The Plant · Ilam, Koshi Province
Upper Puwa-I Small Hydropower Project
A 3 MW run-of-river plant fed by two streams of the Puwa Khola in Ilam District, generating since January 2015.
- Design discharge
- 2.31 m³/s at 40% exceedance
- Installed capacity
- 3 MW
- Gross head
- 159 m
- Design annual energy
- 17.40 GWh
How It Works
Two Streams, One Powerhouse
Water from the Thulo Puwa Khola and the Sano Puwa Khola is cleaned at each intake, carried in buried canals to a shared forebay, and dropped through the penstock to the powerhouse before it returns to the river.
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1
Thulo Puwa Intake
Side intake · 2 openings, 2 m × 0.6 m
Takes water from the Thulo Puwa Khola. A gravel trap and a 27.5 m desander remove stones and sand.
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2
Sano Puwa Intake
Tyrolean weir · 9 m × 1.2 m
A bottom-grill intake on the Sano Puwa Khola, followed by its own gravel trap and a 24 m desander.
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3
Buried Canals
2,133 m and 1,612 m
Two covered concrete canals, laid under the access road, carry 1.36 m³/s and 1.005 m³/s to the forebay.
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4
Common Forebay
15 m × 5.5 m × 3.34 m
Both canals meet here. A spillway and flushing gates hold the level steady before the water enters the penstock.
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5
Penstock
460 m · Ø 1.1 m steel
A steel pipe with 8–16 mm walls, held by 82 saddle supports and 10 anchor blocks, drops the water to the powerhouse.
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6
Powerhouse
2 Francis units · 1,000 rpm
A 336 m² surface building with two horizontal Francis turbines, two 1,875 kVA generators and the control room.
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7
Tailrace
2 m × 1 m box culvert
Returns the water to the Thulo Puwa Khola below the powerhouse.
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8
Switchyard
Generation at 6.6 kV
Connects the plant to the national grid.
See component
Salient Features
Technical Specifications
Location & Type
- District
- Ilam, Koshi Province
- Coordinates
- 26°59′20″–27°01′00″ N, 87°52′36″–87°54′25″ E
- Type
- Run-of-river
- Water sources
- Thulo Puwa Khola and Sano Puwa Khola
- In operation since
- 15 January 2015
Hydrology
- Catchment area
- 30.9 km² (Thulo Puwa) + 22.3 km² (Sano Puwa)
- Design discharge
- 2.31 m³/s at 40% exceedance
Headworks
- Thulo Puwa intake
- Side intake, 2 openings of 2 m × 0.6 m
- Thulo Puwa desander
- 27.5 m × 4.5 m × 2.3 m, 1.50 m³/s
- Sano Puwa intake
- Tyrolean weir, 9 m × 1.2 m, bed slope 1:33
- Sano Puwa desander
- 24 m × 3.5 m × 2.0 m, 1.10 m³/s
Waterways
- Thulo Puwa canal
- Buried, 2,133 m, 1.36 m³/s
- Sano Puwa canal
- Buried, 1,612 m, 1.005 m³/s
- Forebay
- 15 m × 5.5 m × 3.34 m, 2.365 m³/s
- Penstock
- Steel, Ø 1.1 m, 460 m, 8–16 mm thick
- Tailrace
- Box culvert 2 m × 1 m, slope 1:100
Powerhouse & Grid
- Installed capacity
- 3 MW
- Gross head
- 159 m
- Turbines
- 2 horizontal Francis units, 1,000 rpm
- Generators
- 2 × 1,875 kVA synchronous, 6.6 kV, 50 Hz
- Powerhouse
- Surface, 336 m², 9.6 m high
- Tailwater level
- 1,231.5 m
Energy
- Design annual energy
- 17.40 GWh
- Dry / wet season
- 2.64 GWh / 14.76 GWh
Key Facts
Licences and Power Sales
Company
- Incorporated
- 19 April 2005
- Public limited company
- 6 February 2015
- Commercial operation
- 15 January 2015
- Stock exchange
- NEPSE, symbol JOSHI
Power Purchase Agreement
- Buyer
- Nepal Electricity Authority
- Signed / amended
- 6 May 2009 (985 kW) / 2 August 2011 (3 MW)
- Term
- 30 years
- Contracted plant load factor
- 65.42%
Tariff
- First 985 kW
- Rs 4.00 wet / Rs 7.00 dry per kWh
- Remaining 2,015 kW
- Rs 4.80 wet / Rs 8.40 dry per kWh
- Escalation
- 3% a year on the base tariff for 9 and 5 years respectively
Powering Nepal's Progress, Sustainably
Get in Touch With Us
We're here to answer any questions you may have about the Upper Puwa-I Small Hydropower Project.