Wind Energy

[Nitack]

Can Wind Power Get Up to Speed? - TIME

Just read this article. Very nice mention of a scientific report that says that there is enough wind energy swirling around our planet to meet our current energy needs 40 times over. The article also does a very nice job of laying out the challenges to a wind powered future. It sparked a new question for me though. Wind turbines siphon off the energy that carries air as wind. This is all driven by a very complex system of thermal fronts and such well beyond my comprehension because I have not yet read up on them. But, here is the part I do get, we are siphoning off energy, which means there is less energy in the wind.

Could this have an adverse environmental effect that is not yet anticipated? We use such a minor amount of wind power now that we would not notice anything, but surely if we were to move to a completely wind driven energy future we would end up siphoning off enough wind energy to actually see noticeable effects wouldn't we? Given my limited understand of the complicated atmospheric process that creates wind, I may be wrong, but converting energy from that system, to be used as electricity must have some measurable effect.

Will some one enlighten me?

[freeztar]

Below is a non-technical paper from 2004 on the climactic implications of large-scale "wind farming".

Originally Posted by David Keith

Results from climate modeling studies by myself and others suggest that large-scale use of wind power can alter local and global climate. Wind turbines can change wind patterns which can in turn change the climate by (slightly) altering amount of heat and moisture transported by the winds. The fact that an enormous number of wind turbines can change the climate is not important; many human activities can change the climate if they occur at a sufficiently large scale.

I think the work on the climatic effects of wind power raises three interesting questions. First, will climate change due to wind turbines be noticeable in the face of other climate changes caused by humans? Second, how does the unintended climate change due to wind turbines compare to their intended effect in reducing global warming? Third, what will be the impact of climate change caused by wind-power?

Untitled Document

He then goes on to answer those questions. It's definitely worth reading.

There's also this article that is relevant to wind energy feasibility in the face of a GW future.

The idea that winds may be slowing is still a speculative one, and scientists disagree whether that is happening. But a first-of-its-kind study suggests that average and peak wind speeds have been noticeably slowing since 1973, especially in the Midwest and the East.

"It's a very large effect," said study co-author Eugene Takle, a professor of atmospheric science at Iowa State University. In some places in the Midwest, the trend shows a 10 percent drop or more over a decade. That adds up when the average wind speed in the region is about 10 to 12 miles per hour.
...
Still, the study, which will be published in August in the peer-reviewed Journal of Geophysical Research, is preliminary. There are enough questions that even the authors say it's too early to know if this is a real trend or not. But it raises a new side effect of global warming that hasn't been looked into before.

Not so windy: Research suggests winds dying down | Comcast.net

[Boerseun]

Winds slowing down? That's very interesting. I'm sure that should be purely a localized phenomenon. I mean, with Global Warming being what it is, the increased energy in the atmosphere should imply that if winds are slowing down for any given area, it should be speeding up in other locales?

[freeztar]

Originally Posted by Boerseun

Winds slowing down? That's very interesting. I'm sure that should be purely a localized phenomenon. I mean, with Global Warming being what it is, the increased energy in the atmosphere should imply that if winds are slowing down for any given area, it should be speeding up in other locales?

The first article I linked to mentioned how wind farming's effect is most likely only localized. As to this winds slowing down business, I'm not sure. In fact, the amount of doubt in that article is pretty telling. The prime investigator herself concludes that the slow down may be an artifact of changing conditions around monitoring stations (local effects like vegetation growth, building construction, and other local environmental factors).

But, if we assume that the winds slowing down is accurate, then your question is a good one. I think the problem is not so much related to total energy as it is to the amount of variation between temperature extremes. So, as the poles warm, the temp differences between the poles and the equator should start to close the gap with temperature control regulated more by the atmosphere with less contribution from the tilt of the Earth and angle of incidence of the sun's rays. In theory, this could contribute to slowing winds, absent winds, and a breakdown of global currents.

Wind occurs on a range of scales, from local breezes generated by heating of land surfaces and lasting tens of minutes, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two major driving factors of large scale atmospheric circulation are the differential heating between the equator and the poles, which causes the jet stream and the associated climatological mid-latitude westerlies, polar easterlies, and the trade winds, and the rotation of the planet (Coriolis effect), which causes the circular motion of air around areas of high and low pressure.

wind

I wonder if the author considered correlating her data with measurements of global currents?