Earlier quoted context omitted.
Those two coal plants are only being run sporadically now, which probably means that they're being run as "peaking" plants, which is a very expensive mode of operation. A year or so ago TVA closed our local coal plant after replacing it with a natural gas one, and while they were at it they also built a one megawatt solar plant nearby. Which is all well and good, but that solar plant, even under ideal conditions, can…
Thanks for the comment, I think it massively depends on the specific panels and their makeup. You also add a lot of excellent context to the stories I found. There is a ton of cutting edge research going into solar panels and there are many different ways to achieve higher efficiency and/or longer lifespans. My comment wasn't intended to say solar/wind is killing Coal because it isn't. Natural Gas is what is killing…
As to that local installation, I drove by it the other day and saw no obvious tracking issues or anything like that. When I took a tour of it about a year after it opened, they said that it had already become obvious that the inverter system was going to be finicky and that it was going to an ongoing challenge to keep that in tip-top shape, given the expense involved. So after five years I could easily envision a situation where the panels and tracking system are still going strong, but the inverter system has degraded to the point where it can only spit out 60% max.