TEHRI PUMPED STORAGE PLANT

  • 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 stabilisation 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 1321.82 million units). For pumping operation of reversible units, the off-peak energy requirement will be of the order of 1651.66 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.

    4.0 Expected Commissioning of Project
    Project is expected to be commissioned by June-2023.
     

  • SALIENT FEATURES
    i.         Upstream Reservoir           : Tehri Dam Reservoir (Already commissioned)
     
    ii.        Downstream Reservoir      :  Koteshwar Dam Reservoir (Already commissioned)
     
    iii        Head Water Levels
                   Maximum                         :  830 m
                   Minimum                          :  740 m
     
    iv.       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
     
    v.       Upstream Surge Shaft
                 Nos.                                    :          02
                 Dia                                      :          20.92 m
                 Height                                 :          145 m
     
    vi.  Penstocks
                 Number                              :           04
                 Dia                                     :           6.0 m
                 Type                                   :           Steel lined
    vii   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
     
    viii)  Downstream Surge Shaft
               Nos.                                        :          02
               Dia                                          :          19.5 m
               Height                                     :          70 m
     
    ix)   Tail Race Tunnels
               Nos                                          :           02
               Dia                                           :           9.0 m
               Length                                      
               TRT-3                                       :         1151 m
               TRT-4                                       :         1255 m
     
    x)  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.




Updated on : 17/01/2022