Construction of a US $3.17bn clean energy ultra-high voltage (UHV) electricity line in China is complete. It’s the first UHV line in the world built to transmit only carbon-free electricity, its developer, State Grid Corp. of China has said. It will allow more renewables to be developed in Qinghai and Gansu provinces and deliver the electricity all the way to Henan in central China.
China is promoting the technology, which allows long-haul transmission with little loss of power, to solve a vexing problem: Its energy resources are thousands of kilometers inland from its densely populated coastal regions.
Making this line available for only carbon-free sources can help China achieve two of its energy goals, boosting renewable energy consumption while reducing idle capacity, State Grid said. It could also drive more than US $28.2bn and create almost 10,000 jobs in investments in renewables and other related industries.
The long-haul lines are also part of China’s stimulus plan to revive its economy from the impact of the coronavirus pandemic. UHV projects may account for 13% of US $205bn that’s likely to be spent by the nation this year on “new infrastructure”.
Prior to this latest addition, State Grid operated 19 UHV lines covering 27,570km, and the utility was building another four of the links as of June last year. The power networks are usually source-agnostic so they can transmit power from any type of generation, including coal and renewables.
The company expects to put the 1,587-kilometer line from Qinghai to Henan into full operation in December. The project is designed to transport 40 billion kilowatt-hours of clean power a year.
Ultra-High Voltage (UHV) transmission refers to power transmission lines operating at greater than 800,000 volts (800 kV). The primary benefit of UHV transmission is the ability to transport electricity over long distances with minimal power loss.
China is the first to employ 1,000,000 Volt (1,000 kV) transmission lines and has begun an aggressive plan to interconnect major provinces with UHV lines. China has already demonstrated transmission at distances of 2,500 km, with lines up to 5,000 km being planned.
China is also exporting this expertise and working with companies such as Electrobras in Brazil to build a 2,000 km 800kV line which will transport hydroelectric power from northern Brazil to population centres in the south.
So why build a UHV transmission system? UHV allows generating plants to be moved closer to the fuel source and away from population centres, significantly improving local air quality. A secondary benefit is the ability to integrate widely dispersed renewable power sources (hydro, wind, and solar) into a national distribution network.