When a portion of the electric grid goes down, somebody somewhere is without electricity. In most cases, it's a relatively simple matter of rerouting electricity from another grid sector or even another grid interconnection. However, as Texans experienced during the February 2021 winter storm, it may not be possible to import electricity from another interconnection or even another sector within one interconnection.
Unfortunately, large-scale energy storage isn't possible because electricity is a binary commodity (you have it or you don't). However, many utilities use lithium-ion batteries as a short-term energy storage solution. In addition, hydroelectricity relies on abundant water resources, a potential energy resource that is easily accessed in response to increased demand.