Salient Features

Tallo Likhu Jalvidhyut Aayojana-TLJA (28.1 MW) is owned and being developed by Swet Ganga Hydropower & Construction Limited.

The project is a Run of River (RoR) type with its headworks located on the right bank of Likhu River at Likhu Tamakoshi Rural Municipality of Ramechhap District, Bagmati Province and the left bank of weir lies of Likhu Rural Municipality of Okhaldhunga District, Province 1 of Nepal.

The entire project area is located in Saipu-2 and Bijulikot-4 of Likhu Tamakoshi Rural Municipality. Geographically, the project area is located between Longitudes 86015’38” E to 86013’17” E and latitude 27025’50” N to 27022’47” N. Geologically, the project area belongs to the Lesser Himalayas . The project utilizes design discharge of 29.75 m3/s and gross head of 118 m resulting into an installed capacity of 28.1 MW.

The annual energy generation is 170.84 GWh, where the dry season energy contributes 30.94 GWh and wet season energy contributes139.89 GWh.

 

GENERAL

Name of the project Lower Likhu Hydropower Project
Developer Swet Ganga Hydropower & Construction Ltd.
Name of the River Likhu River
Type of scheme Run-of-River
Project location Saipu and Bijulikot VDC's of Ramechhap District and Tarkerabari of Okhaldunga District
Zone Janakpur Zone
Development region Central Development Region
Nearest road-head Up to Sirise at Headworks
Up to Ratamate at Powerhouse
Climate Sub-tropical
Average temperature Maximum : 36.3 0C in May
Minimum : 4.30C in January

GEOGRAPHICAL COORDINATES

Latitude 270 22’ 47” N to 270 25’ 50” N (Generation license)
Longitude 860 13’ 17” E  to 860 15’ 38” E (Generation license)

HYDRO-METEOROLOGY

Average annual rainfall 1796  mm
Catchment area at intake 717.54 km2
Annual mean flow 42.29 m3/s
Maximum mean monthly flow 125.12 m3/s
Minimum mean monthly flow 8.84 m3/s
Design discharge 29.75 m3/s
Flood discharge 737 m3/s
WEIR
Type Concrete ogee
Crest elevation 742.00 m amsl
Length 53 m
Max Dam height (from existing ground) 5.5 m

UNDERSLUICE

Type Radial Gate Mechanism
Number of bays 2
Size, B x H 6.0 x 6.0 m (each)
Sill level 734.0 m amsl
INTAKE
Type Side intake
No. of orifice 4
Size, B x H 3.5 x 2.8 m (each opening)
Intake sill level 738.00 m amsl

GRAVEL TRAP AND GRAVEL FLUSHING

Type Surface
Number of bays 2
Size, L x B x H 11.0 x 8.0 x 7.4 m (each)
Size of Flushing pipe 1.5 m dia. (each)

APPROACH CULVERT

Type Pressurized culvert
Number of branches 4
Size, B x H (m) 2.4 x 2.5 m (each)
Length 83 m (Branch 1st), 68.50 m (Branch 2nd)

SETTLING BASIN

Type Conventional
Numbers 2
Size L x B x H 65 m x 6.7 m x 8.0 m (each basin)
Length of inlet transition (m) 51.50 m
Particle size to be settled (mm) 0.2
Flushing system Intermittent
Size of Flushing canal, B x H (m) 2.0 x 1.5 m (each)

HEADRACE PIPE

Pipe Material Mild Steel
Internal Diameter (m) 3.75
Length 304 m
HEADRACE TUNNEL
Type of Flow Pressurized
Geometry Inverted  D-shape
Length (m) 4965
Size (without payline) 4.9 x 4.9 m
KHOLSI CROSSING (SYPHON)
SETI KHOLSI CROSSING  
Length 218.7 m
Internal Diameter of pipe (m) 3.75 m
POKU KHOLSI CROSSING  
Length 243.5 m
Internal Diameter of pipe (m) 3.75 m
SURGE TANK
Height 46.5 m (from invert)
Diameter 12 m
PENSTOCK
Pipe Material Mild Steel
Length 191 m
Diameter 3.75 / 2.65 m
POWERHOUSE
Type Semi-surface
Length x Width x Height 33.3 m x 21.7 m x 27 m
Turbine setting level 623.00 m amsl (center line)
TAILRACE
Type Box culvert
Length 210 m
Height 3.35 m
Width 4 m
TURBINE
Type Francis, vertical axis
Numbers 2
Rated output capacity per unit 15 MW
Efficiency 91.00%
GOVERNOR
Type Electronic PID control
Adjustment for speed drop Between 0 to 5%
GENERATOR
Type Three phase, Synchronous
No of units 2
Power factor 0.85
Voltage 11 kV
Frequency 50 Hz
Excitation system Brushless
Efficiency 97%
TRANSFORMER
Type Three phase, Oil immersed
No of units 2
Frequency 50 Hz
Rated output capacity per unit 17 MVA
Voltage ratio 11 kV/ 132 kV
Efficiency 99%
SWITCHYARD AND TRANSMISSION LINE
Switchyard type Outdoor, conventional
Transmission line length 23 km
Voltage level and circuit 132 and single circuit
Conductor ACSR “WOLF”
POWER AND ENERGY
Gross head 118.0 m
Net head at design flow Approx. 112.64 m
Installed capacity 28.1 MW
Dry energy 30.94 GWh
Wet energy 139.89 GWh
Average annual gross energy 170.84 GWh