So what if we roll another Eyjafjallajökull in one part of the world, simultaneously with a war breaking out in another, and some large-scale maintenance ongoing in another part still, while everyone's grid is designed to keep "oh half a day's tops" and not a watt more, because ain't anyone gonna pay for it? With globally reduced capacity for, say, a week, that "half a day's average demand" worth of storage may start running dangerously low, and what then? Will we somehow scramble to fire up long-closed fossil fuel plants in that time?
Which one of reports at linked http://www.energynetworks.com.au/projects/electricity-networ... is one that you refer to here?
For the second one - is "more responsive loads" code for "load shedding" which is code for brownouts and blackouts?
https://reneweconomy.com.au/much-storage-needed-solar-wind-p...
"Graham says that the CSIRO modelling showed that at very high levels of wind and solar, a maximum of half a day’s average demand was needed for storage. In some areas of the grid, only around three hours might be needed."
Or:
https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora...
The amount of short term storage to get a grid between 80-95% running on solar/wind is measured in hours.
Electrolyzing and storing hydrogen in an underground cavern can buffer the rest and be stored easily for years if necessary.