[1] 5M Proven Technology in new Dimensions is a presentation on the specification, manufacturing and construction of a 5 MW wind turbine, by REpower Systems AG, Hamburg.

The complexities of the design, manufacturing and construction of the wind turbine of that size described and illustrated in the document are mind boggling.  Still, given that the document is in effect a sales brochure, there are implications that the document does not mention.  Just to bring up a few:

• The practical capacity of a wind turbine in about one quarter of its rated capacity at optimum wind speed.  That means that if using a wind turbine of the massive size promoted in the document practical power output would be 1.24 MW.  That would require the construction of 1,200 such wind turbines to replace a single thermo-electric power plant with 1.5 GW (average size).
• To locate that many wind turbines would require a total land area of about 286 square kilometers.
• A thermo-electric power plant produces electric power about 95% of the time, with maintenance shutdowns requiring to fire up large scale standby power generation that requires about three days to be put on line and therefore needs scheduling well in advance.  In contrast, when the wind stops blowing below the speed where a wind farm can produce even only a quarter of its optimum rated capacity (or if it need to shut down if the wind speed is too excessive), the demand for energy and the sudden lack of 1.5 GW of energy that the wind farm should be producing will bring the distribution network to its knees.  1.5 GW standby capacity cannot instantly be brought on line.  Even gas-turbine-generated energy requires as much as three hours to be brought on line.  However, even though that source of replacement or standby energy is feasible, natural gas is the most expensive conventional energy source.

Wind farms are not cheap, nor is the power they produce.  On account of the expensive nature of the absolutely necessary standby power generation required by wind farms during so much of their operating time, the power generated by wind farms is just about the most expensive electric power imaginable that is on the market.

A more detailed discussion of those issues is contained in [2] Windmills for Suckers: Pickens’ Genocidal Plan (PDF file), by 21st Century Science & Technology.

[3] More on the topic of alternative energy sources.