How would you add an extremely expensive new built nuclear plant to this grid? Would you shut it down for days on end or try to run it as a peaker?
https://explore.openelectricity.org.au/energy/sa1/?range=7d&...
Think 'agile', not 'waterfall'.
Even by their own claims, the caped may be smaller but the $/MWh is substantially higher than large plants, and will stay so even after multiple doubling a of production.
That doesn't follow necessarily. Wind & solar being the most cost effective doesn't mean you remove all backups just because they aren't as cost effective.
My point still stands though given that I specifically did not exclude any scenario. It makes more sense to optimize when you include all energy sources. It's still possible some sources won't end up in the final solution and that's fine.
It is done when moving electricity around when the grid is strained. Buy expensive electricity and sell it at even higher prices. But that is a vanishly tiny portion of the demand.
I'll point to Standard Thermal again here.