Nam Ngiep 2 Dam Hydropower info by Hobo Maps - Go to Hydropower Projects Page - - Home
Nam Ngiep 2 is also sometimes spelled Nam Ngieb 2 or Nam Ngiep II. Much info on the web regarding Nam Ngiep 2 project is outdated and no longer relevant. A prior 261 MW project planned by Japan's Kansai Electric and Thailand's EGAT around year 2007 has apparently been cancelled.
Nam Ngiep 2 hydropower project is not related to the Nam Ngiep 2A, 2B & 2C hydropower projects developed by Nonghai Group further north on the eastern side of the Nam Ngiep river.
Nam Ngiep 2 Dam and reservoir image below (also called Nam Sen Reservoir since it is on the Nam Sen river):
The project is owned by Nam Ngiep II Hydropower Project Company with Electricite du Laos (EDL) holding 10 percent ownership and China International Water & Electric Corp (CWE) holding the other 90 percent. CWE is a subsidiary company of China Three Gorges Corporation (CTG).
The Project is financed, built and operated as a build-own-operate-transfer (BOOT) project under a 25-year concession agreement with the government of Laos starting from the date of commercial operation.
China Development Bank issued a $242.7 million loan to help finance the project.
The project cost was estimated at about US $345 million.
Red marker in satellite images below shows dam location at 19°14'23.6"N 103°17'06.4"E (19.239900, 103.285100).
Nam Ngiep 2 has three generators with an installed capacity of 60 MW per unit for a combined capacity of 180 MW and 723 GWh output of electricity per year into the national power grid for local supply. The operation head of the hydropower station varies from 430 meters to 491 meters.
The main dam on the Nam Sen river is a 70.5 meter-high clay core rockfill dam that creates a reservoir with storage capacity of 163 million cubic meters.
Nam Ngiep 2 project involved diverting water west from the Nam Ngiep River through a 7.4 km-long tunnel to the Nam Sen Dam and Reservoir. Water is then diverted 10.9 km south to the Nam Ngiep 2 powerhouse which contains three Francis turbine-generator units. See diagram below:
Nam Ngiep 2 hydropower project is on Nam Sen and Nam Siam (rivers) - tributaries of the Nam Ngiep (river) about 94 km upstream from the Nam Ngiep 1 dam site. Nam Ngiep 2 powerhouse is only 10 km away from backwaters of the Nam Ngiep 1 reservoir.
The project has an inter-basin transfer between the Nam Sen and Nam Siam rivers and a diversion tunnel to supply the reservoir during the dry season from the headwaters of the Nam Ngiep. The catchment area of the reservoir is 693 square km and the reservoir capacity is 151.8 million cubic meters.
The works comprise a transfer weir on the Nam Ngiep , a 7.4 km long transfer tunnel, a 70 meter high clay core rock dam on the Nam Sen, a 10.9 km long headrace tunnel, a surface power station on the Nam Siam equipped with 3 x 60 MW Francis turbines and generators and a 230 kV transmission line to the Tha Vieng substation.
The operating head of the project varies from 430 m. to 491 m.
Nam Ngiep 2 plant site image below at 19°08'16.7"N 103°18'33.5"E (19.137967, 103.309299):
Nice aerial-view video of dam project at end of construction HERE .
The main structures of the complex are a 70.5 meter-high clay core rockfill dam, a right bank open spillway, a right bank discharge scour outlet for river diversion , a 10.94 km-long right bank headrace tunnel and surge tank (136 meter height and 7 meter diameter), penstock (1,203 meters long with 3.4 meter diameter), ground powerhouse, 20 meter-high tributary dam and 7.4 km long headrace tributary tunnel.
The project's generated power is to be transmitted via a 230 kV transmission line to the Tha Vieng substation.
Nam Ngiep 2 dam structure below:
Nam Ngiep 2 (Nam Sen) Dam & Intake Structures below - unusual to have two intake structures:
Nam Ngiep 2 downriver view below:
Nam Ngiep 2 powerhouse building images below:
Toshiba Hydro Power (Hanzhou) provided 3 units of Francis turbines, each with 60MW nameplate capacity and 3 electric generators for the project whose capacity is 68.8 MVA.
Nam Ngiep 2 turbines and control room below:
Nam Ngiep 2 powerhouse image below:
Nam Ngiep 2 powerhouse was damaged in Sept. 2017 as floodwaters from the Nam Ao-Nam Pot hydropower project accident came 2.5 km down the Nam Siam river to the Nam Ngiep 2 site - see damage images below:
Nam Ngiep & Nam Ao-Nam Pot project plants both shown in image below with powerhouses only 2.5 km apart on the Nam Siam river.
Enlarged section below shows each powerhouse roof color - Nam Pot black & Nam Ngiep 2 as reddish.
Nam Ngiep Hydropower projects shown in middle of map below:
Nam Ngiep 2, 2A, 2B & 2C projects in satellite images below
Satellite image map below for Nam Ngiep River Basin hydropower projects:
Nam Ngiep 2 Hydropower project is a clean green project qualified under the Kyoto Protocol as a greenhouse-gas-reducing project and is estimated to reduce carbon dioxide emissions by about 387,000 tons per year. This qualifies it as a Clean Development Mechanism (CDM) project and able to earn CO2 reduction credits. View or download the CDM application document HERE .
Nam Ngiep catchment area shown in images below:
Projecct History
On August 25, 2010, China International Water & Electric Corp (CWE) and the Government of Laos signed a Nam Ngiep 2 Hydropower Plant Project Development Agreement.
On December 8, 2010, the Government of Laos approved the environmental impact assessment (EIA) for the project.
On June 16, 2011, Nam Ngiep II Power Company Limited and Électricité du Laos (EDL) signed a Shareholders Agreement.
On August 18, 2011 Nam Ngiep II Power Company Limited signed a 25-year concession agreement with the Government of Laos
On October 19, 2011 EDL and CWE signed a commercial (EPC) contract for the Nam Ngiep 2 Hydropower Plant Project.
On December 23, 2011, a groundbreaking ceremony was held.
The project was completed during the first week of April 2015 and was put into operation on October 2, 2015.
The facility was completed and commissioned in December 2015.
Click HERE to see our hydropower web page for the greater Nam Ngiep catchment basin which describes the various dams, reservoirs and diversion projects in the drainage basin that are often inter-connected.