Google Makani – Wind Energy Kites • Hacker News Board

Re: Google Makani – Wind Energy Kites

#121

Post by Retric » Wed, Mar 18, 2015, 2:19 AM UTC

giggles_giggles wrote: post #20

krschultz wrote: post #9

Earlier quoted context omitted.

I've never heard the argument that current wind turbine are unsustainable before. I don't see why that would be so. The base is concrete, the tower is steel, neither of which is exotic. The generator is pretty standard. All of that is industrial tech we invented a century ago, and we know how to maintain it for the long haul. The blades themselves are composite, that may have some longevity issues (you typically need…

My understanding is that, among other things, the generators come under extreme stress during exceptionally windy occasions, causing a lot of wear and tear that happens way up at the top of these giant windmills. These require a lot of manual maintenance, which is dangerous and expensive due to the nature (and location) of the work. Additionally (and as a demonstration of just how much stress they come under), while…

Current designs are not standardized, so the worst case is fairly poor. However, economically on average wind is fairly close to Coal Power and in some cases actually cheaper even without subsidies. So, there is no way for it to be a net loss energy wise because electricity is vary cheap energy.

PS: For scale wind is on target to hit ~8% of total electricity generation in 2018.

Re: Google Makani – Wind Energy Kites

#122

Post by sidcool » Wed, Mar 18, 2015, 2:46 AM UTC

downandout wrote: post #53

xbryanx wrote: post #30

Earlier quoted context omitted.

I'm with you, but I'm a power user. I wonder if anyone has any sentiment analysis showing whether the average web user likes this sort of thing, or finds it annoying.

Google is in the position to have done exactly this kind of analysis, and apparently the majority likes this crap. I'm glad I am not alone in hating it though.

We are hacker news, we are professionally outraged.

Re: Google Makani – Wind Energy Kites

#123

Post by prawn » Wed, Mar 18, 2015, 2:53 AM UTC

robinhowlett wrote: post #22

Would it plummet out of the sky if the wind dropped suddenly?

If problematic wind was forecast, they could be automatically reeled in for some temporary period?

Re: Google Makani – Wind Energy Kites

#124

Post by nether » Wed, Mar 18, 2015, 3:01 AM UTC

frozenport wrote: post #69

MiguelHudnandez wrote: post #6

Earlier quoted context omitted.

Here's a Ted talk from 2009 about the early version of the tech. http://www.ted.com/talks/saul_griffith_on_kites_as_the_futur... The tethered airframe converts wind into high-speed lateral motion, sort of like a sailboat would if it were sailing into the wind. These higher speeds can drive the blades faster than if they were simply pointed at a wind source.

Wow 6+ years.

hardware takes a long time

Re: Google Makani – Wind Energy Kites

#125

Post by airza » Wed, Mar 18, 2015, 3:12 AM UTC

callesgg wrote: post #10

Good, could people just stop messing with how scrolling works.

using two finger back on the OSX trackpad is broken on this site, what a pain...

Re: Google Makani – Wind Energy Kites

#126

Post by Thiz » Wed, Mar 18, 2015, 3:54 AM UTC

callesgg wrote: post #10

Good, could people just stop messing with how scrolling works.

I have a default zooming of 125% and nobody seems to know how to make the web work for us with disabilities, not even gmail works well.

Scrolling pages always look weird for me. Image libraries like lightbox are a special pain in the ass.

Re: Google Makani – Wind Energy Kites

#127

Post by PakG1 » Wed, Mar 18, 2015, 4:19 AM UTC

My friend worked for Makani for quite some time. I remember at the time, they were in financial difficulty and, in his words, laid off all the people who viewed it only as a science project in order to get lean. Not enough people were focused on what would be necessary to bring the tech to market. He ended up finally leaving after some time, but I think before Google took them. A Google X type of environment probably is perfect for people who like working on science projects and can't be hindered by financial constraints that would hold back innovation at this scale. Would be interesting if Google ends up being able to turn this into something used by many parties worldwide.

Re: Google Makani – Wind Energy Kites

#128

Post by avn2109 » Wed, Mar 18, 2015, 4:23 AM UTC

elevensies wrote: post #3

I'm still a bit confused about how the forces line up for the flight path. If I'm understanding: - the wing flies in a circle which is perpendicular to the wind (oriented the same way an ordinary wind turbine would be) - the tether is up-wind from the wing, so the force from the tether pulls the wing into the wind which generates lift, which is used to propel the wing along the circular path - the propellers are driv…

We need a free-body diagram here, talking about the balance of forces in English is madness.

Re: Google Makani – Wind Energy Kites

#129

Post by mkl » Wed, Mar 18, 2015, 4:25 AM UTC

TylerE wrote: post #5

elevensies wrote: post #3

I'm still a bit confused about how the forces line up for the flight path. If I'm understanding: - the wing flies in a circle which is perpendicular to the wind (oriented the same way an ordinary wind turbine would be) - the tether is up-wind from the wing, so the force from the tether pulls the wing into the wind which generates lift, which is used to propel the wing along the circular path - the propellers are driv…

I think that's more or less it. I think what they're doing is a milder version of dynamic soaring, which is a popular technique used among RC glider pilots (and some birds). The speeds attainable are pretty insane, the current RC record is 505 MPH, which in a rather fascinating twist is faster than the fastest POWERED RC aircraft. This a video that shows a pretty good idea of what it looks like, at compartively slowe…

This video explained dynamic soaring for me: https://www.youtube.com/watch?v=SVN-oF6tPLc

The key thing seems to be having different wind speeds available at different heights so you can do the upwind part through slower moving air.

Re: Google Makani – Wind Energy Kites

#130

Post by 69_years_and » Wed, Mar 18, 2015, 4:37 AM UTC

jdmichal wrote: post #33

giggles_giggles wrote: post #20

Earlier quoted context omitted.

My understanding is that, among other things, the generators come under extreme stress during exceptionally windy occasions, causing a lot of wear and tear that happens way up at the top of these giant windmills. These require a lot of manual maintenance, which is dangerous and expensive due to the nature (and location) of the work. Additionally (and as a demonstration of just how much stress they come under), while…

> Additionally (and as a demonstration of just how much stress they come under), while coming under said strain, they've been known to burst into flames I thought all wind turbines were built with brakes now exactly to prevent this and other more spectacular failure modes, like the blades fragmenting. They have a defined operating range, and if the wind isn't in that range the brakes engage and the blades don't move.

Not quite, if the wind is too strong the blades feather (edge on to the wind) brakes exist but are puny and are only for maintenance use. Some blades have a tip that the rotates and causes high drag in the event of feathering failing and going into an overspeed.