CHENGDU - China's second-largest hydropower station became operational Monday with its first power generating unit officially starting work after a three-day test run.

The No 13 power generating unit with a capacity of 770,000 kW at the Xiluodu hydropower station started providing electricity to the China Southern Power Grid, its operator China Three Gorges Corporation said in a statement.

With a total generating capacity of 13.86 gigawatts, the station is the world's third-largest after the Three Gorges and Itaipu hydroelectric projects.

Construction of the Xiluodu hydropower station, located in the Jinsha River, a major headstream of the Yangtze in southwestern Yunnan and Sichuan provinces, started in 2005. It is expected to be completed in 2015 with 18 power generating units.