Pumped hydro storage (PHS) interacts with renewable energy sources during peak demand by acting as a large-scale, flexible energy storage and supply system that balances the variability of renewables like wind and solar.
Interaction During Peak Demand
- Energy Storage When Supply Exceeds Demand: When renewable sources such as wind and solar generate excess electricity—often during low-demand periods or when the sun is shining and wind is blowing strongly—pumped hydro facilities use that surplus power to pump water from a lower reservoir to an upper reservoir. This converts electrical energy into stored gravitational potential energy, essentially “charging” the system.
- Energy Generation During Peak Demand: When electricity demand peaks, often when renewable generation is low (e.g., no wind or sun), water is released from the upper reservoir back down through turbines to the lower reservoir, producing electricity quickly and reliably. This ability to dispatch energy on demand helps meet peak load requirements and offsets the intermittency of renewables.
- Ancillary Grid Services and Flexibility: Due to its rapid response capabilities—sometimes reaching full output within minutes—pumped hydro storage provides essential ancillary services like frequency regulation, voltage control, spinning reserves, and balancing supply and demand in real time. This supports grid stability as the share of variable renewables increases.
- Supporting Renewable Integration: By storing excess renewable energy and releasing it when needed, PHS enables a higher penetration of renewable energy on the grid, reduces reliance on fossil fuel power plants, and supports the transition toward net-zero emissions. It thus ensures a constant, reliable power supply despite renewable intermittency.
Summary Table of Interaction
| Function | Pumped Hydro Storage Role | Benefit to Renewables and Grid |
|---|---|---|
| Excess renewable generation | Pumps water uphill storing energy | Prevents curtailment of wind/solar energy |
| Peak electricity demand | Releases stored water to generate electricity | Meets peak demand reliably and quickly |
| Grid stability and ancillary services | Provides frequency regulation, reserves, voltage control | Maintains grid stability with high renewables |
| Environmental impact | Uses renewable electricity for pumping, minimal emissions | Reduces need for fossil-fuel backup |
| Long-duration storage | Can store energy for hours to days | Enables large-scale renewable integration |
In essence, pumped hydro acts like a giant water battery that stores renewable energy when plentiful and delivers it on demand during peak periods, thereby smoothing out fluctuations in renewable output and helping maintain a stable, reliable, and low-carbon electric grid.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-pumped-hydro-storage-interact-with-renewable-energy-sources-during-peak-demand/
