The Impact of Utility-Scale Photovoltaics Plant on Near Surface Turbulence Characteristics in Gobi Areas

Abstract

With the rapid deployment of utility-scale photovoltaic (PV) plants, the impact of PV plants on the environment is a new concern of the scientific and social communities. The exchange of sensible and latent heat energy and mass between land and air in PV plants is crucial to understanding its impact. It is known that the near surface turbulence characteristics rule the exchange. Therefore, it is essential for understanding the impact to study the characteristics of near surface turbulence. However, it is not well recognized. Turbulent fluxes and strength characteristics for the PV plant and the adjacent reference site in the Xinjiang Gobi area were investigated in this study. Various surface layer parameters including friction velocity, stability parameter, momentum flux, and turbulent flux were calculated using eddy correlation system. Results indicate that compared to the reference site, near the surface boundary layer was more unstable during the daytime due to the stronger convection heating, while it was more stable at night in the PV plant. In the PV plant, Iu was weakened and Iv was strengthened during the daytime, and Iu and Iv were all weakened at night, while Iw was strengthened across the whole day. The significant difference between Iu and Iv in the PV plant indicated that the horizontally turbulence strengths were affected by the plant layout. The turbulent kinetic energy of the PV plant was lower than the reference site and the momentum in the PV plant was higher than the reference site, especially during the daytime. Compared to the reference site, the PV plant had a higher sensible heat flux and less latent heat flux. The turbulent components of wind followed the 1/3 power law in the unstable conditions and stable conditions in the PV plant and the reference site.