Nam Emoun Dam Hydropower Project

Nam Emoun Dam Hydropower Project by Hobo Maps - Go to Hydropower Projects Page - - - HOME

Similar Project Names - In 2023 a new hydropower project was announced with the name Nam Emeun 1 & 2 that is similer to the already-completed Nam Emoun hydropower project. Very confusing with similar names and both projects located in Sekong Province.

Click HERE to see our other web page for this new Nam Emeun 1 & 2 project that is still in the planning stage in 2026.

This rest of this web page below is for the finished Nam Emoun project owned by Chaleun Sekong Energy Co., Ltd. (CS Energy)

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Nam Emoun (Emoon or E-Moun) Hydropower Project was also formerly known as Dak E Meule, Dac E Meule, Dakemeule, Houay Emun, Emoon or E-Moun.

The project was completed in late 2023 with Vietnam-based Songda 5 as the main contractor handing over the finished project. Export of output power to Vietnam is probably now in progress in 2026.

The project site is located in Southern Laos on the Nam Emoun and Houay Het rivers, 30 kilometers north-east of Sekong town in Sekong province, Lao PDR. The site is near Dok Cham Village in Dak Cheun District about 30 km from the Vietnam border by direct line.

The powerhouse location shown in satellite images below is at coordinates 15°34'27.8"N 106°58'09.8"E (15.574400, 106.969400):

The Nam Emoun Hydropower project started construction in 2019 and was finished in 2024. The reservoirs started impounding in March 2022. The First Spin turbine test was a success in Feb. 2023. In May 2024 the transmission line to Vietnam was completed.

Chaleun Sekong Energy Co., Ltd. (CS Energy) in 2026 is the owner and manager of the project. Vietnam-based Songda 5 Company was a main contractor.

The Houay Het river is the main tributary of the Nam Emoun river which is a main tributary of the Sekong (Xekong) river. The Houay Het river has a rather small catchment area of 254 square km at the diversion dam site and the Nam Emoun river has an even smaller catchment area of 208 square km at the main dam site.

The project has at least 20 km of tunnels with two main diversions as seen in project layout map below:

Nam Emoun project generating capacity is 129 MW from two vertical Pelton turbines with 427 GWh annual output ability.

The project was expected to cost about US$ 235 million.

Nam Emoun hydropower project layout image below rotated with north pointing up:

Nam Emoun HPP administration area images below at coordinates - 15°30'01.9"N 107°00'16.9"E (15.500528, 107.004694)

Nam Emoun plant images below:

The project includes construction of a high-voltage power transmission line from the project to the Vietnam border.

The project has sand removal structures at both the Main Dam and at the Houay Het Diversion Dam as seen in images below. Probably needed due to long tunnels that carry diverted water to the surge tank and powerhouse. We don't see sand removal structures in most other Lao hydropower projects.

Nam Emoun Main Dam image below at coordinates - 15°33'19.0"N 107°01'35.0"E (15.555278, 107.02638).

Main Dam site images below include the sand removal structure:

The project includes a Diversion Dam, Main Dam, Waterway Channels, Conveyance Tunnel, Headrace Tunnel, Surge Tank, Vertical Well, Penstock, Powerhouse, Switchyard, Tailrace Channel and a 230 kV transformer station with 53 km of dual circuit high-voltage transmission power lines.

Houay Het Diversion Dam images below with sand removal structure at coordinates - 15°26'26.4"N 107°00'58.5"E (15.440667, 107.016250):

Nam Emoun penstock images below:

Nam Emoun stator installation image below:

Nam Emoun Unit 2 Rotor-Lifting Ceremony image below:

The project has 20.5 km of tunnels dug using tunnel-boring machines (TBM) with final breakthrough in August 2021.

Nam Emoun powerhouse image below:

Nam Emoun controls images below:

Nam Emoun Project statistics below: note very small catchment areas and reservoir storage capacities.

Power Transmission To Vietnam:

Electricity of Viet Nam (EVN) agreed to purchase the plant's output pursuant to a Power Purchase Agreement signed on 4 January 2020.

On 31 March 2022 Electricity of Vietnam Power Project Management Board 2 (EVNPMB 2) organized the signing of Contract "Engineering Procurement and Construction (EPC)" project of Dak Ooc 220kV switching substation and 220kV power lines connecting Nam Emoun Hydropower Plant (Laos) to the Vietnamese power grid system. On 28 May 2024 this transmission line was completed and energizeed.

The power transmission project operates according to a bilateral agreement between the Governments of Vietnam and Lao PDR. The transmission project inside Vietnam is invested by EVN and managed by EVNPMB 2.

Transmission project images inside Laos below:

Nam Emoun Hydropower construction site image below: See powerhouse way down below with red roof.

Maps below show route of 220 kV transmission line to Vietnam.

Original reports had NEM HPP Company Ltd. as the owner and developer of the project with Chaleun Sekong Energy Co., Ltd. (CS Energy) as the major shareholder. Later reports have CS Energy alone as owning and developing the project. Vietnam-based Songda 5 Company was a main contractor.

Project history below from CS Energy website Nov. 2021 plus additions by us in 2023:

Signed a Memorandum of Understanding (MOU) with the Government of Lao PDR.
Project Development Agreement (PDA) was signed in July 2015
The Feasibility study of the project was approved in December 2017
Completed the report of Environmental and Social Impact Assessment in November 2017
Completed the Environmental and Social Management and Monitoring Plans in July 2017
Completed the Environmental and Social Management and Monitoring Plans-construction Phase in December 2018
Completed the preparation of biomass removal plans and approved the plans for November 2019
Signed a power purchase agreement (PPA) with the Electricity of Vietnam (EVN) on January 04, 2020
Signed a concession agreement with the Government of Lao PDR on December 25, 2020
In 2013, a preliminary survey was conducted by GXED & CGGC, the original owner of the project, TK Group.
In 2015, the project proposal presentation was submitted by GXED.
In July 2015, the project proposal presentation was inspected by Poyry Energy Ltd
In 2016, the project owner was changed to Chaleun Sekong Co. Ltd.
In April 2019, a project construction consulting contract was signed with ILF Consultant Engineering
In December 2018, Song Da-5 Joint Stock Company signed a contract for civil and hydropower work.
In April 2019, Voith Hydro Shanghai signed a contract for electrical and mechanical installation.
In April 2019, the original design was redesigned by ILF Consultant
Nam Emoun Main Dam reservoir impounding ceremony March 2022
Nam Emoun spin test first Feb. 25, 2023
Completion of work by Songda 5 EPC contractor in Sept. 2023 & handover
On May 28, 2024, Power Project Management Board 2 energized the 220 kV Dak Ooc switching station for connection from Nam Emoun Hydropower Plant (Laos) to the Vietnamese power system.

Much of the construction at Nam Emoun HPP was done by Vietnamese workers employed by Songda 5 company.

Nam Emoun location on map below at upper-right side: