But they HAD plsnned on periods of no wind, and no solar, which is why the windmills were backed up generously (one FReeper TX power-industry-guy says 115%) by fossil plants. Unfortunately, a lot of the fossil plants (mostly gas, and not just the backups) froze up too, and that loss of output was much greater in total GW than the loss of wind power. Plus, "direct" gas feeds for heat and power also froze up.
The biggest problem with wind power is that it is heavily subsidized and distorts the market, plus it requires backup sitting around a lot ($$$). IMO we should kill the subsidies and require the wind power suppliers to provide that 115% backup from other sources*, ALL required to be winterized.
*One way to do it, if greatly expanded:
https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_Station
(Upper / lower reservoir system that acts as a giant "battery".)
“planned”. How did spell check not catch that? (eye roll)
There is an unlimited source of energy right under our feets, if we can figure how to access it. It is the heat of the earth's interior, which even now is working its way through the earth's crust in unfathomable numbers of BTUs.
Elon, I hope you're reading this! Your Boring Company needs to go vertical and not just horizontal.