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130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

(OP)
latest news from GE- to increase blades to a 130m max, they propose a space frame covered with a geo-fabic, simialr to old airplanes circa 1915. A 260 m rotor diameter might generate 20 MWe, by my guess. One good hail storm, though , and you're back to square one. At least the birds will bounce off.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Is there a generator that big? I wasn't aware of any larger than 5 MW, at least a couple of years ago. A 7.5 was the largest that anybody was talking about at the time, but they still didn't make one that I know of. A 20 MW sitting 270 meters high? Heavy!

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

This showed up in the GIZMAG magazine.
They claim to have developed a better fabric for covering.
Most of the fabrics used, even today for covering aircraft have poor UV qualities, and require protective paints to prolong their life.
B.E.


The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

They just got DOE funding for this concept.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

That's great. Then in effect they are just building a big pinwheel until they can design a generator that large and that weighs so little they could still mount it that high up. As far as I know, nobody's even got one on the dwg board yet and they're kinda' hitting a stone wall at 7.5 MW with current wind generator technology anyway.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

I still remember getting high on the Dope paint we used as kids on the silkspan for the Balsa wood models we used to fly. Frankly, I'm still surprised I have retained mdmories of this.

Mike McCann
MMC Engineering
http://mmcengineering.tripod.com

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Maybe he's remembering the smell of that paint a little too much.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

The thinner in that dope was ethyl acetate and toluene. Which smelled good, and tore up your liver and your brain, brain, brain.
It is still used today.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

(OP)
The 20 MWe generator problem can be adddresed if one proposes the use of the Siemens superconducting technology- roughly 100 times the power density of copper cored generators

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

I'll wait awhile then.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

May we reasonably presume that some of the DOE funding will be for the development of weightless cryogenic equipment to permit the deployment of superconducting generators in the clouds? Surely that technology must be nearing commercial practicality, too. I suppose that for advertising and funding purposes, the power and energy requirements of the cryogenic system would not be deducted from the published ratings of these giant wind turbines. It is always most effective to only announce the niftiest numbers while keeping very quiet about any nasty or troublesome parasitic burdens or costs.

Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

I'd have to believe they will use shafts and gears to drive a generator on the ground.

Driving around the country last summer, I have to say the wind farms are the ugliest thing we've done in a long time.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

130 meter long shaft. There's a reason they don't put ship engines in the bow. I think that's it.

Independent events are seldomly independent.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Why would you not use a hydraulic motor to transfer the energy to the ground level?

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Hydrostatic transmissions work fairly well when the pump and the hydraulic motor are in close enough proximity to be in the same housing. Putting them 130m apart requires 260m of tubing, which adds some friction loss, which gets worse with falling temperature.

Allowing the wind turbine to swivel nominally requires addition of a dual channel rotary hydraulic coupling, or a sturdy right angle gearbox.

I said the coupling is 'nominally' required, and it is if one requires unlimited yaw rotation. ... but I heard of a smaller wind turbine that was allowed to swivel on its own, and never yawed much more than one full rotation. The electric cables just dangled down the interior of the tower. The original mercury slipring was removed after the mercury froze.

Doing the same thing with two hydraulic tubes seems possible, but would require hydraulic fittings that don't leak when the tube is tweaked a little. That might require a little development money...


Mike Halloran
Pembroke Pines, FL, USA

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

(OP)
It looks like GE is also now considering superconducting technology to address the generator atop this monster.

"Nobody expects the Spanish Inquisition! "

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

We've got ~3000 of these things in SW Minnesota, and they seriously mess with your head when you're driving through the area. Have to really concentrate to keep your eyes on the road and focused on the driving. I can't imagine them being nearly twice as large. You'd have that many more miles to gaze at them on the horizon.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

(OP)
latest report is Samsung is testing a 7 MWe offshore wind turbine in the UK ; the nacelle is 9 m tall x 18 m long, generator weight not listed

"Nobody expects the Spanish Inquisition! "

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Exactly. 5 Dec 12 14:26

Independent events are seldomly independent.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Cleverer people than I will probably know why not, but couldn't the generator be located maybe halfway up the tower, maybe orientated vertically, and a drive system transmit the power to it there as a compromise? I suppose the additional complexity might just not justify such a solution, or is there something fundamentally idiotic about such an idea that I'm unaware of?

"I love deadlines. I love the whooshing noise they make as they go past." Douglas Adams

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

Hopefully it is an all-electric variable frequency input, constant frequency output inverter that is being used to save the weight and inefficiencies inherent in having a drive train up there in the first place. So your added drive train, with the extra long shaft will add a lot of weight to the upper half of the tower, perhaps more weight than the generator and probably need some big universal gear at the top, with some intermitant bearings to keep shaft vibrations under control too, not to mention the support structure and weldments to support the generator in the column halfway up. Hopefully they will still have room for the ladder bypassing that assembly to scramble up to the top to service the bearings and universal gear. That does solve the problem of keeping the cables from the nacelle to ground level from getting twisted up though.

Independent events are seldomly independent.

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

(OP)
There may be several ways to address the heavy generator and requisite construction crane. Multiple co-axial generators could reduce the lift load , superconducting generators would reduce the weight by a factor of more than 10, and a voith hydraulic unit might enable hydraulic transmisson to a lower elevation.

But one nagging issue is earthquake loads- the massive load at the top of an 80 story column must generate unbeleivable horizontal shear forces during an earthquake- I would expect the insurance coverage of the wind farms excludes earthquakes.

"Nobody expects the Spanish Inquisition! "

RE: 130m long blade by GE- fabric over frame- 20 MWe , 80 stories tall

I don't think the bankers would be up to the risk without their comfort blankets.

Independent events are seldomly independent.

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