Storage has already been the issue with solar and wind since they both tend to be intermittent and unreliable.
I doubt it will be electronic and also be cheap enough to be competitive. Even inefficient things like pumping water up into a lake and recreating the electricity as it flows back through the turbines sounds attractive when compared to things like the cost of Elon's battery pack.
I am still hoping they figure out this fusion thing but I doubt I will live long enough to buy fusion power.
OTOH I know I won't live long enough to see the ocean in the Disney World Parking from global warming.
