The ability to better store electrical energy would be a game changer. Even solar and wind generators could find viable niches, i.e., without subsidy. Current fossil fuel generators could be more efficient for running at a constant rate, the excess production of some time periods stored for times of need.
The big question at present is what is going on at EESTOR? The EESTOR device sounds like a car which could go 200 - 300 miles at highway speeds and then take five minutes to recharge a device which would never wear out or die and it should have been out by now. Other similar devices are presently being used for buses in Hong Kong but I don’t think they have that much range and a bus wouldn’t need that much range.