China Building Power Transmission Line Of World’s Highest Capacity

URUMQI, May 13 (Xinhua) -- Construction of an ultra-high voltage power transmission line designed with the world's largest capacity started Sunday in China's far western Xinjiang region.

The 800 kv (kilovolt) ultra-high voltage direct current (UHVDC) transmission line connects the energy base of Hami prefecture in eastern Xinjiang with the central city of Zhengzhou, according to the State Grid Corporation of China (SGCC), the project contractor.

The 2,210-km-long line goes through the vast region of Xinjiang, Gansu, Ningxia, Shaanxi, Shanxi, and Henan. It costs 23.39 billion yuan (3.7 billion U.S.dollars), and is designed to have a transmission capacity of 8 million kw (kilowatts) upon completion in 2014, setting up a new world record.

The line will transmit 37 billion kwh (kilowatt-hours) on average annually, according to Liu Zhenya, general manager of the State Grid Corporation of China. "We can reduce 317,000 tonnes of sulfur dioxide and 267,000 tonnes of nitrogen oxide which would otherwise be produced during the transportation," Liu said.   Zhou Yongkang, a member of the Standing Committee of the Political Bureau of the Communist Party of China (CPC) Central Committee, attended the construction launch ceremony in Xinjiang.

In the meantime, a second 750-kv HVDC transmission line which links Xinjiang with the main network of the Northwest China Grid Co. Ltd. kicked off on Sunday.  With an investment of 9.56 billion yuan, the 2,180-km-long line will become the major route to transmit wind and solar power generated in Hami prefecture, Jiuquan city of Gansu province, and Qaidam basin in Qinghai province to the rest parts of the country.

The construction boom of the ultra-high voltage power transmission lines came as the country strives to transmit the electricity from the energy-rich west to the booming central and eastern regions. Xinjiang has 2 trillion tonnes of coal reserve, one third of which is in Hami. Meanwhile, Hami is one of the country's major wind power bases.

“China's large energy bases are mostly distributed in the west and north, more than 2,000 km from the power network load centers in the eastern and central regions,” said Zhang Guobao, director of Expert Advisory Committee under the National Energy Administration.  "The ultra-high power transmission lines are a way out for the country's imbalanced distribution of energy reserve," Zhang said.

Ultra-high voltage power transmission (UHVPT) projects, however, have met many obstacles, as some doubt whether the technology is mature enough and can bring about economic benefit. China has been suffering prolonged and ever worsening power shortage in recent years, a driving force for the country to develop long-distance, high-voltage power transmission lines.

Starting from March 2011, an unprecedented power shortage swept most southern and eastern provinces and municipalities, with a supply gap of 30 million kilowatts, according to China Electricity Council.

"In spite of the controversy, the projects will continuously be carried forward," said Zhou Fengqi, deputy president of China Energy Society.  Industry insiders have said the State Grid Corporation of China will push for the construction of four alternating current and three direct current ultra-high voltage power transmission lines across the country, with an investment exceeding 300 billion yuan in 2012 alone.