>>"..that gravitational potential energy just doesn't give you that much" To that point I'll respond with a quote from Hendl's site: A storage with a radius of

>>"..that gravitational potential energy just doesn't give you that much" To that point I'll respond with a quote from Hendl's site: A storage with a radius of 250 meters could store 124 GWh, which would correspond to the worldwide storage capacity of all pumped storage power stations. http://www.heindl-energy.com/hydraulic-rock-storage/idea-function.html http://www.heindl-energy.com/hydraulic-rock-storage/idea-fun...