A potential energy store has a hydraulic cylinder in which a piston for storing energy in the form of potential energy of the piston is arranged. A position of the piston relative to the earth's surface can be varied. A pump pumps hydraulic fluid via lines into the hydraulic cylinder such that the piston is raised. A generator converts hydraulic energy of hydraulic fluid, which is displaced out of the hydraulic cylinder as the piston falls, into electricity. A seal arrangement is at least partially arranged between the hydraulic cylinder and the piston. The seal arrangement has a sealing section with a flexible support structure for absorbing the acting forces. The support structure may be coated on one or both sides with a layer which is impervious to fluid and which seals against the passage of fluid or may be impregnated with a solidified material which is impervious to fluid.