Nam Sor Dam Hydropower info by Hobo Maps- Go to Hydropower Projects Page - - Home
Nam Sor Hydropower Project is located in Viengthong District, Bolikhamxay Province, Lao PDR. The project dam site is on the Nam Sor (river) which is a tributary of Nam Nagom (river) about 6 km upstream from their confluence at Ban Phadeng
The Nam Sor Hydropower Project location is shown in satellite images below:
The project is owned by Nam Sor Hydropower Company with 4 main shareholders: Vieng Chantech Construction Co., Ltd. (20%), Prixay Thailand (38%), CSS (38%) and V-Hydro Holding Company (4%)
The project is developed by Vientiane Techno Co., Ltd. as EPC contractor and was under construction in year 2023.
The project is a run-of-river hydropower station with installed capacity of 4.2 MW (2×2.1 MW Horizontal Francis) with annual 19 GWh power supply capacity. The power generated is to be delivered to EDL.
Nam Sor Powerhouse is located at coordinates 18°36'17.8"N 104°27'14.4"E (18.604944, 104.454000) below:
Nam Sor Dam is located at coordinates 18°36'43.2"N 104°28'06.5"E (18.612008, 104.468459) below:
The project includes a backfill R.C Concrete dam, reservoir, fixed weir, sand trap, intake, 1300 meter long headrace canal, headrace tunnel, forebay, 800 meter long penstock, powerhouse, 12 km long high voltage transmission line, spillway and a tailrace.
The project has gross head of 128 meters.
Nam Sor Dam description and project layout image below:
Nam Sor Dam project layout image below:
Nam Sor & Nam Ngom Hydropower Projects are close together as seen in topographic map below:
Nam Sor HPP catchment area outlined below:
Nam Sor Dam reservoir imge below:
Nam Sor Dam penstock images below:
Nam Sor Dam power plant image below:
Nam Sor Dam power plant images below:
Nam Sor Dam powerhouse control panel image below:
Nam Sor switchyard image below:
Nam Sor construction images below:
The Nam Sor Hydropower project may have qualified as a Clean Development Mechanism (CDM) project under the Kyoto Protocol allowing it to receive carbon emission reduction credits. The project will help result in CO2 emission reduction as its output may displace power generation that otherwise would be based on combustion of fossil fuels. The reduction in carbon dioxide emissions is estimated to be 10,630 tons per year. View or download the CDM application document HERE . This CDM application was filed a few years before completion of the project and we aren't sure if it actually came into effect as the Kyoto Protocol system benefits may have expired in the interim.
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Info below copied in 2024 from Lao Blogger website at - https://lao-hydropower.blogspot.com/2021/06/namsor-power-plant.html .
Location: Dam site on the Nam Sor River, a Tributary of Nam Gnom, about 6 km
Upstream from the confluence
Main Hydrological Data
- River system Run-of-River
- Grid type Central Grid (Connect to EDL grid)
- Design flows 3.5 m3/s(rated) and 4.8 m3/s (Maximum)
- Gross Head 127.85 m
- Catchment area 85 km2, at the dam site, Level 522 m
- Annual basin rainfall 2,400 mm
- Annual evapotranspiration 877.8 mm
- Mean river discharge 3.60 m3/s
- Mean annual discharge 113.53 x106 m3
Reservoir and water level
- Type Storage
· Water level:
- Full supply level (FSL) 522 m a.s.l.
- Minimum operation level 518 m a.s.l.
- Maximum flood level (PMF) 526 m a.s.l.
· Reservoir
- Surface area at an elevation 522 m a.s.l. 11.82 ha
- Volume at elevation 522 m a.a.l. 0.261 x 106 m3
- Active storage (ei. 522 – 518 m a.s.l.) 0.235 x 106 m3
- Volume below intake invert 0.027 x 106 m3
- Dead storage (below el. 518 m a.s.l.) 0.027 x 106 m3
Power generation
- Head (gross, static) 127.85 m
- Net head 120.43 m
- Installed capacity in the range 4.8 MW = (2 x 2.4 MW)
- While firm capacity 0.6 - 0.9 MW
- annual energy between 20 – 23 Gwh/year
Dam
- Type Backfill Concrete R.C Concrete
- Crest elevation 522 m a.s.l.
- River bed elevation 510 m a.s.l.
- Maximum height 14 m
- Crest length 52 m (including spillway)
- Crest width 14.40 m
- Concrete volume 6014 m3 (without power house)
Spillway
- Inflow flood peaks:
Q100 515 m3/s
Qspill 485m3/s
PMF 2,140m3/s
- Max. outflow 487.3 m3/s
- Type of gates Vertical sliding
- Design head 5.00 m
- Ogee crests elevation 522 m a.s.l.
- Width of piers 30 m
- Crest length 29.4 m
Outlet
- Gate size 1.5 x1.5 (H x W)
- Estimate of sediment bad load 80 ton/km2/year (2,500-3,000 m3)
Headrace Channel
- Flow rate (max) 4.8m3/sec
- Flow rate (rated) 3.5m3/sec
- Section of U canal w x h 2.00 m x 1.70 m
- Bottom slope 1/1000
- Canal Length 1,300 m
- Water Depth (Q = 4.3 m3/s) 1.30 m
- Water Depth (Q = 3.6 m3/s) 1.13 m
- Velocity (Q = 4.3 m3/s) 1.66 m/s
- Velocity(Q = 3.6 m3/s) 1.59 m/s
Forebay and Penstock Intake
- Normal Operating Level 518.00 m
- Crest max 518.20 m
- Crest min 516.5 m
- Qrated 3.50m3/sec
- Qmax 4.8m3/sec
- Fore bay Dimensions 8 m x 20m x 3m
- Flushing Duck 0.50 m x 0.83 m
- Over flow side spillway 15 m
Penstock Pipe
- Steel pipe (length) 800 m
- Designed diameter 1.2 m
- Thickness of rack bars 12 mm
- Max design discharges 4.4 m3/sec
- Height of trash rack at max EL 2,400 mm
- Width of trash rack 2,200 mm
- Gross surface Area 5.28 m2
- Velocity 0.80 m/s
- Clearance between rack bars 75 mm
- Angle of bars with horizontal 66 degrees
- Channel width 1,875 mm
- Number of rack bars 24.4 no
- Approach Velocity through rack 1.0 m/s
Power House
- Location Ban Meexay
- Type surface, reinforced concrete structure
- Dimensions 10.5m x16m x23 m (H xW x L)
- EL floor 391.00 m.a.s.l
- Number of units 2
- Turbine axis elevation 389.75 m a.s.l.
- Spacing of units 8.5 m
- Tail water level:
Max tail water level (nature) 390.35 m a.s.l.
Normal tail water level (nature) 390.23m a.s.l.
Minimum tail water level (nature) 390.10 m a.s.l.
Power Generating Equipment
- Turbines
Type Horizontal Francis
Rated discharge per unit 1.75-2.40 m3/s
Rated output per unit 2.4 MW
Rated net head 120.43 m
- Speed 750 r/min
- Output 2190 kw
- Generators: (Type Horizontal synchronous)
No of pole 8
Output 2200KVA
Frequency 50 Hz
Voltage 606 kv
Power factor 0.9
Transmission Line
- Nominal voltage 22 kV
- Type two overhead double circuit lines
- Length 12 km