LHASA, May 15 (Xinhua) -- Construction of the expansion of the Qinghai-Xizang grid interconnection project began on Tuesday in southwest China's Xizang Autonomous Region, according to State Grid Xizang Electric Power Company.

With a total investment of over 2.6 billion yuan (about 366 million U.S. dollars), the extension contains nine single projects.

The Qinghai-Xizang grid interconnection project ended the isolation of the Xizang power grid when put into operation in November 2011. As of April, over 20 billion kWh of electricity had been transmitted through its lines, which is equivalent to reducing carbon dioxide emissions by nearly 16 million tonnes.

The grid lines of the extension project will be laid at an altitude reaching 4,511 meters, with a temperature that can drop to as low as minus 41.2 degrees Celsius, making its construction very arduous, according to Yin Junqiang, deputy director of the construction department of the company.

Yin added that the annual transmission capacity is expected to double, hitting 1.2 million kilowatts, once the project is completed.

Leveraging its abundant solar, hydraulic and wind power resources, authorities in Xizang have exerted more efforts to develop the clean energy industry in recent years to relieve the power strain during winter and spring. Since 2016, the electricity consumption in the region has increased by more than 16 percent annually, and more and more farmers and herdsmen in high-altitude remote areas have gained access to stable electricity.