Tehri Hydro Development Corporation India Limited (THDCIL) announced start of commercial electricity supply from first unit (250 MW) of 1 GW Tehri Pump Storage Plant located on the Bhagirathi River.

- VSPSP is a hydroelectric power plant that uses variable speed technology to adjust the speed of the turbines and pumps, offering greater flexibility and efficiency than traditional PSPs.
What is Pumped Storage Plant?
- It is a configuration of two water reservoirs at different elevations that can generate power as water moves down from one to the other (discharge), passing through a turbine.
- Principal of Operation:
- It uses principle of gravitational potential energy to store and generate electricity.
- It is a type of hydroelectric long duration energy storage.
- Working:
- When the demand for electricity is low and there is abundant renewable energy available from wind or solar sources this excess energy is used to pump water to upper reservoir.
- During periods of high electricity demand, the stored water is released back down to the lower reservoir through turbines, generating electricity.
- Types: PSP can be characterized as open-loop or closed-loop (refer diagram).
Status of pump-storage Hydropower in India
- Installed Hydro Pumped Storage Project capacity: In India it is approximately 4.8 GW (February 2025).
- Around 175 GW of pumped hydro storage capacity is installed worldwide as of 2022, with leading countries being China, followed by Japan, and the United States.