly ash is accumulated on solar modules reducing their performances. This paper presents results of the outdoor experimental investigation of the impact of accumulated fly ash during the heating season on solar modules surface set at an angle of 0° (horizontal), and at an optimal angle of 32° for the area of ​​Nis on their power. The experiment was carried out for a period of 168 days. The maximum power reduction (greatest reduction of solar modules power due to fly ash soiling) both for the horizontal and optimally installed module due to the fly ash accumulation was measured on the 45th day of the measurement. The maximum power reduction of the horizontal module was 87.2%, and of the optimally set module 30.6%. The morphology of the fuel oil fly ash was analyzed using scanning electron microscopy (SEM). The fly ash particles were generally spherical in shape, of a porous structure and the largest number of particles had diameters of 20 μm to 50 μm.