Pumped-storage hydroelectricity (PSH) systems are a critical form of energy storage, playing a significant role in stabilizing the electrical grid by leveraging the principle of gravitational potential energy. Here’s how they work:
Basic Principle
- Two Reservoirs: PSH systems consist of two water reservoirs at different elevations.
- Pumping and Generating Phases:
- Pumping Phase: During periods of low electricity demand or excess energy supply, typically from renewable sources like solar or wind, electricity is used to pump water from the lower reservoir to the upper reservoir. This stores energy as gravitational potential energy.
- Generating Phase: When electricity demand increases, water is released back into the lower reservoir. As it flows downhill, it passes through turbines, which generate electricity. The turbines act as both pumps and generators, making them efficient for both phases.
Key Components
- Reversible Turbines: Most PSH plants use reversible turbine/generator units, which can operate in both directions—pumping water up or generating power when water flows down.
- Efficiency and Operations: PSH systems are optimized for efficiency through variable speed operations and ancillary services like frequency regulation and grid stabilization.
Types and Applications
- Closed-Loop and Pump-Back Systems: There are closed-loop systems with no natural inflows and pump-back systems that combine with conventional hydroelectric plants.
- Role in the Grid: PSH provides long-duration energy storage and enhances grid reliability by offering flexibility and stability, crucial as renewable energy sources increase.
In summary, pumped-storage hydroelectricity offers a reliable and efficient means of energy storage and generation, contributing to a stable and flexible electrical grid.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-pumped-storage-hydroelectricity-systems-work/
