The grid links Qamdo in Tibet Autonomous Region with the Tibetan Autonomous Prefecture of Garze in Sichuan Province.
The project aims to put an end to electricity shortages of the over 500,000 residents of the Qamdo region and ease power strain in Tibet as a whole, state-run Xinhua news agency reported.
The complex interconnection circuits stretch 1,521 kilometers across the plateau at an average altitude of 3,850 metres. Its construction involved more than 20,000 staff over eight months, the State Grid Corporation of China said.
China has pumped billions of dollars into Tibet in recent years to build infrastructure in the rugged mountainous region with five airports, rail links and road networks.