wholesale electricity markets
In 2017 natural gas fired power plants generated 32 % of the electricity in the United States. Coal fired power plants delivered about 30 % of all power, while nuclear delivered about 20 %. Nearly 20 % came from renewable energy sources, out of which 47 % came from hydro power plants and about 37 % came from wind turbines.
Eight years earlier, 2009, when the shale-gas revolution had started to take off, coal was the number one source, 44 % of all electric generation. Natural gas represented 23 % of the generation and nuclear was at 20 %. Renewable generation, basically hydro and wind, produced 10.5 % of the electric power. (EIA data).
Natural gas has replaced coal as the primary source of power generation. Nuclear is basically unchanged at 20 %, while renewables with the growth of wind and solar generation, has doubled and represents about the same proportion of the power generation as nuclear.
In an industry that traditionally changes slow it is a big shift that has happened fast.