There's a $1.5bn plan to bring wind energy from Wyoming to California, via pumping air into a specially-built salt cave, and letting it out as needed.
It's a wonderful, baroquely over-the-top scheme. And, as BDLGblog says, it all feels like something out of a steampunk Aeneid:
The restless regions of the storms she sought,
Where, in a spacious cave of living stone,
The tyrant Aeolus, from his airy throne,
With pow'r imperial curbs the struggling winds,
And sounding tempests in dark prisons binds.
This way and that th' impatient captives tend,
And, pressing for release, the mountains rend.
High in his hall th' undaunted monarch stands,
And shakes his scepter, and their rage commands;
Which did he not, their unresisted sway
Would sweep the world before them in their way;
To decompose this story into its parts, (i) we have built a new wind farm, (ii) we have built a power storage system (i.e. a large rechargeable battery) to solve the problem of load balancing from our wind farm, and (iii) the power storage system also, by complete coincidence, uses wind power.
In the era of renewable generation where output is at the mercy of the elements, pumped storage is obviously the future. It's nothing new - I remember as a small kid being taken to see the pumped-storage hydro at Ffestiniog (we were really there to go on the steam trains, of course). But pumped-storage wind power is a new one on me. I hope they make it a tourist attraction where you can sit in an adjoining room and lick the salty walls and watch through thick glass as they open the barriers and see the turbines starting up. But I expect there are all sorts of sound engineering reasons why you can't do that.