4 ms·

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 fal

by 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/
  - hugh3 16y ago
    Ah, that's a neat movie. I don't know why it isn't on the front page of their website. Still, the fact that they've got it working once doesn't mean the problem is solved. You need it to work all the time, in all sorts of weather conditions, and automatically stow itself if conditions become unsafe. Failure means plowing into the ground, which is probably going to be expensive each time it happens. I'm sure they'll never get the plow-into-the-ground rate down to zero, but there's gotta be a lot of work still to be done to get it as small as possible.
  - erikpukinskis 16y ago
    It seems like they switch from manual to autonomous once they're at altitude: http://www.makanipower.com/technology/control http://www.makanipower.com/technology/control (page 2)
- siavosh 16y ago
  On the discovery show, it seemed pretty loud too. An annoying buzzing sound...not sure where they're planning on deploying these, but noise pollution might be an issue, not to mention potential crash safety issues.
  - extension 16y ago
    Check the FAQ. It has the same noise level as a wind tower, which is already pretty quiet, but at a higher frequency and higher up, so the sound will dissipate more.
    - Anechoic 16y ago
      The noise info presented in the FAQ is pretty useless - noise from conventional wind turbines depends on wind speed, hub height and distance - saying that the level from the AWT is "consistent with conventional wind turbines" is meaningless. It may be that they haven't done any noise testing at this stage (and the IEC 61400-11 standard for wind turbine noise testing is really not applicable to the AWT configuration) but they would have been better off just saying something like "we'll get back to you on that" rather than setting up expectations that might turn out to be unrealistic.
  - flipper 16y ago
    Yes, it's not just the volume of the noise, it's the nuisance: constant buzzing noises (especially high-frequency ones) are much more annoying than random 'household' noises, even if they are not as loud. I would have thought though that for safety and commercial reasons the wind farms would be built some distance away from population centres.
jemfinch 16y ago
The website clearly shows that the wing draws power to use its turbines as propellers when launching the wing.
- jurjenh 16y ago
  I would imagine that the same principle may be used in slightly fickle winds, so that it could throttle back or even go back into propeller mode during fickle winds. But I do wonder what would happen if the tether did break. It says that there are no batteries on the device, so if the tether is gone, is there any means of providing a gentle landing other than gliding blindly? I'd say they have something worked out, as this is one of the more obvious catastrophic modes of failure imaginable. Of course, the unexpected is more likely to do harm - possibly the tether turning into a giant 200m steel whip ready to sever anyone unfortunate to be within the vicinity... That said, I wouldn't mind one - maybe just a couple of KW for a rural off-grid section...

by tlack 16y ago

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/
- hugh3 16y ago
  Ah, that's a neat movie. I don't know why it isn't on the front page of their website. Still, the fact that they've got it working once doesn't mean the problem is solved. You need it to work all the time, in all sorts of weather conditions, and automatically stow itself if conditions become unsafe. Failure means plowing into the ground, which is probably going to be expensive each time it happens. I'm sure they'll never get the plow-into-the-ground rate down to zero, but there's gotta be a lot of work still to be done to get it as small as possible.
- erikpukinskis 16y ago
  It seems like they switch from manual to autonomous once they're at altitude: http://www.makanipower.com/technology/control http://www.makanipower.com/technology/control (page 2)
siavosh 16y ago
On the discovery show, it seemed pretty loud too. An annoying buzzing sound...not sure where they're planning on deploying these, but noise pollution might be an issue, not to mention potential crash safety issues.
- extension 16y ago
  Check the FAQ. It has the same noise level as a wind tower, which is already pretty quiet, but at a higher frequency and higher up, so the sound will dissipate more.
  - Anechoic 16y ago
    The noise info presented in the FAQ is pretty useless - noise from conventional wind turbines depends on wind speed, hub height and distance - saying that the level from the AWT is "consistent with conventional wind turbines" is meaningless. It may be that they haven't done any noise testing at this stage (and the IEC 61400-11 standard for wind turbine noise testing is really not applicable to the AWT configuration) but they would have been better off just saying something like "we'll get back to you on that" rather than setting up expectations that might turn out to be unrealistic.
- flipper 16y ago
  Yes, it's not just the volume of the noise, it's the nuisance: constant buzzing noises (especially high-frequency ones) are much more annoying than random 'household' noises, even if they are not as loud. I would have thought though that for safety and commercial reasons the wind farms would be built some distance away from population centres.

jemfinch 16y ago

The website clearly shows that the wing draws power to use its turbines as propellers when launching the wing.

jurjenh 16y ago
I would imagine that the same principle may be used in slightly fickle winds, so that it could throttle back or even go back into propeller mode during fickle winds. But I do wonder what would happen if the tether did break. It says that there are no batteries on the device, so if the tether is gone, is there any means of providing a gentle landing other than gliding blindly? I'd say they have something worked out, as this is one of the more obvious catastrophic modes of failure imaginable. Of course, the unexpected is more likely to do harm - possibly the tether turning into a giant 200m steel whip ready to sever anyone unfortunate to be within the vicinity... That said, I wouldn't mind one - maybe just a couple of KW for a rural off-grid section...