Influence of Wind Incidence Angle on the Cooling of Rooftop-Mounted Solar Panels

Abstract

The cooling of PV panels is crucial because their electrical output and lifespan are adversely affected as their operating temperature rises. Considering wind current cooling impacts on the rooftop-mounted solar panels, adopting the local climate conditions such as dominant wind patterns is recommended to the building sector so that new buildings are placed considering the local wind directions. A 3D CFD model employing the URANS approach is developed to show the impacts of wind direction on the cooling rate of a PV panel installed on the surface of a slanted roof. The radiation effect is considered using the surface-to-surface radiation model. Two free stream velocities of 2 and 5 m/s and seven wind angles between 0 and 180 degrees are modelled. The results showed an optimum incidence angle at which the panel experiences lower temperatures. At wind angles below 90 degrees where there is direct contact between the wind flow and PV surfaces, the convective cooling rate is higher which in turn decreases the PV temperature. However, at higher angles, due to the presence of walls and edges of the structure, the wind flow is redirected resulting in the formation of wind flow separation. Therefore, convective cooling degrades, and PV experiences higher temperatures.