The basic idea is that renewable energy needs power lines to get the electricity from some desert site to population centers. China has experience with that, since many of the large-scale projects are in the Western parts of the country. So they build long distance ultra-high voltage transmission lines.
The next step is to think big and get a global grid. That’s exactly what the Chinese idea is, and the GEIDCO (Global Energy Interconnection Development and Cooperation Organization) has been set up in Beijing to help realizing the idea. It turns out that Masayoshi Son is a vice chairman of this organization, which would be an extension of his “Asia Super Grid” proposal.
There is no reason based on technology that only Europe should have a continent-scale grid, or that only China should be able to deliver renewable energy from the Gobi desert to Beijing. Just like the Internet reaches everywhere in the future proposed by GEIDCO the grid reaches everywhere.
Once that happens, electricity generation will naturally flow to the desert areas. They have the best solar resources and plenty of unused space.
Maybe by 2030, when the Saudi Arabia 200 GW solar project is supposed to be done, there will be a grid connection from there to Japan.