Impact of Climate Change on Interregional Transmission during China's Power System Decarbonization

Interregional transmission plays a crucial role in alleviating regional mismatches between power supply and demand, but climate change exacerbates these dynamics, potentially resulting in increased economic losses. In this study, we coupled an ensemble of global climate models with a province-hour-level power system optimization model to explore feasible deep decarbonization pathways for China's power system. The results indicate that climate change impacts the power balance by increasing cooling demand, decreasing heating demand, and shifting wind and solar power generation. Under these effects, achieving China's carbon neutrality target by 2060 will require more than 93.2% of power generation from nonfossil sources and the addition of 4047.6-4053.9 GW in new transmission capacity. This means a 40.4-42.5% increase in transmission line costs ($37.9-39.6 billion) compared to the baseline scenario. Furthermore, under deep decarbonization pathways, abundant solar resources in provinces with insufficient local power supply help mitigate supply-demand imbalances under SSP1-2.6, resulting in a cost reduction of 0.7-1.4% ($1.0-1.7 billion) compared to SSP5-8.5. In conclusion, our findings underscore the potential of interregional dispatch in mitigating renewable energy intermittency, which is crucial for designing decarbonization pathways for power systems that account for climate change adaptation.