Vízenergiatárolás

Vízenergiatárolás, also known as pumped-storage hydropower or pumped hydroelectric energy storage (PHES), is a type of energy storage system that utilizes the potential energy of water stored at a higher elevation. It is currently the most mature and widely deployed form of large-scale energy storage.

The basic principle involves two reservoirs, one at a higher elevation and one at a lower elevation, connected by a tunnel or penstock. During periods of low electricity demand and surplus power generation, water is pumped from the lower reservoir to the upper reservoir, effectively storing energy in the form of gravitational potential energy. When electricity demand is high or renewable energy generation is low, water is released from the upper reservoir to flow through turbines in the lower reservoir, generating electricity.

The capacity of a pumped-storage facility is determined by the volume of water stored and the height difference between the reservoirs, while its power output is determined by the flow rate of the water through the turbines. PHES systems are highly efficient, with round-trip efficiencies typically ranging from 70% to 85%. They are also very flexible, capable of ramping up or down generation rapidly to respond to grid fluctuations.

While PHES is a proven technology, its deployment is limited by geographical requirements, as it necessitates suitable terrain for the two reservoirs. Environmental considerations, such as the impact on local ecosystems and water resources, are also important factors in the planning and operation of these facilities. Despite these challenges, pumped-storage hydropower remains a critical component of grid stability and a key enabler for the integration of intermittent renewable energy sources.