On April 20, China's first 500 kV cross-border AC interconnection project—the China-Laos 500 kV interconnection project—was officially commissioned. This project represents the largest and highest-voltage cross-border power grid infrastructure jointly constructed by China and Laos.
With this development, the power exchange capacity between the two countries has surged from 50 MW to 1,500 MW. The project will enable the annual transmission of approximately 3 billion kWh of clean electricity, a 30-fold increase compared to the previous line. This enhancement will significantly support the optimized allocation of clean energy across broader regions and at larger scales, injecting strong green momentum into deepened power cooperation, improved livelihoods, and regional shared prosperity for both nations.
The two-way power exchange capacity has been elevated from 50 MW to 1,500 MW.
The year marks the 65th anniversary of the establishment of diplomatic relations between China and Laos, also designated as the "China-Laos Friendship Year." As a major project included in the action plan for building a China-Laos community with a shared future, the 500 kV interconnection project stands as another landmark achievement following the China-Laos railway, reflecting deepened practical cooperation and high-quality joint development under the Belt and Road Initiative.
The China-Laos 500 kV interconnection project commenced construction on February 26, 2025. The transmission line spans a total of 177.5 kilometers, with 145 kilometers located in China and 32.5 kilometers in Laos. It connects China's Yunnan Province with Laos' Oudomxay and Luang Namtha provinces. A new 500 kV substation was built in Laos, along with two 230 kV lines connecting to the main power grid in northern Laos, contributing to the formation of an integrated power grid in Laos. The Chinese and Lao sections of the project are constructed and operated by China Southern Power Grid and the Lao National Power Grid Company (EDL-T), respectively.
A representative from China Southern Power Grid stated that the project is not only a "power highway" crossing mountains and rivers to deliver green electricity but also a "road to development and prosperity" built on shared benefits and mutual gain.
—Complementary Advantages Enhance Power Exchange Capacity.
In 2009, the 115 kV cross-border line from Mengla in China's Yunnan Province to Namo in Laos' Oudomxay Province began operations, marking the beginning of high-voltage interconnection between the two countries. Building on the energy resources and load characteristics of both nations, power companies from China and Laos innovatively established a "surplus-and-deficit mutual assistance" power cooperation mechanism starting in 2022. Leveraging the interconnection and the Southern Regional Electricity Market, surplus hydropower from Laos is transmitted to China during the rainy season, while China supplies power to northern Laos during the dry season. By the end of 2025, the total electricity trade volume between China and Laos exceeded 1.6 billion kWh.
With the commissioning of the 500 kV interconnection project, the two-way power exchange capacity has jumped to 1,500 MW. Serving as the main channel for delivering clean energy from northern Laos, the project functions like a "power highway," transmitting about 3 billion kWh of clean electricity annually. This is equivalent to reducing carbon dioxide emissions by approximately 2.5 million tons, effectively enhancing Laos' ability to balance power supply between wet and dry seasons, transforming its clean energy advantages into tangible benefits for people's livelihoods and economic development, and supporting Laos' green transition.
—Green Construction Sets an Eco-Friendly Benchmark.
China and Laos worked closely to integrate ESG management practices throughout the entire lifecycle of the project, establishing a regional benchmark for green infrastructure. During the design phase, the route was optimized to avoid protected areas and residential zones, preserving approximately 170.4 hectares of forest. During construction, an innovative "helicopter + drone" collaborative transport model was adopted. Over 30 drones and 2 helicopters formed an aerial fleet, transporting more than 5,000 tons of materials while reducing ecological disturbance by over 90%. This allowed 88% of the work sites to achieve "zero road access." In areas frequented by Asian elephants, elephant guards were stationed, and real-time tracking of elephant movements was conducted using an early warning app, infrared cameras, drone bases, and ecological monitoring stations to ensure that construction did not interfere with the elephants. New compact towers were promoted, and locally suitable plants were prioritized for greening, enhancing soil and water conservation on substation slopes and lawns, achieving a win-win for technology and ecology.
—Technological Innovation Drives Smart Infrastructure Transformation.
With digitalization and intelligence as the engine, China and Laos promoted the transformation from traditional infrastructure to smart infrastructure through the development of smart construction sites. In the Lao section, the Lao National Power Grid Company introduced technology from China Southern Power Grid to develop a localized smart construction site system, integrating 11 video surveillance points to dynamically monitor medium- and high-risk operations and key construction areas, combining human oversight with technical safeguards. Mechanized construction was widely adopted, with 27 types of equipment used in substation works and 11 types in line works, reducing safety risks and improving efficiency.
In the Chinese section, China Southern Power Grid upgraded construction machinery with intelligent modifications, utilizing BeiDou positioning and IoT sensing technologies for full-element management of construction. Eighty-seven online monitoring devices and 6 tower-based drone nests were deployed, creating a real-time panoramic sensing network for the line corridor. At the 500 kV Xishuangbanna Substation, robotic dogs and drones were introduced to perform "second-level" inspections of equipment status before commissioning, making acceptance work both precise and efficient.
—Exploring Cross-Border Electricity Trading and Dispatch Mechanisms.
The successful commissioning of the project has not only enhanced the power exchange capacity between China and Laos and improved power supply in northern Laos but has also established a green channel for power interconnection and clean energy exchange within the Lancang-Mekong region.
The 177.5-kilometer connection goes beyond physical linkage—it also involves aligning rules, integrating standards, and fostering talent development.
On April 20, China Southern Power Grid organized the first power transaction to determine delivery schedules for renewable energy from clean energy bases in northern Laos through market mechanisms.
A representative from China Southern Power Grid explained that the company overcame key challenges related to mechanisms, processes, and settlement, promoting the compatibility and openness of the Southern Regional Electricity Market to overseas entities. This achieved a "soft connectivity" in market mechanisms alongside the "hard connectivity" of the 500 kV interconnection channel, supporting regular cross-border transactions for renewable energy entities in northern Laos and laying the foundation for exploring a regional common electricity market in the Lancang-Mekong area.
Aligned rules provide a solid foundation for the stable operation of the cross-border grid. In March, the China-Laos 500 kV interconnection dispatch agreement was formally signed in Vientiane, Laos. Based on the operational realities of transnational grid interconnection, the agreement focuses on core aspects of power dispatch, clarifies responsibilities, and establishes an efficient and responsive dispatch system for the interconnected grid. The agreement's生效 marks a new phase of standardized and institutionalized operation for China-Laos power connectivity, providing robust institutional guarantees for the safe and efficient operation of the cross-border grid.
Integrated standards form a "common language" for deeper cooperation. In August 2025, China and Laos jointly established the China-Laos Power Standards Cooperation Committee and co-developed Laos' first standardized technical specification for transmission operation and maintenance. The two sides also collaborated with China's Kunming University of Science and Technology and the Confucius Institute at Laos' Souphanouvong University to compile a "Chinese-Lao Bilingual Dictionary of Power Engineering Technology," addressing language and standard differences.
Talent development ensures that the fruits of cooperation benefit the people. During the project's construction, emphasis was placed on both "localized employment" and "professionalized management," employing over 500 Lao workers. Extensive skills training and practical drills were conducted, including bilingual safety training and emergency drills, resulting in skill enhancements for more than 1,600 participants and fostering a localized power talent pool. Furthermore, China Southern Power Grid and the Lao National Power Grid Company utilized the China-Laos Joint Laboratory for New Power System Technologies to advance technical research, standard conversion, and talent cultivation, continuously improving the local technical capacity of Laos' power sector.
—Strengthening the Foundation of Friendship Through Livelihood Projects.
People-to-people connectivity is the most fundamental, solid, and enduring form of interconnection. The China-Laos 500 kV interconnection project is not only an energy artery spanning mountains and rivers but also a bridge of friendship connecting the hearts of the people in both countries.
In December 2025, a new primary school was put into use in Namo Nai Village, Laos, near the China-Laos border. As a supporting livelihood project of the interconnection project, the 3,185-square-meter campus was funded by the Lao National Power Grid Company, improving educational conditions for local students.
Vilaisay Xaylomsing, a Lao employee involved in the project, emotionally recalled the school's inauguration ceremony: "A teacher quietly pulled my arm and said this school would be the brightest spot in the village from now on."
Education lights the way to the future. In the same month, five "CSG Knowledge" reading rooms built with support from China Southern Power Grid were officially handed over and opened in Laos. Located in five schools near the interconnection project site and in Vientiane, the capital, these rooms are equipped with bilingual books and smart reading devices, using energy-saving materials to provide modern reading spaces for students.
Beyond infrastructure, the project team worked to fill gaps in social services. With support from China Southern Power Grid, Laos launched its first sign language audio-visual news program, allowing 80,000 hearing-impaired individuals in the country to "see" the world. A delegation from the "Hand of Hope" school for the hearing impaired visited Guangzhou, China, to learn about educational concepts and methods.
The project adhered to the principle of "building small yet impactful livelihood projects wherever the engineering goes." During construction, local materials were prioritized, and stable partnerships were established with several Lao quarries and machinery rental companies, directly boosting local employment and related industries. Noticing drainage issues in parts of Namo District, the project team proactively communicated with local authorities, donating and participating in the renovation of road drainage facilities, effectively reducing flood risks during rainfall and improving the living environment for the community.
From physical interconnection to standard integration, from technical exchange to joint talent cultivation, and from infrastructure benefiting people to cultural blending, the project exemplifies the profound significance of China-Laos power cooperation through these "small yet beautiful" livelihood initiatives, making the 65-year friendship between China and Laos tangible and heartfelt.
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