Experimental investigation of wind pressures on photovoltaic (PV) array mounted on a hilly terrain

With the rapid expansion of solar power plants, suitable construction sites are being occupied rapidly, and hilly terrains are increasingly used for the development of solar power plants. Compared to rooftops and flat ground, wind filed on hilly terrain is more complex and can vary significantly from the bottom to top of a hill. Consequently, terrain interference must be considered when estimating the wind effects of hill-mounted PV panels, which complicates the estimation of design wind loads for PV power plants. Most previous studies have focused on wind effects on the ground- and roof-mounted PV panels, while limited attention has been given to conditions specific to hilly terrains. To address this gap, this study employed wind tunnel testing to investigate the wind load characteristics of the PV panel arrays mounted on the typical cosine-shaped hills. The effects of hill slope and ground clearance on aerodynamic characteristics were analyzed. The results show that hill slope significantly affects the wind loads on hill-mounted PV array; specifically, increasing the slope increases the positive and negative peak pressures on the panels at the hilltop by 19.0 % and 27.5 %, respectively. For PV panels on a hillside, an increase in ground clearance leads to higher peak wind pressures and wind suctions. This effect becomes more pronounced under steeper slopes. Accordingly, recommendations for peak net pressure coefficients for PV panel array with hill slopes of 15° and 30° were proposed, to facilitate a cost-effective and safe wind-resistant design of support structures.