With the last 500,000-kW power generation unit officially putting into use, a mega hydropower plant built at an average altitude of 3,000 meters, the highest one of its kind in China, went fully operational on Friday.

With a planned total installed capacity of 3 million kW, the Lianghekou hydropower plant is located on the Yalong River in Tibetan Autonomous Prefecture of Garze, southwest China's Sichuan Province.

Construction of the project, with an approved investment of 66.5 billion yuan (about 10.5 billion U.S. dollars), started in October 2014 and is expected to be fully completed by 2023, according to the Yalong River Hydropower Development Company, Ltd.

The storage capacity of the reservoir is designed to reach 10.8 billion cubic meters, and the annual power generation volume is expected to surpass 11 billion kWh.

The Yalong River basin is one of China's clean energy bases. The operation of the Lianghekou hydropower plant will help ease imbalanced power generation in Sichuan and promote high-quality development of the Yangtze Economic Belt and the Chengdu-Chongqing economic circle.