Concrete columns may be the key to taller wind turbines
Engineers at Iowa State University think concrete columns could be the key to building taller, higher-powered wind turbines. By making the switch from steel to concrete, it's thought that the upper limit of turbine column height could be raised from 80 m (262 ft) to over 100 m (328 ft).
"We have definitely reached the limits of steel towers," says Sri Sritharan, Wilson Engineering Professor at Iowa State in a University press release. "Increasing the steel tower by 20 meters will require significant cost increases and thus the wind energy industry is starting to say, 'Why don't we go to concrete?'"
To answer that question the engineers used the hydraulic testing equipment at the University's Structural Engineering Research Laboratory to see if hexagonal sections of concrete column could withstand 150,000 lb (68,000 kg) of lateral load, which is 20 percent more than the peak load in turbine columns of this height. The team tested three different methods of construction, all of which passed the threshold.
The researchers think that the use of concrete will extend the life of wind turbines, as well as making transportation easier due to the use of smaller parts. Taller columns would allow the user of longer turbine blades, and the harvesting of energy from less turbulent winds; factors which could increase energy production by 15 percent.
"I definitely think we're getting close to being able to use this technology in the industry," said research engineer Grant Schmitz.
Source: Iowa State University, via Clean Technica
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James lives in East London where he punctuates endless tea drinking with freelance writing and meteorological angst. Unlocking Every Extend Extra Extreme’s “Master of Extreme” achievement was the fourth proudest moment of his life.
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I kinda wonder sometimes, they give degrees to total morons! Concrete wind turbines are used all over Europe for more then 10 year already! Its definitively nothing new or radical!
It may be a good idea for the school to invite a bridge engineer that works with pre-stressed concrete for 100+ year bridges, to come over and have a talk on design considerations.
Seriously? 100M towers? REpower already has 140M concrete/steel hybrid towers in Europe. Seriously, this is groundbreaking? Those engineers should get out more
A hundred meters! Wow! That is the past, not the future, at least here in Europe. Maybe the engineers in Iowa should finally get metric. That would help to avoid embarrassing situations such as this one.
In Europe, concrete towers are erected already. Check the German made Enercon E-126 through Google images and be amazed. A 7.5 MW turbine, app. 130 meter tower and app. 65 meter blades, making a tip height of over 195 meter!!!
What I don't understand is why those towers are not cable-braced to a point just under the blades. The savings in foundation work and time would be considerable. The math would probably suggest adding a bit of length to the lower end, since a lower tower/turbine cost would encourage going up for cleaner air.
There should also be a few pennies to be gained from a tail fairing on the upper column that rotates with the power head. A bit more air would go by, and with less variation in blade force.
These guys are just figuring this out ? This is not new news or newsworthy. I'm guessing these are university students and have no engineering experience. They didn't do their research homework from the sound of it. This type of tower design has been around for years.
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