I found that the partial data (we don’t have the wind speed, which can nevertheless be more or less deduced from the reel-out speed) do not seem to indicate a very high power for a gigantic 5000 m² parachute.
Concerning the surface area of 5000 m²:
If the projected area is considered (in case the 5000 m² is not the projected area), the drag coefficient Cd would be just above 0.5 instead of being below 0.5.
In this case, compared to a smaller 139 m² parasail, the power per m² would be about half, at a supposedly comparable wind speed (10-12 m/s). If this is verified and if the Cd of the 5000 m² parachute is comparable to the thrust coefficient Ct (lift and drag combined) of the 139 m² parasail by considering equal surface area for both, massive scaling up would lead to a significant reduction in power produced per m². Is it due to Reynolds number? Of course, I reiterate that I do not have the wind speed at the height of the parachute.
This leads me to wonder if such limits (related to the Reynolds number or for another cause) would not apply to all soft kites, whatever drag-based or crosswind power kites. For example I experienced a small power kite, seeing that the increase in traction was below what I expected when wind speed doubled, which I hadn’t noticed with a small kite parachute.
Rigid kites or blades (see regular wind turbines) probably behave much better at high wind speeds, or when larger, i.e., with a higher Reynolds number.
During the test flight, the S2000 ascended for around 30 minutes and generated 385 kilowatt-hours of electricity. The system measures roughly 60 metres long, 40 metres wide and 40 metres high.
Interesting the brief video shows 4 rotors not spinning. I believe in our previous analysis of how much power can reliably and consistently be provided by turbines of this size and generator weight. Don’t necessarily believe any info from this original source. Over time, this will fall into the category of AWE bloopers like all the rest, to be dug up from The La Brea Tar Pits of wind energy by future historians. We should know by now that zero press-release breakthroughs turn out to be true in this space.
Either one is capable of analyzing and understanding what constitutes true energy breakthroughs, or one is not. One understands the real challenges in wind energy and what makes an economically-viable wind energy solution, or one does not. Most people obviously have no background or basis for making such judgements. Best to check their track record of past accurate statements.
“Thanks to this aerodynamic layout and a total volume of nearly 20,000 cubic meters, the system has a maximum rated power of up to 3 megawatts, according to company data.
Production plans and expert views on the road ahead
The company has already started small-batch production of the S2000 and has signed letters of intent with several coastal cities and high-altitude regions interested in deploying the technology. To support larger-scale manufacturing, Linyi Yunchuan is building a production base”
*** OK, so now the 20-foot diameter turbines are each rated for 250 kW??? And like Skysails, has a factory in production toward a large-scale rollout?
Why such a brief time in the air? Why such low output if it is a multi-MegaWatt machine? Did they quickly burn out their lightweight generators and have to bring it down? Why is it not still up and operating?
Next, we read a bit of honesty:
“However, he cautioned that the technology is still at an early stage, with long-term stability, safety, and cost performance yet to be fully proven.”
In other words, this is more of a stunt than an economical energy solution.
This goes back to one of my oft-repeated sayings that attempt to educate the perpetual newbies: “There are a million ways to generate SOME amount of electricity from the wind, at SOME cost, but the question is, is it a reliable, economical energy solution?”
