Nam Xao (Sao) Dams Hydropower by Hobo Maps - Go to Hydropower Projects Page - - - HOME
The Nam Xao (Sao) hydropower projects are planned as five individual dams and power plants on the west side of the Nam Mo river in Mok District, Xieng Khouang Province, northern Lao PDR. The projects are located on the Nam Xao (Sao) and Nam Samnoi rivers which are tributaries to the Nam Mo river. The satellite image map below shows four of these dam sites along with locations of other hydropower projects in the same area.
Satellite image below shows Nam Xao Dam sites 1 to 4 - not sure where Dam site 5 is.
Nam Xao hydropower projects are apparently being developed by Lao-based Phongsubthavy group with intent to sell all of the output to Vietnam. In 2024 we know Nam Xao 2 is a 5 MW project but unsure what the others are. Probably all in the same range of capacity.
Nam Xao 1 site images below - powerhouse is at coordinates – 19°15'22.9"N 103°49'03.2"E (19.256356, 103.817568):
Nam Xao 1-Nam Samnoi headworks diversion will take water from the Nam Samnoi river and divert it 5.85 km down to a headworks reservoir where the Nam Xao river also feeds into the reservoir. From there water is to be tunneled 3.488 km down to the powerhouse located on the Nam Mo river.
The upper 31.5 meters-high Nam Samnoi dam diversion structure will be gravity concrete style with crest elevation at 565.5 meters above sea level (masl). The reservoir full supply level and overflow ogee-style (double curve) spillway are to be at 557.5 masl. The dam structure is to be gravity concrete type with crest elevation at 555.5 masl. The spillway is to be ogee-style concrete with sill elevation at 550 masl. The diversion channel intake is to be at 551 (masl).
The 5.85 km long concrete diversion channel is to be 3.95 meters in diameter.
The lower Nam Xao dam structure is to be 38 meters high with reservoir full supply level at 550 masl and minimum operating level at 540 masl. The intake from the reservoir into the headrace tunnel is to be at 533.5 masl while the 3.488 km long tunnel is 4.2 meters in diameter.
The Nam Xao 1 Powerhouse will have two Francis vertical turbine-generator sets at 22.5 MW each for 45 MW combined capacity. A short 20 meter long Tailrace Channel will discharge flows into the Nam Mo river.
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Nam Xao 2 & 4 project sites are close together as seen in the satellite image below.
Nam Xao 2 coordinates - 19°11'41.8"N 103°47'18.0"E (19.194956, 103.788334).
Nam Xao 4 coordinates - 19°11'39.4"N 103°47'22.5"E (19.194277, 103.789589)
Nam Xao 2 is a 5 MW project that has started sitework in 2022 in the images below:
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Nam Xao 3 site location image below at coordinates - 19°14'07.4"N 103°47'04.0"E (19.235392, 103.784454)
In 2022 site work and construction for Nam Xao 4 has started as seen in the images below:
Not sure where Nam Xao 5 HPP site is or if it has started construction.
Various news reports in June, 2021 reported that Electricity of Vietnam (EVN) has just exchanged power purchase contracts with a series of hydropower plant investors in Laos. Specifically, EVN exchanged power purchase contracts with Phongsubthavy Group for the Nam Yeuang hydropower plant cluster, the Nam Mo 2 project, Nam Tai, Nam Sak, Nam Sao and Nam Chao hydroelectric plants.
Looks like Nam Xao hydropower plants will have a transmission line connection ready for its output.
See enlarged version of map below HERE.
