In northern Switzerland, a construction team is hard at work excavating a hole in the ground that will end up being over 88 ft (27 m) deep, and spanning the length of two soccer pitches. This pit will be home to Switzerland's first redox flow battery for storing clean energy – and it'll be the most…
There are various working redux flow large capacity batteries operating already (as mentioned in the article as well), e.g. Daillan, in Japan, this one is just a tad bit larger