Transmission project hits operational milestone
The world’s highest-altitude direct current transmission project has operated safely for over 12 years, with a cumulative power transmission of more than 20.3 billion kilowatt-hours, said its operator, State Grid Corp of China.
The Qinghai-Xizang grid interconnection project, linking Xining, the capital of Northwest China’s Qinghai province, with Lhasa, capital of neighboring Xizang autonomous region, is also the longest transmission line crossing permafrost.
Since it began operation in 2011, over 11.3 billion kWh of electricity has been transmitted to Xizang from Qinghai, while 9 billion kWh has been sent to Qinghai from Xizang, said State Grid, the world’s largest utility company.
By integrating the power grid in Xizang with the national grid, the Qinghai-Xizang grid interconnection project could transfer electricity to Xizang to alleviate its power shortages during the dry season in winter and spring. During the rainy season in summer and fall, the project is able to transmit surplus hydroelectric power from Xizang to Qinghai for consumption.
For a considerable period of time, hindered by geographical constraints and other factors, power supply shortage was a prominent bottleneck restricting the economic and social development of Xizang.
The upgrade and rapid development of the power grid have, however, fundamentally solved the region’s long-standing power shortage problem, improving the quality of life of a large number of farmers and herdsmen in Xizang.
At the same time, it has laid the foundation for the transformation of the plateau’s resource advantages into economic strengths, serving as a strong support for local high-quality development and rural vitalization.
State Grid plans to further expand the grid network this year by setting up an additional 600 megawatts of direct current capacity based on the existing 600 MW capacity, significantly enhancing the bidirectional transmission capability of the project.
The company has been stepping up efforts to foster new quality productive forces in recent years, with widespread innovations such as ultrahigh-voltage (UHV) power transmission networks, as the country forges ahead in cutting coal consumption and increasing the use of renewable energy in its power mix amid its energy transition.
The widespread application of such innovations will generate a significant pull effect on the industrial chains, further driving the development of new quality productive forces in the country, said Lin Boqiang, head of the China Institute for Studies in Energy Policy at Xiamen University.
With China entering a new era of green and innovation-led growth, Chinese companies have already achieved breakthroughs in new technologies, including UHV transmission lines, and the country should accelerate independent innovation in the power system, concentrating efforts on breakthroughs in core technologies to ensure the steady operation of new power systems, Lin said.
Transformation of the power sector plays a critical role in facilitating the government’s ambition of achieving carbon neutrality before 2060, he added.
Compared with traditional transmission lines, UHV lines not only increase transmission capacity and extend transmission distances, but also reduce transmission losses. These technologies have the advantages of high efficiency, energy saving, environment protection and high reliability, and are the foundation for large-scale application and promotion.
China’s continuous construction of UHV transmission lines, which usually transmit energy at more than 800,000 volts, doubling the voltage of conventional high-voltage lines and allowing them to transmit up to five times more electricity at minimal energy loss along the way, is considered an answer to the nation’s energy imbalance, said Luo Zuoxian, head of intelligence and research at the Sinopec Economics and Development Research Institute.
The high speed of construction of China’s domestic grid network in recent years, with a focus on UHV power transmission networks, ensures a more robust grid-network structure and greater use of the transmission channels, he said.
China has been at the forefront of UHV technology for over a decade, with its first such line going into operation in 2009 and a current network of more than 30 lines.
As a result, consumption of clean energy in the country’s western regions, where solar and wind resources are abundant, kept climbing as State Grid keeps innovating in environmentally protective power grid technology, which effectively boosts green and highquality development of China’s power grid construction.
Latest data show that the installed capacity of new energy in the Xinjiang Uygur autonomous region’s power grid has reached 66.11 million kilowatts, accounting for 46.3 percent of the total, while that of Qinghai province touched 38.67 million kW, 69.46 percent of the total.
According to State Grid, the electricity transmitted by the QinghaiXizang grid interconnection project has shown consistent growth over the years, surging from 650 million kWh in 2012 to 2.8 billion kWh in 2023.
The growth rates of electricity consumption in Xizang have been among the highest in China for years. The region’s electricity consumption volume increased from 2.89 billion kWh in 2012 to 11.98 billion kWh in 2022, it said.
State Grid has vowed to continue investing in grid network construction, focusing on the construction of UHV power transmission projects, to ensure power supply stability and boost green power consumption.
The company has also committed to stepping up construction of clean energy power transmission, intelligent power distribution systems, new energy storage regulations and vehicle network interaction, among others.