Solar attenuation due to particulate matter in arid environments

The depletion of solar irradiation has several causes such as clouds and suspended particulate matters in the atmosphere. Particulate matters play an important role in decreasing solar irradiation by blocking partly the solar energy from reaching the ground. This lost irradiation must be taken into consideration when planning large installations of PV panels’ fields along with other environmental factors. The blocking effect of PMs is higher in places where the density of PMs is higher due to geographical location or the lack of precipitation. The main objective of this work is to study experimentally the impact of particulate matters of different sizes (PM2.5, PM10, and TSP), measured at ground-level, on global horizontal irradiation (GHI) in arid climates. The measurements were taken over a six months period, from May to October 2022. The city of Riyadh, Saudi Arabia, was chosen to represent arid conditions due to its high suspended particulates density and the lack of precipitation. The PM measurements were recorded every minute from dawn to dusk and were processed to obtain a correlation between the measured PM values and the actual GHI. In addition, a comparison between the GHI obtained by the developed model and the one obtained from ASHRAE clear sky model. During the period of the experiment, the measurements showed that the ASHRAE clear sky model overestimated the amount of solar energy reaching the ground by over 10%.