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Project In Brief

The 410 MW Xe-Pian Xe-Namnoy Hydroelectric Power Project consists of a series of dams, reservoirs and water transfer conduits to contain and divert the waters of the Houay Makchanh, the Xe-Namnoy and Xe-Pian Rivers on the Bolaven Plateau in Champasack Province and thence to a hydropower generating plant at the base of the Plateau in the Province of Attapeu, all in Southern Laos. The dams, reservoirs, upper water channels and surge shaft are located in the eastern corridor of the Plateau in Champasack Province, while the lower water channels, vertical pressure shaft, high pressure tunnel, penstock, powerhouse, switchyard and tail race water channel are position ed about 5 km. to the northwest of the base of the Plateau in the Province of Attapeu.

The hydraulic potential of a system of river flows on the Bolaven Plateau will exploited rationally. Water from the Houay Makchanh will impounded and diverted to the Xe-Pian catchment along the Xe-Pian River whose waters likewise are impounded. The Water from the Xe-Pian Catchment will channeled to the Xe-Namnoy Reservoir which is also fed by the Xe-Namnoy River. The Xe-Namnoy Reservoir will in turn conveys water through an underground water transfer conduit, vertical pressure shaft, high pressure tunnel and penstock to drive the turbines of one Pelton and three Francis generators at the powerhouse to produce electricity. Meanwhile, a tailrace water channel discharges water from the Powerhouse to the Xe Kong River before it reaches the Mekong River. To ensure that the environmental and ecological integrity of the river below the Xe-Pian Dam is maintained, the Xe-Namnoy Reservoir provides a constant and environmental release flow.

The Project generates 1,879 Gwh of electricity per year. The Project exports 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% is sold to the local grid under a Power Purchase Agreement between the PNPC and the Electricite du Laos.
The PNPC currently operates and manages the Project until its 27 years Concession Period expires. Commercial operations commenced in December 2019 after a 5 years Construction Period. After the expiry of its Concession Period, the PNPC will transfer the Operations and Management of the Project to the Government of Laos.
Project History

2019 – 2020 • April 20, 2020: Confirmation of Commercial Operations Date issued by DEB-MEM
• March 30, 2020: Certificate of Completion issued by DEM-MEM
• January 28, 2020: Certification on the Commercial Operations Date issued by EDL
• December 6, 2019: Commercial Operations Date
• December 6, 2019: EGAT Certificate of Readiness for Operation for Generator Subsystem: Joint Operation of all Generator Subsystems
• December 5, 2019: End of Construction Phase
2015 – 2017 • April 9, 2015: The Xe-Namnoy River is diverted.
• February 16, 2015: The Xe-Pian River is diverted.
2012 – 2014 • February 6, 2014: Financial Close with Lenders and Initial Drawdown.
• November 28, 2013: Project Financing Documents are signed.
• November 28, 2013: Construction Supervision Contract between PNPC and RATCH is signed.
• November 15, 2013: Commencement of Construction Phase.
• November 15, 2013: Engineering, Purchase and Construction Agreement between PNPC and SK ecoplant is signed.
• November 14, 2013: Operations and Maintenance Agreement between PNPC and KOWEPO is signed.
• August 22, 2013: Certificates of Fire Prevention and Protection Plan are issued.
• May 10, 2013: The PNPC-EDL Power Purchase Agreement is signed.
• April 18, 2013: Annex G of the Concession Agreement is signed by the Ministry of Natural Resources and Environment.
• March 26, 2013: Certificates for the EIA, EMMP and RMP Report are issued.
• March 23, 2013: Concession Registration Certificate is issued.
• February 6, 2013 PNPC-EGAT Power Purchase Agreement is signed.
• February 1, 2013: Land Lease Agreement is signed between PNPC and the GOL.
• December 6, 2012: Tariff MOU with Electricite du Laos between PNPC and EDL is signed.
• October 22, 2012: Certificates for the Xe-Pian Dam, Xe-Namnoy Dam, Houay Makchanh Weir, Saddle Dams, Powerhouse and Operator’s Village are signed.
• October 19, 2012: Concession Agreement between PNPC and the GOL is signed.
• May 2, 2012: Electricity Business Operations License is issued.
• April 18, 2012: Official Seal approved.
• March 23, 2012 The PNPC is founded by the four major Shareholders.
• March 12, 2012: Certificate of Taxpayer Identification is issued.
2009 – 2011 • June 15, 2011: Shareholders’ Agreement is signed by all major Shareholders.
• September 29, 2011: Enterprise Name Approval Certificate is issued.
• August 16, 2010: Tariff MOU with the Electricity Generating Authority of Thailand is signed.
2006 – 2008 • November 14, 2008: Project Development Agreement between the GOL, SKE&C, RATCH and KOWEPO is signed.
• August 6, 2007: Joint Development Agreement between RATCH and SK ecoplant is signed.
• August 3, 2006: Project Development MOU between the GOL and initial consortium is signed.
2003 – 2005 • October 23, 2003: MOU between the Korea & Laos Power Development Company and The Government of Laos (GOL) is signed.
• July 19, 2005: Project Development MOU between SK ecoplant and KOWEPO is signed.

PNPC is a joint venture company formed among SK ecoplant Co., Ltd. (SKeP), Korea Western Power Co., Ltd. (KOWEPO), RATCH Group Public Co., Ltd. (RATCH) and Lao Holding State Enterprise (LHSE).
Since its founding in 1977, SKeP has continuously pursued stability and growth based on its top-notch technical expertise and outstanding management capabilities in various areas of construction including national infrastructure, housing, plants, eco-friendly incinerators and nuclear power plants, as well as its U-business that includes wireless mobile communication equipment. Through the years, the SKeP has been evolving and developing to create Build the Great, Great Life, Great World.
RATCH Group Public Company Limited, a leading Investment company in the power generation business in Thailand, was founded on March 7, 2000. The Company currently has a registered paid-up capital of Baht 14,500 million. The Company is
listed in the Stock Exchange of Thailand (SET) under the trading symbol of "RATCH".
Korea Western Power Co., Ltd.(KOWEPO), a leading supplier and innovator in the 21st century Korean power industry, started its power business in April 2001. KOWEPO takes up approximately 13% of the national generating capacity mostly comprised of thermal and combined cycle. KOWEPO was initiated in separation from Korea Electric Power Corporation under the Korea Power Industry Restructuring Act. KOWEPO is now in the process of deregulation and privatization process. KOWEPO has about 1,657 employees and its head office is located in Seoul, Korea.
The Lao Holding State Enterprise is a 100% state owned enterprise. It was established as a business company in conformity with the Lao Business Law and the Prime Minister's Decree. The Lao Holding State Enterprise is invested solely by the Government of the Lao PDR represented by the Ministry of Finance.
Technical Information
The principal components of the Project consists of a main large reservoir impounded by a dam on the Xe-Namnoy River, a long underground waterway to develop a high head of some 650 m, an open air switchyard and a powerhouse at the base of the Bolaven Plateau and a straight tailrace channel that connects the powerhouse to the Xe-Kong River.
Supplementing the volume of water in the Xe-Namnoy Reservoir for power generation purposes is achieved by diverting the run-off from two neighboring sources, the Houay Makchanh and the Xe-Pian Rivers. The diversion is made in cascades which starts from the Houay Makchanh to the Xe-Pian catchment which likewise stores water from the Houay Namliang and thence to the Xe-Namnoy Reservoir. The structures for this diversion system are a bottom intake on the Houay Makchanh and a dam and intake in the Xe-Pian River. Two underground water conduits, one working under free flow from the Houay Makchanh to the Xe-Pian Reservoir, and the second one under both pressurized and free flow conditions from the Xe-Pian Reservoir to the Xe-Namnoy Reservoir, ensures the transfer of water to the Xe-Namnoy Reservoir.
From the Xe-Namnoy Reservoir, water is conveyed to the powerhouse units by means of a power intake, a 13.7 km. of low pressure headrace of concrete lined tunnel, 550 m concrete lined vertical shaft, 1,300 m of steel lined high pressure headrace tunnel, 750 m penstock and steel water flow distribution manifolds. At the powerhouse, one Pelton and three Francis units are in charge of power generation. Plant output at rated net head is 410 MW. After power generation, water is released into the tailrace channel which conveys the flow some 6 km. downstream and discharged to the Xe Kong River. Ninety percent of the power generated is exported to Thailand by a 500 kV and 230 kV transmission line and the rest to the local grid by a 115 kV transmission line, respectively.

Catchment Area
Houay Makchan 81 km2
Xe Pian 217 km2
Xe Namnoy 522 km2
Reservoir Area
Xe Pian Dam:
- Reservoir Area 217 km2
- Effective capacity 31.3 ລ້ານ m3
- Effective storage capacity 27.1 ລ້ານ m3
- High water level 791.5 m a.s.l
- Lower water level 776 m a.s.l
Xe Namnoy Dam:
- Reservoir Area 48.3 km2
- Effective capacity 1.043,3 ລ້ານ m3
- Effective storage capacity 843,4 ລ້ານ m3
- High water level 788,5 km2
- Lower water level 760 m a.s.l
Specification of Dam
Xe Pian Dam:td>
Type of dam Concrete-gravity and Clay-core rock-fill
Maximum Height (ASL) 798 m a.s.l
Crest length 1.298 m
Xe Namnoy Dam:
Type of dam Clay-core rock-fill
Maximum Height (ASL) 793,50 m a.s.l
Crest height 77 m
Crest length 1.298 m
Xe Namnoy Dam:
Type of dam Clay-core rock-fill
Maximum Height (ASL) 793,50 m a.s.l
Crest height 77 m
Crest length 1.600 m
Specification of Tunnel
Low pressure headrace tunnel :
- Tunnel Long 13,5 km
- Dimension 5 m
Headrace tunel surge shaft:
- Tunnel heigth 98 m
- Dimension 5-8 m
Headrace tunel surge shaft:
- Tunnel heigth 485 m
- Dimension 4,6 m
ອຸມົງຫົວງານຄວາມດັນສູງ (high pressure headrace tunnel):
- Tunnel Long 1,66 km
- Dimension 4,6 m
- Tunnel Long 732 m
- Dimension 3,6 m

Production And Revenue Data
Measuring Points Water level (masl) Export to EGAT(GWh) Export To EDL(Gwh) Compare Year Plans (%) Production Plan Year 2021 (GWh)
Current Last Weeks Reservoir level Crest of Dam (masl) This Week Last Weeks Total 31/12/2020 This Week Weeks Ago Total 31/12/2020 EGAT EDL EGAT EDL
High (masl) Low (masl)
Xenamnoy Dam 785,26 785,74 788,5 760 798,5 26,15 14,76 1.611,06 5,86 6,41 84,94 98 56,61 1.644 150,03
Xenamnoy Dam 785,62 786,3 791,5 776 794
Houymachan Wier 813,94 807,6 819