Earlier quoted context omitted.
you actually can. it's expensive, but it's an option. what's the cost compared to nuclear? I'm not sure.
Enlighten me how. 1) What do you do at night? 2) What do you do if there isn’t sufficient supply? 3) What if there is too much supply?
2. this is the hard part, but there is good news.
solar and wind over large areas are fairly consistent and with HVDC you can transfer power 1-2 thousand miles with low losses. there's also a small but rapidly growing amount of storage on the grid. right now, we treat hydro as primarily generation with a side benefit of storage, but it's shifting to primary storage with a side benefit of generation. doing so gives most grids a decent ability to scale up and down renewable generation at will. lastly, you can use fossil fuels when everything else isn't giving you enough. a fossil fuel plant that runs a couple times a year for a few hours is a lot better than 40% of the grid being fossil fuel year round.
there's also a decent amount you can do in terms of demand shaping as the grid gets smarter. electric hot water tanks can be used as batteries where you set them up to turn on when there's excess power. you can also do things like make agreements with energy hungry sectors (like ore refining) to throttle output when necessary (compensating them for the lost revenue).
3. this is easy. refill batteries, smelt aluminum, turn off generation.