Spatiotemporal heterogeneity and international positioning of carbon emission factors of electricity in China

In the context of China’s dual carbon goals, the electricity sector is both the primary source of carbon emissions and a key driver of socioeconomic development. A systematic assessment of the evolution of electricity carbon emission factors is critical for tracking electricity system decarbonization and formulating effective emission-reduction policies. This study develops an integrated analytical framework for examining the spatiotemporal heterogeneity and international positioning of electricity carbon emission factors of China. Based on official national- and provincial-level data, the framework combines the statistical analysis modules including spatiotemporal characteristics analysis, spatial autocorrelation analysis, policy-stage comparison, and international benchmarking to characterize the ECEF patterns. Results show that China’s electricity sector has achieved substantial low-carbon transition progress. Based on the available benchmark-year observations, China’s national average ECEF decreased by 13.03% between 2015 and 2023, while interprovincial disparities widened and maintained a “high in the north, low in the south” spatial pattern. The spatial correlation structure has continuously evolved, with weakened global positive spatial autocorrelation, contracted High-High and Low-Low clusters, and strengthened High-Low heterogeneity, indicating diminished geographic proximity effects and more complex spatial differentiation. International comparisons showed that China’s 2024 ECEF was above the mean values of the EU and Umbrella samples and slightly below the median of the developing-country samples, suggesting considerable transition pressure and emission-reduction potential. These findings offer decision support for differentiated regional low-carbon transitions of the electricity sector.