Analysts say that in the next five years, the amount of investment in ultra-high voltage is expected to reach 270 billion yuan, which is a 13-fold increase from the 20 billion investment during the Eleventh Five-Year Plan.
The national 12th Five-Year Plan, announced on March 16, 2011, mentions that “to adapt to the requirements of large-scale cross-regional power transmission and new energy generation to the grid, accelerate the construction of a modern power grid system, further expand the scale of west-east power transmission, improve the regional trunk grid, and develop ultra-high voltage and other high-capacity, high-efficiency, long-distance advanced power transmission, high efficiency, long-distance advanced transmission technologies, rely on advanced technologies such as information, control and energy storage, promote the construction of smart grids, effectively strengthen the construction and transformation of urban and rural grids, and enhance the grid’s ability to optimally allocate power and supply reliability.” This will mean that the extra-high voltage transmission project has been officially included in the national “12th Five-Year Plan”.
State Grid Development Planning Department expert Zhang Ke told the First Financial Daily that nuclear power, wind power, including hydropower as a clean energy, the future development will depend on the construction of ultra-high voltage power grid. Take wind power as an example, the national planning wind power in 2020 to reach 150 million kilowatts of installed capacity, but the installed capacity of the eight wind power bases has accounted for 80% of the total installed capacity, of which five wind power bases are in the three northern regions (North China, Northwest China, Northeast China), only Xinjiang, Gansu, Inner Mongolia, Jilin and other provinces and autonomous regions of wind power installed 80 million kilowatts, so wind power There is a big problem with the consumption of wind power. Only with the help of the UHV grid can such concentrated and unstable power be transmitted to load centres such as North and Central China. He said that after the completion of the EHV, wind power can be developed on a large scale and consumed with high efficiency, thus reducing the once serious phenomenon of wind abandonment to 1%.
Zhang Zhengling, director of the development planning department of State Grid Corporation, told Reuters in an interview that ultra-high voltage (UHV) smart grids are necessary for the development of electricity on the mainland, and that State Grid will invest RMB620 billion in the next five years to build 20 UHV lines to transmit hydropower from southwest China and wind power from northwest China to eastern China. The development of UHV grids is not only a technological innovation, but also enables long-distance transport, addresses the large-scale development and utilisation of renewable energy in China, and improves the severe environmental pressures currently facing the central and eastern parts of the country.
The so-called ultra-high voltage grid refers to a transmission network of AC 1000 kV and DC plus or minus 800 kV and above. Its most important feature is that it can transport electricity over long distances, with high capacity and low losses. 76% of the Mainland’s coal resources are in the north and north-west, 80% of its hydropower resources are in the south-west, while over 70% of its energy needs are in the central-east. The transmission distance of ordinary power grids is only about 500 km, which cannot meet the transmission requirements.
The Mainland’s UHV grid has completed one UHV AC line and two UHV DC lines, amounting to 4,633 km, while two AC and two DC lines, amounting to 6,412 km, are under construction.
On 7 October 2015, the installation of the 6000 MVA 1000 kV UHV main transformer system with the highest transformer capacity in China was completed in Suzhou. The move marked the completion of the core project of the world’s largest 1000kV UHV substation under construction, with the highest substation capacity and the strongest single power supply capacity.