China was investing in UHV lines a few years back to deal with the distance problem. They seem to have a bunch already: https://en.wikipedia.org/wiki/Ultra-high-voltage_electricity...

I’d expect HVDC to deal with power loss well enough. The longest one in China is 3200 km at 1100kv and 12 Gw capacity.

My guess is that the HVDC lines they have isn’t really enough to move all that renewable energy yet, or the strategy might be to build more industry out west closer to solar and wind, although water is then the limited resource.