Likhu 1 is a run-of-river scheme that diverts 17.5 m 3 of water through a 5.75 m high diversion weir and further through a 8.24 km underground water conductor system to the powerhouse. Here, utilizing a net head of approximately 516.05 meters, we are able to generate upto 77 MW.
Project Description
Description
Symbol
SI
Unit
Design Discharge
Qd
17.5
m3 /sec
Gross Head
534.25
m
Net Head
Hn
516.05
Meters
No. & Type of Units
25.67 MW
3
Vertical Pelton
Turbine Efficiency at QD
ŋT
91.72
%
Generator Efficiency
ŋG
98
%
Transformer Efficiency
ŋTr
99
%
Result
Gross Power
PG
77
MW
Annual Energy
EA
363.11
GWh
Key Technical and Financial Feature
General
Total Project Cost
NPR 1285.4 cr (US$ 97.38 M)
Unit Cost of
Generation
NPR 16.69 cr (US$ 1.44M) / MW
EIRR
12.15 %
Period of
Construction
58 Months
Project Layout
Left Bank of Likhu
Catchment Area
253 km2
Head Race Tunnel
Type
Low Pressure Tunnel
Section Type
Inverted D
Finished Diameter
3.4 / 4.2 m
Support Type
Shotcrete / Concrete Lined
Ungated Weir
Weir Height
5.75 m
Length of the
Weir crest
12.9 m
Design Flood (1 in
100 Yr)
219 m3 / sec
Power House
Type
Surface
Size (L * W* H)
41.2 x 21 x 24.65 m
Tail race
44.3 x 4.0 x 3.5 m
Transmission Line
132 kV, Double circuit; 7.1
km with Li 1 & Li 2 sharing
the cost.
Connecting Sub-
Station
Likhu A Switchyard
Salient Features
General
Period of Construction
58 Months
Project Layout
Right Bank of Likhu
Catchment Area
253 km2
Weir location
Tanding
Powerhouse location
Thado Khola
Head Race Tunnel
Type
Low Pressure Tunnel
Section Type
Inverted D
Finished Diameter
3.4 / 4.2 m
Support Type
Shotcrete / Concrete Lined
Surge Shaft
U/G, restricted orifice
Internal Diameter / Height
25×5.1/25×4.8 m/24.6×4.4 m
Leading to an
Underground PPV
Intake
Type
Side Intake
No. of Chambers / Size
3 No. / 3.3 * 2.5 m
Crest Elevation of Intake
2266.5 m
Feeder Channel is
Closed
Length of Feeder Channel
24.95 m
Desilting Basin
Type
Open, Surface
No. of Bays
2 (Two)
Length
60 m
Total Width / Depth
22 m / 12 m
Transmission Line
Voltage
132 kV
Length
7.5 km
Conductor Type
ASCR BISON
Ungated Weir
Weir Height
5.25 m
Length of the
Weir crest
16.5 m
Foundation Level U/S
1719 masl
Minimum reservoir level
2259.50 masl
Silt Pressure is Upto
1720.6 masl
Weir Top Level [Design Flood]
2262.25 m
Tail water level (Min.)
2256.60 m
Design Flood (1 in
100 Yr)
219 m3 / sec
Pressure Shaft
Type
U/G Inclined & Horiz.
Total Length
890 m
Diameter
2.5 m (steel lined) 3.5 m (excavated)
Trifurcation Length
10.275, 15.135, 15.135 m
Trifurcation Diameter
2.2 and 1.2 m
Power House & Tail Race
Type
Surface
Size (L * W* H)
41.2 x 16 x 25.65 m
Capacity
55 MW (Original Capacity)
Tail race of
32.7 m long Box Culvert
Tail Water Level
1725.80 m
Transmission Line
132 kV, Double circuit; 7.5 km
with Li 2 & Li A sharing the
