After successful completion of the test phase, Siemens Energy commissioned the “Guizhou-Guangdong II” high-voltage DC transmission link (HVDC) on schedule at the beginning of January. About 3000 MW of electric power now flows from hydroelectric and coal-fired power plants in western China over 1225 km (760 m) to the urban and industrial centers of Guangdong province at a DC transmission voltage of +/- 500 kV. Siemens built the system together with Chinese partners on behalf of the China Southern Power Grid Company, a state-owned energy power supply company in Guangzhou. The value of the order for Siemens was over EUR100 million.

The burgeoning demand for power in China’s urban and industrial centers requires the transmission of large amounts of energy over distances of several hundred miles or more. This is only technically feasible and economically viable using high-voltage DC transmission. China has increased the DC transmission voltage of future large-scale HVDC transmission links to +/- 800 kV, since China’s demand for power is growing and with it the need for longer power transmission routes.

Siemens is building an HVDC transmission system between the province of Yunnan in the south west of China and the southern province of Guangdong together with Chinese partners, again for the China Southern Power Grid Company, Guangzhou. This system will be the first in the world to transmit 5000 MW of electrical power at a DC transmission voltage of +/- 800 kV. Siemens’ share of the order volume amounts to more than EUR300 million. The system is scheduled to go into operation by mid-2010.

This 800-kV long-distance link is the fifth Siemens HVDC transmission project in China. The first was the “Ge-Sha” HVDC transmission link between Gezhouba and Shanghai (1200 MW, +/-500 kV over 1040 km or 645 miles). This system has been in operation since 1989. The second project “Tian-Guang” was implemented between Tianshengqiao in the south west of the country and Guangzhou (1800 MW, +/- 500 kV over 960 km or 600 miles) and has been in operation since June 2001. The third system “Guizhou-Guangdong I” between Anshun in the province of Guizhou and Zhaoqing in Guangdong province (3000 MW, +/- 500 kV over 940 km or 585 miles) has been transporting electrical power since the end of September 2004. Meanwhile number four, Guizhou-Guangdong II, went into service recently and is already playing its part in assuring China’s power supply.