China has specific needs that almost nobody else does. Most notably, all of China's power generation is in the west of the country (eg Three Gorges, the new Tibet dam) but all the people are in the east. You lose power with long-range transmission and on China's scale that's a real problem.

So China has largely invested in, deployed and perfected Ultra-High Voltage Direct Current ("UHVDC") transmission infrastructure. China has really shown they think 10, 20 and 50 years into the future with their planning.

As for grids, there are a lot of places that could be self-sufficient with solar plus batteries. A lot of remote towns and houses work this way already.