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

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 representation 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. Evaluation against MODIS showed that WRF-PV improved the simulation of skin temperature over PV installations, reducing the RMSE from 3.071 °C in WRF_CTL to 2.560 °C in WRF_PV. PV installations reduced daytime skin temperature by 1.6 °C but warmed near-surface air by 1.2 °C in summer. Additionally, we identified PV-induced atmospheric feedback including an increase in cloud fraction, resulting in a reduction in downward SW radiation of about 1.2 %, as well as a pronounced spatial redistribution of precipitation. This study shows that modeling PV-land surface processes is needed for regional climate models to adequately simulate the impacts of utility-scale PV installations.