The Monsoon wind farm is a 600MW onshore wind project developed in the southern part of Laos. It is the first and largest wind farm to be developed in the country and the first cross-border renewable energy project in the Association of Southeast Asian Nations area.
The $950m (K20.96tn) project was developed by Monsoon Wind Power, which was established by a group of companies including Mitsubishi through its subsidiary Diamond Generating Asia, ACEN Renewables International, Impact Electron Siam (IES), STP&I, BCPG and SMP Consultation.
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Earlier development was carried out by Impact Energy Asia Development (IEAD), a joint venture of Mitsubishi (55%) and BCPG (45%).
Construction of the wind farm commenced in April 2023 and the project began commercial operations in August 2025. A ceremony marking the official commercial operation date of the project was held in November 2025.
The project is capable of producing 1.7 terawatt-hours of renewable energy per year and offsetting more than 32.5 million tonnes of carbon dioxide emissions over its operational life of 25 years.
The project has created more than 1,600 jobs, with Lao nationals accounting for more than 1,000 of these positions. In addition, an annual Community Development Fund of $1.1m is allocated to nearby villages, supporting initiatives in education, healthcare, agriculture and local infrastructure.
Project location
The Monsoon wind farm is located in the Dak Cheung district of Sekong province and the Sanxay district of Attapeu province, both in southern Laos. It is situated 560km south-east of Vientiane, the country’s capital, and 48km east of Sekong city.
The project site covers an area of 708.28km² (70,828ha) and is situated 1,200–1,600m above sea level.
Monsoon wind farm development
IEAD was granted the exclusive rights to develop the project by the government of Laos (GoL) through a development agreement signed in 2015.
In July 2017, the project was recommended by the GoL to the Ministry of Industry and Trade of Vietnam (MOIT) to be developed as a cross-border renewable project. A grid impact study was completed and approved by Vietnam Electricity and MOIT in September 2019, and the project was approved to be connected to Vietnam’s grid network at the Thanh Mi substation.
In January 2022, Keppel Infrastructure, IES and Envision Group signed a memorandum of understanding (MoU) to explore the possibility of expanding the wind farm’s capacity by 1GW. Keppel Infrastructure is a developer of sustainable infrastructure, while Envision is a global green technology company.
The environmental impact assessment (EIA) report for the project was approved by the Ministry of Natural Resources and Environment in July 2022.
A concession agreement was signed by the developers with the GoL for 25 years in December 2022, allowing other projects to be connected to Vietnam’s grid network.
The project was energised in February 2025, and the turbine installation was completed in April of the same year.
Monsoon wind farm details
The Monsoon wind project features 133 EN-171 onshore wind turbines. Each EN-171 wind turbine generates 4.51MW of electricity and has a rotor diameter of 171m, a hub height of 110m, a swept area of 22,965m² (247,193ft²) and a blade length of 84m.
The project includes four internal 33/115kV substations, a 115/500kV substation and 180km of internal road systems, along with the development of underground and above-ground collector transmission cables and other ancillary facilities.
Grid connection
The Monsoon wind farm exports power to Vietnam’s electricity grid through a 71km-long, 500kV transmission line, of which 27km is in Laos and 44km in Vietnam.
The transmission line starts from the 115/500kV substation of the wind farm at Ban Dak Bong in the Dak Cheung district and ends at the 500kV Thanh My substation in Vietnam.
Financing of the project
A group of financing institutions provided a $692.6m financing package under an agreement signed with the developers in April 2023.
The funding structure comprised a $100m A loan from ADB’s ordinary capital resources, alongside $50m of concessional support channelled through ADB-administered blended finance facilities. It also features a $10m grant from ADB’s Asian Development Fund – Private Sector Window.
The $150m syndicated B loan is made up of $100m provided by Siam Commercial Bank and $50m from Sumitomo Mitsui Banking.
In addition, parallel loans include $120m from the Japan International Cooperation Agency, $100m from Kasikornbank, $72.6m from the Asian Infrastructure Investment Bank, $60m from the Export-Import Bank of Thailand and $30m from Hong Kong Mortgage Corporation.
ADB served as the lead arranger, coordinating all banks participating in the financing package.
Power purchase agreement
An MoU on power interchange was signed between the Vietnamese and Laotian governments in October 2016.
The electricity generated by the wind farm is supplied to Vietnam under a 25-year power purchase agreement signed between IEAD and Vietnam Electricity in 2021, which was amended in January 2022.
The plan for importing power produced from the wind farm to Vietnam’s grid was approved in July 2022 by the prime minister of Vietnam.
Contractors involved
Envision Group signed a letter of intent with IEAD for the supply of 133 wind turbines for the wind farm in April 2022.
The Power Construction Corporation of China signed an engineering, procurement and construction contract for the wind farm in November 2022.
ERM-Siam Company, a consulting services provider, was chosen to conduct the environmental and social gap analysis of the local EIA.
AFRY, an engineering, design and advisory services provider, was engaged by ADB to provide the lender’s technical advisory services in March 2023.
Power Project Management Board 2 of Vietnam Electricity constructed the 44km transmission line in Vietnam, while Monsoon Wind Power constructed the 27km line in Laos.
