[stillyslalom]

For long-tail adverse events? It's easy to engineer power distribution systems for the average case, but unless we accept occasional brownouts as a cost of doing business, we need to build robustness into our generation fleet. Let's say we get another Krakatoa-scale eruption that reduces insolation (and thus drops solar & wind output while increasing heating demand). Some amount of firm generation (hydro, gas peaker, nuclear) is insurance against correlated failure in the global climate system.

[sir_bearington]

"Accept brownouts" really just means "keep using fossil fuels" people don't accept brownouts, they buy generators. At this point, it's better to just keep burning natural gas since combined cycle plants are 1.5-2x more efficient than diesel generators.

Hydroelectric is geographically limited, you can just build dams where people need additional power.

That leaves nuclear. And since nuclear costs just as much to run 100% of the time as it does to run part of the time it makes no sense to use it as a peaker. Just run it 24/7, and install less intermittent sources.