AtaMoS TeC Project: Soiling Impact on Bifacial Modules with Different Mounting Geometry in the Atacama Desert in Chile

Soiling is currently one of the major issues for decreasing power production of PV plants in Chile. In order to prevent significant power losses cleaning frequencies of more than one time per month are scheduled. In the present study, we investigate the impact of soiling on energy yield (YA) of bifacial solar modules with different material combinations. We fabricated half-size and full-size one cell modules employing different glass thicknesses, encapsulants, transparent backsheets and glass-glass module configurations. Based on indoor current-voltage (IV) measurements which were carried out on front and rear side of each bifacial module type at different irradiance levels, a mathematical YA model was applied. Front and rear measurements were taken separately and simultaneously assuming the same bifaciality factor at a given irradiation. YA estimations show that module groups with half-cell design achieve the highest YA values compared to full-cell design. In addition, vertically mounted bifacial modules (VMBM) produce higher YA than tilted mounted bifacial modules (TMBM) if the power loss rate due to soiling is higher than 0.10% per day. To validate the YA model, real outdoor measurements were carried out in the Atacama Desert in Chile for TMBM and for VMBM.