NOVELTY - The method for operating a power plant for generating energy, where the plant includes a first inlet (24) for a first liquid solution (1) with a first concentration of a solute, a second inlet (25) for a second liquid solution (2) with a second concentration of a solute, a membrane element (4) and an outlet (26) for a mixture of first and second liquid solutions, comprises receiving the mixture of first and second liquid solutions running out from the outlet in a storage container, and guiding the mixture from the storage container into a separating device in a second time period.    USE - Method for operating a power plant for generating energy.    ADVANTAGE - The method ensures continuous and effective operation of the power plant with less effort, high efficiency and less energy consumption without fluctuations.    DETAILED DESCRIPTION - The method for operating a power plant for generating energy, where the plant includes a first inlet (24) for a first liquid solution (1) with a first concentration of a solute, a second inlet (25) for a second liquid solution (2) with a second concentration of a solute, a membrane element (4) and an outlet (26) for a mixture of first and second liquid solutions, comprises receiving the mixture of first and second liquid solutions running out from the outlet in a storage container, guiding the mixture from the storage container into a separating device in a second time period, and separating the mixture into two liquid solutions with different concentrations of the solute under energy consumption. The membrane element is formed and used for carrying out an osmotic process or an electrodialysis process for energy generation under the formation of the mixture of first and second liquid solutions in a first time period. The second time period is partially downstream to the first time period. The second concentration is different from the first concentration, where the both inlets are introduced into the membrane element. The osmotic process carried out in the membrane element is a pressure-retarded osmosis. The electrodialysis process carried out in the membrane element is a reverse electrodialysis. The separated liquid solutions with different concentrations are guided into two storage containers, which are fluidically connectable with the first and/or second inlets. The concentrations of the solute in the separated liquid solutions are equal with the first and second concentration of the solute in the first and second liquid solution. The liquid solution introduced in the first inlet is taken from a hydrothermal deep water layer. The liquid solution is led through a geothermal power plant before introducing into the first inlet. The liquid solution introduced in the second inlet is taken from a river. The separation of the mixture in the separating device takes place by supplying thermal energy and by magnetic and/or electric field. The thermal energy is taken from a conventional power plant in the form of a process steam, which is provided by the conventional power plant for the operation of a steam turbine, is provided by a solar module, and is provided as geothermal energy and/or waste heat of industrial processes by a combined heat and power unit. The energy generation takes place in a number of parallelly switched membrane elements. The solute is a salt in the liquid solutions. The liquid solutions are ammonium salt solution, organic solution, polymer solution and/or magnetoferritin solution on the basis of nanoparticles. An INDEPENDENT CLAIM is included for a power plant for generating energy.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic representation of an osmotic storage power plant.    First liquid solution (1)    Second liquid solution (2)    Membrane element (4)    First inlet (24)    Second inlet (25)    Outlet. (26)