Interesting to see that economics is what is driving the switch from coal. I think there's something like a 600 year supply of coal, but only about 100 years of natural gas. On the flip side, solar has been improving in efficiency so when natural gas becomes limiting I wouldn't be surprised that economics drive the switch to solar. One of the surprises when I've been traveling is the vast amount of wind farms being constructed in Iowa & Kansas along with seeing more solar farms and solar rooftop panels all across the western USA.
I recently met an engineer who drives a Tesla and who installed a solar grid on his house in Southern California along with a storage battery and never needs to buy electricity from the public utility. Renewable energy has gone from being seen as a fantasy pipe dream 40 years ago to much more realistic and competitive today. About 4 years ago it became more cost effective to set up a solar energy grid than a fossil fuel driven grid in new infrastructure projects in developing countries. Interesting times...