Use trees to increase wind speed?

[CamMan595]

My Mother-in-law has a small farm and I am interested in building a wind turbine and putting it on her farm.  We live in central Kentucky and the wind maps say that this is a poor place for a wind turbine.  Everything I have read talks about getting the turbine up above the trees so that the trees won't affect the wind getting to the turbine.   My question is, "Can you use the trees to create a high wind area and place the turbine in that area?"  If so, where could I look for more information about this?

[imsmooth]

I think you are asking about using the trees to funnel the airflow to the turbine?  If so, you are limiting the directions wind can come from. Just my thoughts.

[dnix71]

You get turbulence with it. Not good.

There was a fairly famous video on LiveLeak showing a Mariann Kramer dying attempting a swooping pond skim with a square ram-air chute. She turned around to line up with the pond past a line of trees and the turbulence brought her down hard. The wind then reinflated the chute and dragged her into the water.

The event ground spotters should never have let her jump. You can't 'see' air turbulence, but the people on the ground knew how hard the wind was blowing and should have radioed the plane to call it off.

There is a tribute video of her here, no crash.

http://video.google.com/videoplay?docid=-3154100085589767618

[ghurd]

I do not believe trees can increase the wind speed.

Gaps in between the trees are areas where the trees slow the wind down less.

It is easier for the wind to go over the trees than between, so most of the wind goes above the trees.

G-

[swamijake]

I'm a wind power developer. Trees slow wind down. You cannot use them to create a funnel.

[electrondady1]

if they are deciduous trees the leave are only a problem for part of the year.

depending on the prevailing wind, perhaps you could get a boost from some of the farm buildings, or silo

[Beaufort]

This link shows a ground-mounted deflector that looks very interesting.  It claims to boost overall performance by 30%, and low wind performance by up to 150%.  

http://www.cleantechnica.com/2009/04/29/wind-turbine-output-boosted-30-by-breakthrough-design/

Not as natural as trees, but for some tubing and canvas it's not bad.  I'm guessing it requires good laminar flow to get the boost shown by their computer modeling.  Of course, the turbine shown is on a 10' tower....so adding another 20'-30' of height would get a wind speed increase anyway, but would it approach their claimed numbers?  

[swamijake]

Sorry, let me be clear. Anything that gets in the way of the wind will only slow it down or create turbulence. Trees with leaves or no leaves, ground mounted deflectors, buildings, etc. It all creates roughness, it all slows wind down which reduces how much energy you can extract.

If you want to get the most power out of a turbine, get everything out of the way, and get it as high as you can.

Jake

[dnix71]

The deflector is shown next to a turbine that is mounted way too close to the ground. That might work with a home-built, but a commercial turbine wouldn't be mounted anywhere near that low.

[electrondady1]

i think that's a simplistic solution to this guys question .

being a "wind developer" clear cutting or bulldozing is perhaps the most expedient way to make the maximum amount of profit.

but that's 19th or 20th century thinking.

this being the 21st century a bit more of a symbiotic approach is required.

[TomW]

In my real world situation here our turbines are about 300 feet up the field drive from the house. It is near the tree line with open fields for several hundred yards towards the prevailing wind [NW]. I know it is less than ideal but it is what we have to work with.

The drive has trees along its length but is a bit of a tunnel running SE from the turbines. I often see the low turbine [30 feet tall] pointing directly down the drive when we have an easterly wind. The tall [65 foot] turbine will be getting wind over the trees and pointing an entirely different direction. If it wasn't for the drive funneling wind that lower turbine would not see much wind.

So, I guess my point in this diatribe is:

Yes, it can work. I would not suggest it as a ground up plan but if you are working with what is there it may be an option.

We like to work with the environment rather than in opposition to it here so others may not see it the same.

Just my experience here.

Tom

[Ungrounded Lightning Rod]

Fricton with the ground vs. coriolis force causes the wind near the ground to be 90 degrees off from the wind aloft within the near-earth wind layer.  Most of that twist is near the ground.

So turbines on different height masts may point in significantly different directions even if the stuff on the ground is only applying fricton rather than forming some specific wind-deflecting structure.

[swamijake]

I am not recommending bull dozing anything. I am recommending against planting trees to try and make a wind funnel. That will not work.

Pick the highest point you can, as far from trees and buildings as you can, and install the highest tower you can. That is your best bet.

Also, look into solar panels. Kentucky has pretty good solar exposure.