Can't get a handle on how big each of those tanks would have to be and wondering if chlorine generation would be a problem. Doesn't strike me as a system to be installed and used in service. more of a manufacturers test facilty. It also doesn't test the changeover switching and cables under proper load conditions. 1 MW 3 phase 240 V/phase is (I think) 1388 A, it doesn't take much resistance at those sort of current levels to make things very hot...
Fascinating stuff, if I hadn't gone into broadcasting I'd have most likely gone into power distribution engineering.