(EcoGeek) Status Check: The Biggest Wind Projects in the World

http://www.ecogeek.org/content/view/2010/86/ (More at the link)

if there were enough of these things could they actually affect wind patterns and then weather? (or maybe my question should be at what point will they?)

think about all the structures around the world that humans have built and realize these windmills will play no more factor than a mountian or small city would.

If you're harvesting energy from the wind, well, then you're taking energy out of the wind. (You're not doing anything chemical or nuclear.)

However, consider, one of the effects of "global warming" is increased wind speeds. (Kinda makes sense, right? Warmer air means more energetic air?)

So, I sincerely doubt the effect on wind patterns by turbines will be greater than the weather effects of coal burning plants for one example... and if anything the effects of one seem to counteract the other (although I'm confident that the magnitudes are quite different.)

...due to less thermal differential at the poles after the ice melts.

It's probably a mix though -- some places will go up and others down. It may be that land winds increase while sea surface winds decrease. Wave activity is supposed to go down overall IIRC.

A friend told me there is a newer mesoscale study out there, but I haven't seen it yet. Conclusion, as I understand it, is little to no effect even if massive development occurs; turbines just don't compare to geologic and biologic structure that affects wind flow.

Here is what I have on file:
Can large wind farms affect local meteorology?
S. Baidya Roy and S. W. Pacala
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
R. L. Walko
Department of Civil Engineering, Duke University, Durham, North Carolina, USA
Received 11 March 2004; revised 9 July 2004; accepted 20 July 2004; published 1 October 2004.
<1> The RAMS model was used to explore the possible impacts of a large wind farm in the
Great Plains region on the local meteorology over synoptic timescales under typical
summertime conditions. A wind turbine was approximated as a sink of energy and source
of turbulence. The wind farm was created by assuming an array of such turbines. Results
show that the wind farm significantly slows down the wind at the turbine hub-height
level. Additionally, turbulence generated by rotors create eddies that can enhance vertical
mixing of momentum, heat, and scalars, usually leading to a warming and drying of
the surface air and reduced surface sensible heat flux. This effect is most intense in the
early morning hours when the boundary layer is stably stratified and the hub-height level
wind speed is the strongest due to the nocturnal low-level jet. The impact on
evapotranspiration is small. INDEX TERMS: 3307 Meteorology and Atmospheric Dynamics:
Boundary layer processes; 3329 Meteorology and Atmospheric Dynamics: Mesoscale meteorology; 3379
Meteorology and Atmospheric Dynamics: Turbulence; 1630 Global Change: Impact phenomena; KEYWORDS:
wind power, wind farm, renewable energy, environmental impact, climate, weather
Citation: Baidya Roy, S., S. W. Pacala, and R. L. Walko (2004), Can large wind farms affect local meteorology?, J. Geophys. Res.,
109, D19101, doi:10.1029/2004JD004763.
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 109, D19101, doi:10.1029/2004JD004763, 2004

Perhaps you posted it here.

(FWIW: A link to what you cited.)
http://www.agu.org/pubs/crossref/2004/2004JD004763.shtml