Climate-driven spatiotemporal restructuring of solar drought risk and system resilience in China

Climate change increases solar PV resource variability, threatening low-carbon power reliability. Existing assessments focus on mean changes, missing compound risks from temporal persistence and spatial coherence of low-resource events. We propose an integrated framework quantifying solar drought risk across three dimensions: resource abundance ( CF ), temporal risk ( CV, MDL ), and spatial risk ( SDI ). Applied to China using CORDEX-EA projections (RCP 2.6/RCP 8.5), results show future risk is driven not by declining mean solar availability, but by prolonged drought duration and large-scale synchronization. Under high emissions, drought duration in major load centers can approach 48 h, with localized events exceeding this duration, challenging conventional storage. Meanwhile, strengthening spatial coherence across eastern China undermines regional grid balancing, while western heterogeneity preserves inter-regional complementarity. Thus, low-probability but persistent droughts deserve greater attention in reliability planning. Storage expansion alone may be insufficient. Achieving resilience requires integrated spatiotemporal flexibility measures, including long-duration storage, transregional transmission, and demand-side management. This framework offers a transferable tool for embedding climate-induced compound risks into clean energy planning and policy design.