And if they went full-nuclear they could use zero coal and have zero green house emissions as well.
The major problem with nuclear energy at that scale is that humans only know how to use fission for it, so tons of extremely harmful (to life) waste is generated and has to be dealt with. They could instead augment some of the nuclear energy generation with renewable energy to help with that without generating greenhouse emissions.
Partially spent nuclear fuel, which some call "waste", can be reprocessed. Moreover, the use of Thorium (LFTR) reactors allows partially spent uranium fuel to be fully used. Unfortunately, LFTR reactors were abandoned in the US because they don't produce plutonium, something the Department of Defense was keen to produce in quantity. For peaceful use -- like charging electric cars -- LFTRs are a much better option.