I worked on software for trading energy/transfer/balancing capacity in EU market a few years ago.

EU is pretty good in that regard, it demonopolized the energy market, so if you build this battery yourself on your land you can just entered the market and start selling balancing offers. You will easily outcompete traditional producers and consumers on that market if the article is right.

The widespread rule of thumb was - batteries on grid level don't work. Seems this isn't true anymore.