Pumped hydro storage (PHS) is a highly effective form of long-duration energy storage that plays a crucial role in stabilizing and supporting modern power grids, especially as renewable energy sources like solar and wind become more prevalent. Here are several ways PHS contributes to long-duration energy storage:
Benefits of Pumped Hydro Storage
- Large Capacity and Long Durations: PHS systems can store large amounts of energy over long durations, making them ideal for balancing electricity demand fluctuations over daily or even weekly periods.
- Efficiency and Cost-Effectiveness: PHS achieves round-trip efficiencies of 70% to 80%, making it one of the most cost-effective means of storing electrical energy on a large scale. This is partly due to its long operational lifespan, often exceeding 100 years.
- Grid Stability and Services: Besides energy storage, PHS provides other essential grid services such as frequency control, reactive power support, and inertia. These capabilities are critical for grid stability, especially as more intermittent renewable sources are integrated.
- Environmental and Operational Flexibility: Closed-loop PHS systems minimize environmental impacts by not requiring natural water inflows, making them suitable for a wide range of geographical locations. This flexibility in site selection is advantageous for integrating PHS into modern power grids.
- Support for Renewable Energy: By storing excess energy generated during periods of low demand from renewables (e.g., wind and solar), PHS allows for the effective use of this energy during peak demand periods, thereby enabling higher penetration of intermittent energy sources into the grid.
Operational Principle
The operational principle of PHS involves two reservoirs at different elevations:
- Energy Storage Phase: During off-peak hours or surplus energy periods (e.g., from solar and wind), excess electricity is used to pump water from the lower to the upper reservoir.
- Energy Release Phase: During peak demand periods or when energy demand exceeds supply, water is released from the upper reservoir back to the lower one, generating electricity through turbines.
Overall, PHS is a vital technology for ensuring grid reliability and promoting the integration of renewable energy sources into the power mix.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-can-pumped-hydro-storage-contribute-to-long-duration-energy-storage/
