A tethered balloon with a two-tonne payload capacity has taken to the skies of China for the first time to build high-altitude power lines
Technology does not just ease labour — it opens paths where none existed before. When conventional methods are powerless before altitude and roadlessness, unconventional solutions come to the rescue, capable of connecting even the most inaccessible corners of the planet.
On Monday, China's first tethered balloon with a two-tonne payload capacity began testing as part of a major power transmission line construction project. This is an entirely new solution for transporting cargo at power grid construction sites in high-altitude and environmentally sensitive areas, according to the State Grid Corporation. The project is a large-scale ultra-high-voltage (UHV) transmission line that will carry clean energy from the Xizang Autonomous Region in southwest China thousands of kilometres to the Guangdong-Hong Kong-Macao Greater Bay Area in southern China.
At the construction site, a large balloon 25 metres in diameter and with a volume of 8,000 cubic metres slowly rose into the air. As several cables were extended and retracted, heavy construction materials suspended beneath the balloon were lifted off the ground and smoothly moved along a predetermined route to the mountain construction site.
"This is our newly developed load-bearing tethered balloon. We have just completed a maximum load test of two tonnes at an altitude of 4,000 metres. Next, we will carry out an operation to lift power supply materials over a straight-line distance of 500 metres with a vertical drop of 120 metres," said Qin Jian, a researcher at the Research Institute of Power Transmission and Conversion Technology of the State Grid Electric Power Research Institute.
A heavy-lift tethered balloon involves launching a helium-filled balloon into the air and connecting it to the ground with one or more cables. By adjusting the cable, the height and horizontal position of the balloon are controlled, facilitating the transport of materials at high altitudes. The balloon can fly up to 800 metres and carry a maximum load of two tonnes with positioning accuracy within 0.5 metres.
As the construction of new power grids spreads ever faster to high-altitude, remote and environmentally fragile areas, transporting materials for power line projects has become a serious problem hampering construction progress. Traditional road construction for cargo transport has long cycles and causes significant environmental damage, while drones, despite their manoeuvrability and flexibility, face limitations in scenarios requiring heavy cargo or prolonged continuous transport. Tethered balloon transport technology effectively overcomes these difficulties.
"The construction section where this technology is applied is located in uninhabited mountainous terrain at an altitude of over 4,000 metres. Many towers are located on steep ridges inaccessible by road, making this section the highest-altitude, most dangerous terrain and most complex operations in the entire project. The tethered balloon with a two-tonne payload capacity is better suited to high-altitude conditions characterised by thin air and strong winds, and its load capacity and stability better meet transport requirements," said Feng Tao, project manager of the State Grid Henan Electric Power Company.
As reported by CCTV+, the test of the tethered balloon with a two-tonne payload capacity marked an important step in developing construction technologies for hard-to-reach areas. The new method promises to speed up power line installation, reduce environmental impact and open new opportunities for energy projects in high mountains.
