No matter how many times you type it, it's still not true. The marginal cost when it's actually running is irrelevant, unless you plan to ignore your customers the 16 hours a day the solar is useless.
You replace a 1000 MW coal or nuke plant, you need 3000 to 4000 MW solar. Plus the same MW worth of batteries. Plus the transmission to place all these renewables where the sun actually shines, and the wind blows, and move the power to where people actually live. Estimates are the transmission infrastructure has to be DOUBLED or TRIPLED (at least) to switch to all renewables.
That's TRILLIONS of dollars that you're conveniently not including in your cost estimate. And we still don't know if it will actually work.
