Hydropower generated in Laos has for the first time been transmitted to China's Guangdong-Hong Kong-Macao Greater Bay Area (GBA) through the China-Laos 500-kilovolt (kV) interconnection project, marking a new milestone in cross-border clean energy cooperation between the two countries, according to Guangzhou Daily reports on Thursday.

The power delivery, which began on Thursday, is expected to continue through the end of October with a total transmission volume of approximately 600 million kilowatt-hours (kWh), according to the China Southern Power Grid Co.

According to the report, the imported electricity is being traded simultaneously through the southern regional electricity market, marking a continued strengthening of mutual power support capacity between the two countries, and a further improvement in the optimized allocation of cross-regional clean energy resources.

The 500-kV cross-border alternating-current power interconnection project officially went into operation on April 20 this year. The project, the largest cross-border grid project and the highest-voltage power link between China and Laos, connects Southwest China's Yunnan Province with Oudomxay and Luang Namtha provinces in northern Laos, the Xinhua News Agency reported.

On its first day of operation, solar power generated from Laos's northern clean energy base was transmitted to Yunnan, marking the first time that an overseas renewable energy project has participated in China's domestic electricity market, according to the report.

The latest hydropower transmission to the GBA shows that the project is now capable of channeling multiple forms of clean electricity to different parts of China, improving the flexibility and reach of power trade across borders, the grid operator said.

In 2026, the total market-based trading volume of solar and hydropower transmitted through the China-Laos 500-kV channel is projected to reach 1.5 billion kWh. Southern Power Grid said it will continue to expand the scale and scope of cross-border electricity trading, leveraging synergies between the China-Laos interconnection and China's west-to-east power transmission program to promote complementary energy advantages.

The company added that the project will help optimize energy allocation in the Lancang-Mekong region, strengthen energy complementarity between the two countries, and support higher-quality Belt and Road energy cooperation.

The latest development caps more than a decade of power grid cooperation between China and Laos. In 2009, Southern Power Grid Co first supplied electricity to northern Laos via a 115-kV line. Bilateral power trade in both directions officially commenced through 115-kV lines in 2022.

According to Xinhua, construction of the 500-kV interconnection project began on February 26, 2025. The transmission line spans 177.5 kilometers (km), including a 145-km Chinese section and a 32.5-km Lao section. The infrastructure was funded and constructed by China Southern Power Grid Co and Electricite du Laos Transmission Company Limited, respectively.

The commissioning of the project in April 2026 ushered in a new phase characterized by higher voltage levels, greater transmission capacity and market-oriented operation, according to Guangzhou Daily.