Tehri PSP is India’s first 1000 MW Variable Speed Pumped Storage Plant, designed to provide 1000 MW of peaking power, enhance grid reliability, and facilitate the integration of intermittent renewable energy sources such as solar and wind by utilizing surplus power during off-peak hours. 
The project utilizes the reservoirs of Tehri Dam and Koteshwar Dam as the upper and lower reservoirs, respectively, and comprises four reversible units of 250 MW each housed in an underground machine hall on the left bank of the Bhagirathi River. A key technical feature is the substantial head variation of about 90 m between the maximum and minimum operating heads of the reversible units. Tehri PSP stands fully commissioned with its entire 1,000 MW capacity as on 12 April 2026.
 

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.
No Data Available
Last Updated on 17/8/2026