High-resolution analysis of rooftop photovoltaic potential based on hourly generation simulations and load profiles

Rooftop photovoltaics (PV) are playing an increasingly important role in building a clean and decarbonized energy system. For such distributed resources, formulating scientific development plans and incentives tailored to local conditions requires a comprehensive potential assessment at high spatial and temporal resolutions. Here, we evaluate the resource volume, power generation potential, economic feasibility, and market returns on electricity sales of rooftop PV in Jiangsu Province, China at hourly and 500-m resolutions by combining remote sensing survey, PV output simulation and load dispatching. The province's annual rooftop PV generation meets approximately 30% of the total social electricity consumption, and the entire region has reached both plant-side and user-side grid parity. Based on the case study, we investigate the suitable development scale of rooftop PV subject to different owners, as well as the impact of grid's system flexibility and energy storage on rooftop PV curtailment. For household use, the installation of a 3-kW rooftop PV is suitable, while for grid power supply, rooftop PV development needs to be sized to accommodate the grid. We find that increasing system flexibility significantly reduces PV curtailment for the same penetration rate, and that the use of energy storage helps increasing PV penetration under the curtailment constraint. This study represents a relatively extreme case of high penetration of variable solar PV generations, high uncertainty of PV outputs, and high variability in user-side loads, providing a reliable reference for rooftop PV development in other China's provinces.