(I think my answer disappeared.) Yes, it is very different to existing power plants. While power plants have varying capabilities of fast turn on/off, they CAN do it. With wind and solar you have to cross your fingers and boil water you don't need. (also, doing it unneccessarily fast because wind/solar are so unpredictable causes excess wear. With a good baseload and no added noise, this won't happen as much) What batteries exist that can handle the overproduction? Cars? Do they, really, and will they, at the scale needed? Those smelters you mentioned are off for the holidays, though. I think the companies running them would prefer to run them when people are there working, not just when it's windy.