Speicherkraftwerke, or pumped storage power plants, are a type of hydroelectric power station that store energy by moving water between two reservoirs at different elevations. During periods of low electricity demand, excess energy is used to pump water from the lower reservoir to the upper one. This process effectively stores energy for later use. When electricity demand increases, the stored water is released back down to the lower reservoir, passing through turbines that generate electricity. Speicherkraftwerke play a crucial role in balancing supply and demand in the energy grid, making them an important component of renewable energy systems.