Marking the first time that overseas new-energy electricity has participated in the nation's power market, the China-Laos 500-kilovolt power interconnection project officially commenced operations on Monday, signifying a major leap in regional energy integration.

The milestone was marked by the delivery of 4.81 million kilowatt-hours of electricity from a clean energy base in northern Laos to Southwest China's Yunnan province. Industry experts noted that this is not merely a technical connection but a structural breakthrough in how renewable energy is traded across borders in Southeast Asia.

Construction of the interconnection project began on Feb 26,2025. Spanning a total length of 177.5 km, the transmission line includes a 145-kilometer Chinese section and a 32.5-km Lao section.

While Lao hydropower has previously been transmitted to Yunnan via lower-voltage lines and subsequently delivered to the Guangdong-Hong Kong-Macao Greater Bay Area, this project — the largest cross-border grid project and the highest-voltage power link between China and Laos — introduces solar power.

The current transaction involves electricity generated by Laos' first large-scale mountainous photovoltaic project, a gigawatt-scale facility, said China General Nuclear Power Group, the operator of the solar project.

Following its grid connection, the solar energy is now being transmitted through the 500-kV backbone, marking the formal entry of overseas intermittent renewables into China's marketized trading system, said CGN, which is also the country's largest nuclear power plant operator in terms of installed capacity.

According to China Southern Power Grid, Monday's transaction was the first instance of new energy being delivered to Yunnan through this mechanism.

However, the scope is set to expand. The company stated that it will continue to organize power transmission to Guangdong province, creating diverse trading scenarios where the ultimate destination of the clean energy from Laos extends far beyond Yunnan to the high-demand hubs of the GBA.

The project is expected to transmit roughly 1.1 billion kWh of solar-generated electricity to China this year, signaling a transition toward a more standardized, institutionalized, and market-oriented phase of power interconnectivity between the two neighboring nations.

Industry experts believe the integration of Lao solar power into the Chinese market demonstrates the maturity of the country's regional trading platforms.

It provides a blueprint for how the Lancang-Mekong region can balance resource-rich but demand-light areas with the massive green energy needs of China's coastal economic engines, said Lin Boqiang, head of the China Institute for Studies in Energy Policy at Xiamen University.

The application of 500-kV and higher voltage levels in cross-border lines effectively reduces transmission losses over long distances, making the import of wind and solar power — which are often located in remote frontier regions — economically viable, he said.

Looking ahead, China Southern Power Grid said it will normalize cross-border electricity trading as a standard practice.

By pursuing even higher-voltage interconnections and expanding the scale of regional power trade, the company aims to deepen energy synergy and provide high-quality support for the regional green transition.

This evolving "Power Silk Road" is expected to become a vital artery for the "dual circulation" of international and domestic energy markets, ensuring that the benefits of the green transition are shared across borders, it said.

zhengxin@chinadaily.com.cn