The China-Laos 500-kilovolt interconnection project, China's first 500-kV cross-border alternating current interconnection cable system, was commissioned on April 20, with the massive power line linking the countries officially switched on.
It's rated as the biggest cross-border power grid project in terms of construction scale and the highest in voltage level between the two neighboring countries.
Another landmark achievement in the wake of the China-Laos Railway, the 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.
That is equivalent to reducing about 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.
On the day of commissioning, China Southern Power Grid Co., Ltd. (CSG) opened China's southern regional power market to foreign participants, clearing the path for the finalization of northern Laos' clean energy base's transmission schedule of delivering its new energy power through power trading for the first time.
It's said that this achieved the simultaneous integration of the physical connectivity of the transmission channel and the institutional connectivity of market mechanisms. That, in turn, facilitates regular cross-border trading by foreign entities from northern Laos, laying the groundwork for exploring a common power market in the Lancang-Mekong region.
The project's 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 Southwest 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 grid in the northern part of the country.
The Chinese section of the project was built and is operated by CSG, while the Lao section is handled by Electricite du Laos Transmission (EDL-T).
The project used digital and smart technologies to transform traditional construction methods into smart approaches.
In the Lao section, EDL-T adopted CSG's technology to develop a localized smart construction site system. This system allowed for dynamic monitoring of operations and key areas, promoted mechanized construction to minimize safety risks and improved overall efficiency.
In the Chinese section, CSG implemented intelligent retrofitting of construction machinery. The company used Internet of Things (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 in China's Yunnan, robot dogs and drones were utilized to ensure precise, efficient inspection and acceptance processes.
The two companies collaborated closely to integrate environmental, social and governance practices throughout the entire life cycle of the project. During construction, the route was optimized to avoid protected areas and residential zones, preserving about 170.4 hectares of forests.
Local procurements were prioritized, fostering stable cooperation with multiple quarries and machinery rental companies in Laos.
The project also prioritized localized employment and professional management, with more than 500 jobs created for Lao workers and more than 1,600 individuals receiving training.
When the project team discovered that some areas in the Namor district in Laos had poor drainage, they took the initiative to communicate with the local government and donated funds to actively participate in upgrading local road drainage facilities, which effectively reduced the risk of rainwater flooding and improved the living conditions of the local communities.
In December 2025, a new primary school was inaugurated in Namor Tai village in Laos, near the China-Laos border, with a campus spanning 3,185 square meters. This public works project was established with donations from EDL-T as part of the public welfare plan for the 500-kV power interconnection project, improving the access of local students 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, and they were 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 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 in Laos to Guangzhou, the capital of South China's Guangdong Province, to learn about effective concepts and methods in education for the hearing-impaired.
Moving forward, CSG and EDL-T plan to use the commissioning of the project as a new starting point to further collaborate to help upgrade Laos' power grid and facilitate its energy transition with advanced technologies and equipment.
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.
(Executive editor: Wang Ruoting)
