Located in the southern provinces of Lao PDR straddle between Attapeu and Champasack, the 410 MW Xe-Pian Xe-Namnoy Hydroeletric Power Project is under construction and scheduled for commercial operation on February 6th, 2019. The project owners, Xe-Pian Xe-Namnoy Power Company Limited, PNPC comprises of four main shareholders, SK E&C (EPC), KOWEPO (O&M), Ratcha (Supervision) and GOL (Admin), all entered into a project development agreement on November 14th, 2008 and officially signed the founding of PNPC on March 23, 2013.
The project utilizes the river resources of the Bolaven Plateau consisting of Xe-Pian River, Houay Makchan and Xe-Namnoy River to provide the necessary hydraulic energy for powering the turbines to generate electricity. The concept is to construct two dams, Xe-Namnoy and Xe-Pian along with reservoirs, water channels, transfer conduits and surge shaft on the Bolaven Plateau to control and divert the water. The elevation difference between the upper source of water and the powerhouse located at the foot of the Bolaven Plateau is approximately 650m, therefore through a series of low pressure horizontal tunnels, vertical pressure shaft, high pressure tunnel, penstock and tailrace channel, the water is discharged back to the Xe-Kong River located approximately 6km from the powerhouse. The turbines will consist of 3 Francis and 1 Pelton type to generate 410MW, 390MW to be purchased by EGAT and remaining 20MW to EDL under the Power Purchase Agreement, both of which are electrical governing companies from Thailand and Lao PDR respectively.
The timeline for commissioning and commercial operations is scheduled for September 6th, 2018 and February 6th, 2019 respectively, therefore construction completion date should be mid-2018. The operation and maintenance of the powerhouse generating systems under the O&M Agreement between PNPC and KOWEPO (KLIC substitute) will be a term of 27 years and then ultimately transferred to the GOL for takeover under the Concession Agreement.
Catchment Areas:
• Xe Namnoy : 522 sq.km
• Xe Pian : 217 sq.km
• Houay Makchan : 81 sq.km
Dam Structures:
• Xe Pian : Concrete Gravity & Clay Core Rockfill ; 48m height
• Xe Namnoy : Clay Core Rockfill ; 75.5m height
• Houay Makchan : Concrete Intake; 8.5m height
Reservoir:
• Xe Pian : 3.4 sq.km
• Xe Namnoy : 483 sq.km;
Powerhouse:
• 3 x Francis-type turbines
• Installed capacity 3 x 123MW = 370 MW
• 1 x Pelton-type turbine
• Installed capacity 1x 40MW = 40MW
Tunnels:
• Low-pressure tunnel: 13.6 km
• Pressure tunnel : 1.6 km
High Pressure Tunnel
• Diameter: 3.6 m
• Length: 1564 m
Penstock:
• Diameter: 3.6 m
• Length: 768 m
Tailrace Channel:
• Width: 20 m
• Length: 6.3 km
Vertical Shaft:
• Diameter: 4.4 m
• Length: 458 m
Transmission Line:
• 110 Km 230 kV – Xe-Namnoy Switchyard to Pakse 230/500 kV substation
• 60 km 500 kV – Pakse Sunstation to Delivery Point at Lao-Thai border
• 75km 500kV – Lao-Thai border to Ubon 3 substation