The Xepian-Xenamnoy Hydroelectric Power Project is located in the 2 Provinces: Champasak and Attapu on the southern of lao PDR. As part of this 390 Home MW Scheme, one river diversion and two dams shall be constructed across the following three rivers: Houay Makchane, Xe Pian- Xe namnoy. The scheme’s main dam and other major structures will be located in Champasak Province. while the proposed powerhouse, tailrace channel and high voltage transmission line located in Attapu Province In 1995, a feasibility study for this project was already carried out.
the Project is expected to generate 1,879 Gwh per year. The Project will export 90% of the electric power it generates to Thailand under a Power Purchase Agreement between the Electricity Generating Authority of Thailand and the PNPC, while the remaining 10% will be sold to the local grid under a Power Purchase Agreement between the PNPC and the Electricite du Laos. The Project will operate and manage the Project during the 27-years Concession Period after the 5-years Construction Period and commencement of commercial operations by 2019. After the expiry of the Concession Period, the PNPC will transfer the Operations and Management of the Project to the Government of Laos.
Joint Development Memorandum of Understanding (MOU). between SK Engineering Construction (SKEC) and Korea Western Power Co.,Ltd (KOWEPO) on the date july 19, 2005. Memorandum of Understanding (MOU) With Government of Lao PDR (GOL). on the date August 3, 2006. Foreign Investment Application Submitted to Government of Lao PDR. Memorandum of Understanding between Government of Lao PDR (GOL) and the Consortium SK Engineering Construction (SKEC) and Korea Western Power Co.,Ltd (KOWEPO) Consortium Representative Office in Lao on the date May 25, 2007.
Development Cost Sharing SKEC:KOWEPO: RATCH = 34%: 33%:33%.The Feasibility Study Approval From Government of Lao PDR. On the date January 4, 2008.
Completion of Project Development Agreement(PDA) Negotiation With GOL On the date February 16, 2008.
Presentation to Electricity Generating Authority of Thailand (EGAT) for Technical Aspects on the date May 14, 2008
The Project Development Agreement (PDA) Signed for 18 month on the date November 14, 2008.
Proposed Tariff to Electricity Generating Authority of Thailand (EGAT) on the February 20, 2009.
The Project has a gravity dam by means of RCC construction method, which creates about 70 km long reservoir. Reservoir water will be used by two units of turbine at the powerhouse located on immediate downstream of the main dam. The general layout of the main dam is shown in Figure 2. The facilities around the main dam are composed of one lane of river diversion tunnel, a gated spillway, an intake structure and penstock, a surface type powerhouse, outlet facilities, related accessory equipment, etc. The dam is 148 m high and 540 m wide and the total volume is around 2.3 MCM. Further, the re-regulation dam is installed at 6 km downstream from the main dam to release the 16-hour peaking inflow from the main dam evenly on a 24-hour basis. The river water will be diverted by one diversion tunnel driven through the left abutment, together with two cofferdams to be installed at the upstream and downstream sides of the main dam. After completion of its function as river diversion the tunnel will be permanently plugged with concrete.
The spillway is a gated overflow structure on the main dam. Maximum outflow equivalent to 1,000-year flood can be discharged through the spillway at Food Water Level.
Power intakes, intake gates and penstocks are installed in the main dam body. The powerhouse will be located at the downstream of the main dam, semi-underground type of power house.
Transmission lines of the Project will be comprised of a double-circuit 230 kV line for the electricity exportation to Thailand and a single-circuit 115 kV line for the domestic electricity supply (Figure 3). The 230 kV transmission line will be from Nam Ngiep (Main Dam Switchyard) to Nabong substation. The length of the transmission line is approximately 130 km. The 115 kV transmis sion line will be from Nam Ngiep (Re-regulation Dam Switchyard) to the existing Pakxan Substation. The length of the transmission line is approximately 40 km.