Makani's flying windmills win Breakthrough award

Oct 08, 2011 by Nancy Owano report

(PhysOrg.com) -- Makani Power, of Alameda, California, creators of the high-altitude wind turbine, is one of this year’s winners of the Popular Mechanics seventh annual Breakthrough Awards. Naming Makani team members Corwin Hardham, Kenny Jensen, and Damon Vander Lind, the award honors these creators of a “sleek, 20-kilowatt Wing 7 prototype” that is “equal parts airplane, helicopter and robot.”

The device elsewhere is being referred to as the “power station in the sky” and described as a “cross breeding between a windmill and a model plane.”

This video is not supported by your browser at this time.

The airborne turbine takes off and moves like a plane, designed to reach winds that blow stronger and more consistently. This ability to reach the stronger winds is no small feat. The system bears an advantage over traditional wind turbines, unable to reach stronger winds that are over one thousand feet above ground. Wing 7 can reach heights of 1,500 feet. The device is said to be able to generate nearly double the energy of conventional turbines. The Wing 7 has a wing span of 8 meters, weighs 56 kg and has a rated power of 20 kW.

Once it reaches a height of about 1,500 feet, the device is flying in swooping circles and is generating electricity. It is called a "20kW power plant" because it can generate 20 kW of energy off of 22 mph winds.

According to a description on the company’s site, the turbines on the leading edge of the wing face into the wind as it flies and generate energy, which is then transmitted to the ground along the tether. Makani’s technology is designed to operate most efficiently at middle altitudes between 1000 and 2000 feet. This flying turbine would carry an unsubsidized real cost that Makani says is “competitive with coal-fired power plants,” the current benchmark of the lowest-cost source of power.

Responding to questions about the device’s possible threat to birds, the company’s FAQ page says that the share the airspace with avian life, as the system flies at an altitude well above that of most birds. Also, the absence of a tower makes the system less prone to nesting or perching, according to the company.

Plans are to have these systems to market by 2015. Makani has been on a multi-year development roadmap bolstered by funding from the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) and from Google.

Explore further: Tiny power plants hold promise for nuclear energy

Related Stories

Vestas Announces New 7 megawatt offshore wind turbine

Apr 01, 2011

(PhysOrg.com) -- Vestas Chief Executive Officer Ditlev Engel announced in London their new V164 wind turbine, designed specifically for offshore wind power. Optimized for conditions in the North Sea, Vestas ...

Computer model optimizes wind farm

Jul 25, 2011

A new software from Siemens will improve wind farms’ energy yields and extend their service life. When the wind causes the huge rotors to turn, it generates turbulence, which interferes with the operation ...

Global wind map identifies wind power potential

May 16, 2005

A new global wind power map has quantified global wind power and may help planners place turbines in locations that can maximize power from the winds and provide widely available low-cost energy. After analyzing more than ...

Recommended for you

Obama launches measures to support solar energy in US

22 hours ago

The White House Thursday announced a series of measures aimed at increasing solar energy production in the United States, particularly by encouraging the installation of solar panels in public spaces.

Tailored approach key to cookstove uptake

22 hours ago

Worldwide, programs aiming to give safe, efficient cooking stoves to people in developing countries haven't had complete success—and local research has looked into why.

Wireless power transfer achieved at five-meter distance

22 hours ago

The way electronic devices receive their power has changed tremendously over the past few decades, from wired to non-wired. Users today enjoy all kinds of wireless electronic gadgets including cell phones, ...

User comments : 37

Adjust slider to filter visible comments by rank

Display comments: newest first

antialias_physorg
4.3 / 5 (4) Oct 08, 2011
Next should be a long term test because it seems like wear and tear on the tether might be a real cost issue. But if it isn`t then this sounds great.
FreeRangeRadical
5 / 5 (3) Oct 08, 2011
I'm just trying to get clarification on this sentence: "Responding to questions about the devices possible threat to birds, the companys FAQ page says that the wind turbines share the airspace with avian life, as the system flies at an altitude well above that of most birds."

I think the point is that it does NOT share airspace with most avian life, correct?

Not trying to be nit-picking because it's a great article. Thank you!
Isaacsname
4.5 / 5 (2) Oct 08, 2011
Good stuff. I wonder why we haven't seen any designs using Archimedean screws...
Nanobanano
1.8 / 5 (11) Oct 08, 2011
Coal fired plants are NOT the lowest cost source of power.

The price of a year of 10MW worth of the Coal itself is as much for just one year as the purchase price for a 10MW wind turbine, which has a 30 year life time.

So the Coal itself costs 30 times as much as a 10MW wind turbine.

So double the purchase price to cover install, and it's still 15 times cheaper than the coal itself for 30 years, and the coal company still hasn't payed for their boilers and stuff.

----

20KW is impressive though, because you could easily run a house on it and sell 3/4 of the power back to the grid, or the neighbors.

Then again, of course the government wouldn't allow you to own it because you'd probably need 9 kinds of permits and licenses that would eat up the savings...
gmurphy
5 / 5 (4) Oct 08, 2011
Around 60 seconds into the video clip, you can briefly see the tether, I'm quite impressed, as I had thought that the power transmission system would be the main blocker to this type of technology. The problem, however, with wind-based energy generation is that it's dependent on a highly mercurial resource. In December of 2010, Ireland, we experienced a savage cold snap during which very little wind blew. I've heard informal reports that entire wind farms were offline for extended periods (> week)
Bob_Wallace
3 / 5 (4) Oct 08, 2011
Coal fired plants are NOT the lowest cost source of power....


Correct. If we're talking new generation coal is fairly expensive. It's only inexpensive at the meter if we're talking about older, paid off plants and even then coal-electricity is not inexpensive.

Second, there are very significant health and environmental costs for burning coal. We pay those hidden costs with our tax dollars and with our health insurance premiums.

Electricity from coal plants, all costs included, is very expensive.
jmlvu
3.7 / 5 (3) Oct 08, 2011
Another benefit is the mobility. If there is a glut of power in the northwest united states just fly it to Texas or California.
MrPhysOrg
5 / 5 (1) Oct 08, 2011
Having recently paid to have wire placed from the street to the house, I'm wondering what that 2000 foot tether costs (ad weighs). Must be high voltage?

Fionn
1 / 5 (4) Oct 08, 2011
This seems like it might really be a viable, bird-friendly source of wind power. The mobility and higher altitudes are perfect.

Two ideas:

-slap some high-efficiency solar panels on it for added productivity
-instead of a tether, why not transmit energy through a beam, like they've proposed for space-based solar?
fmfbrestel
5 / 5 (3) Oct 08, 2011
you need a tether anyway, because it is a kite, not an airplane. without the tether the craft would either have to push itself forward (and become a net drain of electricity) or just flutter to the ground. So if you have to have a tether anyway, you might as well use it for power transmission instead of adding some other complex component.

My question is how large is the range for a single kite? How many of these can you put up per square mile?
CHollman82
1 / 5 (2) Oct 08, 2011
wouldn't it be easier to keep a tethered blimp aloft? Or would it be impossible to keep the turbine pointed into the wind?
Vendicar_Decarian
not rated yet Oct 08, 2011
What is this swooping buisiness about?
Callippo
1 / 5 (7) Oct 08, 2011
IMO we should start to use cold fusion and forget all these toys, which are actually just a waste of materials and life environment. My conception is, the production of energy should be as unobtrusive and material effective, as possible. I'd like return to the original "wild nature" and restricted the problems with energy consumption and production just to the production units isolated from it. Maybe in future such units could be dislocated outside of Earth completely and we would use the Earth only for comfortable living in the same way, like we are using accommodation by now.

I know, it's still an utopia - but we should decide, whether we want to have the sky full of strange toys, which kill the birds, generate infrasounds, attract lightning and make countryside ugly - or not. The contemporary strategy is just a return to exploitation of materials, when the classical sources of energy appear depleted. So we should start to use new ones instead of wasting materials.
Callippo
1 / 5 (2) Oct 08, 2011
We should realize, all so-called "sustainable" sources of energy are substantially more material hungry, than the existing technologies based on oil burning, because they're exploiting very diluted sources of energy.

For example, the production of energy from solar light appears nice, but it would require to build and recycle immense amount of solar panels. The cost of their recycling and energy transportation (cables) isn't calculated in the existing economical models yet. In addition, these energy sources are very unreliable and they require huge overhead and robust grid to compensate it. Do we really need to bother with such technologies by now, when we can get the energy of 500 tons of oil from each gram of hydrogen? In future we could build solar plants outside of Earth, but currently I don't see any actual reason for it. Apparently the people didn't start to consider the cold fusion as an reality. But if we will not do it, we are facing a much more serious problems soon.
MorituriMax
4.6 / 5 (10) Oct 08, 2011
Callippo, IMO we should just use magic to generate power. Why go with the old antiquated cold fusion technology. Magic, I say!
SR71BlackBird
5 / 5 (1) Oct 09, 2011
Callippo, I don't understand.... You spend so much time on this website reading and commenting, yet you're still completely ignorant about science in every regard. Doesn't it get tiring, spewing your nonsense day in and day out? Don't you have better things to do? Like learning, you know, about facts.

Anyways, in regards to the article.. This actually seems brilliant. I share the same skepticism about the tether. Since it's attached to the flying windmill, than I wonder what kind of fatigue would occur at the attachment point as a result of cyclical stresses. Also, what occurs if the wind speed drops dramatically? I.e. does it have control systems?
dbob
not rated yet Oct 09, 2011
Then again, of course the government wouldn't allow you to own it because you'd probably need 9 kinds of permits and licenses that would eat up the savings...


Nanobanano, I'd certainly hope the government would require licensing for these devices-- generators are HEAVY, and could result in loss of life and property if they malfunction.

Could the turbine wing be designed to fly in circles to provide extra lift? Also, does anyone know the name of the song played in the video?
antialias_physorg
4 / 5 (1) Oct 09, 2011
Also, what occurs if the wind speed drops dramatically? I.e. does it have control systems?

It can land under ist own power autonomously in the case of little wind (and take off under its own power when the wind picks up again)
Nanobanano
1.3 / 5 (3) Oct 09, 2011
Look how tiny the rotors are on that craft compared to the total mass and materials used.

How can that possibly be more cost efficient or more productive?

Yes, I know when you get way above the boundary layer you get better and more consistent wind, but then again, atmospheric density goes down as well, so the mass component of the POWER equation drops...

But even still, you are limited by the area swept by the ROTOR for power production.

Given the wing span is given as 8 meters, the rotors cannot possibly have a radius greater than about a half meter.

Using the power equation:

power (watts) = (1/2)*e*m*a*v^3

m = mass of 1 cubic meter of air at altitude ~1kg/m^3.

A = area swept by the rotors, maybe 1 square meter...

v = 9.77777... m/s

e = efficiency (maybe 0.3)

The maximum power this could generate at 22mph winds, based on the laws of physics, is around 330 watts, or 0.33kw.

This is nowhere near 22kw of power.
Nanobanano
2 / 5 (3) Oct 09, 2011
See here, for reference:

http://www.reuk.c...ower.htm

0.5 * air density * swept area * velocity

In metrics.

They used 1.23 for air density, but that is at the surface/boundary layer.

Up in the air it's closer to 1.

So these people are fraudsters.

this is absolutely outrageous, as there is no way in HELL those little rotors produce that much power at 22mph.

In order for those rotors on this glider to produce the alleged 22kw of power, the wind would need to be blowing 89mph sustained...
gareth_Ph
4 / 5 (1) Oct 09, 2011
The article quite clearly states that the device produces 20kW in 22mph winds. I don't think they would make this claim if it were false, as it is easily disproved. (like Callipo's cold fusion)
Or does the all-knowing nanobanana have secret intel not privy to the people who designed, built, tested and measured the thing...?
Nanobanano
1 / 5 (2) Oct 09, 2011
The article quite clearly states that the device produces 20kW in 22mph winds. I don't think they would make this claim if it were false, as it is easily disproved. (like Callipo's cold fusion)
Or does the all-knowing nanobanana have secret intel not privy to the people who designed, built, tested and measured the thing...?


yes, apparently I do.

It's called a well known physics formula.

I even linked you to a site proving that to you, do you need more links?

I can give many more.

http://morechrist...quation/

and

http://www.ftexpl...rgy.html

and

http://winds-ener...ind.html

I never said I know everthing, not hardly. LOL.

I do have this memorized though. LOL.

But I don't have to know everything, I got a damn internet.

If some of you people would learn to double check shit for yourself...
Nanobanano
1 / 5 (2) Oct 09, 2011
Now if they want to retract their comment, or claim the wind was blowing 90mph sustained at 1500ft, they are welcome to.

However, even at 1500 ft altitude, 90mph wind only happens in like thunderstorms, tornadoes, category 1 or greater hurricane, maybe derechos...stuff like that..

Doesn't look like they were trying to fly in a hurricane or anything similar, so their numbers must be faulty or fraudulent...
gareth_Ph
5 / 5 (1) Oct 09, 2011
All your links contained formulae relating to (and photographs of) traditional fixed wind generators. This article relates to a different type of device. I don't assume that, simply because they both use wind power, that all formulae are exactly transferrable, or that we can say 'hey - those rotors are smaller than your average windmill so they must produce a proportionally smaller amount of power...
I think the whole point of what these guys are doing is high-efficiency (which would alter the equations). It's a bit premature to be calling them fraudulent.
antialias_physorg
5 / 5 (1) Oct 09, 2011
Given the wing span is given as 8 meters, the rotors cannot possibly have a radius greater than about a half meter.

Who says that you can't scale these things up? Or put a number of them in the same rotating pattern instead of side by side?

It all depends on how much wear and tear you get in the system. Current windfarms aren't very service intensive, so having a lot of these instead of one big windmill might actually be worth it.

They definitely should go and make a test power plant and see how it works out over a year or so.
Nanobanano
1 / 5 (2) Oct 09, 2011
Gareth PH:

The equation is the same regardless of altitude.

This IS a "fixed" wind generator. It's anchored to a tether and all its going to do is fly like a Kite and the turbines will be turned, pretty much exactly as if it was a 1500ft tall pole.

The tallest wind turbine, according to wiki anyway, has a horizontal axis atop a 525ft pole.

Even if those turbines on this glider were 100 percent efficient, they'd make no more than 1kw combined, given 22mph wind speed.

Now because the kite is going to be flying around in loops, it will from time to time experience slightly more relative wind speed, but at other times it will experience slightly less relative wind speed, which is going to cancel out and stay about the average sustained anyway.
bamfarooni
5 / 5 (1) Oct 09, 2011
The whole point is that it is moving and NOT exactly like it was a 1500ft tall pole. It goes around, up and down at speeds upwards of 100mph. The wind just keeps it aloft, that's not what's driving the propellers.
PatrikD
not rated yet Oct 09, 2011
Hi Nanobanano. I think this is why they are swooping in circles like that: although they are flying in 22mph wind, the "kite" is actually flying at 90 mph in broad circles.

Alternatively, you can think of the kite itself as a blade of a giant rotor, moving in 22mph wind. The area swept would then be given by the 8m wingspan and the radius of the big circle they're swooping in.

I'm guessing that another benefit of the circling is that they can keep the speed of the kite itself fairly constant, regardless of the wind speed. At 90mph wind they would essentially fly as a fixed kite. At lower wind speed they start making wider and wider circles by changing the angle of attack of their main wing, so the kite itself keeps going at 90 mph.
pauljpease
5 / 5 (2) Oct 09, 2011
The article quite clearly states that the device produces 20kW in 22mph winds. I don't think they would make this claim if it were false, as it is easily disproved. (like Callipo's cold fusion)
Or does the all-knowing nanobanana have secret intel not privy to the people who designed, built, tested and measured the thing...?


yes, apparently I do.

It's called a well known physics formula.

I even linked you to a site proving that to you, do you need more links?

I can give many more.

http://morechrist...quation/

I never said I know everthing, not hardly. LOL.

I do have this memorized though. LOL.

But I don't have to know everything, I got a damn internet.

If some of you people would learn to double check shit for yourself...


The power is not just a function of the rotor as you suggest, this thing generates lift from the wing, which in effect collects power and transfers it to the turbines. Be careful how you apply equations...
rwinners
1 / 5 (1) Oct 09, 2011
Ah, well, have they run this by the FAA yet? I mean, it sounds cool, but it at an altitude that would have to be shared with light aircraft. Knowing some pilots, even 500' could be a problem....
CapitalismPrevails
1 / 5 (4) Oct 09, 2011
This isn't going to last long because it's not a stable design. Also, it's going to have a lot of drag. The Maggen rotar balloon is better. http://www.magenn.com/
Humpty
1 / 5 (3) Oct 09, 2011
It's stupid to have it going all over the place - it should be flying straight and level.
Shanti
1.5 / 5 (2) Oct 10, 2011
I would like to know what kind of fuel it uses to get aloft, if it continues to use it once aloft and if so is it polluting to the atmosphere?
ricarguy
1.4 / 5 (5) Oct 10, 2011
As is often the case, the claims (let's say insinuations) don't pass the smell test. Also, what goes up must come down! Anyone care about a 125 pound airplane with the wingspan of a UPS truck falling out of the sky?

Best conclusion is that this is a really big self flying kite that may intermittently generate as much as 20kW when it "swoops". I'd bet you lunch that the duty cycle of the claimed 20kW is quite low at the mentioned 22mph wind. On average a larger version of one of these "kites" might come close to powering a house.

Can you imagine your neighborhood, each home with its own kite 1/4 mile up? A gust comes through, a weather front or a developing storm, lines get tangled and crash!

This might have some use for a temporary remote, open location in the right conditions.
antialias_physorg
5 / 5 (2) Oct 10, 2011
I would like to know what kind of fuel it uses to get aloft,

I'd wager small sums of money that it just uses electricity fed to it via the wire from the grid.

I mean, it sounds cool, but it at an altitude that would have to be shared with light aircraft. Knowing some pilots, even 500' could be a problem....

It'll just be like with any other power plant out there: you're not allowed to fly over it.

Also, what goes up must come down! Anyone care about a 125 pound airplane with the wingspan of a UPS truck falling out of the sky?

Since when do planes fall out of the sky? They have this technique which I heard of: They call it 'land' or some such technical mumbo-jumbo.

This is not a technology for having one per home. This is for small powerplants (i.e. some dedicated acres of land) where an array of these are based. Or maybe even offshore.
Isaacsname
not rated yet Oct 10, 2011
So I'll ask again, why no screws ?

http://www.youtub...U5ubTD2c

Things like the Maggen system seem to be as aerodynamic as the Stay-Puft Marshmallow man.
Scottingham
not rated yet Oct 10, 2011

Antialias, I'm glad to see somebody commenting is using their head. Yikes.

More news stories

LADEE mission ends with planned lunar impact

(Phys.org) —Ground controllers at NASA's Ames Research Center in Moffett Field, Calif., have confirmed that NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft impacted the surface ...