> I still don't quite understand the pricing during emergencies or shortages, though.

Unpredictable supply shortages (almost always from emergency shutoffs at fossil plants) happen on the grid all the time. To deal with this, grid operators contract with "operating reserves", which are sources of supply that stay ready to make up for a supply shortfall. Often this takes the form of running natural gas turbines (hence the subcategory called "spinning" reserves).

This is very expensive electricity because usually you must pay for the fuel spent while the reserve isn't being used also.

As more battery storage is added to the grid, this service will be increasingly provided by batteries instead of natural gas turbines.

It can also be provided by voluntary (and compensated) demand curtailment programs.

None of this can make up for a grid that is under-invested in resilience (in exchange in the short term for extremely low electricity prices), which is basically what happened in Texas.