Because the cost of transmission will be even higher. Moving large amounts of electricity over large distances is hard; it’s much cheaper to move gas or oil.
Not any more. China's longest power transmission link is 3324 km. 1.1 megavolts DC. 12 gigawatts. Running for over a year. Equivalent to moving 30 million tons of coal per year.
China's cheap power sources (coal and hydro) are in the northwestern part of the country, and the big loads are in the southeastern part. So many HVDC links are going in.
The US's biggest HVDC link is Oregon to California, opened in 1970.
Interesting, though I would like to see more cost comparisons.
Some negatives I've found are UHV lines used for renewable transmission will see low utilization and the switching equipment is quite unreliable so overcapacity is needed.
