Lower Marsyangdi Hydropower Station, Upper Modikhola Hydropower Station, Lower Modi Khola Hydro Power

1. Presentation
on
Hydropower Engineering Field Visit
Presented By :
Arjun Sigdel (1305)
Lochan Shrestha (1313)
Nirmal Dangi (1317)
Suman Gautam (1327)
Tek B. Nepali (1329)
Group No:- 1
BE (Civil )
Asian Institute of Technology & Management (AITM)
(Khumaltar, Lalitpur, Nepal)
Department of Civil Engineering
October 29, 2017

2. Introduction
• Hydropower is the power derived from the energy of
falling water.
• In the late 19th century, hydropower became a source for
generating electricity.
• World's first hydroelectric project was developed
at Northumberland in 1878.
• And the first commercial hydroelectric power plant was
built at Niagara Falls in 1879.
• First hydropower plant in Nepal is Pharping Hydroelectric
Plant ( 500 KW) constructed in 1911.

4. Background
• The hydropower field visit was organized by the
Department of Civil Engineering , WhiteHouse
Institute of Science and Technology.
• The hydropower field visit was held on 20th July to
22th July, 2017.

5. Objectives
• Study about the head work component
• Study about the components like Gravel trap,
Approach canal, Desander/ settling basin, Head race
Tunnel/ canal/ pipe, Adit, Inlet & Outlet portal etc..
• Study about forebay and surge tank/Vertical Shaft
• Study about penstock pipe, Anchor Blocks, Support
Piers.
• Study about the Power house.

6. Status of Hydropower in Nepal
• Nepal’s theoretical hydropower potential has been
estimated to be around 84,000 MW.
• But only 42,000 MW has been identified as economically
viable.
• Currently, Nepal’s installed hydropower capacity is 753
MW.
• The first large-capacity interconnection between India and
Nepal (1,000 MW) was completed in February 2016.

7. • 2015 saw Nepal connect over 45 MW of hydropower to the
national grid.
•A further seven projects in Nepal were scheduled to
be completed in the first half of 2015 but delayed due
to April-may earthquake.

8. Components of Hydropower Project
• Weir/Dam/Barrage
• Intake
• Under Sluice
• Gravel Trap
• Settling Basin/ Desander
• Headrace canal/ Tunnel
• Forebay / Surge tank
• Spillways
• Anchor Block
• Support pier
• Penstocks
• Power House
• Tail Race
• Transmission and
Distribution line

10. Lower Marsyangdi Hydropower Station
• Marsyangdi hydropower is a peaking run of river type
hydropower.
• Marsyangdi hydropower station is located at 114 km west
of Kathmandu on Prithivi highway, right bank of
Marsyangdi River , Aanbukhaireni, Tanahu.
• It is owned by Nepal Electricity Authority.

11. Salient Features
Type Peak- run- of- the- river
Rated Net Head 90.5 meter
Rated Turbine Discharge 30.5 m3/s
Head Race Tunnel 7199m, 6.4m dia., concrete lined
Pressure Shaft 75m long, 5m dia., steel lined
Surge Tank 20.5m dia., 56m high concrete throttle shaft
Installed Capacity 69 MW
Turbine Generator Set 3 sets
Turbine Type Francis
Rated Output 23 MW x 3
Rated Speed 300 rpm

12. Generator Type Vertical shaft synchronous
Designed Annual Average Capacity 30 MVA
Voltage Ratio 11/132 KV
Power Transformer
11/132 KV single phase, 3x
10 KVA, 9 Nos.
Generation 462.5 GWh
Catchment Area 3850 Km2
Average Annual Discharge 210 m3/s
Construction Started February, 1886
Commercial Operation Started 5 November, 1989
Construction Cost 21.57 million USD

13. Different Component of Marsyangdi HPS
(i). Weir:
• 5 Steel Radial Gate of about 102 m length has been
constructed to divert Marsyangdi River.
• It controls the design discharge upto 9100 m3/sec.
(ii). Headrace Tunnel
• Headrace tunnel is of length 7199m and diameter of
6.4m.

14. Figure 1 : Bird eye View of Headwork site

15. (iii). Power House
• The Power House is Semi-underground type with three shafts to
power Generating Equipment.
• Three Francis Turbines are installed in Powerhouse each
with capacity of 26 MW.
(iv). Transformer Line
• Marsyangdi Power Plant is connected to the Central Grid
system with two transmission lines.
• These transmission lines links the power plant with Kathmandu
and Chitwan(Suichatar and Bharatpur substations).

16. Figure 2: View of Power House

17. Upper Modikhola Hydropower Station
• Upper Modikhola Hydropower is the Run-of-River type
hydropower.
• It is located at Dimuwa, Parbat.
• It was commissioned in 2000 AD and in the assistance from
EDCF (Korea), Government of Nepal and NEA at a cost of
USD 30 million.

18. Figure 3 : Layout of Upper Modikhola hydropower details

19. Figure 4: View of inside Powerhouse

20. Figure 5: View of inside Powerhouse

21. Figure 6 Modi Power Station

22. Type Run of river
Location Dimuwa, Parbat
Installed Capacity 14.8 MW
Annual average energy 92.5 GWh
Maximum Net Head 66.96 m
Catchment area 510 km2
Average annual flow 25 m3/s
Total length of the waterways 61 m (canal), 2,071 m (tunnel)
Turbine Number and Type 2, Francis
Salient Features

23. Rated Discharge 12.5 m3/s
Rated Output 7.6 MW
Rated Speed 428.6 rpm
Generator Rated Output 8260 kVA
Rated Voltage 6.6 kV
Rated Frequency 50 Hz
Power Factor 0.9
Power Transformer 7.8/8.3 MVA, 6.6/132 kV, 3 phase
Transmission line Single circuit 132 kV, upto Lekhnath s/s

24. Lower Modi Khola Hydro Power
• Lower Modi Hydroelectric Project is located in Parbat
district is an under construction project.
• It is the Run-of-River type hydropower project.
• Installed capacity of Lower Modikhola Hydropower project
is 20 MW

25. Different Component of Lower Modikhola HEP
(i). Surface Structure
• The weir is ogee shaped, located at about 120 m
downstream from the confluence of Pati and Modi khola.
• The weir diverts stream flow through side intake to the
gravel trap and then to settling basins through approach
canal.
• There are 3 undersluices and 6 orifice type side intakes.
• Two deep hopper shaped gravel traps are provided
immediately after the intake.

26. • Two approach canals of about 153 m each are provided
after the gravel traps to carry water to the settling basin.
• Two hopper type surface settling basins are provided to
trap at least 90% of sediment above 0.2 mm.
• The outlet transition zone of Settling basin functions as a
headpond of dimension 7 m x 32.4 m x 10.20 m..

27. Figure 7: Headworks

28. Figure 8: Gravel Trap

29. Figure 9: Desander

30. Figure 10: Desander

31. Figure 11: Forebay ( Underconstruction ) with Inlet Portal

32. (ii). Adit Tunnels
• There are two adit tunnels namely Adit-1 and Adit-2
being excavated.
• The excavation of two Adits each of length 181 meter
and 122 meter.

33. Figure 12: Adit-1

34. (iii). Headrace Tunnel
• Excavation of 4,021 meter of headrace tunnel was in
progress.
• All the primary support including shotcrete, rockbolting
and forepoling has been done along these excavated
length of the Tunnel Figure.

35. Figure 13: Inner View of HRT tunnel

36. (iv). Surge shaft and Penstock pipe
• a vertical non‐spilling type surge shaft is provided at the
end of headrace tunnel.
• Surge shaft is 57.50 m high with internal diameter of 10
m.
• From the surge shaft, a 454 m long steel penstock pipe
with 3.5 m internal diameter runs to the powerhouse.
(v). Power House
• It is located at the right bank of Modi Khola of Chuwa VDC.
• Two Vertica axis Francis turbines are installed in the
powerhouse to generate 10 MW each.

37. Salient Features
Location Deopur, Bajung, Tilahar and Chuwa VDC
Catchment area 560 km2
Net head 83.37 m
Designed discharge 28.8 m3/sec.
Annual average energy 117.53 GWh
Average annual flow 54.62 m3/s
Speed 750 rpm
Generator Rated output 12.5 MVA
Rated voltage 6.3 kV
Rated frequency 50Hz
Power transformer 12.5 MVA, 6.3/132 kV, 3 phase

38. Conclusion and Discussion
• We gain the practical knowledge about the different component
of the hydropower plant
• We also get the knowledge of the current situation of the
hydropower plant and the current problem in the plant.
• We also got the chance to make the comparison between the
different hydropower plant
• The performance of the upper modikhola plant is largely
unsatisfactory during rainy season due to abrasive sediment
so we recommended to construct a good settling unit

39. Reference
• (2016). Retrieved from http://www.modihydro.com/index.php.
• Dandekar, M. (2010). Water Power Engineering. Vikas publicating
house pvt ltd.
• Garg, S. K. (2011). Irrigation Engineering And Hydraulis Structures.
khanna publications. (n.d.). http://nea.org.np/generation/index.php.
• marsyngdi power station. (2017).
• Retrieved from
http://www.nea.org.np/generation/index.php?page=powerhouse&pi
d=7#
• Nea. (2017). Modikhola Hydropower Station

40. THANK YOU