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

[davefitz]

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.

 

[BigInch]

Exactly. 5 Dec 12 14:26

Independent events are seldomly independent.

 

[RobWard]

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

 

[BigInch]

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.

 

[davefitz]

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! "

 

[BigInch]

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

Independent events are seldomly independent.