Abstract: There are provided a method for the bottom-side separation of a body which is to be worked out of rock (2000), in which a first part of the bottom surface of the body to be worked out of the rock (2000) is separated by removing the rock (2000) situated below the bottom surface, and a second part of the bottom surface is separated by replacing rock (2000) situated below the bottom surface with a layer system (140, 240, 440, 540) which has two unconnected separating layers (141, 142, 241, 242, 441, 442, 541, 542, 1310, 1320), with the result that the body to be worked out of the rock (2000) is supported in the region of this second part of its bottom surface by the layer system (140, 240, 440, 540), and a system (1000), which is suitable for carrying out such a method, for the bottom-side separation of a body to be worked out of a rock (2000), having an advancing unit (1100) for removing a rock layer, a discharge conveying unit (1200) for conveying away rock (2000) removed by the advancing unit (1100), a laying

Abstract: 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.

Abstract: A system for storing potential energy includes a hydraulic cylinder, a mass to be lifted, and a sealing ring at the edge of the mass to be lifted. The mass to be lifted is a solid rock mass in the form of a cut-out solid rock. The hydraulic cylinder is formed by the cavity between surrounding rocks and the cut-out solid rock. The cavity is sealed with respect to the surrounding rocks by the sealing ring. A method for producing such a system is also provided.