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Caltech Study Says Vertical Axis Wind Turbines 10X More Efficient Than Horizontal Axis Turbines

Wind energy production has so far been dominated by the horizontal axis wind turbine (HAWT).  They can be scaled up to reach high in the air where the click here generic viagra for sale wind blows faster and produce a lot of energy per turbine (a 10 MW turbine is not far away), but researchers at Caltech say that vertical axis wind turbines (VAWTs) may actually be the better choice.

A recent study of turbine placement and output found that because VAWTs can be placed closer together, they're capable of generating ten times as much energy per square meter than HAWTs.

In a series of indian levitra field tests that placed six VAWTs in different configurations, it was found that a spacing of four turbine diameters apart (about five meters) got rid of any aerodynamic interference between the turbines.  HAWTs require 20 turbine diameters of spacing in order to eliminate aerodynamic interference, equaling more than a mile between each turbine. The six VAWTs were able to produce 21 to 47 watts of power per square meter, while a comparable HAWT farm only produces about two to three watts per square meter.

The study also found that having each VAWT spin in the opposite direction of its neighbor allowed them to spin faster because the opposing spins reduced the drag on each turbine, which upped their efficiency even more.

To add to the list of benefits, VAWTs are also cheaper, smaller and less intrusive, allowing them to be installed in lots of places where large HAWTs just wouldn't do.

via Caltech

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Comments (17)Add Comment
written by chuck, July 13, 2011
the statement about a vertical axis being 10x more efficient is deceptive. on an indivual basis vawt's are far less efficient than hawt's. it's the fact that you can put many more vawt's on a parcel of cialis angioplasty land is wow look it cialis next day what leads to the efficiency.
it is also stated that the vawts are cheaper which isn't true if you have to buy 5 for every 1 hawt.
written by paul, July 14, 2011
I think its an interesting concept. It would be interesting to levitra order see which type is more cost efficient. an equivalent system would require more VAWT's but it would also require less land to build on.
written by GEE, July 14, 2011
to continue on Chuck's comments: Just change the generic viagra india title to "Caltech Study says Vertical Axis Wind Turbines 10x More Land-Use Efficient than Horizontal"
written by Cameron, July 15, 2011
It strikes me that this negates one of the advantages that HAWTs give wind power, namely that the land remains useful for agricultural purposes. The density of turbines shown in the picture would make any kind of capital intensive agriculture very difficult.
written by Jon, July 29, 2011
These things are really noisy.
To each need a solution
written by Matt, August 16, 2011
Will I agree it is a misleading head line, that is the head line game.

KW per square meter of ground is not important when setting up on a farm or in the ocean. But in location where space is limited say on a roof. Then the dense packing of VAWT's could be useful.

But they still have to be cost effective, which was not considered in the study.
Try Combining Solutions
written by Pierre, August 19, 2011
This is a 3-part diatribe, so please be patient.

1. What if these VAWT's can be designed / built / arranged / spaced to create faster winds through the wind farm, to create some sort of synergy that could translate into even greater power output? And can they be close enough to be geared together to create some sort of gigantic flywheel effect?

2. I read a bit further into VAWT's (through links in this and other articles) and an idea that pops up is to retrofit these onto existing vertical poles, like light poles. And they can be found on every block of every city! Light poles in any city on any coast will never stop turning. Must be good for something besides lip service...

3. Since the most important thing you can change is your point of view, what if we change our way of thinking about making and storing our own power? In the past (and still today), central utilities produce the power so we can use it on mexican viagra demand (kind of like on-demand storage, if you think of it that way). Now we want to cheap prescription cialis create our own power and save on our central utility bills but infrastructure costs (batteries, inverters, etc.) are a heavy burden, and they're already installed by the utilities. Maybe we can compromise and produce our own power to put into the where to find viagra grid, using it as storage? Actually, it's more like passing it to those who need it more at any particuler time, like when we're at work yet the sun still shines and tramadol fed ex no memberships the wind still blows. Kind of like an internet for power. Just as the power/creation of the internet was decentralization of information, why can't power be decentralized but still use the existing infrastructure for delivery and storage, a kind of symbiotic relationship, if you will? Sometimes, hybrid systems are better than the parts that created them...
complaints about the noise
written by ron, September 03, 2011
In Canada we are getting complaints about the noise, are vertical turbines quieter. This would reduce one NIMBY complaint.
written by Thomas, October 25, 2011
Horizontally placed bearings carrying VAWT load are likely to wear out far more quickly. Result: reduction in power generation efficiency, noise, and extra maintenance cost for replacement.
advantage of cialis generic wind source energy
written by S. R. Morbley, November 03, 2011
A main advantage of wind energy over solar energy is
the time frame.
When the sun goesdown so goes the source of energy.
Wind can provide it's energy source 24 hours a day.
Water current is the most reliable renewable power.
written by sjrw11, July 17, 2012
Wind power is intermittent
Solar power is intermittent
Tidal or river flow is pretty reliable, and predictable.Dams are abhorant, but turbines in the flow, without dams ar really good. They can have grills on the intakes to keep fish out.

A combination of Solar and VAWT on a house is also better than either alone. Wind is higher in the winter and Solar is better in the summer.
VERTICAL AXIS will be more effecient that HORIZONTAL AXIS soon
written by Conrad Timothy, July 31, 2012
I am working on a way to make the vertical axis turbine more efficient than the horizontal. I have just registered my machine.

This is by using a housing that traps the moving air rather than letting it pass after giving just a little of its energy.smilies/grin.gif
written by Steve, March 01, 2013
Reply to Conrad Timothy - ROPATEC Italian company has had such a system working since 2007 in the Alps. The center housing is designed as a wing that helps to start the rotation in low wind and acts as a brake to the wind when it reaches a maximum speed set by the design. (operational example was 25 m/s)
Free Flying Whooping Cranes May Be Wiped Out In 5 Years
written by davidgmills, May 21, 2013
Due to HWAT design according to Avian Wildlife Expert. The law of unintended consequences at work.

written by mark, February 19, 2014
while I can appreciate this study and this could lead to something more cost effective and efficient, out here in the real world, wind turbines need to co-exist with agriculture production being the primary use of land. It is a lot easier to knock on a farmers door and say we want to place one driveway and one 8 foot diameter tower on two opposite corners of your farm and we want to pay you 6000 a year for your trouble, than to say we need 10 acres of your ground to build a wind farm. In an area where the land is laying in waste it might be more cost effective to have multiple smaller vawts, but here it would never work. Land is simply too valuable.
Sharing land use
written by Marc, February 25, 2014
A lot of wind turbines in Europe are on ridgelines. No conflict with agricultural use at all.

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