The Real Story from Texas
Lots of misinformation here. I actually had a client two years ago involved with the Texas power grid. Most of the news & info on the internets, to put it politely, is just repeating "inaccurate" or "horribly biased" information.
First, Texas has a state of the art power grid and gets a lot of its power from renewables like solar and wind, up to 11% (not 7% as publicly stated), most of it wind. Despite performing all the recommended cold weather maintenance on the windmills most of the blades are iced over. If there is sufficient weight on the blades the wind turbine safeties will not permit the blades to turn. It's reported that only 10% of wind turbines are operational.
Second, a lot of Texas power comes from natural gas and a lot of the equipment has freezed up. If just the natural gas or wind had problems everything would be fine, but with both wind and gas curtailed it creates a power shortage.
The Texas power grid is CAPABLE of being completely independent, but despite what you've read online Texas regularly buys and sells electricity to surrounding states and anyone who tells you differently is repeating false information. In times of heavy summer demand Texas has purchased up to 15% of its power from nearby states and regularly sells power to other states. However, the news even in Texas has been incorrectly reporting that the Texas power grid is not connected to the rest of the USA. The reason for this deliberate misinformation is complicated and has nothing to do with the power outage, but today the CEO of ERCOT, Bill Magness, came clean and enigmatically said that electricity from surrounding states is "restricted", claiming that they also have frozen power delivery issues. This unusual restriction of neighboring states to supply power is now the subject of investigations, and in response these states might find power they buy from Texas to be more expensive in the coming months.
One thing Texas is great at doing is not repeating mistakes. Two or three years ago we had winter weather that caused frozen trees & branches to take down power lines. In response ONCOR waited until spring to examine all the trees near power lines (by helicopter & drone) and trimmed everything. Took almost a year to do it right. So I don't see a repeat of the present situation in coming years.
So the remaining questions are, 1) Why is Texas gas production really down, and 2) Why are neighboring states not supplying power to Texas? Once again, like the past year, I see what's really happening & then I see the news and internet report a fictitious account of reality.