PUNATSANGCHHU-II HYDROELECTRIC PROJECT (1020 MW)
Punatsangchhu River
Surge Shaft –full section
Diversion Tunnel Intake
Punatsangchhu-II is the second Project of the 10,000 MW initiative taken by
the Royal Government of Bhutan (RGoB) and the Government of India (GoI) in
May 2008, for development by 2020. Agreement between the GoI and the
RGoB for implementation of the Punatsangchhu-II Hydroelectric Project was
signed on 30 April 2010 by H.E. Shri S.M. Krishna, Hon’ble Minister for
External Affairs on behalf of the GoI and H.E. Lyonpo Khandu Wangchuk,
Hon’ble Minister for Economic Affairs on behalf of the RGoB. On the same
auspicious day, the foundation stone of the Project was laid jointly by H.E. Dr.
Manmohan Singh, Hon’ble Prime Minister of India & H.E. Jigmi Y. Thinley,
Hon’ble Lyonchhen of Bhutan.
The Project is located on the right bank of Punatsangchhu along the WangdueTsirang highway between 22 km and 35 km downstream of Wangdue Bridge.
The dam site is about 94 km from Thimphu and connected by a highway. The
project sanctioned at a cost of ₹/Nu. 37.78 billion excluding IDC on March
2009 price level with installed capacity of 990 MW (now revised to 1020 MW)
is being funded by the GoI: 30% grant and 70% loan @ 10% interest p.a.
repayable in 30 equated semi-annual installments commencing one year after
the mean date of commercial operation.
Punatsangchhu-II Hydroelectric Project Authority (PHPA), an autonomous body
was set-up for implementation of the Project on 08 June 2010. The project
implementation started on 17 December 2010 with a completion schedule of 7
years including 2 years of infrastructure development.
The Punatsangchhu-II Hydroelectric Project is an environment friendly run-ofthe river scheme. The Project area starts from dam site about 22km
downstream of Wangdue bridge to Tail Race Tunnel which is located about
35km downstream of Wangdue bridge. The Project involves construction of the
following:
Concrete Dam, 86m high and 213.5m wide at the top
Diversion Tunnel, 12m diameter, 888m long.
Four Desilting Chambers, each of 420m length x 19m width x 24.7m
depth.
Dam
HighwayTunnel
Intakes
DesiltingChambers
Punatsangchhu River
HeadraceTunnel
Layout of Dam, Intakes, Desilting Chambers& Highway Tunnel
Headrace Tunnel, 11m diameter, 8.6km long.
Surge Shaft, 31m diameter 137m height.
Three Pressure Shafts, 5.5m diameter 997m long & 6 penstocks of
3.86m diameter.
Underground Power Station, 236m x 23m x 51m size to house 6
turbo generators.
Tailrace Tunnel, 11m diameter 3.3km long.
Underground Transformer Cavern, 215.4m x 14m x 26.5m size to
accommodate 20 single phase generator transformers each of
13.8kV/400kV & 70MVA capacity.
Two Double Circuit 400kV LILO with Punatsangchhu-I Transmission
Lines.
Underground Power House
Transformer Hall
Surge Gallery
Headrace Tunnel
Punatsangchhu River
Surge Shaft
Tailrace Tunnel
Layout of Power House Complex
One Double Circuit 400kV line from PHEP-II to Jigmeling.
PROJECT CONSULTANTS
WAPCOS Ltd. (a Government of India Undertaking) are the engineering design
Consultants to the Authority.
The expertise of premier organizations of
GoIe.g., CEA, CWC, Central Water & Power Research Station (CWPRS), Central
Soil & Materials Research Station (CSMRS), GSI and Survey of India (SoI) are
made available to the Project through WAPCOS.
LAND ACQUISITION
The concerned RGoB authorities have approved lease/acquisition of 479 acres
of GRF land, 14 acres of private land (involving 17 land owners) and 5 acres of
Institutional Land (3 institutions) till the end of April 2013 for the project
construction.
MAIN CIVIL WORKS
The Main Civil Works of the Project have been divided into three packages:
C-1, C-2 & C-3
C-1: Construction of Diversion Tunnel, Dam, Intake and Desilting
Arrangement including Hydro-Mechanical works and Highway tunnel was
awarded to M/s Jaiprakash Associates Ltd. at a contract sum of
₹/Nu.12.24 billionon 26 June 2011 with a completion time of 66 months.
Diversion Tunnel
Highway Tunnel
C-2:Construction of Headrace Tunnel (HRT) from Adit-I &Adit-II was awarded
to M/s Gammon (India) at a contract sum of ₹/Nu.3.98billionon 26 June
2011 with a completion time of 60 months.
C-3: Construction of Headrace Tunnel (from Surge Shaft end), Surge Shaft,
Butterfly Valve Chamber, Pressure Shafts, Power House, and Tailrace Tunnel
(TRT) including Hydro-Mechanical works was awarded to M/s Jaiprakash
Associates Ltd. at a contract sum of ₹/Nu.8.56 billionon 26 June 2011 with
a completion time of 66 months.
MAIN ELECTRO-MECHANICAL (EM) WORKS
Generating Plant & Equipment: The first EM works contract of Generating
Units and Associated Auxiliaries was awarded to M/s Bharat Heavy Electricals
Limited, a GoI Undertaking (BHEL) at a cost of ₹/Nu.9.5 billion on 18 June
2012 with a completion period of 57 months.
Transformers: The second EM works contract of Generator Transformers,
Reactors etc., was awarded to BHEL at a cost of ₹/Nu.1.07 billion on 08 April
2013.
Gas Insulated Switchgear: The third EM works contract of 420kV Gas
Insulated Switchgear was awarded to Hyosung Corporation, South Korea at a
cost of ₹/Nu.0.96 billion on 08 April 2013.
400kV XLPE Cables:The fourth EM works contract of 400kV XLPE cables was
awarded to L.S. Cables, South Korea at a cost of ₹/Nu. 0.36billion on 08 April
2013.
TRANSMISSION SYSTEM
The Authority has entrusted the execution of the transmission System to BPC,
a RGoB Undertaking on ‘Deposit Work’ basis.
POWERGRID is providing
consultancy to the BPC.
CLEAN DEVELOPMENT MECHANISM (CDM)
Intention to get the Project registered for availing Carbon Emission Reduction
(CER) benefits communicated to National Environment Commission (NEC),
Bhutan, Ministry of Environment and Forest, GoI and United Nations
Framework Convention on Climate Change (UNFCCC), was accepted by the
concerned. Consultancy work of CDM Project was awarded to M/s ITP Synergy
Ltd. & RITES Ltd. Consortium, New Delhi on 14th Jan., 2012 at a fixed fee of
₹/Nu. 3.0 million and Success-Sharing Fee of 0.29%.
COMPLETION SCHEDULE
The Project is scheduled to be completed in seven years w.e.f17thDecember
2010(zero date),the start date of construction i.e. on 17thDecember 2017.
ENERGY GENERATION
The 1020MW Punatsangchhu-II Hydroelectric Project is envisaged to generate
4.36billion units in an average year.