China's first 500-kilovolt cross-border alternating current interconnection project — the China-Laos 500 kV interconnection project — was commissioned on April 20. It is also the largest cross-border power grid project in terms of construction scale and the highest in voltage level between the two countries. This project increases the bidirectional power exchange capacity from 50 megawatts to 1,500 MW, enabling the delivery of about 3 billion kilowatt-hours of clean electricity annually. This is equivalent to reducing approximately 2.5 million metric tons of carbon dioxide emissions. The project will support Laos' transition to greener energy sources and facilitate the optimized allocation of clean energy on a larger scale.
This year marks the celebrations for the 65th anniversary of the establishment of diplomatic relations between China and Laos and the Year of China-Laos Friendship. As a major project included in the action plan on the China-Laos community with a shared future, the 500 kV interconnection represents another landmark achievement following the China-Laos Railway, demonstrating the two countries' deep cooperation and high-quality Belt and Road cooperation.
Construction began on Feb 26, 2025. The transmission line spans 177.5 kilometers, with 145 km in China and 32.5 km in Laos. It connects Yunnan province in China to Oudomxay and Luang Namtha provinces in Laos. To facilitate this connection, a new 500 kV substation and two 230 kV lines have been built in Laos to integrate with the northern grid. The Chinese section of the project is built and operated by China Southern Power Grid (CSG), while the Lao section is managed by Electricite du Laos Transmission (EDL-T).
The two sides collaborated closely to integrate environmental, social and governance practices throughout the entire project life cycle, setting a benchmark for green infrastructure in the region. During the design phase, the route was optimized to avoid protected areas and residential zones, preserving about 170.4 hectares of forest. During construction, an innovative coordinated transport model was implemented, utilizing a fleet of more than 30 drones and two helicopters to transport over 5,000 tons of materials. This approach reduced ecological disturbance by more than 90 percent.
Driven by digital and smart technologies, the project revolutionized traditional construction methods through smart construction site management. In the Lao section, EDL-T adopted CSG's technology to develop a localized smart construction site system. This system allows for dynamic monitoring of operations and key areas, promotes mechanized construction to minimize safety risks and improves overall efficiency.
In the Chinese section, CSG implemented intelligent retrofitting of construction machinery. The company integrated IoT sensing technologies to achieve comprehensive control over all construction elements, and established a real-time panoramic sensing network along the construction corridor. At the 500 kV Xishuangbanna Substation, robotic dogs and drones were utilized to ensure precise, efficient inspection and acceptance processes.
During construction, both sides prioritized localized employment and professional management, hiring more than 500 person-times of Lao employees. In terms of capacity building, the project conducted extensive skills training and hands-on exercises, delivering over 1,600 person-times to enhance skills and develop a local workforce in the power sector.
Furthermore, with the support of the China-Laos Joint Laboratory on New Power System Technology, CSG and EDL-T coordinated technology research and talent development to continuously improve Laos' local technical capabilities in the power sector. The two sides also jointly compiled a Chinese-Lao bilingual dictionary of power engineering technology in partnership with Kunming University of Science and Technology and the Confucius Institute at Souphanouvong University, addressing language barriers and standard differences.
On April 20, the day of commissioning, CSG kick-started the opening of China's southern regional power market to foreign participants, enabling new energy power from northern Laos' clean energy base to have its delivery schedule determined through power trading for the first time. This achieved the simultaneous integration of the physical connectivity of the transmission channel and the institutional connectivity of market mechanisms, facilitating regular cross-border trading by foreign entities from northern Laos, and laying the groundwork for exploring a common power market in the Lancang-Mekong region.
The project has always adhered to the principle: "Wherever the project is built, small yet beautiful livelihood projects are built as well." During construction, local procurement was prioritized, fostering stable cooperation with multiple quarries and machinery rental companies in Laos. This directly contributed to local employment and the development of related industries.
When the project team discovered that some areas in the Namor district had poor drainage, they took the initiative to communicate with the local government. They donated funds and actively participated in upgrading the road drainage facilities, which effectively reduced the risk of rainwater flooding and improved the living conditions of local communities.
In December 2025, a brand-new primary school was inaugurated in Namor Tai village, Laos, near the China-Laos border. This 3,185 square meters campus was established as part of a livelihood project of the 500 kV interconnection and was funded by donations from EDL-T, improving local students' access to education.
In the same month, five "Zhixing Reading Rooms", donated by CSG, were opened at five schools in the Namor district and in the Lao capital, Vientiane. These libraries are equipped with Chinese-Lao bilingual books and smart reading devices, constructed with energy-saving and environmentally friendly materials to create modern reading spaces for students.
Beyond providing hardware, the project team also focused on filling gaps in social services. With the support of CSG, Laos launched its first sign language TV program, enabling some 80,000 hearing-impaired people in the country to "see" the world. CSG also invited a delegation led by the principal of the "Hands of Hope" School for the Deaf to Guangzhou, China, to learn about effective concepts and methods in education for the hearing-impaired.
Going forward, CSG and EDL-T will use the commissioning of this project as a new starting point. They will collaborate to deploy advanced technologies and equipment to enhance the upgrading of Laos' power grid and facilitate its energy transition. Their efforts will also aim to deepen regional power interconnections and contribute significantly to building a high-quality, high-standard and high-level China-Laos community with a shared future.
Editor：Evan
