1.0 BACKGROUND

Tehri PSP has been envisaged to generate 1000 MW of peaking power for enhancing system reliability and also to provide balancing load to the thermal and renewable generation during off peak hours. The reservoir created by the Tehri Dam and Koteshwar Dam would function as upstream and downstream reservoir for Pump Storage Plant. This Plant will contribute in stabilization a big way by meet the peak load and balancing requirement.Tehri PSP comprising of four reversible pump turbine units of 250 MW each, involves construction of an Underground Machine Hall on the left bank of river Bhagirathi. The main feature of the Project is the large variation of about 90 m between the maximum and minimum head, under which the reversible units shall operate. The operation of Tehri PSP is based on the concept of recycling of water discharged between upper reservoir to lower reservoir. On completion, additional generating capacity of 1000 MW, peaking power, will be added to the Northern Region (annual generation of 2475 million units). For pumping operation of reversible units, the off-peak energy requirement will be of the order of 3104 MU. With the construction of Tehri PSP, Tehri Hydro power Complex shall function as a major peaking station having an installed capacity of 2400 MW.

2.0 PROJECT APPROVAL

Govt. of India approved the execution of Pumped Storage Plant (4X250 MW) in July-2006, at a cost of ₹1657.60 cr. including IDC of ₹81.64 cr. at Dec.’05 price level with debt equity ratio of 70:30.

3.0 REVISED COST ESTIMATE

RCE-I of ₹ 2978.86 at Apr’10 PL was approved in Nov’11. RCE-II of ₹ 4825.60 Cr. (incl. IDC & FC of ₹1089.80 Cr.) at Feb'2019 PL, has been approved on 31.07.2021.

Revised Cost Estimate-III: RCE-III at Jun’2023 PL has been prepared and submitted to CEA for approval. Proposal for Time over run is being examined in CEA.

4.0 Expected Commissioning of Project

1st and 2nd Unit are targeted to be completed by 15.03.2024 and 31.03.2024 respectively except constraint of River Joining.

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.
Date Event
04.06.1987 Receipt of Stage-I Forest clearance 
Received along with PIB of Tehri HPP in 1992 Receipt of Working permission
09.02.1988 Receipt of Stage-II Forest clearance
13.12.1989 Submission of proposal for Environment Clearance (if applicable)
19.07.1990 Receipt of EnvironmentClearance
29.08.2005 PIB/EFC proposal Approval
20.05.2006 CCEA Note Submission
18.07.2006 (Original)
08.11.2011 (RCE-I)
31.07.2021 (RCE-II)
CCEA Approval/Investment approval
30.08.2007 Publication of Tender (EPC Contract)
23.06.2011 Contract 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).
30.03.2023 Boxing up of Unit - 1