Mewa Khola

Mewa Khola Hydropower Project

Background

With an installed capacity of 23 MW, Mewa Khola Hydropower Project is run of river hydropower project located in Taplejung district. The progress of the project can be summarized in the table below.

SN Description Status Remarks
1. Feasibility Study Completed  
2. Initial Environment Examination Completed  
3. Power Purchase Agreement Completed (Take or Pay)  

Salient Features

General
Source River : Mewa River
VDC : Papung
District : Taplejung
Zone : Mechi
Development Region : Eastern
Province no. : One
Toposheet no. : 2787 07
Type of Scheme : Run-of-River
Latitude : 27035’48” N to 27032’55” N
Longitude : 87035’14” E to 87037’00”
Gross Head : 893.00m
Net Head : 879.21m
Design Discharge : 3.16 m3/s
Installed Capacity : 23.00 MW
Plant Factor : 70%
Net Annual Generation : 136.797 GWh
   
Hydrology & Meteorology
Catchment Area at Intake : 66.75 km2
Catchment Area at Power house : 94.30 km2
Average Annual Precipitation : 2344.6 mm
Design 100-yrs Flood : 78.00 m3/s
20-yrs Flood Discharge at Intake : 23.90 m3/s
Long-term Average Flow : 4.04 m3/s
Design Discharge : 3.16 m3/s
Riparian Release : 0.094 m3/s
   
Diversion Weir
Type : Overflow
Length : 11.50 m
Crest Level : 2923.00 amsl
Height : 2 m
   
Intake
Type : Side Intake
No : 2
Opening Size : 2.90 X 1.5 m (W x H)
Sill Level : 2922.00 amsl
   
Undersluice
Size (WxH) : 2.5 X 2.7m (WXH)
No. of Bays : 1
Sill Level : 2921.00 amsl
   
Gravel Trap
Length of Gravel Trap : 4.5 m
Width of Gravel Trap : 2.4 m
Water Depth : 2 m
Depth of Storage : 0.8 m
Total Depth at Beginning : 2.8 m
   
Approach Canal
Type : Open
Length : 30 m
Length of Spillway : 12 m
Length of Bifurcation canal : 14 m
   
Desilting Basin
Location : Surface
Type : Double bay intermittentflushing
No of Basin : 2
Size (L x W x H) : 60 m x 10 m x 4.5 m
Particle Size to be settled : 0.1 mm
Size of flushing opening : 0.5 mx 0.5m
   
Headpond
Location : Surface
Type : Trapezoidal
Side slope : 0.5 H : 1 V
Size (L x W x H) : 13 m x 6.80 m x 4.2 m
   
Headrace Pipe
Type : Circular
Diameter : 1.1 m
Length : 106 m
   
Headrace Tunnel
Type : Inverted D-Shape pressurized
Size : 2.2 m x 2.5 m (W X H)
Length : 3642.00 m
   
Surge Shaft
Type : Top over to sky
Diameter : 4 m
Height : 28.50 m
Normal Water level : 2923.00 amsl
Max. Upsurge : 2930.45 amsl
Max. Down surge : 2906.20 amsl
   
Pressure Shaft
Type : Buried
Pipe Material : Mild Steel
Length : 1571.00 m
Diameter : 1.10 m
   
Bifurcation Penstock
No : 2
Length : 13.5 m
Diameter : 0.78 m
   
Powerhouse
Location : Underground
Clear Size (L x B x H) : 56 m x 13.2 m x 22.7 m
Number of Units : 2 Nos.
Type of Turbine : Pelton
Rated Capacity : 11.5 MW x 2 Nos.
   
Access Tunnel
Type : Inverted D shaped
Diameter : 5 m
Length : 160.00 m
   
Tailrace Tunnel
Type : Inverted D shaped tunnel
Diameter : 3.00 m
Length : 200.00 m
   
Transmission & Grid Connection
Specification : 132 kV Single Circuit
Conductor : SC ASCR Wolf
Length : 27 km (up to Dhungesanghu   substation, Common Transmission Line)
   
Transformers
Step-up Transformer  
Type : In door Oil Immersed
Cooling : OFWF
Number of Units : 7 Nos.
Rated Capacity : 4.7 MVA x 7 Nos.
   
Generator
Type : Synchronous, salient pole
Specification : 14000 kVA, 11000 V, 50 Hz
Synchronous Speed : 1000 rpm
No. of Pole : 3 pairs
   
Power and Energy
Installed Capacity : 23.00 MW
Dry Season Energy : 42.593 GWh
Wet Season Energy : 94.205 GWh
Total Annual Energy : 136.797 GWh
Plant Load Factor : 70.00%
   
Financial Indicators 
Project IRR : 15.18%
B/C ratio : 1.54
Average DSCR : 1.52
Construction Period : 42 months