Towards Understanding of Cementation of Particulate Soils on PV Cover Glass Materials

Accumulation of soils and other particulate matter on the front cover glass of solar photovoltaic (PV) modules results in transmission losses that detrimentally affect the power output of PV installations. Cementation reactions, which occurs due to interactions between the dust and the glass surface in the presence of temperature, humidity, and pH, results in the dust becoming rigidly attached and potentially difficult to remove with conventional cleaning methods. In this study, accelerated soiling and cementation tests on glass coupons have been performed using a custom instrumented soiling chamber and several standardized soils (Arizona Test Dust, ARAMCO Test Dust, and China Test Dust) to assess soil adhesion and cementation behaviors. Micromechanical scratch testing, along with supporting water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS) measurements are used to characterize the surface chemistry of the soiled coupons and surface energy evolution of the deposited soils before and after cementation. The end result of this study is a better understanding of the surface properties of cemented soils, which can potentially lead to the development of novel soiling mitigation technologies for PV applications.