Impact of Different Types of Dust on Solar Glass Transmittance and PV Module Performance

The accumulation of dust on photovoltaic modules in arid and semiarid regions results in significant energy losses. However, evaluating these losses in different locations is complex, time-consuming, and expensive. To address this challenge, our study collected dust samples from various sites and conducted soiling experiments in the laboratory using standardized methods. The investigation correlated the transmittance loss (T_loss), short-circuit current loss (Isc_loss), and dust density with the surface coverage. As a result of this analysis, a direct and precise comparison of the individual soiling losses is possible based on the gradient of the correlation lines. Additional characterization of the dust enables an exact allocation of the soiling losses to the chemical composition, optical properties, water content, and particle size. Our study used dust samples from Morocco, Qatar, and two from Thailand. The data analysis indicates that three dusts exhibit a comparable slope in soiling loss relative to surface coverage. However, one dust from Thailand has a significantly higher slope of 12.8% in transmittance loss. A comparative evaluation of the Isc_loss reveals an identical ranking. A root cause analysis identified the differences in the soiling behavior through detailed dust characterization. In addition, the calculated Isc_loss based on the transmission measurements showed a discrepancy between measured and calculated Isc_loss. The deviation is quantified, and possible causes are described. The newly evaluated evidence of the different correlation slopes between the measurement methods not only contributes significantly to our understanding of the effects of dust on photovoltaic systems but also has practical implications. These findings will guide further development and refinement of mathematical models, potentially optimizing the efficiency and performance of photovoltaic systems in arid and semiarid regions.