Dust accumulation is one of the important factors that degrades the efficiency of photovoltaic (PV) panels. As a result, this research paper experimentally investigates the correlation between sand dust accumulation density and changes in the electrical performance of PV modules. This study is highly significant as it helps predict the behaviour of photovoltaic solar panels under varying densities of sand dust in a desert region where such conditions have not been previously studied. Based on the obtained results, it aims to propose solutions that contribute to enhancing the performance of photovoltaic solar systems in similar regions. For that, numerous practical tests were conducted in southeast Algeria to demonstrate the impact of sand dust accumulation on the power output of PV panels in an arid climate. To achieve this objective, four identical PV panels (TE 500-P, 55 Watts) were installed on the rooftop of the Higher Normal School of Ouargla (southern Algeria). These modules were fixed, tilted at 30 degrees, and oriented due south. Sand dust deposition levels of 0 g/m(2) (always clean) as a reference, 3.49 g/m(2), 7.8 g/m(2), and 12.17 g/m(2) were applied, respectively. The electrical power output for the different modules was recorded every hour from 09:00 to 17:00 local time on a typical day. The results show an average decrease of 3.34 %, 5.36 %, and 10.92 % in the maximum electrical power produced by the PV panels with sand dust densities of 3.49 g/m(2), 7.8 g/m(2), and 12.17 g/m(2), respectively, compared to the clean one, which makes the regular cleaning of PV solar panels essential to consistently achieve optimal performance.