Salient Features
Project Details
| Project Name | Mathillo Midim Hydro Power Project |
| Province Number | Four |
| District | Lamjung |
| Location of Project Site | Kwholasothar Rural Municipality |
| Water Source | Midim Khola |
| Type of Scheme | RoR |
| Installed Capacity | 7500 kW |
Hydrology
| River | Midim Khola |
| Total Catchment above Intakes | 31.44 Km2 |
| Mean Annual Discharge | 3.52 m3/sec |
| 100-year Design Flood @ Intake | 143.5 m3/sec |
| Environmental Release | 0.046 m3/sec |
| Design Discharge to Plant Q40% | 5.02 m3/sec |
Headworks
| Diversion Structure | Boulder Lined Free Overflow Weir |
| Length of Weir | 15.30 m |
| Height of Weir | 3.0 m |
| Under Sluice | 1 Vertical Sluice Gate |
| Crest of Sluice EL | 1836.75 mamsl |
| Size of Sluice Gates (b × h) | 2.0 m × 2.0 m |
| Intake | Gated Side Orifice Intake with Course Trash Rack |
| Size of Intake Gate | 1.5 m × 1 m × 2 nos. |
Connecting Canal
| Type | Open Duct Type Canal |
| Dimension (width × height) | 1.25 m × 1.8 m |
| Bed Slope | 0.10% |
| Length | 31 m |
Gravel Trap
| Type | Gravity Flushing Type |
| Dimension (width × height) | 3.90 m × 1.70 m |
| Bed Slope | 1:25 |
| Length of Gravel Trap | 6.40 m (overall length) |
| Particle to Settle | 5 mm |
| Flushing Duct Size | 0.5 m × 0.5 m |
Desander
| Type | Two Chambers, Gravity Flushing Type |
| Dimension (width × height) | 4.2 m × 4.47 m |
| Length of Effective Basin | 35.00 m |
| Length of Inlet Transition | 12.40 m |
| Bed Slope | 1:50 |
| Particle to Settle | 0.2 mm |
| Trap Efficiency | 90% |
Penstock Pipe
| Type | Surface, Mild Steel Circular Shaped |
| Length | 710 m of 1.0 m internal Dia, 2050 m of 0.9 m internal Dia, 921 m of 0.8 m internal Dia, 24 m of 0.6 m internal Dia (after bifurcation) |
| Pipe Material | Mild Steel Conforming to IS 2062-B Grade IS 2062 B, E250 & E350 |
| Size of Pipe | 1.0-0.6 m, 8-20 mm shell thickness |
| Supports | S/M Support with Concrete Cap |
| Number of Supports | 438 nos. |
| Number of Anchor Blocks | 57 nos. including bifurcation and thrust blocks |
Power House
| Type | Surface with Outdoor Substation |
| PH Dimension (L × B) | 29.30 m × 16.5 m (including control room) |
| Height of PH Building | 13.50 m |
| PH Floor Level EL | 1381.50 msl |
Tailrace Canal
| Type | Rectangular RCC |
| Size (W × H) | 1.26 m × 1.50 m |
| Length | 47.00 m |
| Slope | 1:500 |
Turbine
| Number of Units | 2 |
| Type of Turbine | Pelton (2 Units) |
| Shaft Arrangement | Horizontal |
| Rated Discharge for Each Turbine | 0.97 m3/s |
| Rated Head | 436.22 m |
| Rated Output for Each Unit | 3745 kW |
| RPM | 750 |
| Rated Efficiency | 91% |
Generators
| Number of Units | 2 |
| Generator Type | 3 Ph AC Synchronous |
| Excitation | Brushless Excitation |
| Rated Voltage | 6.6 kV |
| Power Factor | 0.85 |
| Rated Output | 4412 kVA |
| Rated Frequency | 50 Hz |
| Rated Efficiency | 96% |
Power Transformer
| Type | Step Up, 9500 kVA, 3 Ph, 50 Hz, ONAN Cooling |
| Primary (LV Side) | 6.6 kV |
| Secondary (HV Side) | 33 kV |
| Rated Efficiency | 99% |
Station Supply Transformer
| Type | Outdoor Type |
| Capacity | 200 kVA (Outdoor) & 160 kVA (Indoor), 2 nos. |
| Voltage Ratio Indoor | 6.6/0.4 kV |
| Voltage Ratio Outdoor | 6.6/11 kV |
Transmission Line
| Type of Circuit | Single Circuit 33kV Line, Mathillo Midim PH to Bhorletar Substation |
| Transmission Length | 28 km |
| Transmission Voltage | 33 kV |
| Interconnection Point | NEA 33 kV Busbar at Bhorletar Substation |
Power and Energy
| Installed Capacity | 7.5 MW |
| Contract Energy for PPA | 42.1672 GWhr |
| Dry Season Energy | 12.829 GWhr |
| Wet Season Energy | 29.337 GWhr |