For the first time, the flight test was completed in an urban scene. See how an "aerial power station" was born.

Today (6th), the world’s first 4,000-meter-level floating wind power generation system successfully tested in Yueyang, Hunan. This is the first time that a 4,000-meter-level floating wind power system has completed a flight test in an urban scene.

Following the take-off command, the S4000 floating wind power generation system slowly took off and carried out multi-subject verifications such as attitude stability control under complex airflow and complex magnetic field power generation performance. The S4000 floating wind power generation system that has completed the flight verification this time is 67 meters long, 40 meters wide, and 23 meters high. It can reach an altitude of 4,000 meters, has an output voltage ranging from 10 kV to 35 kV, and has a designed service life of 20 years. This system uses a helium-filled floating platform to send lightweight power generation modules to an altitude of several thousand meters, using stable high-altitude wind resources to continuously generate electricity. The generated electricity is then returned to the ground via mooring cables.

Dun Tianrui, Chief Architectural Designer of the Floating Wind Power System: What we want to test more today is its performance in connecting to the grid, and whether it will cause interference to power and attitude stability when the generator is turned on. The test of urban test flight is whether it can test flight safely and reliably around citizens and crowds. Cities are the core areas that consume electricity. Ultimately, the power supply system must begin to move towards more densely populated areas.

High-altitude wind energy, as a new energy "no man's land" that has not yet been developed on a large scale, has the advantages of high wind speed, stable wind direction, and high wind energy density, and contains huge potential. At present, there are mainly two technical routes: land-based and air-based. Land-based systems leave heavy generators on the ground and rely on aerial components such as parafoils and aerostats to pull cables to perform work; space-based systems send generator sets to the sky with aerostats to generate electricity on-site at high altitudes. The S4000 floating wind power generation system completed the 4,000-meter full-process verification at a test base in northwest China in August this year, verifying its extreme adaptability under conditions of plateau, strong ultraviolet rays, and large temperature differences.

Cai Rong, a researcher at the Institute of Aerospace Information Innovation, Chinese Academy of Sciences: This urban scene test flight is mainly to verify the reliability of the entire floating system, and also to verify the possibility and completeness of project delivery under real working conditions around the city, and the ability to quickly deploy on site. It opens up key links in R&D, testing, and operation, paving the way for airworthiness certification and scene demonstration, and effectively promoting high-altitude wind power generation equipment from technical verification to industrialization.

"Capturing energy from the air"

The birth of an “air power station”

From drawing to launch, an aerostat aircraft needs to go through five core links: design and development, production and manufacturing, final assembly and integration, in-field testing, and out-field test flight, with a cycle of one to two years. At the aerostat assembly base, see how an "aerial power station" turns from parts into a complete machine, and what it relies on to continuously generate electricity at high altitudes.

Headquarters reporter Li Yanjun: In the Yueyang assembly workshop of the floating wind power generation system, a complete aircraft is anchored and hovering. The most heavily used material is the skin, which is a key material that directly determines flight altitude, payload and service life.

Dun Tianrui, Chief Architectural Designer of the Floating Wind Power System: At an altitude of 4 kilometers, the skin needs to be light enough and strong enough. It needs to be woven with liquid crystal fiber, and then a weather-resistant layer is placed on top, and there is also an adhesive layer in the process. On the premise of maintaining the same mechanical properties, our weight can reach half of that of foreign countries.

Technicians told reporters that a skin that can withstand high-altitude ultraviolet rays and temperature differences, a generator that is light enough, and a mooring cable that can pull and return electricity are the three most difficult parts of a floating power station. The power generation modules and tethering cables use a large number of lightweight materials such as composite materials and titanium alloys. The tethering cables use ultra-high molecular weight polyethylene fiber composite cores instead of steel cables. The tensile strength is three times that of steel cables and the weight is only one-quarter of steel cables. It can not only hold the airship, but also send back high-voltage electricity. The lighter the material is, the higher it flies. The assembled aerostat first completes a full set of detailed debugging tests in the boat garage to confirm that the complete machine is in stable condition and meets standards, and then leaves the warehouse and is launched into the air for field release and power generation.

Dun Tianrui, Chief Architectural Designer of the Floating Wind Power System: We changed the arrangement of the motors, allowing them to generate electricity in groups of three. We also integrated the traditional conversion device between DC and AC with the motors. They are accompanying each other, and each one can be a silent worker.

High-altitude wind power generation has strong adaptability

Great development potential

In recent years, with the development of material technology, aerostat technology, and lightweight motor system technology, the value of my country's high-altitude wind power generation technology has gradually become apparent, and it has also provided sustainable and renewable solutions for building new power systems and promoting global energy transformation.

At present, my country's high-altitude wind energy development mainly has two technical routes: land-based and space-based. The floating wind power system tested in Yueyang belongs to "space-based" high-altitude wind power generation technology. The core principle is to mount lightweight wind turbines on aerostats and use the advantages of ducts to achieve aerial power generation. In addition, there is a parachute-ladder type "land-based" high-altitude wind power technology, which uses a tethered balloon to lift the cable and power parachute to the corresponding height. The power parachute is retracted and released to drive the ground generator to reciprocate, converting high-altitude wind energy into electrical energy.

Relevant research shows that the average wind energy density at an altitude of 6,000 meters is more than 20 times that of surface wind energy, and the wind energy contained in the sky exceeds the current total energy demand of human society by more than 100 times. Compared with traditional onshore wind power, it is estimated that high-altitude wind power can save 95% of the land, reduce the amount of steel used by 90%, and reduce the cost of electricity by 30%. High-altitude wind power generation has strong adaptability and can be deployed in deserts, coastal areas, islands, mining areas, mountainous areas, etc. It does not occupy cultivated land or ecological land, and the output can be dynamically adjusted according to wind conditions.

Our country is one of the countries with rich high-altitude wind energy resources in the world. Currently, our country has a series of independent intellectual property rights in the field of high-altitude wind energy utilization. The entire industrial chain can be localized. With later development, it will provide important support for the construction of new power systems.