Extended Data Fig. 3: County-level multiyear complementarity stability (2000–2022).
From: Advancing solar and wind penetration in China through energy complementarity
a–c, Inter-annual variability of Kendall rank correlation τ. a, Same-county solar–wind complementarity (interquartile range (IQR) of τ across 2000–2022). b, Optimal partner selected under the solar-source strategy (IQR of τ). c, Optimal partner selected under the wind-source strategy (IQR of τ). Across all counties, inter-annual IQR values are small (typically <0.02–0.04), indicating that year-to-year meteorological fluctuations perturb complementarity only within a narrow band relative to the much larger spatial heterogeneity observed in the baseline year (2022). d–f, Stability of optimal partner relationships across meteorological years. Panels report the frequency with which the 2022 top partner remains within the top 10 candidate partners ranked by τ during 2000–2022. d, Solar–wind links. e, Wind–solar links. f, Wind–wind links. The top-1-in-top-10 frequency commonly exceeds 0.7, demonstrating that inter-annual variability mainly reshuffles a small set of near-equivalent candidates while preserving the broader spatial structure of complementarity. Counties with no solar or wind generation are shown in grey.
