Wind load evaluation on photovoltaic modules with flow deflector

Abstract

The wind load on a photovoltaic system and the effects of adding a flow deflector around the panel are studied. The deflector is a reinforce measurement aiming to reduce the aerodynamic wind loads over the PV system, which can lower the collapsing risk when the system is under extreme weather conditions. Simulations of wind flow over both standalone and arrayed PV modules are performed by using the SST k-w turbulence model based on the Reynolds-Averaged Navier-Stokes equations. The inlet velocity profile is specified to describe the conditions representing the flows over a PV system located on a large open terrain with the atmospheric boundary layer. The calculations are compared to the data from the published wind flow simulations of the drag and lift force coefficients along the centerline of the module, and to the net pressure coefficient on the PV module. Further, the wind load over the PV system are compared for both stand-alone PV module and arrayed PV system with and without a flow deflector placed around it. The effects of the wind directions, the PV module inclination angles, the shapes of the deflector, and the spacings between the deflector and the module are investigated. The results show that when the inclination angle of the PV module is fixed to 25°, placing the deflector around the stand-alone module can generate a wind load reduction of up to 40%. For an arrayed PV system, the wind load is reduced by 8% on the first-row modules under the wind direction of 0°. Thus, the deflector offers an economical solution for reducing the wind load on the existing PV projects without modifying the modules or installation arrangements.