To my way of thinking the storage of wind produced electricity is not an issue if wind is given priority in usage. Other fossil fuel, hydroelectric or nuclear facilities should be reduced when there is ample wind available.

The savings in other forms of energy are the de facto storage mechanism.

For example, the water does not have to be pumped uphill, just don't let as much through the dam when wind is available. Then let the saved water flow though the dam when the wind dies down.

Fossil fuel saved by wind is in effect stored wind energy to be used to fire up plants when wind is inadequate or the demand exceeds wind availability.

Nuclear plants are harder to shut down but their out put can be scaled back during high wind availability. The saved nuclear fuel is the stored energy derived from wind.

It's just a matter of looking at things a little differently or maybe from outside the box.