Well, the energy scales with the diameter to the third power (we go from 3m to 30m, so x1000) and linearly with the depth (we go from 100m to 700m, so x7). So i

Well, the energy scales with the diameter to the third power (we go from 3m to 30m, so x1000) and linearly with the depth (we go from 100m to 700m, so x7). So in total, a factor of 7000 if everything is ideal. What I mentioned in the post above (4MWh) is a 30m sphere at 100m. I agree with your point, but am unconvinced that the system is scalable.