At to end of the day it comes down to this:

Is it cheaper to store steel stock in a warehouse or terrawatt-hours of electricity in a battery farm?

Is it cheaper to perform maintainance on 2 or 3x the number of smelters or is it cheaper to maintain millions of battery or pumped hydro facilities?

I’m sure production companies would love it if governments or electrical companies bore the costs of evening out fluctuations in production, just like I’m sure farmers would love it if money got teleported into their bank account for free and they never had to worry about growing seasons. But I’m not sure that’s the best situation for society as a whole.

EDIT: I guess there’s a third factor which is transmission. We could build transmission cables between the northern and southern hemispheres. So, is it cheaper to build and maintain enormous HVDC (or even superconducting) cables than it is to do either of the two things above? And how do governments feel about being made so dependent on each other?

We can do a combination of all three of course, picking and choosing the optimal strategy for each situation, but like I said above I tend to think that one of those strategies will be disproportionately favorable over the others.