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Kite Power: The Latest In Green Technology (thebulletin.org)
New submitter Dan Drollette writes: The solution to producing energy without contributing to global warming may be to go fly a kite. Literally. Researchers in Switzerland and Italy — high-altitude places where the winds are strong, steady and predictable — have been working on ways to generate electricity from kites that fly hundreds or thousands of meters high. The scientists already have a prototype cranking out 27 megawatts; they expect to have a 100-megawatt plant big enough to power 86,000 households. And they say that they can produce electricity for less that 4 cents per kilowatt-hour, which is better than fossil fuel. Plus, the kites look really cool (as does the "Darrieus rotor vertical axis wind turbine" at the base of the St Bernard Pass, on the Swiss side, which I've seen in operation in person).
I think they forgot to google for the technology first: https://www.google.com/makani/
What happens if the wind stops? Do I get a free repair to my roof?
_ _ _ Go for the eyes Boo! GO FOR THE EYES!
27Mw is no small prototype, but there seems to be nothing about it anywhere.
This has been around a while; kites, windbelts, and laddermills were my area to cover for presentations when taking classes on sustainable energy in 2010, and they were a lot of fun. Anything that gives you an excuse to play footage of the Tacoma Narrows Bridge collapsing and demonstrating the awesome power of wind is pretty cool.
Kites hold a lot of promise; they're far safer for wildlife than any turbine, even the large slow ones that don't deserve their bad rap, and they produce up to a third of a turbine's power given similar operating area, for a tiny sliver of the material cost. Solar's cool and all, but wind power has become surprisingly diverse in its options tailored for different environments, and is becoming more so.
is dirt-cheap. Here in Austria, I pay around 18 cents per kWh for power that comes for 80% from wind and water plants. I guess this part of the country would have a potential comparable to that of Switzerland, due to comparable geography: a rather flat basin (of the Danube) with the Alps close.
Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
The second (and perhaps less researched) approach is to minimize power utilization . It finally has to be a balance between clean power generation and efficient utilization .
Up until a year ago I was doing research in this field. Google/Makani is by far the closest to commercialization at utility scale. They are already on their 8th prototype, a 600 kW version. Nothing public is operating anything airborne in the Megawatts yet.
I can see a lot of fun with aeronautical obstacle databases if this takes off in a big way. Essentially a power plant will need an airspace allocation up to 10000 feet AGL and a nautical mile or two across. Put a lot of these around a city and there are many aeronautical procedure designers that will certainly be cursing as they try to thread an aircraft safely between them.
Patent litigation: A doctrine of Mutually Assured Destruction... in which everyone seems willing to push the button
Yes, sure, for us it does. I am pretty convinced though that the folks living in the neighborhood of such a power plant will have a different opinion on that.
The 27MW takes 9 kites flying at 10km altitude. That means a measly 100MW plant will consist of 33 kites. A 1GW plant requires ~330 kites.
Nobody wants this in their neighborhood, just as everybody likes wind-power but nobody wants the windmill in his backyard.
Also, the large scale introduction of kites, flying at 10km height, is going to be an issue for aviation.
Actually, even more noisy and higher pitched. The Makani turbines are quite small but the kite is going very fast, so plenty of power, but the result being that the turbine are spinning like crazy.
The more people I meet, the better I like my dog.
1) I've stood directly underneath a 1MW turbine in the middle of a large wind farm on a windy day. There wasn't much noise at all, just a light whoosh... whoosh... whoosh.... I don't know where this concept that wind turbines are "terribly noisy" comes from, but it doesn't at all match my experience.
2) You're concerned with noise about something that's hundreds of meters up? What about kite-based systems that operate at thousands of meters up, would you be worried about noise from them too?
He's the sort of person who would sell the Red Cross to Dracula.
The global wind resource is 72TW. You're going to have a hard time denting that. You might alter things locally - might - but not globally.
And besides that... if any evil greedy megacorp wants to move into my valley and setup something that will rob the wind of its energy... Please Do! Seriously, someone should really work on wind turbines specifically designed to act as windbreaks, in a manner that can be affordably mass produced and deployed in lieu of traditional manufactured windbreak systems.
(Before anyone says "just plant some trees..." I do, every year. They usually get killed by the weather, sometimes outright uprooted. I may have to start spending more time on each tree individually, encasing each one in its own individual PVC windbreak in addition to the broad rows of pallet windbreaks)
He's the sort of person who would sell the Red Cross to Dracula.
If I remember this company's tech correctly, the wind drags it out, turning a generator as it goes. They then switch it to a low-drag mode and reel it back in. So it cycles between high power generation and low power consumption. The concept being that you'd have many of them so that you'd get continuous net generation.
He's the sort of person who would sell the Red Cross to Dracula.
Having read the article, I'm entirely convinced this is not scalable; we're not going to power cities with this. I'm not convinced it is not useful in some places at some times; small remote towns that don't have anything else would find it cheap and useful. It is clever. Assuming the wind blows [way up yonder] with great consistency, this has a lot of promise. My gut tells me you'll need to fly at least three to make it close to distributable; Like juggling. Obviously the more that are flying, the more consistent the result will be (as long as the wind keeps blowing). My gut is often wrong. Can any of you smart guys model this?
"If you want to be smart figure out how to improve the steam cycle or cumbustion cycle most LARGE power plants operate off of."
Spoken as someone who really and truly has no idea what has happened to date in the power industry, and who has no clue about the laws of thermodynamics.
These processes have been optimized for decades. Thermodynamics defines the maximum efficiency of all cycles used in combustion and heat transfer. The cycles used to generate power are already operating very close, or at the very least as close as practicable, to these theoretical limits.
This is why the power industry is so focused on load management. They cannot build any new power plants because government, and they cannot squeeze any more capacity out of existing generation because physics. So, the only thing left is to manage load.
Linear motion, like the expansion of a gas, into rotational motion, like the spinning of a turbine?
If I remember this company's tech correctly, the wind drags it out, turning a generator as it goes. They then switch it to a low-drag mode and reel it back in. So it cycles between high power generation and low power consumption. The concept being that you'd have many of them so that you'd get continuous net generation.
Slow and powerful drag out is going to have a massive, complicated, and hard to maintain gear box to run a generator. Generators run at hundreds of RPM. This is the same problem with big wind turbines, making power into RPM in a gear box is hard. If you have a wind farm around, look at the ones that are stopped they'll have black stains on them where the gear box failed.
On a tower, they are difficult to service.
On a floating, bobbing, need to use a boat to get to, they are probably going to have to un-hook them and bring them to shore to fix.
Those kite things are overly optimistic given the state of the gearbox technology used today.
We increased forcing from CO2 50%. The power didn't come from our putting energy into the system, it came from stopping the sunlight leaving so quick. Hence your comparison is ridiculous and moronic.
But it was the "best" you had, so you went with it.
Sounds a lot easier than for a large scale wind turbine, the RPM is surely much higher - even if you need to gear it up somewhat.
He's the sort of person who would sell the Red Cross to Dracula.
Well... to some extent. You can always run hotter to be able to get more efficiency - for example, that's why coal gassification is more efficient than burning solid coal, you can run it very hot through a gas turbine. Also, recovery of heat once it gets to lower temperature differentials is often not done, so some new work is in making that more affordable, which is a big boon to resources that are fundamentally lower temperature (like geothermal). And of course pairing the two, high temperature cycles with low temperature cycles.
Thermal generation tech does keep improving. But you're right, it's not easy, and there are limits.
He's the sort of person who would sell the Red Cross to Dracula.
Since the anti-environmental types tend to be the pro-capitalism types, I ask the parent post writer to look at it this way: the biggest expense for a fossil fuel power generation plant is the fuel itself. So they have the best reason in the world to pursue maximum efficiency: profitability.
So unless someone presents credible evidence the fossil fuel power industry has been intentionally wasting billions of their own dollars, we have to assume modern energy plant efficiency is pretty close to optimal for the technology being used.
It looks like a parachute. How exactly is that "really cool looking"?
So wind blows in one direction for the most part and they want to use kites to generate power? Kites blow in one direction too. It takes energy to pull them back. That's why you don't make an unlimited magical energy generator that uses the power of gravity. Gravity pulls in one direction so eventually you have to lift the item against gravity. The same basic principal happens with wind and kites.
So use that as a starting point and then look at the diagram of the ridiculously over-complicated kite system they somehow "invented" and compare it to a rotating wind turbine, one of the simplest machines ever created. I'll stick with the turbines, thanks.
In the USA they are classified as buildings. They even blink at the top and bottom of their circular flight path so that they look like radio towers to airplanes. As such, they are not regulated as aircraft, and for better or worse, have freedom in how much systems redundancy they add, how rigorously their software is tested, etc... In Europe, similar systems (i.e. like the one from Ampys) are regulated as planes, and have to use all aircraft certified stuff.
I keep on hearing this but it's a long ago solved problem. One solution is in Japan where horizontal traffic lights are used in the south but in the north they have vertical ones with large gaps in the shrouds designed to not get clogged up with snow.
Just because your area has not bothered to solve it due to fragmentation of government services does not mean that they cannot solve it by simply buying the solution of of a catalogue!
It's also like arguing that solar panels are useless due to snow buildup while ignoring that the majority of the world's population live in places where it does not snow at all.
Thank you for repeating my point.
He's the sort of person who would sell the Red Cross to Dracula.
1) I've stood directly underneath a 1MW turbine in the middle of a large wind farm on a windy day. There wasn't much noise at all, just a light whoosh... whoosh... whoosh.... I don't know where this concept that wind turbines are "terribly noisy" comes from, but it doesn't at all match my experience.
I've held a megaphone in front of my mouth and spoken into it. All I heard was my own regular voice, therefore I don't believe they work as advertised. In other words, it's all about direction.
I've also been visiting a house about 1.5km(1 mile) away from the nearest wind turbine, with the noise disturbance inside the house being at such a degree that I couldn't believe our government could let this happen. When the noise hits them, the residents can't sleep and neither would you in similar circumstances.
The issue seems to be mostly coming from the low frequency noise forming from the air pressure of the wing hitting the tower after the wing has passed. It seems to be very directed - directly sideways of the turbine.
Another contributing factor is weather. Certain conditions can cause noise that is emitted on a rising angle to curve back downwards. When these rare weather conditions are met, we've found people much father away complaining about the noise while the residents much closer had no issue with it.
Often there's more going on than immediately meets the eye.