China's cross-regional transmission drives cleaner energy mix conditionally

⚡ AI Executive Summary

A panel study of 30 Chinese provinces from 2000 to 2018 investigates whether the West-to-East Electricity Transmission program—China's flagship infrastructure initiative to move renewable generation eastward—correlates with decarbonization of provincial energy systems. The research finds that higher transmission intensity does associate with lower-carbon energy consumption patterns, though the effect is non-linear and varies by region and regulatory strength. The findings underscore a nuanced implication for grid planners: transmission infrastructure alone cannot drive the energy transition without complementary mechanisms. Exporting regions show benefits primarily through technology innovation, while importing regions benefit from access to cleaner electrons. Critically, the study suggests that environmental regulation strength amplifies the decarbonization effect. For utilities and system operators, this indicates that transmission investment should form part of an integrated strategy encompassing storage, regional industrial policy, and governance frameworks—a lesson relevant to grids globally as they expand interconnections to unlock distributed renewables.