Soiling Quantification Using an Image-Based Method: Effects of Imaging Conditions

Solar power generation continues to grow as a dominant renewable energy source. Soiling because of dust accumulation is one of the important challenges facing large-scale solar photovoltaic (PV) plant operations, particularly, in the arid regions. The assessment and mitigation of soiling effects on large arrays of PV panels are often limited by the area coverage and how often data can be collected. To overcome this limitation, in this article, we propose a method to directly use images to quantify soiling on PV panels. A prototype lab system and image processing algorithm are developed to test the feasibility of the method. Specifically, a metric called black/white ratio is calculated from images of a surrogate surface with controlled dust loadings. Effects of different camera settings and view angles are investigated using lab experiments. The experimental results show that dust loading can be quantified under a range of proper imaging conditions, which indicates the potential to use aerial images for PV panel soiling quantification in the future.