Experimental investigation of the soiling effect on the performance of monocrystalline photovoltaic systems

Abstract

Due to the high solar irradiation records, desert regions are the most suitable for hosting photovoltaic power plants [1]. Nevertheless, these regions are characterized by the presence of dust and aerosols that can be deposited on the surface of the panels causing a considerable drop on the plants efficiency, thus, the power production.The objective of this study is to measure and understand the soiling’s effect on the performances of a 16.56 kWc monocrystalline grid connected PV system, after six months of exposition without cleaning at Green Energy Park research facility [2]. This facility is located in the mid-south of Morocco and characterized by a semi-arid climate. Besides, chemical analysis of the dust composition has been conducted to have an idea on the aerosols origin emission source.Results shown, that the cumulative power drop of the soiled string after six months was around 124 kWh. The daily power drop, in average, is of 2.7kWh/day during the dry period and of 0.07kWh/day during the rainy period. This is linked to a daily soiling rate of 0.32%/day and 0.02%/day during the dry and the rainy periods respectively.Regarding the dust chemical-analysis, the XRD results highlight the presence of silicon, alumina, calcium, iron, which are may be coming from a construction site close by. Besides, potassium, magnesium and phosphorus that may be coming from a phosphate mine in the area of our field of study.