Abstract:
The global capacity of solar panels installed during the last decade was estimated at 462 GW, with the total global capacity reaching 485 GW in 2018 (International Renewable Energy Agency (IRENA), 2019). Moreover, the rate at which renewable energy is being utilized has been witnessing a continuous growth over the past seven years, with an average annual growth rate of 8.3% (International Renewable Energy Agency (IRENA), 2019). As the sector continues to grow, there is a need to better quantify the effects of environmental factors (such as heat, wind, humidity and dust) on the efficiency of solar panels. This is of particular importance for the Middle East and North Africa (MENA) region that has a high potential to integrate solar energy within its existing energy sources. Yet, the region experiences frequent dust storms and high levels of urban pollution that can impact energy production. Previous work has shown that dust size and the rate of its deposition are two important factors affecting PV efficiency. Several experimental studies have attempted to quantify the impact of dust particle size on PV efficiency; yet few have worked with dust sizes below 10 µm. In this paper, we set up an experimental design that allowed us to assess and quantify the impact of dust, with particle sizes ranging between 0.1 and 8 µm, on the efficiency of PV cells. Our results showed that efficiency dropped as the concentration of particles in the air increased; yet the rate of the drop was a function of particle size. The largest reduction in efficiency occurred for particles whose diameter was between 2 µm and 10 µm. A linear regression model was developed to explain the relationship between efficiency reduction and the concentration of particles given their particles size. The model was able to explain around 71% of the observed variability in the sampled data.
