In That Texas, some of the gas-fired power plants were offline for maintenance. Fair enough, the usual peak load time is in the summer, for air conditioning.
About 2/3 of the wind turbines iced up (because no heaters on the blades, unlike further north). The remaining ones produced well above their rated ability.
Coal-fired plants had problems with coal stockpiles freezing solid; operating gas-fired were short of gas, since others were using it for heating; nuke plants had to operate at lower capacity because cooling equipment iced up.
All told, for the gas-fired part alone, the amount of electricity they weren't able to generate was about equal to what California uses on a daily basis.
Texas is #1 in energy use per capita in the USA. They used to take it for granted.
And, then of course, water mains don't get buried very deep, because "what's a frost depth?", and the resulting bursting is to be expected.
There were similar, but smaller scale, cold weather tests in 1989 and 2011. After each one, the toothless regulatory group made suggestions that energy suppliers examine their cold weather resilience. Few did. Even last week, during their regular conference call, they spent more time joking about cowboy boots than discussing the weather forecast.