In the face of increasingly severe climate change and environmental deterioration problems

the energy development mode of high consumption and high emission for the past will not be sustainable. A cleaning and low-carbon development mode

which will be achieved by utilizing large-scale renewable energy as the main energy supply system

especially as the main power supply system

can be an alternative choice to cope with the challenge of future energy transformation. Firstly

a research methodology for the medium and long-term electric power development to consider high proportion of renewable energy is introduced. Then

a multi-region multi-scenario medium and long-term electric power planning model with the objective of minimizing the cost of power supply of the whole society is presented

in which the constraints of power system expansion planning

operation

power generation resources

policy

and others are taken into account. The model integrates a power system operation model and the panning model in a moderate way

so the randomness and volatility of wind/photovoltaic and other renewable energy can be reflected in the process of power system planning. Finally

the power supply patterns and power flows of China's power systems with high proportion of renewable energy and the operation results in 2050 are analyzed based on the proposed planning model.