Using oil for electric power in the early 70's were in the large single digits nationwide. In one year after the oil embargo it fell to low single digits in it's share of providing electric power. now it is only 1% https://en.wikipedia.org/wiki/Energy_in_the_United_States#/media/File:USenergy2009.jpg
Same thing can be done to phase out coal power, do not build new ones and when the time is up, keep them retired. Why open new mines when output is reduced or even mines are shut down? And the article mentions how good the mines are about pollution "up stream" yet heavy metals and other bad chemicals somehow end up in the streams, DOWN RIVER. And what makes payments grantee to the insurance company if the operator claims bankruptcy? Their is no silver bullets, just a lot of silver BB's. Replace coal with critical boiler natural gas supplemented by wind and solar. Additional hydro is welcomed as well as geothermal. The last two can be used to supplement peak loads and some baseline.