Tatopani Mini hydroelectric Project
Executive summary
The Tatopani Mini-hydro Project is located on the left bank
of Marsyangdi River along the popular trekking route to Manang. The project
lies within the Ghermu Village Development Committee of Lamjung District,
Western Development Region, Nepal.
The Tatopani Mini-hydro Project is a run-of-the-river type scheme, Tatopani
Khola being its source. The installed capacity of the plant is 210 kW. The
headworks consist of a gabion weir with RCC wall sandwiched between the
gabion boxes, which diverts the flow of 200 l/s through the intake to the
intake canal. Grits and coarse sediments get deposited and flushed out from
the gravel trap located just after the intake. The excess flow is spilled
through the spillway incorporated in the intake canal and the rest of the flow
enters the settling basin. The settling basin is of 2.5 m wide and 18 m long. The settling basin also acts as a forebay since the penstock pipe
starts right from the settling basin end. The settling basin is designed to
trap particles upto 0.2mm size with a settling efficiency of 90%. The sediments
get deposited and flushed out from the settling basin and the sediment-free
water then enters the penstock pipe. A suitable submergence depth is provided
for the penstock pipe. A spillway and a flushing canal are provided to discharge
the excess flow and the sediments to a nearby stream through a spill canal.
300 mm internal diameter, mild steel penstock pipe conveys the design discharge
of 200 l/s to the turbine. The 600m long penstock pipe is supported all along
the length by support piers at a regular interval of 5 m and anchor blocks
at the bends. To economize the volume of mild steel, the thickness of the
penstock is varied from 5mm to 7mm along the length of the penstock pipe.
Turbine could be a single unit of turgo or a pelton. The turbine is directly
coupled to a generator, which then generates the electricity. The generated
electricity will then be transmitted through an 11kV line to the national
grid.
The gross and the net head of the scheme are 151 m and 132 m respectively.
The design flow of the scheme is 200 l /s.
The project is expected to be commissioned after about 8 months from the start
of the construction work and the estimated total cost of the project is about
21.6 Million Rupees.
This study has shown that the scheme is technically viable and economically
attractive with the current energy buying rates of Nepal Electricity Authority
(NEA).
Project salient features
| Location |
Lilibhir, Ghermu VDC, Lamjung |
| Name of the River |
Tatopani |
| Installed Capacity |
210 KW |
| Gross head |
151m |
| Net head at runner |
132m |
| Inflow design flow |
200 1/s |
| Catchment area |
5.75 km2 |
| Penstock type/ length / size / thickness |
Mild Steel / 600m / 300mm / 5mm-7mm |
| Settling basin/Forebay |
18m long, 2.5m wide |
| Turbine type |
Turgo/Pelton with deflector system |
| Dam type |
Gabion Weir with RCC cutoff wall |
| Powerhouse plinth area |
66.5 m2 |
| Transmission line length |
0.3km |
| Transmission voltage |
11 KV |
| Total project cost |
NRs 21.6Million |
1 Introduction
Lamjung Electricity Development Company (LEDCO) on behalf of Syange Bidyut Company
undertook a detail feasibility level study of the Tatopani Mini-hydro Project
(TMHP). The purpose of the study is to provide an updated financial and technical
assessment of this project using a grid connection and selling power to the
Nepal Electrical Authority (NEA). The TMHP is being developed by Syange Bidyut
Company as a locally owned grid connected mini-hydro. The owners of the present
183 kW Syange Mini-hydro Project along with other members of the community have
committed to invest in developing the scheme. LEDCO will provide the engineering
and technical support that is necessary to develop the scheme.
The experience gained from developing Syange Mini-hydro Project
of similar size will be an added advantage to develop this project.
The study has shown that the installed capacity of the plant
will be 210 kW with a design discharge of 200 l/s. The minimum power will be
less than this during the dry period. The electricity generated will be connected
to the 11kV line, which has already been constructed from Bahundanda to Syange.
1.1 Location
The village of Lilibhir is in the Ghermu VDC of Lamjung district. It is located
on the tourist trekking route along the Annapurna Circuit. Lilibhir is a small
village located at latitude of 280-20'' and longitude of 840-25'. The project
area lies to the left bank of Marsyangdi River.
The project area is shown in Appendix A.
1.2 Access
The nearest road-head (black topped) to the project site is at Besisahar, the
headquarter of Lamjung District. A seasonal road suitable for motor vehicles
is extended to Bhulbhule. Lilibhir is 5-hour walk from there. Mules take one
day to reach Lilibhir from Bhulbhule and it is cheaper than using porters for
bulk supply of goods.
2 Background
2.1 Pre-feasibility
The developers of the Syange Mini-hydro Project showed interest in implementing
another grid-connected mini-hydro project of similar size in this region as
such projects proved very attractive economically. Moreover, the projects of
this size required capital cost that could be raised by the shareholders themselves
and could be constructed within a year. LEDCO performed the pre-feasibility
study of Tatopani Khola. The results of this report were the following:
The scheme is a run of the river type with an installed capacity of 210 kW.
The scheme consists of a semi-permanent diversion structure
with an intake at the left bank of Tatopani Khola. The water from Tatopani Khola
is conveyed to the settling basin cum forebay through a masonry intake canal.
Mild steel penstock pipe conveys the design discharge to the turbine, which
is coupled to a generator. The electricity generated will be transmitted to
the 11kV national grid to be sold to NEA.
2.2 Market Summary
Although Nepal is characterized as a hydro rich country, only a small portion
of its total hydro capacity has been harnessed to produce hydroelectricity.
At present the Integrated Nepal Power System (INPS) has a total installed capacity
of about 610 MW of which about 545 MW is generated from hydro resources. Of
the hydropower plants only 92 MW (cascaded between Kulekhani I of 60 MW and
Kulekhani II of 32 MW) is from storage plants and the rest is from run-of the
river schemes. The annual energy generation is about 2380 GWh. The entire system
has about One million consumers.
The Nepal Electricity Authority (NEA) resorted to load shedding to manage the
supply of power by cutting off supply at different load centers of the country
on a rotational basis, until very recently.
There are several power plants that are under construction, which will significantly
contribute to the grid capacity. The forecast carried out by NEA, however, predicts
that even with the augmentation of power supply from the power plants under
construction, there will be a shortage of power supply after a few years. The
NEA, in 1998 announced a policy to support the private sector of small hydropower
developers. With this policy it is envisaged that numerous small-scale hydropower
projects will be developed in the near future.
For more information, please contact our ledco
office in Kathmandu.
Last modified:
8 May, 2005
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