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.
That last graph is very impressive, but the shortfalls worry me. They're too small to make it cost effective to have an alternative source handily available, but if you don't you're resigning yourself to major power outages.
I'd quite like to know how much we need to overbuild capacity to remove them completely.