- Task: Feasiblity study &Tender document preparations
- Capacity: 3 MW
- Status: Completed
Salient Features (as per Feasibility Study Report, 2009):
Location : Bhairabkund Khola (Tributary of Bhotekoshi khola), Tatopani VDC, Sindhupalchowk District, Central development region of Nepal.
Latitude : 27o55’52”N to 27o56’30”
Longitude : 85o55’53”E to 85o56’28”
Purpose of project : To supply for domestic use and promote rural development in the most economically viable way.
Geology
Region : Lesser Himalayan Crystalline Zone
Rock composed : Gneiss, schist, schistose phyllite and quartzite
Geotechnical zoning : Fair to good
Hydrology
Catchment area : 21.00 km2
90% firm flow in the driest month : 0.52 m3/sec
Design flow (Q53) : 1.70 m3/sec
Flood 1 in 100 years : 141.52 m3/sec
Weir
Type : RCC gravity
Size : 6.50 x 11.0m x 4.5 m (w x l x h)
Crest level : 1638.80 masl
Intake
Type : Tyrolean and side intake
1. Tyrolean Intake
Size : 1.60 x 6.00 x 0.9(w x l x h)
Crest level : 1638.50 masl
Bottom level : 1636.75 masl
Gate : 2 nos.
2. Side Intake (to be operated optionally)
Number of orifice : 2 nos.
Size : 1.75 x 1.0 m (w x h)
Top level orifice : 1638.8 masl
Bottom level orifice : 1637.8 masl
Gate : 2 nos.
Gravel trap
Type of Structures : Surface
Length : 7.5 m (including transition)
Width : 3.50 m
Average Height : 4.9 m
Normal water level : 1637.10 masl
Spillway level : 1638.00 masl
Spillway length : 5.00 m
Flushing, stoplog gates : 2 nos.
Coarse trash rack : 1 nos.
Coarse trash rack size : 3.86 x 3.17 m (w x h)
Flushing culvert length : 23.7m
Flushing culvert size : 1.20 x 1.00 (h x w)
Canal from Gravel Trap to Settling Basin
Type : Rectangular with concrete wall and base
Length : 6.00 m
Bottom width : 3.50 m
Height : 3.37 m
Settling basin
Type of structure : Surface
Length : 36.0 m (including transition)
Chamber width : 3.50 m each
Chamber height : 4.54 m
No. of chambers : 2 nos
Sand flushing channel size : 2 nos., 1.00 x 0.60 m (w x h) steel lined
Flushing gates : 4 nos. (2 for each chamber)
Settling basin outlet gates : 4 nos. (2 for each chamber)
Normal water level : 1637.02 masl
Tunnel intake chamber
Surface area : 56 m2
Normal water level : 1636.77 masl
Fine trash rack : 3.15 x 2 m (w x h)
Tunnel
Length : 680.00 m
Shape : Rectangular with semicircular roof
Size : 2.00 x 2.50 (b x h)
Cross sectional area : 4.57 m2
Support : Shortcrete lining and Rock bolt
Surge shaft
Internal diameter : 3.50 m
Height : 12.0 m (minimum)
Support : RCC/ Shortcrete lining
Penstock Pipe :
Material : Steel
Length : 370.00 m
Internal diameter : 1.00 m
Thickness : 6 mm-20 mm
Anchor blocks : 10 nos.
Saddle supports : 62 nos.
Trifurcation pipe : 1 nos.
Branching : 2 pipes of 0.7m diameter
Powerhouse
Type : Surface
Size : 24.60 x 10.25 (l x w)
Number of generating units : 2 units
Turbine type : Horizontal Axis Pelton Turbine
Installed capacity : 3000 KW
Level of Turbine Nozzle center line : 1410.00 masl
Switchyard
Type : Outdoor
Area : 12 x 16 m
Tailrace
Type : Rectangular box closed duct and open channel
Length of closed duct : 24.63 m
Size of Tailrace culvert : 2 x 1.2m (w x h)
Transmission Facilities
Transmission line Length : 31km from Powerhouse to Sunkoshi through proposed Chaku Sub-station
Voltage level : 33 KV
Power and Energy
Gross Head : 226.77 m
Net Head at design discharge : 222.73 m
Installed Capacity : 3000 KW
Gross annual energy : 19.25 GWh
Net annual energy : 18.67 GWh
Wet Energy : 15.20 GWh
Dry Energy : 3.47 GWh
Access road/Construction Road
Length : 3.00 Km (proposed)
Alternative : Airlift or Ropeway
Financial Indicators
Energy rate, NPR/KWh : NPR 4.62/KWh at base year** and 3% escalation up to 9 times from generation year (From the dry season rate of NPR7.0 and wet season rate of NPR 4.0)
Base Case:
Benefit Cost ratio (B/C ratio) : 1. 25
Internal Rate of Return, (IRR) : 14.29%
Return on Equity (FIRR, 70/30 ratio) : 17.57%
Net Present worth, (NPV, at 10% discount rate) : 149 MNPR
Project Development Cost : 455 MNPR
Cost per kW, USD/kW (at 1 USD=78 NPR) : 1944.44 USD/kW
* The financial indicators are tentative and subject to change after the PPA energy rates are finalized within the validity of unit costs considered in year December 2007.