Plus failure to winterize the gas infrastructure in the way that is standard in places where extreme cold occurs regularly.
Coal and nuclear both underperformed, but not by much, due to non-winterized equipment.
Solar underperformed for a few days but is back, although is far too intermittent to help without storage except during heat waves.
And Texas’ grid couldn’t buy enough power from neighbors to make up the difference
The simple 5-step solution according to Cascend:
Require power reserve
Connect the Texas grid better
Add solar with storage (storage is key)
And add more natural gas.