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Dordi Khola Hydropower Project (27 MW)

Technical Summary

Dordi Khola Hydropower Project is a Run-of-River type hydroelectric project with generating capacity of 27 MW. The project is being developed by Himalayan Power Partner Ltd. (HPPL) Kathmandu, Nepal. IME Group and NRN Infrastructure & Development Ltd. to develop Dordi Khola This is the first corporate investment of Non Resident Nepalese (NRN) in Nepal.

Feasibility Study of the Project was completed in March 2010. Detail Project Report (DPR) is prepared by international consultant Entura Hydro Tasmania.

The whole project area lies in Chiti, Dhodeni and Bansar VDCs in Lamjung district in western Nepal. It is connected from Kathmandu by 170 km all weather metallic roads up to Udipur at Dumre-Beshisahar Road. A fair weather road from Udipur to Hile passes near by the headworks site (12 km). Initial Environmental Examination (IEE) study was completed and approved from the Ministry of Energy in September 2010. About 50 ropani out of 150 ropani private land needed for different project components have been purchased. The negotiations for the purchase of rest of private land are on the process and planned to complete by February 2014. The generated power will be evacuated to Integrated Nepal Power System (INPS) through a 132 kV single circuit Transmission Line (TL) up to the proposed Udipur Hub of Nepal Electricity Authority (NEA). Length of TL will be 1.2 km.

The connection agreement with the Grid Department of NEA for the power evacuation was concluded on 2067/03/23 (July 7,2010). The company acquired generation license in July 7, 2011 from the ministry of Energy for the period of 35 years including one year for Power Purchase Agreement and financial closure and another four years of construction period.

Facility agreement to provide Term Loan of amount NPR 3,170 million, 75% of total project cost including IDC, NPR 4,235 million, was concluded with Bank Consortium led by Prime Commercial Bank Ltd. on 7 November 2013.Financial progress up to July, 2019 is NPR 3,002 million (70.89%).HPPL has completed the process of IPO after allotting equity shares worth NPR 319.625 million (30% of equity capital NPR 1, 065 million) to general public including project effected area people and company employees in Shrawan 2074. The public shares of HPPL have been listed in Nepal Stock Exchange & being trading in Secondary Market.

The Power Purchase Agreement (PPA) between the company and Nepal Electricity Authority (NEA) was concluded for the period of 34 years (including 4 years for construction) on June 15, 2012 @ NRs. 8.40/kWh for dry energy and NRs. 4.80/ kWh for wet energy and will be escalated @ 3% (compound) for nine years.

Developer Himalayan Power  Partner Limited 
Location Chiti,Dhodeni, & Bansar VDC of Lamjung Distrcit
Installed Capacity 27 MW
Design Discharge 15.28 m3/s
Survey License Issued 26 May,2005
Grid Connection Agreement 7th July,2010
Generation License Obtained 7th July,2011
PPA Signed 15th Jun2,2012
Facility Agreement Signed 7th Novemeber,2013
Contract of Main Civil Works April,2014
Required Commercial Date of Operation 12 April,2020
Dry Energy 21.367 GWh
Wet Energy 120.952 GWh
Average Annual Energy 142.319 GWH
Construction Works Started April,2014
Total Project cost NPR 4,498 Million

Salient Features of the Project:

Location
Country Nepal
District Lamjung
Development Region Western
Location of Intake and Project site Chiti VDC
Nearest Airport Pokhara
Geographical Co-ordinates of Project Area
Longitude 84° 26’E to 84° 28’30”E
Latitude 28°10’ N to 28°13’ 32”N
Hydrology
River/Stream Dordi-Khola
Catchment area at Diversion site 277 km2
Design Discharge 15.28 m3/s
Design Flood at diversion site (100 year return period) 614 m3/s
Design Flood at Powerhouse site (1000 year return period) 3251 m3/s
River Diversion Arrangement
1 in 20 years dry season design flood 27.24 m3/s
Top of coffer dam at upstream El. 762.0 m
Top of coffer dam at downstream El. 756.0 m
Diversion Structure
Type Ogee Type weir, free over flow with under sluice bays
Average river bed level El. 758.0 m
Bridge deck level El. 768.0 m
Width of diversion structure 55 m
Highest flood level El. 767.75 m
Full supply level El. 764.50 m
Weir
Crest elevation of overflow weir El. 764.75 m
Width of overflow weir section 41.2 m
Under Sluice Bay
No. of under sluice bays 2
Width of each bay 4.25 m
Thickness of pier 1.5 m
Crest level of under sluice bay El. 758.0 m
Clear width of under sluice bays 8.5 m
Type and height of gate Vertical gates, 3 m high.
Energy Dissipation System Hydraulic Jump Type Stilling Basin
Length of stilling basin from toe of sloping glacis 25 m
Total width of basin 49.725 m
Cistern level El. 754.0 m
End Sill Level El. 757.0 m
Intake Structure Side Intake
Type 4.75 m (W) x 4.0 m (H)
Track rack size
Numbers of trash rack 2
Intake diversion flow (including 20% flushing discharge) 18.33 m3/s
Intake size Two bays; each 2.25 m (W) x 2.7 m (H)
Invert level of Intake El. 760.50 m
Intake stop log 1 no. Vertical lift gate (2.25 m x 2.7 m)
Intake service gate 2 nos. Vertical lift gate (2.25 m x 2.7 m)
Feeder Pipe
Type Circular steel
Numbers 2
Size 2.25 m Dia.
Length 131.30 m & 140.10 m
Desilting Basin
Type Hopper Type
Numbers of chambers 2 nos
Size of particles to be removed 0.2 mm and above
Dimension (L x B x H) 60 m x 8.5 m x 8.0 m
Design discharge 18.33 m3/s
Flow through velocity 0.26 m/s
Silt Flushing Pipe
Type Circular
Dia 0.9 m
Total length 100 m
Water Conductor Pipe
Type Steel Pipe
Size 2.65 m dia
Total length 3282 m
Head Race Tunnel (Concrete Lined)
Type & shape Underground, D-shaped
Dia 3.3 m
Total Length 2661.67 m
Steel Lined Tunnel
Type & shape Underground, circular
Dia 2.65 m u/s of HRT, 2.3 m d/s of HRT
Total length 25 m, 82 m respectively
Surge Shaft
Type Restricted orifice type
Height 45 m
Dia 7 m
Orifice size 1.3 m dia, circular
Top of surge shaft El. 780.0 m
Maximum upsurge level El. 778.06 m
Minimum down surge level El. 746.39 m
Valve House
Type Surface
Number 1
Size ( L x W x H) 16 m x 9.5 m x 12 m
Type of valve Buttery valve
Diameter of valve 2.3 m
Penstock
Type Surface and Buried Penstock
Nos. One no. starting from outlet portal and trifurcating before Power House.
Diameter 2.3 m, circular shaped
Liner thickness 10 mm to 20 mm
Length 830.5 m
Length of penstock after trifurcation 163.8 m
Branch penstock Circular, 1.3 m diameter each
Power House
Type Surface
Gross Head 214 m
Rated Head 203.32 m
Design discharge 15.28 m3/s
Normal Tail water Level El. 552.0 m
Center line of penstock El. 550.45 m
Size of Powerhouse at machine floor 44.225 m (L) x 15.0 m (W) x 31.25 m (H)
Tail Race Channel
Type RCC Box culvert
Length 333.66 m
Size 3.5 m x 2.5 m
Normal tail water level El. 552 m
Switchyard
Size 30 m x 40 m
Voltage level 132 kVA
Turbine
Turbine Type Horizontal axis Francis
Number 3
Rated Capacity of each turbine 9.3 MW
Governor
Type Electro-Hydraulic
Generator
Generator Type Synchronous three phase
Number 3
Rated Capacity 3 x 10590 kVA
Power Factor 0.85
Voltage 11 kV
Frequency 50 Hz
Excitation system Brushless/ static
Transformer
Rated capacity Bank of 3 x 10.67 MVA, 11/132/√3, single phase
Voltage ratio 11 kV/ 132 kV
Transmission Line
Voltage level 132 kV Single Circuit
Length 1.2 km
Power Generation
Installed capacity 27 MW
Net annual energy after transmission & outage losses 142.75 GWh

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