Dynamic geospatial modeling of solar energy expansion potential in China: Implications for national-level optimization of solar photovoltaic plant layouts

Solar energy utilization plays a critical role in facilitating the transition of low-carbon energy systems and achieving carbon neutrality goals. Accurate quantification of the complex dynamics and factors controlling solar energy expansion is of considerable value to the broader deployment of clean energy. This paper proposes a data-driven geospatial modeling framework to analyze the spatiotemporal dynamics of solar energy expansion potential in China from 2011 to 2022. By combining a time-series photovoltaic (PV) power plants inventory dataset, random forest modelling, and multidimensional conditioning factors layers, we predict firstly the annual solar PV installations probability maps at 1 km spatial resolution over last decades across the country. The pixeled characteristics of spatiotemporal trends of solar expansion potential are then detected based on linear regression, coefficient of variation, spatial Gini coefficients and Hurst exponent analysis. We also identify the priority zones and temporal dynamic of underlying drivers for China's onshore solar expansion at plant level. Results show that the factors of surface vegetation covers and access to power grid were identified as the primary determinant in the spatial expansion processes of solar energy, and both of them have the highest cumulative effects. Over the past decades, the spatial planning principles for the siting of solar energy plants have gradually transitioned from “socioeconomic dominance” to a comprehensive “resource-environment-socioeconomic” dominance. Trend analysis revealed that the predictive PV installations probability experienced a significant increasing for the majority area of North and Northwest China. When considering the trade-offs and synergies between PV installation probability and power outputs, the northern parts of China, covering 6 % of the total area, were identified as priority zones for solar energy development. We highlight that the dominant roles of socio-economic and geographical determinants in solar energy expansion may vary over time. Our results have practical implications for optimizing the spatial planning and layouts of solar power plants to achieve the sustainable development of national clean energy.