I've written on this a couple of times in the last few pages, but more information is coming through so I can a (edit: amended, but not shortened) version of the Texas power situation:
- Texas's grid is mostly its own thing, walled off from interstate connections (unlike most states). They do this in part to avoid federal regulatory authority from FERC. While this does prevent most of the state from getting electricity from other states in situations like these, those other states are also not doing great right now and so only have so much to share/sell.
- Texas's grid is normally about 47% natgas, 20% coal, 20% wind, 10% nuclear (plus some smaller bits and pieces). But in winter the renewable general is lower in Texas for various reasons, and so the 20% is actually more like 10% expected. (Some comparisons of lost capacity are comparing to maximum capacities instead of expected capacities.)
- ERCOT, the texas electric grid regulator, has a planned worst-case scenario for situations like this. Compared to their projections, total electric demand was about 3 GW higher than expected (roughly 5%), wind was about 1 GW worse than expected (roughly 10-20%), and thermal power (this includes natural gas, coal, and nuclear) was between 16-30 GW worse than expected (roughly 40%!).
- As noted by others, frozen turbines did end up a problem here but other parts of the world already have systems to deal with it and prevent freezing.
- Frozen machinery is actually a common problem across lots of power sources! Frozen machinery at natural gas plants, coal plants, and even one nuclear plant caused significant outages. Edit: forgot to mention that freezing of coal piles can also be a significant problem - up until this TX situation it was by large the main source of generation-side reliability problems. (The vast majority of reliability problems writ large remain in the realm of the transmission infrastructure such as power lines.)
- That said, the biggest problem in Texas was availability of natural gas. Due to the way their pricing system is designed, electric generation is kind of last in line for getting resources (to provide the advantage of being cheaper theoretically). Natural gas for heating spiked at the same time as natural gas for power. (You may remember this from the NE power problem several years back.)
- Theoretically one can keep better reserves of natural gas on hand, but the Texas system is more focused on cheap power than preparedness and so didn't keep proper contingencies in place. (Some natural gas pipelines also ended up freezing, which doesn't help, and from what I've read drawing natural gas from reserve containers is actually harder in the cold.)
So a bunch of different factors in play, all of which combined in a very bad way.
ONE MORE EDIT: I should note that DOE has already issued an emergency order waiving environmental pollution laws for power plants (letting them run more / with less controls), so please don't blame those too.