You don't need batteries for this. You could build concentrated solar power (CSP), instead. These have trailed PV development for years because they have not be

You don't need batteries for this. You could build concentrated solar power (CSP), instead. These have trailed PV development for years because they have not been paid a premium for being able to deliver power on demand. Thus PV has outcompeted them. But with better regulation giving them a premium for delivering power at night they are getting a comeback. Also thermal storage and cryogenic storage can easily provide enough capacity. The problem is that they are not as efficient as batteries. If you buy electricity but only get 50% of that electricity back after storage, then you need to sell at 200% the price you paid. Electricity prices don't swing enough today to make the feasible. But if far more wind and solar was built, then you would get much cheaper power at peak, which storage providers could buy and sell with a profit.