Intermediate power store for power generating systems

An energy buffer for at least one power generation plant from a time-varying energy source, the energy buffer including:

• an osmosis device configured to:
• in a loading process, separate a mixed liquid with a loading pressure into a permeate and a concentrate, or
• in an unloading process, mix the permeate with the concentrate while providing an osmotic pressure to form the mixed liquid;
• a permeate reservoir fluidly communicating with the osmosis device and configured to store the permeate;
• a concentrate reservoir fluidly communicating with the osmosis device and configured to store the concentrate;
• and
• a control device configured to control the following functions:
• the loading process with utilization of energy from the at least one power generation plant, the loading process being started in response to a loading signal indicating an excess of electrical energy, or
• the unloading process while providing electrical energy, the unloading process being started in response to an unload signal indicating a lack of electrical energy.