> It basically means they can't compete with solar during the day (unless it's cloudy and solar isn't available), whereas nuclear can because the negligible fuel cost means it can take any current price as long as it hits a given average price, and it can bring the average up at night. Which means that coal isn't even competitive with nuclear, since nuclear is getting something during the day whereas coal gets nothing, requiring coal to receive an even higher price than nuclear when renewable output is low and then gets out-competed by nuclear

You keep saying that nuclear can keep operating during the day, because of neglible fuel cost. But fuel cost has absolutely nothing to do with any of this. So even we ignore opex, if you have to earn $100 a day to earn back your capex investment, if the price during the day is such that you can sell electricity for $0, yes you can still run your plant, but if prices allow you to only earn $80 during the night, you're still loosing money. So it's still a terrible investment. Calculations get worse if prices go negative during the day (but your plant can't easily be switched off) or if we include opex.

Moreover, other technology like batteries, are on an exponential trajectory. So average price differences between night and day are likely going to drop.