1.0 BACKGROUND

Tehri PSP is envisaged to generate 1000 MW peaking power to enhance system reliability and to provide balanced power to thermal and renewable generation during off peak hours. The reservoirs created by Tehri Dam and Koteshwar Dam will act as upstream and downstream reservoirs for the pumped storage plant. This plant will contribute in stabilization by meeting peak load and balancing requirement. Tehri PSP consists of four reversible units of 250 MW each, involves construction of underground machine hall on the left bank of river Bhagirathi. The main feature of the project is that it has a large head deviation of about 90 m between the maximum and minimum head from which the reversible units will operate. The operation of Tehri PSP is based on the concept of recycling of water between the upper reservoir and the lower reservoir. On completion of the project, there will be an additional generation capacity of 1000 MW (annual generation 2442 million units) of peaking power in the northern region. The pumping operation of the reversible units will require 3075 MU of peak power. With the construction of Tehri PSP, the Tehri Hydro Power Complex will have a capacity of 2400 MW. It will serve as the major peaking power station with an installed capacity of 2400 MW.

2.0 PROJECT APPROVAL

Government of India approved the execution of Pumped Storage Plant (4x250 MW) in July 2006 at a cost of Rs. 1657.60 crore including IDC of Rs. 81.64 crore at December 2005 price level with debt equity ratio of 70:30.

3.0 REVISED COST ESTIMATE

Revised Cost Estimate-II: Approved RCE-II of Tehri PSP is Rs. 4825.60 Cr at Feb'2019 PL.
Revised Cost Estimate-III: Preparation of RCE-III at Feb’25 PL.

4.0 Expected Commissioning of Project

Unit-1: COD declared w.e.f. 00:00 hrs. of 07.06.2025.
Unit-2: COD declared w.e.f. 00:00 hrs. of 10.07.2025.
Unit-3 & 4: Unit-3 & 4: Nov’25 & Dec’25 respectively.

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 (annual generation of 1321.82 million units)
  2. Reliable, economical and best available means for banking of electricity
  3. Grid stability
  4. Banking of power
  5. Ancillary grid services such as network frequency control and reserves.
DateEvent
04.06.1987Receipt of Stage-I Forest clearance 
Received along with PIB of Tehri HPP in 1992Receipt of Working permission
09.02.1988Receipt of Stage-II Forest clearance
13.12.1989Submission of proposal for Environment Clearance (if applicable)
19.07.1990Receipt of EnvironmentClearance
29.08.2005PIB/EFC proposal Approval
20.05.2006CCEA Note Submission
18.07.2006 (Original)
08.11.2011 (RCE-I)
31.07.2021 (RCE-II)
CCEA Approval/Investment approval
30.08.2007Publication of Tender (EPC Contract)
23.06.2011Contract Awarded to consortium of Alstom Hydro – France (renamed as GE Hydro France), Hindustan Construction Co Ltd and Alstom Project India Ltd (renamed as GE Power India limited).
30.03.2023Boxing up of Unit - 1
20.08.2022Stator Lowering U-6
31.05.2023Stator Lowering U-7
28.11.2023MIV Lowering of U-6
22.12.2023Runner Lowering U-8
26.12.2023Boxing up U-6
12.01.2024Stator Lowering U-8
08.03.2024Rotor Lowering U-7
15.07.2024Commissioning BFV-5 & 6
22.07.2023Rotor Lowering U-6
15.09.2024Boxing Up U-7
25.09.2024MIV Lowering of U-7
25.09.2024MIV Lowering of U-8
28.09.2024Rotor Lowering U-8
31.05.2025Boxing up U-8