Pumped Hydro Electrical Storage
Energy is stored in the form of water, pumped from a lower elevation reservoir to a higher elevation. At times of low electrical demand, excess generation capacity (low-cost off-peak electric power) is used to pump water into the higher reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine, generating electricity.
How Do Pumped-Storage Hydro Plants Work?
1. Upper Reservoir – When power from the plant is needed, water stored in an upper reservoir is released into an underground tunnel.
2. Intake Tunnel – The water rushes down the intake tunnel.
3. Turbines – The force of the water drives huge turbines, which are underground at the base of a dam. The spinning turbines are connected to large generators, which produce the electricity.
4. Discharge Tunnel – The water then flows through a discharge tunnel into a lower reservoir.
5. Recharging – When demand for electricity is low, the turbines spin backward and pump the water back up into the upper reservoir to make it available to generate electricity when it’s needed.
The 9 Main Benefits Are…
- Conversion of base load energy into peak load energy (revenue increase)
- Utilization of excess generation capacity resulting from base load production
- Instantaneous coverage of peak load demand
- Optimizations of the operation of thermal plants by reducing the necessity to regulate their power output (increasing the operation time with constant power output)
- Providing for momentarily usable energy reserves (Adding to the operational reliability of the grid)
- Quick take-up of surplus power output at the drop out of big power consumers
- Balancing given meteorological and atmospheric conditions, which can lead especially on producer side, to non consumer conform fluctuations (e.g. calms or storms at wind farms, day and night at solar power station etc.)
- Frequency regulation of the grid
- Tension regulation