Some key insights from the article:
Basically, what they did was to look at how much batteries would be needed in a given area to provide constant power supply at least 97% of the time, and the calculate the costs of that solar+battery setup compared to coal and nuclear.
The difficulty there is that there are a lot of places where you frequently get multiple weeks of both solar and wind at <10% capacity (google for dunkelflaute) that would need an implausible amount of storage to cover.
The OP article is already talking about 5x overbuilding solar with 17h of storage to get to 97% in the most favourable conditions possible. I dont see how you can get to an acceptably stable grif in most places without dispatchable power.
It’s not that bad. This is an actual technique in use, and it drastically decreases how much storage you need.
The biggest problem has been convincing capitalism to do it. They’ve been building solar like nuts because that’s the cheapest per MW of anything on simple Excel spreadsheets. More mathematical nuance would show that if everyone does this, it’s just going to cause overproduction and wasted potential on very sunny days. You need all three, and toss in some hydro and geothermal, as well.