[ZeroGravitas]

Interesting example about the TV switching off. That would of course be inconvenient but there's already multiple large industries and consumer level smartmeters that will turn things off when electricity demand is high in return for cheaper energy:

https://en.wikipedia.org/wiki/Energy_demand_management

The basic reason for this to exist, even before renewable energy was a thing, is that, as you point out in your comment, building enough capacity just to serve a peak that may only last for a few hours a year is stupidly expensive. So you take the money that you would have spent on a power plant that would only run for a few hours and you give it to people for turning down their air con or their blast furnace for a few hours, keeping a portion to yourself for being so clever. Free-market solutions that save customers and utilities money, save energy, and save the planet. Everyone is happy!