Evaluation and spatiotemporal characteristics of the structural equilibrium of China’s energy system

China’s energy system is undergoing a critical phase of green and low-carbon transition. However, structural issues characterized by disequilibrium and inadequate development within the energy system have constrained this transition to some extent. Adopting a structural equilibrium perspective, this study constructs a comprehensive evaluation index system comprising three subsystems: energy structure equilibrium, ecological structure equilibrium, and governance structure equilibrium. Utilizing panel data from 30 provincial regions in China spanning the period 2013–2022, we analyze the development level, spatial characteristics, and evolutionary trends. The findings reveal that: (1) The overall structural equilibrium of China’s energy system exhibits an upward trend; (2) Significant regional disparities exist, with the eastern region leading, the central region accelerating its catch-up, and the western and northeastern regions lagging relatively; (3) The radiation effect of cities with high equilibrium levels is pronounced; (4) Fiscal expenditure on R&D, industrial SO2 emission intensity, and the growth rate of resource taxes are identified as the primary constraining factors for energy structure equilibrium, ecological structure equilibrium, and governance structure equilibrium, respectively. Enhancing regional coordinated development, fostering cross-provincial energy cooperation, and addressing development gaps constitute effective pathways to improve the equilibrium level of China’s energy system.