People build manufacturing capacity to come online when they predict demand will be high enough. So there isn’t lag involved with building capacity just viability.

As to solar it’s only 2.8% of total supply right now but it’s growing fast. That can ramp to ~20-40% without significant storage depending on how cheap solar becomes and how expensive storage stays and how much transmission capacity is available. The tipping point where daily rates are cheaper than nighttime rates will shift a lot of nighttime demand.