do you happen to know why we can't dump the energy into something like smelting, desalination or other heavy industry?
There is a very small amount of people working on low-capital industries (normally with higher operational costs), and they seem to be close to some gain here or there. But almost all of our knowledge is biased against turning things off.
that's the bit I don't quite understand - yes, in a simple economic model where you want the numbers to go brrr, it makes sense, but is there a physical limit? could a country decide to own the big facility and use the excess electricity and sell the results to commercial ventures? the government can afford to have a piece of land taken that doesn't return a profit 100% of the time?
No one will want anything from your desalination plant in Norway, and shipping water is not a thing because it becomes too expensive.
The next problem is energy cost vs. duty cycle. The less you run due to only utilizing cheap prices the higher the impact of fixed costs on your business.
Except for a significant portion of the GDP of Fiji