In southwest China's Xizang Autonomous Region, reliable electricity was once far from guaranteed for many families living in the remote mountain city of Changdu. But a major power grid interconnection project has transformed daily life. Our reporter Wang Tianyu has the story.

For decades, reliable electricity was a luxury for many residents in Changdu, Xizang Autonomous Region.

NIMA SENGE Construction Worker Changdu, Xizang Autonomous Region "To be honest, using electricity used to be really troublesome. Sometimes I'd carry water home, and suddenly the power would go out. We couldn't even cook."

Like many families in the region, Nima Senge once struggled with unstable power supplies.

Today, things are very different. His family now enjoys modern home appliances, from large refrigerator to big-screen TV.

NIMA SENGE Construction Worker Changdu, Xizang Autonomous Region "Now the electricity is very reliable. The power basically never goes out anymore – no matter winter or summer."

The region relied largely on generating electricity for its own use, with limited ability to import power from elsewhere when shortages happened.

WANG TIANYU Changdu, Xizang Autonomous Region "This is a hydro-power station here in Changdu, Xizang Autonomous Region, where almost all electricity comes from clean energy. There's very little coal or fuel power here – partly because it's expensive and difficult to build in this environment."

In 2014, the Sichuan-Xizang Power Grid Interconnection Project officially went into operation.

With a total investment of more than 6.6 billion yuan, or around one billion US dollars at the time, the project connected Changdu's grid with the larger Sichuan power network, fundamentally improving electricity access for more than 700,000 people in the region.

XU TAO Deputy Director, Power Dispatching and Control Center State Grid Changdu Power Supply Company "We completely ended the history of our isolated power grid."

The connection allows electricity to flow between Changdu City and Sichuan Province, helping balance power supply throughout the year.

But building the project was not easy. More than 20,000 workers built the 1,500-kilometer power network across high mountains and difficult terrain.

XU TAO Deputy Director, Power Dispatching and Control Center State Grid Changdu Power Supply Company "Transportation was very difficult. A lot of the towers had to be built on mountain tops. Workers not only had to transport materials there, but also deal with high-altitude conditions and oxygen shortages."

Today, stable electricity has changed life in Changdu. For many residents, reliable power is no longer a luxury, but part of daily life. Wang Tianyu, CGTN, Changdu, Xizang Autonomous Region.