The 6,400MW Xiangjiaba hydro power plant is located downstream of Jinsha River between the Yibin County of Sichuan Province and the Shuifu County of Yunnan Province, China. The power plant is being developed by state-owned China Three Gorges Corporation (CTG).
Construction of the $6.3bn hydroelectric power project started in November 2006 and four out of the eight generating units were commercially operational by July 2013. Full commissioning of the project is scheduled for 2015.
Xiangjiaba, upon completion, will be the third biggest hydroelectric power plant in China after the 22,500MW Three Gorges power plant and the under construction 13,860MW Xiluodu hydro power project.
Xiangjiaba hydropower project background
The Xiangjiaba hydropower facility exploits the lower mainstream water of Jinsha River, a tributary of the Yangtze River. After the successful launch of the Three Gorges hydro power project in 1994, the CTG was authorised for building four hydropower plants namely Xiluodu, Xiangjiaba, Wudongde and Baihetan, all located either on the mainstream or on the tributaries of the Yangtze River.
The Xiangjiaba project was estimated to displace about 85,000 people during its construction and operation. More than 8,000 people were relocated before the construction started, according to official sources.
Besides the main purpose of power generation, the Xiangjiaba project will also provide flood control, sediment trapping, navigation improvement and irrigation facilities.
Xiangjiaba project financing
China Yangtze Power Corporation (CYPC), China Development Bank (CDB) and the China Construction Bank provided financing for the construction of the Xiangjiaba hydropower project.
Xiangjiaba hydropower project details
The Xiangjiaba hydropower project consists of a 162m tall concrete gravity dam with 896.26m crest length, a dam-toe power house on the left bank and an underground powerhouse on the right bank. Other components of the project include flood discharge facilities, sand flushing outlets, navigation structures and irrigation intakes.
Each powerhouse of the plant consists of four 800MW Francis turbines. The turbine runners with 10m diameter weigh more than 400t. Each turbine is fitted with an 889MVA air-cooled generator with 23kV windings.
The hydroelectric units used at the Xiangjiaba power plant are claimed to be the most powerful in the world. Each unit of the plant can serve the annual electricity needs of about five million people.
The underground powerhouse on the left bank, with an installed capacity of 3,200MW, started commercial production in July 2013. The dam-toe powerhouse with similar capacity on the right bank is expected to be commissioned in 2015.
Power transmission from the Xiangjiaba hydroelectric power plant
The power output of the Xiangjiaba hydroelectric plant is supplied to central China and east China via the 800kV Xiangjiaba-Shanghai UHVDC (Ultra High Voltage Direct Current) transmission link.
The 1,980km UHVDC overhead transmission link, one of the biggest of its kind, was commissioned by the State Grid Corporation of China (SGCC) in July 2010.
The estimated annual power output of the Xiangjiaba plant is 30.7billion kilowatt-hours (kWh).
Contractors involved with the Xiangjiaba hydro power project
Alstom was awarded the contract by CTG in 2008 for the supply and commissioning of four generating units at the Xiangjiaba hydropower plant. Alstom designed and manufactured the four units at its factory in Tianjin, China, and delivered them between November 2012 and June 2013.
ABB provided the overall system design as well as the main equipment for the Xiangjiaba-Shanghai UHVDC transmission link.