The Texas crisis's proximate causes were two unanticipated shocks induced from the sub-zero temperatures (‐2 � F in Dallas): a failure of conventional (thermal) generating supply, mostly from lack of natural gas, and a surge in electricity demand. Inadequate winterization caused freezing of the gas supply and many plants' control instruments. In a system with a winter peak of 66 GW, about 30 GW of thermal plants were unavailable. In its worst-case extreme-winter analysis, ERCOT had expected a loss of 14 GW of thermal resources. The February storm caused more than double the anticipated thermal outages.