In the last 15 years the electric industry has evolved the most through the changing mix in resources for electric generation. In the 1980s, 1990s, and into the 2000s the building of coal plants was a thing of the times. Nuclear was struggling due mainly to massive cost overruns for nearly every nuclear project that was undertaken. Coal plants were reliable (and still are), and a known technology making them less complicated to build than nuclear. Then along came natural gas as a reliable resource that became higher in demand, particularly in recent times. Here is a link to an article and interactive chart of the changing use of resources for electric generation.

NY Times