Surya Kunda Hydro Electric Limited
Surya Kunda Hydro Electric Limited, a company established and incorporated for the development and operation of hydro and solar projects to generate and supply electricity to National grid as its prime objective. The company is currently constructing 11.0 MegaWatt, Mathilo Tadi Khola Hydroelectric Project a run off river type project in Tadi river, a tributary of Trishuli river located at Dupcheswor Rural Municipality, Nuwakot district of Bagmati Province in the central region of Nepal. The major promoter/investor behind this company is Api Power Company Limited, a leading company in Nepal's Power Sector with Power Generation and Supply to National Grid as its core business. Api Power Company Limited has invested and has owned the 32,90,000 units shares i.e. 54% stake holding in the Company. As a Promoter in this Suryakunda Hydro Electric Limited, Api Power Company Limited invest Equity required for the development of the Projects owned.
Geographically the Project is located between the Latitude 270 59' 03" to 270 57' 32” North and longitude: 850 25' 01" to 870 26' 00" East. The intake and powerhouse sites lie in the Nuwakot District at altitudes of 1500.0m amsl and 1280 m amsl respectively. The effective catchment area of Tadi River at the proposed intake site is around 96 km2. Based on the hydrological analysis, a design discharge of 6.3 m3/s is derived at 40.00% probability of flow exceedance.
A ungated diversion weir of 6m height from river bed and 28m long weir is designed for intake at EL 1495.0m amsl. The diversion weir and its appurtenances are designed considering a one in 100-year high flood event whose magnitude is estimated to be 247 m3/s. Powerhouse of the project is located at EL 1282m amsl.
With the available gross head of 215m and considering the losses in water conveyance, a net head of 207.16m is available at Powerhouse. Two units of Vertical axis Pelton turbines 5.5 MW (each) is designed to generate 11.0 MW power at design discharge of 6.3 m3/s and 207.16m head. 7 km long 33 kV double circuit transmission line is being erected to evacuate the power from the switchyard to NEA’s substation at Samundratar Substation, Nuwakot district. The total annual energy generation from the plant will be 61.319GWh, out of which 50.893 GWh is the wet seasonal energy and 10.425 GWh is the dry seasonal energy.
The company has obtained survey license of the Project from the Department of Electricity Development, Ministry of Energy and completed the Detailed Survey of the Project. Company has entered into the Power Purchase Agreement with Nepal Electricity Authority on dated 3rd Chaitra, 2068 B.S. The IEE has already been approved by the Ministry of Energy and the Land acquisition for the Project has been completed. Company has obtained the Generation Licence from Ministry of Energy, Department of Electricity Development (DOED) on dated 22nd Ashwin, 2072 B.S.
Salient Features
Name of River : Tadi Khola
Type of Scheme : Run-Off-River
Latitude : 270 57’ 32” to 270 59’ 03”
Longitude : 850 25’ 01” to 850 27’ 20”
Catchment area at the intake site : 96 km2
Design Flow(Q40%) : 6.3 m3/s
Maximum monthly flow : 28.2 m3/s
Minimum monthly flow : 2.08 m3/s
100Years Flow at the intake site : 247 m3/s
Weir
Type : Ungated Diversion
Material : Boulder Armoring
Length : 28 m
Height : 6 m
Design Flood : 247 m3/s
Weir crest elevation : 1497 masl
Intake
Type : Orifice Side Intake
No of orifices : Two
Size of each orifice : 2.5m x 2.0m
Orifice invert level : 1495.0 masl
Intake flow : 6.93 m3/s
Penstock Pipe
Shape : Circular
Length : 2420 m
Internal Diameter : 1.7 m
Thickness : 6 mm – 25 mm
Number of Anchor Blocks : 24 nos.
Pipe support Foundation : 301 nos.
Powerhouse
Type : surface
Size : 23.1m x 16.3m x 9.1m
Turbine Center line Elevation : 1282 masl
Type of Switchyard : Outdoor
Tailrace Channel
Shape : Rectangular
Size of Tailrace tunnel : 3.0 m x 2.5 m
Length of tailrace tunnel : 80 m
Electrical and Mechanical equipment
Turbine type : Pelton (6 jet Vertical)
No of units : 2 no
Turbine speed : 500 rpm
Turbine efficiency : 91%
Generator type : A.C Synchronous
Generator efficiency : 97%
Rated voltage of generators : 11 kV
Rated frequency : 50 Hz
Type of Transformer : 3-phase, ONAN, outdoor
Rated capacity of transformer : 3*4300 kVA
Transformer efficiency : 99%
Transmission Line
Length : 6 km (Project site to Samundratar)
Type : 33kV
Power and Energy
Gross Head : 215 m
Net Head : 207.16 m
Design Discharge : 6.3 m3/s
Installed Capacity : 11 MW
Annual Energy Generation : 61.319 GWh
Dry season Energy : 10.425 GWh
Wet season Energy : 50.893 GWh
Financial Indicators
Total Project Financial cost : 1,890,988,554 NRs.
Return on Equity (equity 25%) : 25.29%
IRR : 15.51%
Benefit / Cost Ratio : 1.50