Ultrahigh-voltage power networks spell the next frontier

Country's top two utility operators make massive investments in green energy

China said it will continue accelerating domestic grid network construction this year with a focus on ultrahigh-voltage power transmission networks.

It will mark an attempt to further ensure power supply stability and boost green power consumption in the country.

State Grid Corp of China, the country's largest State-owned utility, plans to invest 501.2 billion yuan ($79 billion) in domestic grid network construction this year, up nearly 9 percent year-on-year and an all-time high.

The company had promised to invest 473 billion yuan last year in grid network infrastructure after investing 460.5 billion yuan in 2020.In all, it plans to invest 2.23 trillion yuan in grid network construction during the 2021-25 period.

It plans to kick off 13 ultrahigh-voltage lines this year, as part of the company's five-year plan to build a domestic ultrahigh-voltage grid network, comprising 38 ultrahigh-voltage lines with a total investment of 380 billion yuan, covering more than 30,000 kilometers.

China Southern Power Grid－one of the country's two major power grids whose business covers Guangdong, Yunnan, Guizhou and Hainan provinces and the Guangxi Zhuang autonomous region－also said it will invest 670 billion yuan in grid network construction during the 2021-25 period to ensure power supply stability and boost green power consumption.

The company said the investment is meant to push forward construction of a digital and modern network with new energy as the mainstay, and will be dedicated to clean energy power transmission, intelligent power distribution systems and smart power consumption.

Total investment in the grid network by the two utilities will exceed 2.9 trillion yuan during the 14th Five-Year Plan period (2021-25), 13 percent higher than that of the previous five-year plan period and 45 percent higher than that of the 12th Five-Year Plan period (2011-15).

These massive investment outlays are a follow-up to China's pledge to work toward an optimized distribution of clean power generation on a broader scale, with the new grid channels set to include at least 50 percent of renewable energy.

The country had pledged to build a new electric power system with a higher share of new energy resources, so as to peak carbon emissions by 2030 and achieve carbon neutrality by 2060.

While the intermittent nature of new energy has long been a factor hindering its use on a large scale, the construction of a major power network is considered one of the solutions to this problem.

For instance, Northwest China's Xinjiang Uygur autonomous region has become one of the major regions taking the lead in China's renewable energy push, thanks to long-distance, large-capacity and low-loss ultrahigh-voltage power grids.

The region currently has 56 power transmission lines with a total length of 7,764 km, which have played a major role in boosting local economies and facilitating the consumption of more renewable energy.

The region, with an abundance of strong winds and long hours of sunlight, has transmitted plenty of renewable energy resources to energy-hungry coastal regions. By the end of October, the region boasted 107 million kilowatts of total installed capacity for power connected to the grid.

Another example is the Qinghai-Henan ultrahigh-voltage direct-current project, a 1,587-km, 800-kilovolt DC line to transmit renewable energy from the country's western parts to central parts. The Qinghai DC project kicked off construction on Oct 15 last year and is likely to commence operations by the end of the 14th Five-Year Plan period, said State Power Investment, its operator.

As the government plans to build massive wind and solar power facilities in the country's Gobi Desert and other arid regions, it is expected that regions like the Xinjiang Uygur autonomous region and Qinghai province are expected to become major clean energy industry bases in the country, which will in turn help increase demand for ultrahigh-voltage transmission lines in the country, said Wei Hanyang, a power market analyst at research firm BloombergNEF.

China is the first country currently deploying ultrahigh-voltage technology on a large scale and its efforts to internationalize ultrahigh-voltage standards will also yield greater global market share for Chinese ultrahigh-voltage technologies, according to a report from the Paulson Institute.

According to a recently released report by Royal Dutch Shell on Jan 17, investment in reliable and renewables-based electricity networks is one of the key actions planned for this decade to put China on the path to carbon-neutrality.

One important area of change will be expanding high-voltage transmission line capacity to connect renewables-rich regions－notably in the north and west－with areas of high energy demand on the coast, it said.

China, who launched the world's first 1,100-kV ultrahigh-voltage direct-current transmission network in 2019, has been investing in high-voltage electricity transmission lines for more than a decade.

It has ambitious plans to further expand the grid to support larger amounts of cleaner electricity. A shining example is the first green ultrahigh-voltage power transmission line that will transmit solar power generated in Qinghai province to users in Henan province. The line was opened by State Grid in 2019.

Another example is the country's first large-scale wind power network to collect the output of 36 wind farms in the Inner Mongolia autonomous region and inject it into an ultrahigh-voltage power line to the coastal provinces of Shandong and Jiangsu.

It is very important to enhance distribution networks through adequate investments, said the Paulson Institute report. Network capabilities will need to be improved to balance diverse sources of electricity supply and demand in real time, while digital technologies and solutions can be harnessed to build an optimized, reliable and resilient grid, it said.

An analyst said against the backdrop of China transitioning toward a greener energy mix, demand for ultrahigh voltage is expected to continue growing in the future.

"State Grid had achieved a highest utilization rate of ultrahigh-voltage network above 50 percent in 2020, proving the effectiveness of the grid networks," Wei said.

"Better utilization and fast installation of renewable energy in recent years also point to the need for building new ultrahigh-voltage lines, which will help quicken China's race toward carbon peaking."

In the future, ultrahigh-voltage networks will still rely on proper design of affiliated power plants and a strong cluster of demand centers, in order for State Grid to achieve an even better efficiency in utilizing ultrahigh voltage, Wei said.

Luo Zuoxian, head of intelligence and research at the Sinopec Economics and Development Research Institute, said improving power market structures to manage intermittency in a high-renewables power system is as important, and adequate incentives are needed for investments in flexible sources of generation and large-scale storage to manage fluctuations in demand.

The two grid network companies also plan to further accelerate their digitalization of grid networks during the 2021-25 period to guarantee sufficient energy supply while providing more green power in the energy mix of the country.

Shares of electricity generated from non-fossil fuels have also been increasing during the past three quarters last year.

State Grid Corp of China said its new grid-connected electricity generated by new energy had reached 41.74 million kW during the first three quarters of last year, up 39 percent year-on-year, while China Southern Power Grid said the five regions that it covers have consumed 540 billion kilowatt-hours of clean energy during the first nine months of 2021, with the renewable energy generation efficiency reaching 99.81 percent, up marginally year-on-year.