This is capitalism in action: solar is cheaper than anything else per kwh. The obsession with fossil in the West is due to the fossil fuel lobbies, not because of the rational market forces. China doesn't have that.
If you are trying to use American made panels near population centers in the Northeast or the Midwest, the economics become much more challenging.
So, similar dynamic. If the oil fields, coal mines etc would be sitting on prime land, you wouldn't have it this cheap. If there weren't subsidies, they wouldn't have been this cheap. It's very hard to compare different energy sources because of this. But solar being cheap isn't only a Chiblnese phenomenon. India, Spain etc all prove this. It's cheap when you have a lot of empty land and sunshine.