XINING, Jan. 7 (Xinhua) -- Over 5.5 billion kwh of electricity has been transferred to Tibet through the Qinghai-Tibet grid interconnection project, according to State Grid's Qinghai Electricity Power Company.

The grid interconnection project, put into operation in November 2011, ended Tibetan power grid's isolation. Apart from transferring electricity to Tibet, it has sent out 2.3 billion kWh of electricity from Tibet during the past seven years.

Tibet is rich in hydraulic power resources. However, it faces power strains in the dry season during winter and has power surplus in the summer.

The project starts in Xining, capital of Qinghai Province, and ends in Lhasa, the regional capital of Tibet. The 2,530 km grid lines are laid at the plateau with an average altitude of 4,500 meters.

Low temperatures, lack of oxygen and strong winds on the plateau challenge the operation and maintenance of the grid.

Maintenance staff examines the grid during extreme weather and monitors the grid for frozen soil on a regular basis. In order to ensure smooth operation of the grid and the safety of birds, a total of 118 artificial nests were built in safe areas on the towers of the grid.