Has the inter-regional transmission grid promoted clean power development? A quantitative assessment on China's electricity sector

Abstract Inter-regional transmission has always been taken as an important measure to better the power mix in China, however, not all the people think it effective in boosting the development of clean power because not all the intensively invested transmission lines are fully occupied. To objectively evaluate the impacts of the introduction of inter-regional transmission lines, especially the ultra-high voltage (UHV) grid, may clarify the disputes and benefit China's electricity policy reform. This work simulates an equilibrium model of China's electricity market through the mixed complementarity problems (MCP) method, to investigate the impacts of the construction of the UHV transmission lines on the deployment of clean power and reduction of carbon emissions under different scenarios. The results indicate that the introduction of the UHV grid has increased the competition in both the power generation and consumption sides, but it has limited contribution to mitigate the curtailment of clean power and carbon emissions, there may exist the hysteresis effect of the UHV grid. We propose the following suggestions to better the development of China's power system. (1) With regard to electricity market coupling, it is more appropriate to firstly connect the regional market in the central and eastern China. (2) Promoting the installed capacity of clean power in a short-run is a necessary auxiliary method to effectively reduce the carbon emissions.