Incremental techno-economic benefits of interregional generation-grid-load-storage coordination in China's power system decarbonization: A long-term evolutionary and provincial heterogeneity analysis

Interregional generation-grid-load-storage coordination offers critical pathways for the economic decarbonization of power systems. However, decentralized regional decarbonization decisions may crowd out the interregional coordination optimization space through suboptimal technology lock-in. This study develops a multiperiod optimization model for interprovincial generation-grid-load-storage coordination and employs provincial self-reliant decarbonization scenarios as a counterfactual comparative baseline to reveal the long-term techno-economic benefits of interprovincial generation-grid-load-storage coordination and their regional heterogeneity. Using China as a case study, the results show that, compared with provincial self-reliant decarbonization, interprovincial coordination increases renewable energy and nuclear power capacity, particularly wind power, while reducing fossil fuel and negative emission units, particularly coal-CCS. The energy storage capacity declines significantly, with a 24.25 % reduction in the national capacity by 2060. Interprovincial coordination significantly reduces cumulative system costs, saving 11.91 % by 2060 compared with provincial self-reliant decarbonization. Moreover, interprovincial coordination plays a crucial role in balancing regional economic development by substantially increasing cumulative investment in the western and northeastern provinces with relatively lagging economic development and reducing it in the developed central and eastern provinces. Sensitivity analysis of future technology costs indicates that the main conclusions are robust. This study provides valuable insights into coordinating interregional power resource cooperation and local resource deployment.