[Weryj]

How's the gravity storage going, it looked really promising and simple.

[dragontamer]

If you count pumped hydro, gravity storage is the #1 storage of the USA.

Turns out that pumping water up-hill and running generators when the water flows backwards is a very efficient energy storage mechanism.

[thinkcontext]

Aside from pumped hydro I'm only aware of tiny, one-off pilot projects.