China's major ultra-high voltage transmission lines in smooth operation

China has long depended on coal-burning power plants to fuel its explosive growth over the past three decades. As a result, air pollution has risen to alarming levels in central and eastern regions.

Policymakers have been working hard to shift the country's energy profile to greener cleaner technology.

Just one problem – that energy is mainly generated in Western regions.The answer has been the creation of ultra-high voltage power lines.

A part of the ultra-high voltage transmission line in Inner Mongolia [Photo: baidu.com]

Ultra-high voltage or UHV is defined as voltage of 1,000 kilovolts or above in alternating current and 800 kilovolts or above in direct current.

Currently there are about 30,000 kilometers of ultra-high voltage power transmission lines under construction and in operation in China.

The lines can deliver large quantities of power over long distances with less power loss than the more commonly used 500-kilovolt lines.

The newly built 2,383-kilometer long ultra-high-voltage transmission line connecting Jiuquan city, in northwest China's Gansu Province with central China's Hunan Province is a symbol of China's leading role in the clean energy revolution.

The transmission line, possibly the world's longest power transmission artery, can transfer clean energy generated by solar and wind in Gansu directly to Hunan.

A technician examines transmission line on the Huainan-Nanjing-Shanghai Ultra-high voltage (UHV) Transmission Line Project in Huai'an, east China's Jiangsu Province, Nov. 27, 2015. The Huainan-Nanjing-Shanghai UHV Transmission Line Project, which has a length of 759 kilometers and spans east China's Anhui, Jiangsu and Shanghai, is expected to come into stream in 2016. [Photo: Xinhua]

Deng Qinghong is the deputy director of the construction department of State Grid Hunan Electric Power Company.

"This ultra-high-voltage transmission line can transfer 40 billion kilowatt-hours of power to Hunan each year, meeting one fourth of the total power demand in the province. This power can also benefit other central China provinces through the central China power grid," Deng said.

With more clean energy available, Hunan is beginning to wave goodbye to the era of coal burning as part of the industrial cycle.

A foundry industrial park in Chenzhou city of Hunan has been replacing all its coal-fired boilers with electric ones. A total of 1.59 million tons of coal will eventually be saved in this way.

Huang Qili is with the Chinese Academy of Engineering.

"With the world's largest power transmission capacity and longest transmission route, this ultra-high-voltage transmission line has practical significance for the world's clean energy transmission and China is playing a leading role in the field," Huang noted.

A technician examines transmission line on the Huainan-Nanjing-Shanghai Ultra-high voltage (UHV) Transmission Line Project in Huai'an, east China's Jiangsu Province, Nov. 27, 2015. The Huainan-Nanjing-Shanghai UHV Transmission Line Project, which has a length of 759 kilometers and spans east China's Anhui, Jiangsu and Shanghai, is expected to come into stream in 2016. [Photo: Xinhua]

Brought on stream in 2014, the 1,680-kilometer-long ultra-high-voltage transmission line sees clean power carried from Xiluodu Hydropower Station in southwest China to east China's Zhejiang Province around the clock.

During the peak summer season, it contributes up to 17 percent of Zhejiang's power, saving more than 30 million tonnes of coal and helping reduce about 85 million tonnes of carbon dioxide emissions.

Such super-efficient power transmission lines are not only helping to rejuvenate China's industry and environment, but have proved China's position as a world leader in the technology that is vital to meeting the challenge of climate change.

The State Grid Corporation of China, the world's largest utility company, has already signed a deal on an ultra high-voltage electricity transmission project in Latin America.

The 2,500-kilometer power line in Brazil will link the world's third-biggest hydroelectric dam to the country's largest market.

The first phase of the Belo Monte UHV DC Transmission Project is expected to start commercial operations by February 2018.