> You can't only run your datacenters and factories when the wind blows or the sun shines.

This has been false in the real world. Factories that use a lot of energy do work with the power company and shutdown all the time based on demand. Large steel mills have their own power plant onsite, but smaller ones just buy grid energy and they want the cheapest. They arrange their factory maintenance schedules with the power company so that the power plants are maintained as the same time they are shutdown. They shutdown every December so the power company can sell the power they were using to run Christmas lights. They often run overnight shifts only because that is when power is cheapest. Even the large factories with their own power generation have shutdown for a couple weeks to sell power to the grid (this is very rare, but it has happened).

Wind and solar is a little more difficult because it isn't as predictable, but that is different from unpredictable. The power companies already are running models to predict the wind and solar cycles because it is important for many things they do. You can bet those smaller factories are already working with the power company to schedule shutdowns when power is predicted to be expensive - factories have to do regular maintenance anyway so it is just a matter of being ready (spare parts) when asked, and wind/solar is predictable enough for this.