Optical characterization of accumulated dust particles and the sustainability of transmitted solar irradiance to photovoltaic cells

This study aims at characterizing the optical properties of dust particles accumulated over time and its sole effect on transmitted solar irradiance. Several glass samples positioned at different orientations were kept in an outdoor environment allowing dust accumulation over a one-year cycle in Sharjah, UAE. A sample of each orientation was collected and examined on a weekly basis throughout the study period. The analysis of accumulated dust density and its effect on irradiance and optical spectrum transmissions through the glass samples is assessed for each sample orientation. Results showed dominance of some surfaces compared to others in terms of dust accumulation and reduction of transmitted optical spectrum against a wavelength range of 210-1029 nm. Throughout the study period of one year, the accumulated dust density and reduction of transmitted irradiance reached a maximum value of 22.6, 4.4, 16.8, 4.8, 6.0 g/m2 and 68.4, 12.3, 63.1, 12.1, 16.4 % for the 0 degrees top, 0 degrees bottom, 25 degrees top, 25 degrees bottom, and 90 degrees surfaces, respectively. Moreover, the results were extended to estimate the reduction in available solar irradiance throughout the one-year study period. It was found that the estimated reduction reached as high as 67 % for the samples installed horizontally at 0 degrees orientation.