
Monster Wind Turbine Blades Could Help Offshore Wind Compete with Fossil Fuels - iProject
http://www.technologyreview.com/news/510031/the-quest-for-the-monster-wind-turbine-blade/
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startupfounder
I've repelled off wind turbines inspecting 40 meter blades and they are
massive. I hope they really get their process down for mass production,
because many of these blades are low quality and need to be replaced under
warranty. Ice is obviously a major issue with this size, for both the
balancing of the turbine and for a potential hazard to passers by.

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jessaustin
Presumably there aren't too many passers-by in an offshore installation.

Couldn't the blades be heated using some of the power produced by the turbine?

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startupfounder
1) What you really have to worry about is the maintenance staff, people are
in, on and around wind turbines all the time. If you are not able to maintain
them due to the dager of ice buildup then the longevity of the turbines
decrease.

2) It is kind of funny, but on all of the wind turbines I have been on, for
complex reasons I will not get into here, don't use any of the energy they
produce. They pull power from the grid to run internal computers and lighting.

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jessaustin
One challenge I would expect is the difficulty of running current from the
(relatively) stationary generator (or the grid if the generator's power isn't
suitable) to the rotating blades. You can't just use a wire; it would get
wound around until it broke. Presumably there could be some sort of slip ring,
or perhaps an inductive circuit like that found in Reelights.

Of course the engineers have already solved the similar problem of running
power to and from the hub that must rotate to face the wind, but that rotation
is much slower than that of the rotating blades.

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ricw
I'm unsure how exactly this is supposed to be news. Of course economies of
scale are going to pay off. Of course better technology is going to pay off.
But how in earth and when is it going to compete with fossil fuels? No answer.
Rubbish article. Sorry for the rant.

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andrewcooke
_As wind turbines get bigger, the loads on the blades, and therefore their
weight, goes up exponentially._

is that true? i would have expected it to be some fixed power, like length^3.
exponential means (technically) that it goes as k^length. maybe here it just
means "quickly"?

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ars
I think it is actually exponential. The longer the blade the heavier it is, so
the stronger it has to be, which means more material, which makes it heavier,
so you need even more material for strength.

A feedback loop like that means exponential.

The volume goes up as length^3, but the strength has to go up faster than
that, since the end of the blade must hold the entire weight plus the weight
of the piece next to it, which also got heavier as it got longer.

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eric-hu
What other feedback loops like that have exponential growth?

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dwiel
Amount of fuel in a rocket necessary to send a mass X into orbit? I dont know
the math, but i've heard the exact same feedback explination used.

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eric-hu
My mind went there too. I didn't mention that one because it doesn't seem to
be exponential. I actually found a past entry on the xkcd what-if blog:

<http://what-if.xkcd.com/7/>

For a given amount of ship mass, you need 20x that mass in fuel to get it into
space. That seems to be multiplicative growth, unless I'm interpreting
something wrong.

