PumpspeicherKapazitäten

Pumped-storage hydroelectricity is a form of energy storage that uses gravitational potential energy of water to balance electricity supply and demand. In a typical installation, two reservoirs exist at different elevations. During periods of low demand and surplus generation, water is pumped from the lower to the upper reservoir using electric pumps. When electricity is needed, water is released back down through turbines to drive generators, converting potential energy into electrical energy.

Most pumped-storage plants use reversible turbine-pump units that can operate as pumps or as runners in turbine mode, sharing a single set of machinery and penstocks between the reservoirs. The arrangement enables rapid changes in output and high ramping capability, making pumped storage well suited for smoothing renewables, providing peak power, and supporting grid stability.

Performance varies by design, but typical round-trip efficiencies are around 70 to 85 percent. Storage capacity depends on reservoir size and head, with plants generally delivering hundreds of megawatts of power for several hours, and some facilities achieving multi-gigawatt capacity for a day or more.

Geographic and environmental factors influence siting, including water supply, ecological impacts, land use, and the need for suitable hydrology and topography. Construction is capital-intensive and the lead time can be long, but operations can last for many decades with relatively low operating costs.

Globally, pumped-storage is a mature technology that provides rapid response, long-term energy storage, and essential support for systems with high shares of intermittent renewables.