The best possible economic return for wind power - or any alternative power - is achieved by on-site consumption of the power produced. 

  Just outside of Dunnville, Ontario are a number of commercial nurseries with acres of plants in glass hot houses.  One nursery - Rosa Flora - in 2006 installed a Pfleiderer Wind Energy 650 kW turbine (PWE 650).   The PWE 650 was the second electricity generating wind turbine in which the nursery invested.  The two bladed turbine in the photo is a Lagerwey.  The nursery uses the entire electrical production of the two turbines.  

 I find the Rosa Flora installation significant because it is entirely private.  I have not found any reference  to  either the Ontario Provincial or Canadian Federal government providing any subsidies to Rosa Flora.   And Rosa Flora is a experienced energy producer - using both conventional engine driven electrical generators as well as wind turbines. 

So, at least for Rosa Flora, it seems that the economics of generating electrical energy from wind turbines has reached a tipping point.

I have had a difficult time finding a Pfleiderer web site  which lists the costs and characteristics of this model, but it appears from a few reports about the Rosa Flora turbine that the installation ran about 1.2 million Canadian - if the cost was about C$2,000/kW.    I found the info below on Pfleiderer at this Invest Green link:

 Pfleiderer (WKN 676474 on FSE)- this is a wood products co., also is Europes 2nd largest maker of insulation. past business: at some time Pfleiderer bought see Fuhrlander- a turbine co, in 2003 Pfleiderer, see Pfleiderer-Wind got out of the wind business- selling Pfleiderer Wind- the Fuhlander turbine part to independent Fuhrlander and the rights to the +3MW Multibrid technology to ProkonNord- see Enertrag. The Pfleiderer-Wind link goes to Fuhrlander- the turbines and turbine tech from such time are (except on the Fuhrlander website- with new tech) still called Fuhrlander-Pfleiderer turbines see Bolcar.

Since I couldn’t find any information about Pfleiderer turbines being sold new in 2006, I bet that the Rosa Flora turbine installed in 2006 is a used machine. 

In a position directly underneath the machine there is no audible noise from the operating turbine. 

Several years ago I visited North Star Blue Scope Steel - west of Toledo - after I met one of their engineers who expressed interest in putting a turbine or two in the cornfields which surrounded Blue Scope’s galvanizing factory.               Blue Scope never went ahead with the wind turbine idea - maybe they should look at the economics again.