Patent ID: 8166760

Claim:
A system for storing energy, the system comprising: at least one body; a hollow shaft structure having an interior volume for containing a fluid, the at least one body being disposed within the interior volume of the hollow shaft structure for movement with gravity from a first elevation position to a second elevation position within the interior volume of the hollow shaft structure; a fluid return path structure coupled in fluid flow communication with the hollow shaft structure, for communicating fluid with a first portion of the interior volume of the hollow shaft structure, the first portion of the interior volume of the hollow shaft structure being located vertically below the at least one body; and an electrical energy generator operatively coupled with the fluid return path structure to drive the electrical energy generator to generate electricity upon movement of the at least one body with gravity from the first elevation position to the second elevation position; wherein the at least one body comprises a plurality of bodies, and wherein the system further comprises a structure for suspending each of the bodies and selectively releasing the bodies for individual movement with gravity from the first elevation position to the second elevation position.