There's a very dark scenario where for some reason or another (all out nuclear war or asteroid hit) sunlight is blocked, in which case having stable base load energy production from nuclear would be very useful. I know this is an unlikely scenario and hopefully it never happens, but it's always good to think about tail risks like these.
If sunlight is blocked the amount of people who die due to starvation from crop failures will probably more than make up for the difference in lost solar power energy. That is to say, we'll have much larger issues than a stable power grid to contend with.
If we directed worldwide LED production all into artificial light for farming, and grew whatever was most calorie-efficient, I think we could theoretically feed every human alive if the sun was blocked out tomorrow.
Obviously that isn't what would happen. The poor would starve whilst the rich still fed cows to eat steak.
It doesn't necessarily take a full blockage of sunlight. Extreme weather conditions that create multi week collapse in solar outputs is enough to create grid stress, if one is totally dependent on solar and 24hr batteries.
Volcanic winters are far more frequent than catastrophic asteroid blasts. Disregarding a volcanic winter possibility and its impact is like disregarding the possibility of a pandemic.
True. But if you're working in public policy in a vaguely-democratic country, and trying to get anything useful done - then the public feels vastly more familiar with "giant asteroid wiped out the dinosaurs" than with volcanic winters. So, just like "Zombie Apocalypse (wink)" disaster prep - you go with a "close enough" scenario which lets you achieve some actual preparation.
Surely you must realize that the fuel for nuclear power plants is not more freely available than sunlight. In the event of "all out nuclear war or asteroid hit", you're not getting those shipments from Kazakhstan.
