Simulating the impacts of utility-scale photovoltaic installations with a physically based coupled WRF-PV model

Abstract. Utility-scale photovoltaic (PV) installations are expanding so significantly that they may alter the surface energy balance and affect the local climate. Yet, simplified or non-coupled PV schemes in regional climate models limit the understanding of the PV climatic impacts. In this study, we developed a physically based, fully coupled WRF-PV model based on the Weather Research and Forecasting (WRF) model. WRF-PV maintains surface energy balance closure between the PV panels and the ground and enables the PV-induced radiative and thermal effects to feed back to the atmosphere dynamically. We used this model to perform two regional simulations, WRF_PV (with PV panels) and WRF_CTL (without PV panels), in northwestern China, a major PV deployment region. Our results indicated that WRF_PV captured observed spatial and diurnal climate features, and improved the simulation of skin temperature relative to WRF_CTL. PV installations reduced daytime skin temperature by 0.9 °C but warmed near-surface air by 1.8 °C in summer. Additionally, PV-induced enhanced sensible heating, weakened lower-atmospheric stability, and promoted low-level cloud formation, causing a reduction in downward shortwave radiation by about 1 %. Moreover, precipitation shifted toward extremes, accompanied by minor reductions in moderate rainfall. This study shows that modeling PV-land surface processes is needed for regional climate models to adequately assess the impacts of utility-scale PV installation.