I have been in the Electric Power Industry for forty years. It was obvious 30 years ago.
The EPA worked hard to eliminate the exemption for small old coal burners to be update to current regulations.
It is economical impractical spend millions updating a 50 megawatt plant to current EPA standards when it will only operate on a few days a year when the load is at its highest.
Instead the utilities spent those millions on gas turbine plants that could be built and operated without any emissions controls at all and could be fired up and loaded remotely within a few hours.
But now even those plants are under attack because the standards have changed and even a plant that produces no other waste gas than CO2 is under the EPA’s attack.
The EPA is a rogue agency that only exist now to destroy industry.
I worked on GE’s frame E prototype 200MW that went to Virginia Power. GE had issues with the ceramic coatings on the blades forty years ago.
From what I’ve heard blade erosion is still an issue for combustion turbines.