The Tehri Pumped Storage Plant (PSP), India’s first 1000 MW Variable Speed Pumped Storage Plant, is designed to generate 1000 MW of peaking power to enhance grid reliability and balance intermittent renewable (Solar & wind) generation during off-peak hours. The project utilizes the reservoirs created by the Tehri Dam and Koteshwar Dam as the upper and lower reservoirs, respectively, facilitating efficient pumped storage operations. Tehri PSP comprises four reversible units of 250 MW each, housed in an underground machine hall on the left bank of river Bhagirathi. A key technical feature of the project is the substantial head variation of about 90 m between the maximum and minimum operating head of the reversible units. With an Annual Generation capacity of 2441.75 million units (MU) and an approximate round-trip efficiency of 79.41%, the Tehri PSP will efficiently convert off-peak energy to peak energy. All four units (Unit I to IV) have been synchronized with the grid and declared under commercial operation with effect from 7th Jun’ 2025, 10th Jul’ 2025, 12th Dec’ 2025 & 12th Apr’ 2026 respectively. With the commissioning of Tehri PSP, the total installed capacity of the Tehri Hydro Power Complex has reached 2400 MW, positioning it as a major peaking power hub.

 

 

 

SALIENT FEATURES

  1. Upstream Reservoir : Tehri Dam Reservoir (Already commissioned)
  2. Downstream Reservoir : Koteshwar Dam Reservoir (Already commissioned)
  3. Head Water Levels
    Maximum : 830 m
    Minimum : 740 m
  4. Head Race Tunnels : Two nos concrete lined HRTs (HRT-3 & HRT-4)
    Dia 8.5 m Length HRT-3: 932m, HRT–4 :1060m already constructed
  5. Upstream Surge Shaft
    Nos. : 02
    Dia : 20.92 m
    Height : 145 m
  6. Penstocks
    Number: 04
    Dia: 6.0 m
    Type: Steel lined
  7. Power House
    Type: Underground
    Size of Machine hall: Width : 28.2 m
    Height : 56 m
    Length : 203 m
    Location: Left Bank
    Rated unit capacity : 250 MW
    Installed capacity : 1000 MW
    Number of units : 04 nos.
    Type of Machine: Variable speed vertical Francis type reversible Turbine.
    Turbine Net Head Range : 120.4m to 219.4 m
    Pump delivery Head Range : 130.5m to 229.5 m
    Design Head : 188 m
    Rotational Speed : Variable speed
    Distributor axis: approx. EL 568 M
    Submergence : approx. 38 m
    Output
    -Nominal value : 278 MVA
    -Maximum capacity : 306 MVA
    Rated electrical power output : 250 MW at about 188m WC of rated net Head
  8. Downstream Surge Shaft
    Nos. : 02
    Dia : 19.5 m
    Height : 70 m
  9. Tail Race Tunnels
    Nos : 02
    Dia : 9.0 m
    Length
    TRT-3 : 1151 m
    TRT-4 : 1255 m
  10. Tail Water Levels
    Maximum : 612.5 m
    Minimum (in pump mode): 606 m
    Minimum (in turbine mode) : 603 m
    Average : 609.5 m
  1. Peaking power of 1000 MW (expected annual generation of 2442 million units)
  2. Reliable means for efficient banking of surplus power.
  3. Provides Ancillary grid services.
  4. Contribution to 100 GW of PSP capacity required by 2035-36.
Last Updated on 16/4/2026