An to answer your question, let me quote the first sentence of the article:
Germany can shift its entire electricity system onto solar, wind and batteries by 2030 for less than 1% of its GDP.What nuclear energy is bad at is as a backup for renewable energy when there is no wind. Because nuclear costs the same whether you use it or not, so you pay for an energy source you don't use most of the time so that you can use wind instead. If you use nuclear, scrap wind.
If we want to unscrew ourselves of the ticking time bomb we set, we need all the "clean" energy we can get, and then some. Nuclear is potentially an existential requirement to the mix.
I imagine something like this as well https://en.wikipedia.org/wiki/Tesla_Megapack
(but my understanding is that there are many other battery technologies in development that work too, e.g. older chemistries and/or mechanical/gravity/heat batteries)
Won't happen all geographically advantageous places are already taken.
Second option (and also a boring one) is distributed home storage using traditional led-acid or lithium-ion batteries. This is already rolled out and can be increased to scale pretty easily.
A more exciting answer is liquid metal (or molten salt) batteries that works as large scale grid storage by heating the batteries elements (Calcium and Antimony) to very high temperature that keeps them separated while charged slowly mixing into a new liquid alloy as it discharges. You can read more about the technology here https://ambri.com/technology/ However I think before 2035 this will at best be a distant third from the two (boring) storage options above.
I think it is OK to be loose on the technicalities in this instance, we all know what was meant.
Batteries are fine for shifting the "when", just like power lines are fine for shifting the "where".