BEIJING - Construction on the country's second ultra-high voltage (UHV) power transmission project will commence soon and is expected to be completed in 2013, according to the State Grid Corporation of China.

Authorities with the State Grid, one of China's two power grid operators, reviewed the design of the Huainan-Shanghai UHV alternating current pilot project earlier this week, marking the final step before embarking on construction, according to State Grid sources.

The pilot project, which will carry power eastward from east China's Anhui Province to Shanghai, represents the world's highest level of UHV technology and is a breakthrough in the field, Sun Xin, the head of the company's UHV department, was quoted as saying by Friday's China Securities Journal.

After construction begins, it usually takes three years for such a large project to be put into commercial service, said another source with State Grid, speaking on condition of anonymity.

"Once the project starts, it will benefit electrical equipment producers and other manufacturers producing relevant construction materials," the source said.

UHV, which is defined as a voltage of 1,000 kV or higher alternating current and 800 kV direct current, is designed to deliver large quantities of power over long distances with lower power losses than traditional lines.

The State Grid plans to invest about 1.6 trillion yuan (over 250 billion U.S. dollars) in smart grid system development in China in the 2011-2015 period, during which the backbone network for UHV alternating current power transmission will be constructed, Shu Yinbiao, the company's vice general manager said during a forum last month.

The company completed the first UHV power grid in 2009, establishing a 640-km alternating current line that linked the southeastern part of coal-rich Shanxi province with the city of Jingmen in central China's Hubei province.