Nam San 3 Dams Hydropower Info - Go to Hydropower Projects Page - - Home
Nam San 3A & 3B dams info is combined on this web page. These projects were at one time called Nam Sane 3A & 3B while planned under a MOU by Thailand-based Padaeng Industry Public Co Ltd. before Lao-based Phongsupthavy Group took over the project.
BCPG Plc, the renewable power arm of Bangchak Corporation Plc, later took over Nam San 3A & 3B projects from Phongsupthavy Group and is now the 100% owner.
Nam San 3A is located in Khoun District, Xieng Khouang Province while Nam San 3B is in Thathom District of Xieng Khouang Province, Lao PDR.
Both projects are close together on the Nam San (river) that flows south eventually merging with the Mekong River near Paksan. Thathom District at one time was in Xaysomboun Province but in 2006 it was transferred to Xieng Khouang Province.
Nam San 3A dam is located near Muang Nga village while 3A powerhouse is near Ban Hine Toc. Nam San 3B powerhouse and valve house are both located just north of Thathom town.
Nam San 3A generates 69 MW from 2 Dongfang Electric pelton turbines at 34.5 MW capacity each and is able to generate annual electricity output of 364 GWh.
Nam San 3B generates 45 MW from 2 Dongfang Electric turbines at 15 MW capacity each and is able to generate annual electricity output of 232 GWh.
Nam San 3A & 3B projects satellite image layout below. We are guessing about the two underground conduit pipes added to this image as we don't have evidence that they exist other than logic that the water must somehow get from the dam reservoirs to the powerhouses and nothing is visible on the satellite image.
Nam San 3A dam site images below:
Nam San 3B dam site image below at coordinates - 19°05'05.7"N 103°37'12.4"E (19.084924, 103.620103).
:
China-based Dongfang Electric was involved as a major contractor.
Nam San 3A and Nam San 3B hydropower plant projects were developed by Lao-based Phongsupthavy Group but the project has been sold to Thai-based BCPG Plc. Nam San 3B may have been called "Nam So HPP" at some time in the past but we aren't sure.
BCPG Plc, the renewable power arm of Bangchak Corporation Plc, took over Nam San 3B Power Sole Co, operating a hydropower plant and transmission line system for US$ 113 million. BCPG invested through its wholly-owned subsidiary BCPG Indochina Co. (BIC), acquiring all shares owned by Phongsupthavy Group.
This is the second takeover of a hydropower plant in Laos by BCPG. The first project was the Nam San 3A HPP with power generation of 69 MW, located in Xieng Khouang Province, Laos. The Nam San 3A project was acquired in September 2019 for US $174 million.
On Jan. 4, 2020 - Power Purchase Agreements were signed with Electricity of Vietnam (EVN) for sale and export of the power output from Nam San 3A & 3B to Vietnam.
From 2022 onward the two hydro power projects Nam San 3A and Nam San 3B will be under a power purchase agreement with EVN for 25 years. This involved an extension of the power purchase agreement period from 2042 to 2047. The prior power purchase agreements with EDL were terminated.
The 27 year Build-Operate-Transfer (BOT) Concession Agreements with government of Lao PDR has Nam San 3A with a Commercial Operating Date (COD) of 29 January 2016 while Nam San 3B has Commercial Operating Date of 25 August 2015.
Image below shows Nam San 3A & 3B locations and offtake terms.
Nam San 3A dam site location shown in satellite images below at coordinates 19°07'49.2"N 103°39'44.3"E (19.130329, 103.662314)
Nam San 3A powerhouse location shown in satellite image below at coordinates - 19°05'15.9"N 103°37'40.5"E (19.087742, 103.627918):
Nam San 3A powerhouse & 3B Dam sites shown in satellite images below:
Nam San 3A powerhouse satellite image below:
Nam San 3B powerhouse and valve house locations shown in satellite image below:
Nam San 3B powerhouse site shown in satellite image below at coordinates - 19°00'59.5"N 103°36'00.1"E (19.016524, 103.600029):
Nam San 3B dam structure images below:
Nam San 3B powerhouse and switchyard images below:
It seems the original Thai developer had designed the two plants for export of the output to Thailand. But in order to export power output to Vietnam instead it was necessary to revise the entire control and protection system of these plants to meet the technical standards of the Vietnamese power grid and synchronize with it. In 2023, Vietnam Energy Engineering and Trading Joint Stock Company was selected for this project and completed it successfully.
Nam San 3A control images below:
Nam San 3B control images below:
Nam San 3B powerhouse interior image below:
Nam San 3B switchyard below:
Nam San 3 switchyard below (unsure if 3A or 3B):
Nam San 3A & 3B Hydropower projects are located on right side of map below:
Nam San 3A & 3B hydropower projects are two of 11 hydropower plants planning to sell electricity to Vietnam through a 100 km long 220 kV transmission line Nam Mo - Tuong Duong (Nghe An). This transmission line was invested by Phongsupthavy Group for the section in Laos and by Electricity of Viet Nam (EVN) for the section in Vietnam. BCPG Indochina Co. later became a joint investor in this transmission line.
The output from both plants is now being exported to Vietnam since June 15, 2023 under a 25-year power purchase agreement with EVN.
Nam San 3A has a capacity of 69 MW connected to the 110 kV side of the Nan San 3B distribution yard by a 110 kV single circuit line 10.5 km long. The distribution yard is designed according to the diagram of a female bar, generating power to the grid through two 110/11 kV 45 MVA turbochargers.
The 220 kV Nam San 3B substation receives and collects the output from the Nam San 3A plant. Nam San 3B is connected by 220 kV single circuit line about 46 km long to the 220 kV Nam Mo 2 substation.
Nam San 3A & 3B transmission line maps below for export to Tuong Duong Vietnam. Not all distances and routes agree between charts since these are long-term planning maps.
The chart below shows about 100 km distance of transmission line from Nam Mo 2 station to Tuong Duong station in Vietnam.
Map below has old info from early long-term planning.
Nam San 3 transmission line connection seen in map below. See enlarged version HERE.
Nam San 3 - 220 kV transmission line images below:
Satellite image map below for Nam Ngiep River Basin hydropower projects:
