Ningxia builds a major "West-to-East Power Transmission" channel

China Energy Storage Network: Ningxia is an important transmission point for China's West-to-East Power Transmission, and is responsible for transmitting electricity to more than a dozen provinces across the country. In 2021, Ningxia's cumulative power transmission was 90.4 billion kWh, setting a new annual transmission record. As of the end of 2021, Ningxia has successfully built and operated two large direct current transmission channels, Yindong and Lingshao, in the past 10 years, and the cumulative power transmission has exceeded 500 billion kWh. How does Ningxia open up a large channel for transmitting electricity?

Choosing the coal-to-electricity path

Ningxia is rich in coal resources, which were originally distributed in the four major mining areas of Lingwu, Shizuishan, Zhongwei and Guyuan. With the discovery of a number of super-large coal mines covering Yanchi, Tongxin and Hongsibao areas in 2003, Ningxia's proven coal reserves have reached 31 billion tons. The annual coal production has jumped from one million tons to tens of millions of tons, making it one of the country's 13 billion-ton-level large-scale coal production bases.

"Ningxia's industry is small, and its huge coal reserves cannot be consumed locally. You can't beg for food with a 'golden bowl' in your hands, right?" Li Yuhua, Party Secretary and Director of the Ningxia Development and Reform Commission, told reporters that there was controversy over how to deal with this issue at the time. One idea was to send coal from the west to the east, drawing on the common methods of surrounding coal-rich provinces to build a dedicated railway line to transport Ningxia's surplus coal to the east; another suggestion was to send electricity from the west to the east, converting Ningxia's coal resources into electricity resources, and transporting surplus electricity to economically developed provinces by building an aerial "highway". The former is both convenient and effective, while the latter is beneficial in the long run, but the investment is huge. What should I choose?

As the West-to-East Power Transmission Project has become a reality, it has provided a new historical opportunity for Ningxia to finally decide to transform its coal resources into power resources. In 2006, the Party Committee and Government of the Ningxia Hui Autonomous Region put the "Ningxia Power East Transmission" on the agenda while planning and building the Ningdong Energy and Chemical Industry Base.

Building a "highway in the sky"

Hai Tao, director of the Energy Department of the Ningxia Development and Reform Commission, said that the key to transmitting electricity from west to east is the word "transmission". Where is the channel for "transmission"? Who is willing to be the first "buyer"? A series of problems need to be solved urgently.

For Ningxia Power Grid, 2008 was an unforgettable year. Shandong became the "first stop" of Ningxia's first large-scale power transmission channel. The Yindong ±660 kV DC transmission project (Ningdong, Ningxia-Qingdao, Shandong) was approved by the National Development and Reform Commission, with a total static investment of 10.385 billion yuan. On December 15, 2008, the project officially started, and on February 28, 2011, the project was completed and put into operation. "It is not only one of the important channels for my country's West-to-East Power Transmission Project, but also the most advanced DC transmission 'highway' in the world at that time." said Min Ning, director of the dispatching and control center of State Grid Ningxia Electric Power Co., Ltd.

With the successful completion and operation of Yindong, Ningxia is determined to build on the momentum and launch the second "highway in the sky", namely the Lingshao ±800 kV UHV transmission direct channel. This line starts from the Lingzhou converter station in Ningxia in the west and ends at the Shaoxing converter station in Zhejiang in the east. The line is 1,722 kilometers long with a rated transmission capacity of 8 million kilowatts. It can transmit 50 billion kilowatt-hours of electricity annually, with a total investment of 23.732 billion yuan.

In 2014, the state planned to build 12 air pollution prevention and control transmission channels. The Lingshao UHV DC transmission project was identified by the state as a key project for West-East power transmission during the 12th Five-Year Plan, i.e. the fifth UHV DC project of the State Grid Corporation of China. In 2016, it was the first of the 12 air pollution prevention and control UHV projects to be put into commercial operation.

As of 2021, the successful operation of the two direct current "sky highways" of Yindong and Lingshao has not only promoted the economic transformation of Ningxia's coal resources, but also realized the "bundled transmission" of new energy power generation, transmission and consumption such as wind and solar power, laying a solid foundation for Ningxia to create the country's first new energy demonstration zone.

Technological innovation to ensure electricity supply

"When I learned that many media reported that Ningxia's cumulative power transmission had reached 500 billion kWh, I was so excited that I couldn't sleep at night!" said He Mingfeng, captain of the electrical equipment construction team of Ningxia Power Transmission and Transformation Engineering Co., Ltd. When they undertook all the civil engineering projects and 70% of the equipment installation projects of the Yindong ±660 kV DC transmission project, the pressure was unprecedented because there was no precedent to follow.

"To complete such a project, hard work alone is not enough, innovation is also needed," said Yang Lei, deputy general manager of Ningxia Power Transmission and Transformation Engineering Co., Ltd. The power transmission and transformation installation procedure boldly explored a new method of advancing from the middle to both ends, which not only greatly improved the installation quality, but also shortened the construction period by 5 days compared with the original plan. With a large amount of work and a long construction period, innovation in management mechanisms is also indispensable. In terms of management, operation, and maintenance, the Yindong and Lingshao DC transmission projects have boldly explored dozens of new methods of management, operation, and maintenance.

"The most important innovation is the comprehensive application of new technologies," said Li Wei, director of the Equipment Management Department of State Grid Ningxia Electric Power Co., Ltd., pointing to various simulated intelligent objects in the West-East Power Transmission Achievement Exhibition Hall. "These are the outdoor single-station inspection robots, relay room S-type track robots, water ice room H-type track robots and other intelligent robots that we independently developed. As the power grid operation and maintenance plant with the largest number of robots, the most complete types and the highest level of operation and maintenance automation in the country, we have realized both manual and intelligent inspections, ensuring the long-term, high-efficiency, safe and stable operation of the power transmission artery."

Li Yuhua introduced that at present, the Ningxia-Central China UHV DC transmission and supporting new energy projects have been included in the "14th Five-Year Plan" energy plan, and the State Grid Corporation has started the preliminary feasibility study. Ningxia and Hunan Province have successively signed the "Ningxia Power into Hunan" strategic cooperation framework agreement and the energy cooperation memorandum, and jointly strive to make the project a national source-grid-load-storage integration and multi-energy complementary development demonstration project.

"The 'Ningxia Power into Hunan' project is the country's first ultra-high voltage transmission channel that focuses on developing large-scale desert photovoltaic bases and transmitting new energy. After the completion of this third 'highway in the sky', Ningxia's electricity consumption will reach 'two 100 billion', that is, 100 billion kWh of annual electricity sales in the region and 100 billion kWh of annual electricity transmission; the development of renewable energy will achieve 'two 50%', that is, 50% of installed capacity and 50% of power generation." said Yi Lidong, Party Secretary and Chairman of State Grid Ningxia Electric Power Co., Ltd.

Source: Economic Daily Author: Xu Ling