Excellent roundup of grid-scale energy storage solutions by
Conversation
Lithium chemistry seems like a bad solution at scale. Green hydrogen seems cleanest overall but it can… explode I guess.
5
10
Pumped hydro takes up too much room, but I’m intrigued by the railroad car systems (not yet covered by Sarah). Rocks are ~3x the density of water. Steel is ~8x. So on average a railroad car filled with rocks can replace an elevated lake of 5x the volume.
3
4
20
Replying to
this one I haven't seen! I'll look into it! "gravity storage" in general seems like it's expensive (other examples involve lifting up and putting down bricks within a stationary tower)
1
1
Replying to
there were several startups pursuing this a few years ago when I did a project on this... the density is 5x but the technical complexity is much higher than a dam and pump

