This is the article I spoke to you about.

George

Do they agree the results may not be due to climate change? Sure. But that’s not quite the same as agreeing on what Seth asked them and it’s not what they focused on in their responses to Seth.

It appears they felt embarrassed to seem to disagree in public. But they did disagree on some issues and those were the ones Seth was writing about.

http://www.realclimate.org/ind.....ent-126887

It turns out Seth Borenstein’s article was entirely accurate and neither gavin nor mike were quoted out of context.

On a slightly different topic the VORTEX2 tornado hunters seem to have had a poor hunting season with few targets in their search area. Related?

The design speed will be tailored to the amount of wind expected at a location and the available power varies as V^3. You read this value off an operating characteristic for any tower or plant.

And sorry about the hanging HTML tag.

I tried to fix it but it didn’t stay fixed.

Note the blue line is the exponent and the red line is the total power generated. (Details on how I generated the exponent forthcoming if need be.]

You see exponents of 3 only for wind speeds below 5 m/s. At the expected operating point of V=10 m/s, the coefficient is only 2.2.

I also suspect someone, somewhere does have information on the conversion rates of existing facilities.

In practical installations, the designers do impose a top speed to prevent damage to tower. So, no real machine of any sort ever follows an idea curve. The efficiency of a real turbine will vary with wind speed. In the case of wind turbines, this is designed in, as Tom noted. ( Recognizing this, I tagged on “Of course, both estimates assume the turbine maintains the same level of efficiency to convert wind energy to power at both speeds. ” at the end of the post.” I didn’t go on to explain why this is never true for an already built turbine operating at it’s top capacity.)

So, Tom is correct that I was discussing recoverable power and you are correct that what I was describing was operation of ideal towers.

But it’s difficult to figure out the correct way to simplify a blog discussion. But, the fact is, available power in a location goes as V^3. If wind speeds differ in different locations, engineers will design somewhat different towers. So, if the average wind speed did increase across the US, and engineer designing a new plant would want to take advantage of the higher local velocities and recover that power. To do so, they would design towers that wouldn’t be damaged when operating at higher speeds.

Obviously, another engineer running and existing plant would still need to put the brakes on an existing tower to prevent it from being damaged if the winds get too high. So, the more complete reality is:

* For existing plants if the wind decreases, the turbine will generate less power. (Unless they had been designed to not take advantage of the local wind level in the first place.) If the wind increases, there will be little increase in power generated because the turbines aren’t sturdy enough to take advantage of the potential power.

* For future plants that have yet been developed, the available power goes as V^3. The engineers can design new plants to dovetail with the known wind velocity levels.

for the eastern slope of the Rocky Mountains, the mountain lee effect (referring here to a stable low pressure zone on the less side of the mountains) is more important for the stable wind flow there than equatorial-polar temperature differences.

Yes. There are two separate questions:
1) What is happening to the wind levels and what causes them to vary? and
2) If they do vary, how does that affect the potential for wind energy.

My post really only addresses (2).

The available wind power is indeed proportional to V^3 what is quite easy to show .

First it can be anywhere from V^2 to V^3, only an ideal wind turbine would ever give the full V^3 exponent.

And more importantly, not what measurement says.

In the range of wind speeds we are talking about, the wind power is nearly independent of the wind speed.

Also, I understand it, for the eastern slope of the Rocky Mountains, the mountain lee effect (referring here to a stable low pressure zone on the less side of the mountains) is more important for the stable wind flow there than equatorial-polar temperature differences. That’s why they are talking of putting the major wind farms there.

“It seems that less wind would have an impact on temperature trends due to less mixing.

Does that make any sense?”

Of course . Slow down the fans in your computer and you will see what the impact on your global computer temperature and from there on your blog activity will be

It seems that less wind would have an impact on temperature trends due to less mixing.

Does that make any sense?

There’s also this cool calculator power curve calculator…

Sure. Turbines, like many types of power generating equipment, have levels of inefficiency that will depend on operating characteristics. I did ignore those here.

Squrrlly– If gavin’s notion is that potential wind power so greatly exceeds needs that a 30% decrease in potential wind power doesn’t matter…. well.. then he made that point, shall we say, indirectly? Maybe that’s what he means; or not. Anyone who wants to know for sure would need to ask him.