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- rawakholahydro@gmail.com
- LOWER MID RAWAKHOLA HYDRO POWER PROJECT LTD.
LOWER MID RAWAKHOLA HYDRO POWER PROJECT LTD.
LOWER MID RAWAKHOLA HYDRO POWER PROJECT LTD.
1.
Description of Project Area
1.1
Location
LMRKHEP is a run-of-the-river type project lying in the Rakha Bangdel, Sapteswor (Khotang) of Province
No. 1 of Nepal. Geographically the project lies between 27°20°00” and 27°21°00”
latitude North and between 86°47°01” longitude East on the Rawa
Khola which is major tributary of DudhKoshi
River.
1.2 Physical Features
1.2.1 The Catchment
Rawa khola is the tributary of Dudhkoshi River, which itself is the main tributary of the SaptaKoshi River System, the biggest river system of Nepal.
Rawa khola originates from Runa Danda at an elevation of
3613m amsl. It is a rain-fed river flowing from North-east
to West meeting Dudhkoshi near Rabuwa
bazar. There are no glaciers in the catchment. The catchment area at the
proposed intake site of Rawa khola
is 102.46 km². Rawa khola
catchment has an elevation ranging from 987m to 3613m with average elevation of
2214m amsl at the proposed headworks site. The
proposed intake is approximately 19 KM upstream and the powerhouse site is
approximately 16 KM upstream from the confluence of Rawa
khola and Dudhkoshi River.
The catchment area at the proposed powerhouse site is 111 km². The catchment
areas are extracted from SRTM DEM data of 90m * 90m resolution using GIS
analysis tools.
1.2.2 Climate
and Ecology
Khotang is a district in the eastern zone with a diverse range of
climatic condition. Its topography has influenced the climatic conditions.
These vary from temperate in mid-hills, and sub - alpine in middle mountains.
The annual maximum temperature in the project area generally increases reaching
a maximum value of 35°C prior to southwest monsoon from January to May. The
minimum temperature goes dawn in December and January that range between 9°C
and 10°C. The average temperature is 24°C. The catchment lies in the
subtropical region. Shrub settlements and cultivated land are the major
vegetation cover within the lower level of catchment area of the Rawa khola whereas dense mixed
forest and open scrub and scattered trees are found in the upper reaches of the
catchment area.
1.2.3
Accessibility
The project site is approximately 310 KM east from Kathmandu. From
Kathmandu to Halesi it is connected by bituminous
road of about 265 KM. From Halesi to Project area it
is accessible by gravel road of about 4SKM.
SALIENT FEATURES OF THE PROJECT
|
General |
|
|
Project Name |
Lower Mid Rawa Khola
Hydroelectric Project |
|
Source River |
Rawa Khola |
|
District |
Khotang |
|
Geographical boundary |
27°20'03”N to 27°21'00”N |
86°46'49”E to 86°49'00”E |
|
Power Development |
|
|
Type of the Project |
Run-of-River |
|
Gross head |
140.12m |
|
Project Name |
Lower Mid Rawa
Khola Hydroelectric Project |
|
Net head |
122.93m |
|
Installed Capacity |
4.00 MW |
|
Estimated annual energy |
24.08GWh |
|
Dry Energy |
3.62GWh |
|
Wet Energy |
20.46FGWh |
|
Outage |
5% |
|
Overall Efficiency |
95% |
|
Hydrology |
|
|
Catchment area at the intake |
102.46 km² |
|
100 years return period flood |
534.00 m³/s |
|
Design discharge |
3.80 m³/s |
|
Weir and Undersluice |
|
|
Type of weir |
Broad Crest Weir |
|
Crest length of weir |
17.0 m |
|
Crest elevation of weir |
967.32masl |
|
Height of weir |
3.00m from the river bed |
|
Undersluice gate size (W * H) |
2.50m * 2.50m |
|
Intake |
|
|
Type |
Orifice type side intake |
|
No. of opening |
2.00 |
|
Width * Height |
3.20m * 2.00m |
|
Invert Level |
965.82masl |
|
Gravel trap |
|
|
Size (L * W * D) |
8.50m * 7.50m * 6.00m |
|
Spillway Length |
6.60 m |
|
Normal Water Level |
967.00masl |
|
Crest Level of Spillway |
967.05masl |
|
Setting basin |
|
|
Type |
Surface, Intermittent Flushing |
|
No. of bays |
2.00 |
|
Size of each Chamber (L x W x D ) |
40.00m x 5.00m x 6.40m |
|
Particle size to be removed |
0.20mm |
|
Size of headpond
(L x W x D) |
2.50 m x 10.50m x 5.33m |
|
Normal Water Lever |
966.90masl |
|
Penstock Pipe |
|
|
Diameter |
1.50m |
|
Length |
4180.22m |
|
Thickness |
8mm to 14mm |
|
No. of Anchor Blocks |
80.00 |
|
No. of Saddle support |
525.00 |
|
Powerhouse |
|
|
Type |
Surface |
|
Size (L x B x H) |
22.70m x 9.50m x 10.52m |
|
Tail water Level |
827.20masl |
|
Switchyard |
|
|
Size (L x B) |
30.00m x 20.00m |
|
Tailrace Canal |
|
|
Type |
Open Chanel |
|
Length |
17.81m |
|
Size |
2.50 m x 2.50m |
|
Turbine |
|
|
No. of turbine units |
2.00 |
|
Type |
Horizontal axis, Francis |
|
Rated Output |
2.00MW x 2 units |
|
Efficiency |
90% at rated discharge |
|
Rated net head |
122.93m |
|
Transmission line |
|
|
Transmission voltage |
22kV single circuit line |
|
Length |
7.00KM |
|
Feeding point to grid |
BaghshilaS/S |
|
Generator |
|
|
Type |
Synchronous with Brushless
excitation |
|
No. of Generators |
Two(2) |
|
Capacity |
2.35 MVA |
|
Capacity @ 10% intermittent. OL |
2.58 MVA |
|
Power Factor |
0.85 |
|
Generating Voltage |
6.60 kV |
|
Generating Current |
341.60 A |
|
Frequency |
50 Hz |
|
Class of Insulation |
F |
|
Protection |
IP54 |
|
Excitation System Type |
Brushless |
|
Efficiency |
97% |
|
Heating class |
B |
|
No. of poles |
12.00 |
|
Synchronous Speed |
500 RPM |
|
Project Cost |
|
|
Total Project Cost (including Tax
& Duties) |
833.543(million NRs) |
|
Generating Cost Per MW |
208.385(million NRs) |
|
Construction Period |
2.00 Years |
|
Financial indicators |
|
|
Internal Rate of Return (IPR) |
15.47% |
|
EIRR |
22.97% |
|
Benefit/Cost(B/c) Ratio |
1.56 |
|
Net Present Value (NPV) |
116.586(million NRs) |
|
Discounted payback period |
11.96 years |