On land you just can’t make it tall enough, you get roughly 2.5kWh of potential energy per km of delta-h per ton of mass. I think if you store energy in a grav

On land you just can’t make it tall enough, you get roughly 2.5kWh of potential energy per km of delta-h per ton of mass. I think if you store energy in a gravity battery out in the ocean where the depths are 10km, you may end up with a system competitive with pumped hydro. The incremental cost of a ton of mass and a ton of buoyancy are probably gonna be a factor of 2 to 10 less than lithium batteries. For any storage project: if it needs $1B of infrastructure costs for wires, dynamos, robots etc. just to start then you must be talking about building at least 10GWh before it is practical. so probably millions of tons for an oceanic gravity battery