A new method to determine the effects of hydrodynamic surface coatings on the snow shedding effectiveness of solar photovoltaic modules

As solar photovoltaic (PV) installations have become more common in regions that experience substantial snowfall, losses in energy production due to snow coverage have grown in concern. Several post-production surface coatings have been proposed to enhance snow shedding to reduce these snow related losses. In this paper, a novel methodology is developed to determine the effectiveness of a snow clearing from a PV module and is used to evaluate the snow shedding effectiveness of any module surface treatment. Measured PV output is compared to modeled PV output in a generalizable method that allows for the determination of the length of time a panel is covered with snowfall using electrical performance data. This model accounts for module degradation during long-term outdoor testing and other external factors effecting performance, such as persistent soiling losses. This methodology was tested on modules that had one of four hydrodyanmic surface coatings, as well as one module with a prismatic glass front in order to determine the snow clearing effectiveness of these surfaces as compared to conventional plain glass. The methodology was validated, but the surface coatings tested did not have an appreciable positive effect on snow clearance, and in some cases tended to impede the shedding of snow. The physical mechanisms responsible for the results are discussed.