An apparatus for storage of potential energy using water from a deep body of water is described. The apparatus comprises one module including a cylinder (1), a piston (2) slidably connected to the cylinder, a column (3) for storing the water from the sea received through an inlet (4) being in communication with the cylinder/piston, and a connecting tube (5) which mutually connects the cylinder and the column. The apparatus further comprises driving means for reciprocally displacing the piston in relation to the cylinder, wherein the driving means is a crankshaft (6) drivingly connected to the piston and at least one flywheel (7) mounted to the crankshaft for counteracting the pressure as result of the water stored in the column. |