There are interesting large scale projects that use hydro directly as power storage for renewables.

When the sun is out or wind is blowing, use excess energy to pump water up hill. When you're low on energy supply, open up the dam to run the water back down hill and through a hydro plant.

I've toyed with the idea of doing the same thing at a small scale on our farm but would need to build a second decent sized pond up hill of our main one.