The successful launch and testing of a giant airship-come-wind-turbine earlier this month has prompted discussion on whether they could be the future of sustainable power in China.
Called the S2000 Stratosphere Airborne Wind Energy System (SAWES), this 197-foot (60 meters) long, 131-foot (40 meters) wide, and 131-foot-high airship can, reportedly, generate megawatts worth of juice when connected to the grid.
The airship is an example of a technology called high-altitude wind energy (HAWE), which is effectively a floating wind turbine or generator. The S2000, in particular, is helium-filled and remains tethered to the ground when in operation.
To this end, the S2000 can operate where winds are stronger and more consistent than near the ground. At altitudes of between 1,641 feet (500 meters) and 9,843 feet (3,000 meters), winds tend to be faster, more stable, and more consistent.
Because wind power scales with the cube of wind speed, even modest increases in wind speed can massively increase energy output. That’s why the idea of using airships to host wind turbines keeps resurfacing despite being technically difficult.
Airship wind turbines: the future for China?
During its groundbreaking test earlier this month, an S2000 ascended to around 6,561 feet (2,000 meters) in about 30 minutes. Once in position, it was able to generate around 385 kWh over a few hours of testing.
That is enough electricity for about 6 electric vehicle charges, or enough to supply an average city household in China for about a month. That might sound modest, but it is important to note that the test was not at the technology’s full potential.
The claimed maximum capacity is 3 megawatts, which would put it roughly on par with a medium-sized conventional wind turbine.
Visually, the S2000 resembles a fantasy-style airship featuring a large egg shaped fueslage siting inside a large donut-shaped ring. This ring also features large stabilizers.
Sited between the main body and outer ring is a series of turbine blades in a concentric setup. This ducted-typed setup, its designers explain, helps guide and compress wind before it reaches the turbines, improving overall efficiency.
“It’s like wrapping the wind from all sides, constraining the airflow within this duct so that as much wind as possible is captured by the blades. We have deployed 12 wind turbines on this duct,” Weng Hanke, chief technology officer of Linyi Yunchuan, told Hunan TV at the time of the test.
The test was a huge success, and, according to the South China Morning Post (SCMP), led to something of a media storm. This is not just because the S2000 is visually stunning, but also because of its novelty.
Looks like an alien spaceship
Commentators were quick to point out its “alien spaceship” appearance and other science fiction comparisons. However, the Chinese government could potentially be very interested in the technology moving forward.
China has strong incentives to experiment with this kind of technology, especially in densely populated locations or areas with competing land use requirements. Such locations make it difficult to authorize the construction of large wind farms that require a lot of space.
By placing wind turbines in the air, this overcomes land use pressures and also makes the technology more flexible for places like cities. To this end, China is willing to fund and test large, risky infrastructure ideas like the S2000.
Even partial success of this technology could be valuable at the national scale, the SCMP reports. That all said, it is important to note that large flying/floating wind farms are not yet proven at scale.
While recent testing was successful, it is to be seen how durable things like long-term tethering are. It is also unclear how durable airships like the S2000 are to storms and how they fit into airspace safety regulations.
There is also the issue of longterm maintanence requirements and protocols, and the economics might not be favorable over continental wind turbines and storage.
