I think there are some dueling issues that hit and while ERCOT I do not believe was even in charge at the time of some things people went after them because they were the overarching head.

Previously, ERCOT/Texas had been warned that they needed to winterize the grid for below-freezing temps. I would estimate most if not all of that wasn't done. There were some places in the panhandle that did to an extent but it turned out not to be enough.

The baseload power is the amount of power that is consistently on the grid and so when there are surges or plummets grid operators have to scramble to either turn things on or turn them off. At the time the freeze set a crazy high new record demand which baseload wasn't close to even reaching. BTC miners because they can be flipped on and off rather quickly help adjust for this dramatic change since they are such a huge power draw.

I want to say there were a handful of pretty large plants that were idled for maintenance without getting approval from ERCOT and that was a huge issue that ERCOT couldn't manage because they were not told.... Natural gas plants froze up because there is a section of pipe that goes roughly out of the ground and into the wall of the building.... these were bare pipes and warming them up isn't exactly simple cause if it gets to hot ya blow yourself up so it was a nightmare situation.

No one expected not only the state to suffer widespread freezing (the Rio Valley was in the teens... that's right by Mexico) to the Panhandle being under 0 it was significant. The wind turbines though were the wildest thing since it was the first time that high humidity (cause ya know its Texas) and below freezing temps clashed and broke even the winterized turbines. Those that didn't break were because essentially shut down.