Particle deposition onto the surfaces of solar energy conversion technologies leads to effective energy output losses. This study* shows a full year of measurements using a semi-automatic apparatus, based on short-circuit measurements of two PV modules. Annual trends are shown and compared to older studies for the same region, as well as, seasonal behavior. Soiling rates, i.e. the soiling ratio variation overtime, is calculated for the driest season of the year, showing results between 0.07% and 0.14% per day, demonstrating a certain constancy regarding other studies. The soiling rates have been calculated for the P1, P2 and P3 periods. Rainfall, the main natural cleaning agent, is also related to soiling recovering showing that a value around 2.2 mm has 50% chance to reduce the soiling effect.
(*) R. Conceição, I. Vázquez, L. Fialho, and D. García, “Soiling and rainfall effect on PV technology in rural Southern Europe,” Renew. Energy, vol. 156, pp. 743–747, Aug. 2020, doi: 10.1016/j.renene.2020.04.119.
More information: Ricardo Conceição, Postdoctoral researcher, High Temperature Processes Unit, email@example.com
Soiling ratio, SR, from 2018 to 2019