Temporal and spatial heterogeneity analysis of wind and solar power complementarity and source-load matching characteristics in China

Wind and solar energy are expected to become the main sources of electricity supply in China, which requires addressing the balance problem between intermittent generation and random fluctuating loads and overcoming the seasonal and spatial distribution differences between wind and solar resources and electricity demand. Therefore, analyzing the spatial and temporal complementarity of wind and solar power and their matching characteristics with electricity demand is of great significance for constructing reliable and cost-effective high-proportion renewable energy systems. The study develops an assessment framework for the temporal and spatial heterogeneity of wind and solar power complementarity and source-load matching characteristics at the provincial level in China, which incorporates correlation and fluctuation measurement methods and divides annual and seasonal scales. The results show that the temporal complementarity of wind and solar power among provinces is strong and exhibits significant seasonal differences, with the strongest complementarity in summer. Wind and solar power joint output can smooth individual output fluctuations, particularly in provinces and seasons with richer wind and solar resources. Wind power output between different provinces exhibits a certain degree of spatial complementarity, while there is no significant spatial complementarity for solar power. Electricity demand fluctuation is negatively correlated with wind power output but positively correlated with solar power output. However, solar power has a stronger exacerbating effect on the net load demand fluctuation compared to wind power, and the net load demand fluctuation is larger in provinces and seasons with richer wind and solar resources. Wind and solar power joint output can mitigate the anti-peak characteristic of wind power and the duck curve issue of solar power, improving the matching degree between power supply and demand.