With the energy crisis and environmental pollution problem becoming increasingly conspicuous

renewable energy is favored by countries all over the world. However

most of the renewable power plants are located near their primary resources far from the load center. Moreover

the greater part of renewable energy sources (RESs) have an intermittent and

to a certain degree

unpredictable output. To solve these problems

the concept of supergrid is proposed by Europe. Supergrid is defined as a wide area transmission network with various energy sources

multiple time scales

large spatial span

and multi-users. Capable of integrating multiple power generation sources

including renewable and conventional energy sources

and transferring and distributing the bulk of electricity thousands of miles

it balances fluctuations and uncertainty of the RES output by their complementary role in terms of time and space. As for the development of power grid in China

enlightenment can be gained from the European supergrid project. The definition and characteristics of the supergrid are given

furthermore

the key technologies and the challenges faced by its development are pointed out. Based on China’s resources and load conditions

the prospects of supergrid development in China are presented. This work is supported by National Key Technologies R&D Program (No. 2013BAA01B04).