and you would be incorrect in saying that coal is the primary source for creating energy in the US. NG surpassed coal as of last year. With the abundance of NG and being cheaper to produce and use, coal is slowly fading into the background as the fuel of choice, when it comes to producing electricity. 

King Coal will never be what is once was, no matter what trump says or does.

https://www.washingtonpost.com/graphics/national/power-plants/?utm_term=.55f403c190bf