The Xiangjiaba Hydropower Plant is located on the lower mainstream of the Jinsha River, a tributary of the Yangtze, across the border of Yunnan Province and Sichuan Province in China.
The 6.4GW project is one of the largest hydropower projects in the country. It is operated by renewable energy company China Yangtze Power, a subsidiary of state-owned China Three Gorges Corporation (CTG).
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The project features eight hydropower units at the downstream of Jinsha River, providing it with an installed capacity of 6,400MW.
In 2018, Xiangjiaba, with no non-scheduled stops, generated 30.88TWh of power.
Besides power generation, the hydroelectric project also supports flood control, sediment trapping, agricultural irrigation and navigation. The project is estimated to reduce 12 million tonnes of carbon dioxide emissions per year.
Xiangjiaba Hydropower Project Development History
The planning for the Xiangjiaba Hydropower Project started in 1950s. The preliminary survey and design of the project took 40 years.
Preparatory works of the project commenced in July 2004 and construction was officially started in November 2006.
River closure was realised in December 2008. The gate was closed for initial impoundment in October 2012.
The first generating unit of the project was commissioned in November 2012, and the final one in July 2014.
In 2016, the project cleared the safety assessment upon completion.
Xiangjiaba Hydropower Project Details
The project infrastructure comprises primarily a water retaining structure, flood release and energy dissipation structure, sediment flushing structure, headrace and power generation system with a dam toe powerhouse on the left bank, another headrace and power generation system with an underground powerhouse on the right bank, navigation structure, and irrigation water withdrawal structures on both the sides.
The concrete gravity dam has a maximum height of 162m and a crest elevation of 384m.
The project has a normal storage level of 380m with a total reservoir capacity of 5.163 billion m3. The flood control capacity of Xiangjiaba is around 903 million m3.
At the headrace and power generation system on left bank, every turbine features a separate headrace and tailrace in arrangement. At the right bank, each turbine has a separate headrace tunnel and two turbines share one tailrace tunnel.
Xiangjiaba-Shanghai Ultrahigh Voltage Direct Current Link
The power generated by the Xiangjiaba project is transmitted to central and east China via the 800kV Xiangjiaba-Shanghai Ultrahigh Voltage Direct Current (UHVDC) link.
The Xiangjiaba-Shanghai UHVDC was commissioned in July 2010. It is owned by the State Grid Corporation of China (SGCC).
The 1,980 km long transmission link, with a bipole configuration, is designed to transmit up to 7,200MW of power from the Xiangjiaba hydropower plant to Shanghai, situated around 2,000km away.
Contractors Involved
In 2008, Alstom was contracted for the delivery of four 812MW class Francis-type turbine and generator units at the Xiangjiaba power plant. The scope of the contract also included training, supervision of installation and commissioning works.
Weighing 406 tonnes, the runner of the turbine is one of the largest in the world. It has a diameter of 10.5m and a height of 4.7m.
GGB Bearings, now a Timken company, delivered its specially designed, fibre-reinforced composite bearings for the assembly of the wicket gate for the turbines of the hydropower plant.
GeoSIG partner Earth Products China (EPC) was chosen to equip Xiangjiaba dam and hydropower station with a system for full seismic and structural monitoring. In August 2014, EPC installed 18 units of GMSplus and 18 AC-73 triaxial force balance accelerometers.
Hitachi Energy was the main technology supplier for the Xiangjiaba-Shanghai UHVDC link. The company was responsible for providing overall system design and supply of the main equipment, including 28 high- and ultrahigh-voltage converter transformers, thyristor valves, DC and AC switchyard equipment and the DCC800 HVDC control system.
In August 2023, GE Vernova secured a contract from Yangtze Power to upgrade the Xiangjiaba Hydropower Plant and improve its efficiency.
The scope of work includes the design, manufacturing, delivery, installation, and commissioning of three sets of main shaft air supply pipes. The upgrade is expected to be completed in the first half of 2024.
