The spatial deployment of renewable energy based on China's coal-heavy generation mix and inter-regional transmission grid

China has set a goal of 20% non-fossil energy in total primary energy consumption by 2030. The decision of where to invest in renewable energy, and to what extent, needs to be considered from a forward-looking perspective. This article presents a power sector optimization model that integrates unit commitment with long-term generation expansion planning framework. Power dispatches at an hourly level are combined with yearly investment decisions. Based on the model, this article analyzes the optimal spatial deployment of renewable energy. The results show that regional differences in non-hydro renewable energy are significant. Approximately 75% should be deployed in the north of China. With the increase of combined heat and power, more renewable energy facilities, especially solar photovoltaic, should be located in the south of China. Inter-regional power transmission is beneficial to onshore wind in resource-rich areas, and could mitigate the conflict between coal-heavy generation mix and renewable energy.