14 ms·

Makani Power, a Google funded wind energy startup, comes out of stealth

155 points by miratrix 16y ago

extension 16y ago
Did they convert a fire engine into a mobile ground station? http://www.makanipower.com/wp-content/uploads/2010/06/IMG_7011.jpg http://www.makanipower.com/wp-content/uploads/2010/06/IMG_70... EDIT: yup http://www.makanipower.com/wp-content/uploads/2010/07/20100610-IMG_2189.jpg http://www.makanipower.com/wp-content/uploads/2010/07/201006...
cmurphycode 16y ago
This looks pretty interesting. They have some nice explanations of their concept- particularly the fundamentals link: http://www.makanipower.com/concept/fundamentals/ http://www.makanipower.com/concept/fundamentals/ It looks pretty complex, but if the numbers work out right, this is probably the cheapest way to tap into the great winds available high in the sky.
troygoode 16y ago
"Makani AWTs will produce energy at an unsubsidized real cost competitive with coal-fired power plants, the current benchmark of the lowest cost source of power." If this is true, it could be huge. Would these be deployable basically anywhere that is reasonably open?
- Retric 16y ago
  No, even at altitude wind is fairly local phenomenon. As the price of wind power drops, more places become competitive with coal, but the best drip below the price of coal. http://www.windpoweringamerica.gov/wind_maps.asp http://www.windpoweringamerica.gov/wind_maps.asp Edit: You also need to transport that energy, so while much of the Midwest above average resources powering L.A. with that energy would would require a lot of new power lines.
  - sasvari 16y ago
    Considering the miserable state of the US grid system new power lines have to be built anyway.
    - houseabsolute 16y ago
      Is the US grid system really in that miserable of a state? It seems to work just fine where I live. And is the right solution really building more power lines? It's not clear to me why that would solve any potential problem with the system, other than that more power needs to be transported than can currently be. And if that is so, how do things work at all now?
      - sethg 16y ago
        The best places for generating (conventional) wind power in the US are the prairie states, and the best places for generating solar power are in the Southwest. But since both of these regions are sparsely populated, there isn’t very much grid infrastructure there—there is enough to bring power to the people who do live there, but not enough to handle taking power from a power plant to population centers farther away. Also, if a substantial portion of our power supply is going to come from intermittently available sources, then the switching technology in the grid is going to have to be a little more sophisticated.
        houseabsolute 16y ago
        I'm fine with the idea that more lines would have to be built in the case of wind-power. That's not what I was questioning. I was questioning the claim that the US power grid is in a "miserable state" for current applications, which is a notion I see bandied about a lot with nary a citation. Also would you please describe what about the switching technology in the grid is going to have to get better? Or cite some source that does so?
        sethg 16y ago
        I think this is basically what people mean by “miserable state”. It’s not just more lines, but more very-very-high-voltage lines. Also, these lines are generally regulated at the state level: the government of Nebraska may not be exactly eager to authorize a high-tension swath being cut through its land just so that power can get from North Dakota to Texas. Regarding switching technology, Technology Review had an article a while ago (http://www.technologyreview.com/microsites/spain/wind/ http://www.technologyreview.com/microsites/spain/wind/) mentioning the wind-power industry in Spain: “Because wind is an intermittent resource, providing power only when it blows, the grid has to be able to cope with fluctuations and dips in electricity. When wind accounted for only a small percentage of the country’s power, such dips made little difference. But as this resource achieved greater prominence, split-second losses of power could have caused problems, especially since Spain doesn’t have strong grid connections with neighboring countries....” The article goes on to describe how the grid management system adapts to this problem.
- hugh3 16y ago
  I suspect there may be some voodoo hidden in that term "real cost" -- i.e. it's dependent on some "cost" of CO2 emissions which they've derived ex anum.
- prbuckley 16y ago
  In the "Fundamentals" section of the website (http://www.makanipower.com/concept/fundamentals/ http://www.makanipower.com/concept/fundamentals/) Makani claims that their system can operate in 85% of the areas in the US vs. traditional windmills that need class 4 wind which is only present in 15% of areas in the US. Also there is some interesting info about why their approach could be better for offshore wind generation. I know some of the Makani guys and they are the real deal. These guys are seriously smart, and talented. I am glad everything is going so well for them.
  - c1sc0 16y ago
    Offshore wind generation seems to be an obvious win, although the materials will have to be tougher.
tlack 16y ago
It's an interesting idea (more wind higher up, without the expensive tall shaft required for a regular wind turbine), but how does it get relaunched when it falls to the ground? Wouldn't a balloon or regular kite be simpler and just as effective?
- hugh3 16y ago
  how does it get relaunched when it falls to the ground? I'm guessing: the same way you'd launch a regular kite: by starting with it off the ground and slowly letting out the line. Possibly the propellors can be switched from generators to motors if it needs an extra boost. A balloon would lose too much in drag. If they can actually solve the software problem to get these things up and flying autonomously, it'd be pretty darn effective.
  - tlack 16y ago
    I thought the drag could be beneficial in a way similar to wave power generators: pull on the balloon would operate a hydraulic piston, etc.
  - jemfinch 16y ago
    Why guess when the answer is clear on the second frame of http://www.makanipower.com/concept/makani-m1/ http://www.makanipower.com/concept/makani-m1/ ?
- godel 16y ago
  This was on the Discovery Channel last night, currently(or as of the taping of the show), you need somebody with a remote control to fly the kite. They said they were working on making everything autonomous - which will most likely be one of the more difficult challenges for this project.
  - snewe 16y ago
    This post suggests they have autonomous down: http://www.makanipower.com/2010/06/wing4e-test-june-18-2010/ http://www.makanipower.com/2010/06/wing4e-test-june-18-2010/
aheilbut 16y ago
What happens when the wind stops blowing or changes direction?
- diziet 16y ago
  It lands! (The tether gets it done, and the rotors also back up as engines)
smhinsey 16y ago
They are mentioned on Discovery Channel's Powering the Future. I believe it was Saturday's episode. It has interviews and demos. No mention of Google but they do say they feel their problem is control systems for the kites, not the actual energy generation.
keeptrying 16y ago
This is an incredible idea and an amazing feat of engineering. I'm sure they'll face huge challenges in deploying this thing but it just shows that real engineering is still alive. Damn, makes me wanna break out my fluid mechanics textbook :).
thibaut_barrere 16y ago
The concept looks amazing! I'm a bit concerned about how to protect human lives around - will it be required to forbid access to a large area ? The FAQ states that the peak altitude is 600 meter. Does that mean a circle with a radius of 600m must be protected ? Pretty sure they thought of it already, it looks like a well thought out project, I'm just wondering.
- extension 16y ago
  There is so much flexibility in where these can be deployed that you would probably never find them near a populated area anyway, just for economic reasons. They can also be deployed at sea much more practically than a tower turbine. EDIT: according to the FAQ, there are failsafes for both navigation and tether failure. It can even land itself untethered!
hop 16y ago
This looks way better than than the giant fixed turbines they are putting in Eastern Oregon which cost $2.4 million a pop, interrupt the view, and can't pay for themselves. It's also funny Oregon has abundant hydroelectric power, but subsidizes these wind projects with rate hikes and taxes - while selling billions of dollars of these electrons to California at market rates.
- deleted 16y ago
  [deleted]
tsally 16y ago
The anser to the FAQ "Will this harm birds or bats?" was obviously crafted with the careful help of a PR and Legal team. :-p http://www.makanipower.com/faq/faq/#2 http://www.makanipower.com/faq/faq/#2
borism 16y ago
Rotors are tiny compared to conventional wind turbines. Even with six of them, just no comparison. Sure they harvest the wind much higher and it flys in circles quite fast, but I'm not quite sure how they'll be able to generate 1MW with on of those production things. It has the wingspan of B737! It's a neat idea, but do benefits outweigh problems?
- krakensden 16y ago
  I was under the impression that most of the reason conventional wind turbines are so huge is so they can have the blades move slowly, to be more hospitable to local birds.
  - jacquesm 16y ago
    That impression is completely wrong. The tip speed is what counts, the key governing factor is called the 'tip-speed-ratio', the apparent wind speed (as seen by the tips of the rotor) versus the real wind speed (as seen by an observer relative to the ground). Almost all windmills that want to be efficient have design TSRs somewhere between 6 and 8, and consequently, in a given wind they all travel about as fast at the tips. The design constraints are the speed of sound and the forces on the blade root as well as the tendency of the blade to start fluttering. It has absolutely nothing to do with birds. Birds will fly in to a stationary building just as easily as they'll fly in to windmills, it's rare but it does happen every now and then. The larger a windmill, the slower the blades will rotate. The reason why they are so large is because the power harvested by a windmill goes up with the square of the rotor diameter, many small windmills are more costly to maintain and operate than a single larger one. Right now the sweet spot is somewhere around 2MW and 80 meter rotors for best $/W.
    - erikpukinskis 16y ago
      The reason why they are so large is because the power harvested by a windmill goes up with the square of the rotor diameter Doesn't the Makani wings get around this issue by equivalent to a turbine with a massive wingspan and a wingtip that generates power, but without the rest of the structure?
goooooaaaalll 16y ago
Joby Energy is another company in the area working on this problem. http://www.jobyenergy.com/ http://www.jobyenergy.com/
ph0rque 16y ago
So, does the M1 produce 1 MW on average, or peak?
- brainsik 16y ago
  1 MW is the rated capacity. The actual amount of energy produced depends on where it is deployed. They go into detail about how much energy is produced on the "fundamentals" page: http://www.makanipower.com/concept/fundamentals/ http://www.makanipower.com/concept/fundamentals/
dalton 16y ago
I used to live in a co-op with Corwin (the CEO/CTO). The main thing I remember about him was that he was really into kite surfing. He was also scary smart and about as good of a mechanical engineer PhD as I have ever met. Him being the CEO/CTO of makani makes a whole lot of sense. Good luck, makani!
- c1sc0 16y ago
  Interesting, when I saw the video I was immediately thinking it must have been a kiter dreaming up this contraption ;-)
mdolon 16y ago
The only question I have is: how does it deal with harsh weather? Especially with offshore setups where storms are frequent, can it handle high winds and strong waves? Overall it's an incredible step towards innovation in energy, kudos to the entire team.
hartror 16y ago
This idea has been batted around for a while and in fact the biggest risk to getting a project like this aloft will be regulators like the FAA.
CptMauli 16y ago
This will not work. It uses too much space and It looks like it will need repairs or at least maintenance all the time.
jacquesm 16y ago
Wow, where to begin. First off, I'm really happy that Google continues to fund energy related start-ups, their solar and wind efforts are commendable. Also, I'm fairly sure that the engineers behind this project are top notch and giving this project all they've got, it sure looks like they have picked some interesting challenges. That said, I don't think this will ever 'fly' (pun intended) on any appreciable scale. Wind is a fickle thing, and if you look at the design parameters of even the smallest windmills you realize that it takes bullet proof engineering to get a windmill to operate at all for any stretch of time without catastrophe, tying one to a kite seems to compound those problems to the point where even if the power generated were substantially higher than that on the ground you'd still be left with a higher per KW bill. Being able to operate in places where windmills are otherwise not viable is nice, but at 600 meters above the ground there will be substantial risk from getting kits entangled so the closest spacing will probably be such that a 'farm' of these will generate relatively little power for a given area of the planet over which the kites fly. 1 MW seems to be a pretty ambitious goal for a first setup, think about it, a 1 MW turbine sitting on the other side of a line will pull on the tether with a very impressive force, the kite will have to pull aloft a tether strong enough to withstand that force and up to 600 meters of power transmission cabling. These are not simple challenges. What I don't understand is why they don't build a 10 KW or so scale model and gain experience from that before going for a full MW, even a 10KW system flown for a year or two would give them plenty of experimental data to help design a larger one. Then there are the liability issues, windmill towers are pretty solid and yet they've been known to fail. I figure the failure rate of kite lines+power lines would be substantially higher than that of a tower and so you'd have to contend with the occasional free flying kite+windmill combination. All that said I wish these folks best of luck with what they're doing, but unlike the cheap solar panel revolution I highly doubt that this will ever be deployed at a scale large enough to be notable. Neat project though!
- jurjenh 16y ago
  From what I remember, most problems with windmills are due to 2 factors: Not enough wind Too much wind I believe the generating curve is exponential, in that it isn't worth generating below a certain wind speed, which most locations don't reach. Just a little drop in wind speed can more than halve your generating power. Added to that, turbulence makes steady wind speed attainable mainly at higher altitudes, therefore requiring elevation (high towers) Once you do have good generating capacity, what do you do when the wind is over the maximum threshold? A lot of older / smaller windmills need to be stowed during high wind, as they just can't cope with the amount of power developed. Putting the windmills on a kite could indeed manage these issues somewhat - I'd imagine similar to sailing - where you can generate more speed than the wind provides, and possibly free-wheeling to dissipate excess speed / power. Indeed an interesting area to watch!
wooster 16y ago
So, uh, a bunch of my friends are working on this: http://www.jobyenergy.com/ http://www.jobyenergy.com/ Which is pretty awesome.
jamie 16y ago
I thought this was Saul Griffith's startup, but I see no mention of him on the about page. At his Long Now talk last year, I recall him talking about Makani as being his new effort. http://en.wikipedia.org/wiki/Saul_Griffith http://en.wikipedia.org/wiki/Saul_Griffith Saul seems totally awesome; his Long Now talk "Climate Change Revisited" was a fantastic survey of alternative energy solutions, and how no one was the answer, but that a cocktail of solutions is. His ability to put big numbers in context was stunning, especially his equating of industrial output in the US pre-WWII to the effort required to build wind turbines to cover half the usage of the current US electricity grid. Here's the video of the talk: http://fora.tv/2009/01/16/Saul_Griffith_Climate_Change_Recalculated http://fora.tv/2009/01/16/Saul_Griffith_Climate_Change_Recal...
known 16y ago
Hope Google also invests in solar powered http://www.bogolight.com/ProductDetails.asp?ProductCode=BOGO-BUYONESN2&Show=TechSpecs http://www.bogolight.com/ProductDetails.asp?ProductCode=BOGO...
tjlynn 16y ago
Since this is a hacker site, any control theorists in the house? From observation and experience, controlling a tethered airplane is the most pressing technical challenge facing the team right now. Anyone ever modeled the dynamics of a glider or a turboprop?
aufreak3 16y ago
The contrarian in me has always been curious about how tapping "eco friendly" energy sources impact the environment. (Any here have some serious pointers?) For example, if the energy of the wind at high altitudes is tapped, the wind will (duh) lose its force. How will that impact weather systems? Same for solar power - we'll be trapping radiation that will otherwise be reflected back into space. How does this affect thermodynamic equilibrium? Same for geothermal energy - how does it affect deep-earth physics? Maybe the effects in these cases are indeed linear in the small - like taking a drink from a river, but it is hard to be sure about whether they can be scaled with continued linear behaviour. Just as with fossil fuels ... one car probably didn't do much damage. 8 orders of magnitude later, its a different story altogether.
- roel_v 16y ago
  This has been brought up since the first wind/solar/tidal energy plants were being brought in production. I don't have any links at hand but this has been studied; watch the comments under stories like this one, they come up often. Basically as far as I understand the general consensus, even when evaluating worst case scenarios, is that the amount of power that is taken away is negligible, even compared to the total power consumption on earth (i.e. even if all power on earth would come from e.g. wind power, that would still be only a minuscule part of the total power that is in winds blowing all day, or sunshine that is emitted by the sun each day.)
- jacquesm 16y ago
  There is an easy way to see why this would not happen. A mountain range is a pretty sizable obstacle to the progress of airflow. It affects the weather directly around the mountain, and as much as 50 miles before the mountain and after it. But that's as far as the influence extends, and you'd need some pretty good data gathering and analysis to prove that. The effects that you can actually feel with your senses usually don't extend more than 10 miles or so beyond the mountain in the leeward direction, upwind you'd be hard pressed to notice any change at all. There will never be a windfarm that has a cross section comparable to a mountain range.
  - 16y ago
noverloop 16y ago
my nephew got recruited by a similar wind startup. http://www.jobyenergy.com/tech http://www.jobyenergy.com/tech
- relix 16y ago
  Looks like they're still some time away from having a working prototype though.
daychilde 16y ago
So... do they makani power?
yuan 16y ago
If they can make it work, this could be perfect for powering ships, too.

155 points by miratrix 16y ago

Did they convert a fire engine into a mobile ground station? http://www.makanipower.com/wp-content/uploads/2010/06/IMG_7011.jpg http://www.makanipower.com/wp-content/uploads/2010/06/IMG_70... EDIT: yup http://www.makanipower.com/wp-content/uploads/2010/07/20100610-IMG_2189.jpg http://www.makanipower.com/wp-content/uploads/2010/07/201006...

cmurphycode 16y ago

This looks pretty interesting. They have some nice explanations of their concept- particularly the fundamentals link: http://www.makanipower.com/concept/fundamentals/ http://www.makanipower.com/concept/fundamentals/ It looks pretty complex, but if the numbers work out right, this is probably the cheapest way to tap into the great winds available high in the sky.

troygoode 16y ago

"Makani AWTs will produce energy at an unsubsidized real cost competitive with coal-fired power plants, the current benchmark of the lowest cost source of power." If this is true, it could be huge. Would these be deployable basically anywhere that is reasonably open?

Retric 16y ago
No, even at altitude wind is fairly local phenomenon. As the price of wind power drops, more places become competitive with coal, but the best drip below the price of coal. http://www.windpoweringamerica.gov/wind_maps.asp http://www.windpoweringamerica.gov/wind_maps.asp Edit: You also need to transport that energy, so while much of the Midwest above average resources powering L.A. with that energy would would require a lot of new power lines.
- sasvari 16y ago
  Considering the miserable state of the US grid system new power lines have to be built anyway.
  - houseabsolute 16y ago
    Is the US grid system really in that miserable of a state? It seems to work just fine where I live. And is the right solution really building more power lines? It's not clear to me why that would solve any potential problem with the system, other than that more power needs to be transported than can currently be. And if that is so, how do things work at all now?
    - sethg 16y ago
      The best places for generating (conventional) wind power in the US are the prairie states, and the best places for generating solar power are in the Southwest. But since both of these regions are sparsely populated, there isn’t very much grid infrastructure there—there is enough to bring power to the people who do live there, but not enough to handle taking power from a power plant to population centers farther away. Also, if a substantial portion of our power supply is going to come from intermittently available sources, then the switching technology in the grid is going to have to be a little more sophisticated.
      - houseabsolute 16y ago
        I'm fine with the idea that more lines would have to be built in the case of wind-power. That's not what I was questioning. I was questioning the claim that the US power grid is in a "miserable state" for current applications, which is a notion I see bandied about a lot with nary a citation. Also would you please describe what about the switching technology in the grid is going to have to get better? Or cite some source that does so?
        sethg 16y ago
        I think this is basically what people mean by “miserable state”. It’s not just more lines, but more very-very-high-voltage lines. Also, these lines are generally regulated at the state level: the government of Nebraska may not be exactly eager to authorize a high-tension swath being cut through its land just so that power can get from North Dakota to Texas. Regarding switching technology, Technology Review had an article a while ago (http://www.technologyreview.com/microsites/spain/wind/ http://www.technologyreview.com/microsites/spain/wind/) mentioning the wind-power industry in Spain: “Because wind is an intermittent resource, providing power only when it blows, the grid has to be able to cope with fluctuations and dips in electricity. When wind accounted for only a small percentage of the country’s power, such dips made little difference. But as this resource achieved greater prominence, split-second losses of power could have caused problems, especially since Spain doesn’t have strong grid connections with neighboring countries....” The article goes on to describe how the grid management system adapts to this problem.
hugh3 16y ago
I suspect there may be some voodoo hidden in that term "real cost" -- i.e. it's dependent on some "cost" of CO2 emissions which they've derived ex anum.
prbuckley 16y ago
In the "Fundamentals" section of the website (http://www.makanipower.com/concept/fundamentals/ http://www.makanipower.com/concept/fundamentals/) Makani claims that their system can operate in 85% of the areas in the US vs. traditional windmills that need class 4 wind which is only present in 15% of areas in the US. Also there is some interesting info about why their approach could be better for offshore wind generation. I know some of the Makani guys and they are the real deal. These guys are seriously smart, and talented. I am glad everything is going so well for them.
- c1sc0 16y ago
  Offshore wind generation seems to be an obvious win, although the materials will have to be tougher.

tlack 16y ago

It's an interesting idea (more wind higher up, without the expensive tall shaft required for a regular wind turbine), but how does it get relaunched when it falls to the ground? Wouldn't a balloon or regular kite be simpler and just as effective?

hugh3 16y ago
how does it get relaunched when it falls to the ground? I'm guessing: the same way you'd launch a regular kite: by starting with it off the ground and slowly letting out the line. Possibly the propellors can be switched from generators to motors if it needs an extra boost. A balloon would lose too much in drag. If they can actually solve the software problem to get these things up and flying autonomously, it'd be pretty darn effective.
- tlack 16y ago
  I thought the drag could be beneficial in a way similar to wave power generators: pull on the balloon would operate a hydraulic piston, etc.
- jemfinch 16y ago
  Why guess when the answer is clear on the second frame of http://www.makanipower.com/concept/makani-m1/ http://www.makanipower.com/concept/makani-m1/ ?
godel 16y ago
This was on the Discovery Channel last night, currently(or as of the taping of the show), you need somebody with a remote control to fly the kite. They said they were working on making everything autonomous - which will most likely be one of the more difficult challenges for this project.
- snewe 16y ago
  This post suggests they have autonomous down: http://www.makanipower.com/2010/06/wing4e-test-june-18-2010/ http://www.makanipower.com/2010/06/wing4e-test-june-18-2010/

aheilbut 16y ago

What happens when the wind stops blowing or changes direction?

diziet 16y ago
It lands! (The tether gets it done, and the rotors also back up as engines)

smhinsey 16y ago

They are mentioned on Discovery Channel's Powering the Future. I believe it was Saturday's episode. It has interviews and demos. No mention of Google but they do say they feel their problem is control systems for the kites, not the actual energy generation.

keeptrying 16y ago

This is an incredible idea and an amazing feat of engineering. I'm sure they'll face huge challenges in deploying this thing but it just shows that real engineering is still alive. Damn, makes me wanna break out my fluid mechanics textbook :).

thibaut_barrere 16y ago

The concept looks amazing! I'm a bit concerned about how to protect human lives around - will it be required to forbid access to a large area ? The FAQ states that the peak altitude is 600 meter. Does that mean a circle with a radius of 600m must be protected ? Pretty sure they thought of it already, it looks like a well thought out project, I'm just wondering.

extension 16y ago
There is so much flexibility in where these can be deployed that you would probably never find them near a populated area anyway, just for economic reasons. They can also be deployed at sea much more practically than a tower turbine. EDIT: according to the FAQ, there are failsafes for both navigation and tether failure. It can even land itself untethered!

hop 16y ago

This looks way better than than the giant fixed turbines they are putting in Eastern Oregon which cost $2.4 million a pop, interrupt the view, and can't pay for themselves. It's also funny Oregon has abundant hydroelectric power, but subsidizes these wind projects with rate hikes and taxes - while selling billions of dollars of these electrons to California at market rates.

deleted 16y ago
[deleted]

tsally 16y ago

The anser to the FAQ "Will this harm birds or bats?" was obviously crafted with the careful help of a PR and Legal team. :-p http://www.makanipower.com/faq/faq/#2 http://www.makanipower.com/faq/faq/#2

borism 16y ago

Rotors are tiny compared to conventional wind turbines. Even with six of them, just no comparison. Sure they harvest the wind much higher and it flys in circles quite fast, but I'm not quite sure how they'll be able to generate 1MW with on of those production things. It has the wingspan of B737! It's a neat idea, but do benefits outweigh problems?

krakensden 16y ago
I was under the impression that most of the reason conventional wind turbines are so huge is so they can have the blades move slowly, to be more hospitable to local birds.
- jacquesm 16y ago
  That impression is completely wrong. The tip speed is what counts, the key governing factor is called the 'tip-speed-ratio', the apparent wind speed (as seen by the tips of the rotor) versus the real wind speed (as seen by an observer relative to the ground). Almost all windmills that want to be efficient have design TSRs somewhere between 6 and 8, and consequently, in a given wind they all travel about as fast at the tips. The design constraints are the speed of sound and the forces on the blade root as well as the tendency of the blade to start fluttering. It has absolutely nothing to do with birds. Birds will fly in to a stationary building just as easily as they'll fly in to windmills, it's rare but it does happen every now and then. The larger a windmill, the slower the blades will rotate. The reason why they are so large is because the power harvested by a windmill goes up with the square of the rotor diameter, many small windmills are more costly to maintain and operate than a single larger one. Right now the sweet spot is somewhere around 2MW and 80 meter rotors for best $/W.
  - erikpukinskis 16y ago
    The reason why they are so large is because the power harvested by a windmill goes up with the square of the rotor diameter Doesn't the Makani wings get around this issue by equivalent to a turbine with a massive wingspan and a wingtip that generates power, but without the rest of the structure?

goooooaaaalll 16y ago

Joby Energy is another company in the area working on this problem. http://www.jobyenergy.com/ http://www.jobyenergy.com/

ph0rque 16y ago

So, does the M1 produce 1 MW on average, or peak?

brainsik 16y ago
1 MW is the rated capacity. The actual amount of energy produced depends on where it is deployed. They go into detail about how much energy is produced on the "fundamentals" page: http://www.makanipower.com/concept/fundamentals/ http://www.makanipower.com/concept/fundamentals/

dalton 16y ago

I used to live in a co-op with Corwin (the CEO/CTO). The main thing I remember about him was that he was really into kite surfing. He was also scary smart and about as good of a mechanical engineer PhD as I have ever met. Him being the CEO/CTO of makani makes a whole lot of sense. Good luck, makani!

c1sc0 16y ago
Interesting, when I saw the video I was immediately thinking it must have been a kiter dreaming up this contraption ;-)

mdolon 16y ago

The only question I have is: how does it deal with harsh weather? Especially with offshore setups where storms are frequent, can it handle high winds and strong waves? Overall it's an incredible step towards innovation in energy, kudos to the entire team.

hartror 16y ago

This idea has been batted around for a while and in fact the biggest risk to getting a project like this aloft will be regulators like the FAA.

CptMauli 16y ago

This will not work. It uses too much space and It looks like it will need repairs or at least maintenance all the time.

jacquesm 16y ago

Wow, where to begin. First off, I'm really happy that Google continues to fund energy related start-ups, their solar and wind efforts are commendable. Also, I'm fairly sure that the engineers behind this project are top notch and giving this project all they've got, it sure looks like they have picked some interesting challenges. That said, I don't think this will ever 'fly' (pun intended) on any appreciable scale. Wind is a fickle thing, and if you look at the design parameters of even the smallest windmills you realize that it takes bullet proof engineering to get a windmill to operate at all for any stretch of time without catastrophe, tying one to a kite seems to compound those problems to the point where even if the power generated were substantially higher than that on the ground you'd still be left with a higher per KW bill. Being able to operate in places where windmills are otherwise not viable is nice, but at 600 meters above the ground there will be substantial risk from getting kits entangled so the closest spacing will probably be such that a 'farm' of these will generate relatively little power for a given area of the planet over which the kites fly. 1 MW seems to be a pretty ambitious goal for a first setup, think about it, a 1 MW turbine sitting on the other side of a line will pull on the tether with a very impressive force, the kite will have to pull aloft a tether strong enough to withstand that force and up to 600 meters of power transmission cabling. These are not simple challenges. What I don't understand is why they don't build a 10 KW or so scale model and gain experience from that before going for a full MW, even a 10KW system flown for a year or two would give them plenty of experimental data to help design a larger one. Then there are the liability issues, windmill towers are pretty solid and yet they've been known to fail. I figure the failure rate of kite lines+power lines would be substantially higher than that of a tower and so you'd have to contend with the occasional free flying kite+windmill combination. All that said I wish these folks best of luck with what they're doing, but unlike the cheap solar panel revolution I highly doubt that this will ever be deployed at a scale large enough to be notable. Neat project though!

jurjenh 16y ago
From what I remember, most problems with windmills are due to 2 factors: Not enough wind Too much wind I believe the generating curve is exponential, in that it isn't worth generating below a certain wind speed, which most locations don't reach. Just a little drop in wind speed can more than halve your generating power. Added to that, turbulence makes steady wind speed attainable mainly at higher altitudes, therefore requiring elevation (high towers) Once you do have good generating capacity, what do you do when the wind is over the maximum threshold? A lot of older / smaller windmills need to be stowed during high wind, as they just can't cope with the amount of power developed. Putting the windmills on a kite could indeed manage these issues somewhat - I'd imagine similar to sailing - where you can generate more speed than the wind provides, and possibly free-wheeling to dissipate excess speed / power. Indeed an interesting area to watch!

wooster 16y ago

So, uh, a bunch of my friends are working on this: http://www.jobyenergy.com/ http://www.jobyenergy.com/ Which is pretty awesome.

jamie 16y ago

I thought this was Saul Griffith's startup, but I see no mention of him on the about page. At his Long Now talk last year, I recall him talking about Makani as being his new effort. http://en.wikipedia.org/wiki/Saul_Griffith http://en.wikipedia.org/wiki/Saul_Griffith Saul seems totally awesome; his Long Now talk "Climate Change Revisited" was a fantastic survey of alternative energy solutions, and how no one was the answer, but that a cocktail of solutions is. His ability to put big numbers in context was stunning, especially his equating of industrial output in the US pre-WWII to the effort required to build wind turbines to cover half the usage of the current US electricity grid. Here's the video of the talk: http://fora.tv/2009/01/16/Saul_Griffith_Climate_Change_Recalculated http://fora.tv/2009/01/16/Saul_Griffith_Climate_Change_Recal...

known 16y ago

Hope Google also invests in solar powered http://www.bogolight.com/ProductDetails.asp?ProductCode=BOGO-BUYONESN2&Show=TechSpecs http://www.bogolight.com/ProductDetails.asp?ProductCode=BOGO...

tjlynn 16y ago

Since this is a hacker site, any control theorists in the house? From observation and experience, controlling a tethered airplane is the most pressing technical challenge facing the team right now. Anyone ever modeled the dynamics of a glider or a turboprop?

aufreak3 16y ago

The contrarian in me has always been curious about how tapping "eco friendly" energy sources impact the environment. (Any here have some serious pointers?) For example, if the energy of the wind at high altitudes is tapped, the wind will (duh) lose its force. How will that impact weather systems? Same for solar power - we'll be trapping radiation that will otherwise be reflected back into space. How does this affect thermodynamic equilibrium? Same for geothermal energy - how does it affect deep-earth physics? Maybe the effects in these cases are indeed linear in the small - like taking a drink from a river, but it is hard to be sure about whether they can be scaled with continued linear behaviour. Just as with fossil fuels ... one car probably didn't do much damage. 8 orders of magnitude later, its a different story altogether.

roel_v 16y ago
This has been brought up since the first wind/solar/tidal energy plants were being brought in production. I don't have any links at hand but this has been studied; watch the comments under stories like this one, they come up often. Basically as far as I understand the general consensus, even when evaluating worst case scenarios, is that the amount of power that is taken away is negligible, even compared to the total power consumption on earth (i.e. even if all power on earth would come from e.g. wind power, that would still be only a minuscule part of the total power that is in winds blowing all day, or sunshine that is emitted by the sun each day.)
jacquesm 16y ago
There is an easy way to see why this would not happen. A mountain range is a pretty sizable obstacle to the progress of airflow. It affects the weather directly around the mountain, and as much as 50 miles before the mountain and after it. But that's as far as the influence extends, and you'd need some pretty good data gathering and analysis to prove that. The effects that you can actually feel with your senses usually don't extend more than 10 miles or so beyond the mountain in the leeward direction, upwind you'd be hard pressed to notice any change at all. There will never be a windfarm that has a cross section comparable to a mountain range.
- 16y ago

noverloop 16y ago

my nephew got recruited by a similar wind startup. http://www.jobyenergy.com/tech http://www.jobyenergy.com/tech

relix 16y ago
Looks like they're still some time away from having a working prototype though.

daychilde 16y ago

So... do they makani power?

yuan 16y ago

If they can make it work, this could be perfect for powering ships, too.