E.g.

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.

That's the kind of just-in-time thinking that's one unfortunate dice roll from plunging people back to pre-industrial levels.

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?

It seems to be about Australia, right? While not really applicable to for example Poland where solar and wind are far less stable.

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?

If you need to utilize 2 weeks of storage as a worst case once or twice per year then it doesn't seem an issue to just burn fossils for those instances.

The goal is to reduce Co2 emissions and replace fossil usage.