The invention relates to a pumped storage power plant (1) comprising at least one lower storage space (11) that is arranged underground and at least one upper storage space (12) that is separate from the lower storage space and arranged above ground or underground, wherein the lower storage space (11) is arranged in a greater depth than the upper storage space (12), and comprising at least one liquid line (15, 16) that is/are guided within the upper storage space (12) and within the lower storage space (11) respectively and that is/are connected to at least one hydraulic force and/or work machine (26, 27) of the pumped storage plant or can be connected via switchable valves (28, 29), and comprising at least one pressurized gas line (17, 18) that is/are guided within the upper storage space (12) and within the lower storage space (11) respectively and that is/are connected to a pressurized gas force and/or work machine (21, 22) of the pumped storage power plant or can be connected via switchable valves (24, 25), wherein the pumped storage power plant is configured for transporting a liquid medium (5, 7) from the upper storage space (12) into the lower storage space (11) and vice versa through the liquid lines (15, 16) and the hydraulic force and/or work machine (26, 27), and the pressurized gas force and/or working machine (21, 22) is configured for optionally producing a pressurized gas pressure of a pressurized gas (4, 6) at least in the lower storage space (11), which gas pressure can differ from a gas pressure in the upper storage space (12). Furthermore, the invention relates to a power plant and to methods for energy storage.