The effect of wind direction on the performance of solar PV plants

The impact of wind direction on the overall performance of a utility-scale PV plant was studied by analyzing field data from Hadley solar farm in the UK. The solar PV plant utilizes a fixed-tilt system with the PV panels facing south at a 20 degree angle. The hypothesis is that when wind blows from the south the total power production of the solar PV plant increases in comparison with non-southerly wind events, provided that all other determining factors, such as solar irradiance, ambient temperature, and wind speed are the same. During the case study of January 1 to July 1, 2017, 42 pairs were identified, each of which includes two cases with equal solar irradiance, equal ambient temperature, and equal wind speeds but different wind directions; in one case wind is from the north and in the other one wind blows from the south. The hypothesis was found to be true across all 42 pairs, i.e., the power production of the solar PV plant was always greater in the event of southerly winds. One takeaway from this finding is that wind direction and wind speed frequencies need to be taken into account along with other climatic factors to have an optimal site selection for establishing a solar PV plant. The more frequent the southerly wind occurs, the more power can be extracted from the PV panels. The other practical conclusion of this study is that it is more efficient to build fixed-tilt solar PV plants on areas oriented along the west-east direction.