T is for Turbine: The anatomy of a 400 foot tall industrial machine: Below Ground Level
The turbine tower will be anchored to a foundation consisting of more than one thousand tons of steel rebar and concrete.
The foundation's depths can vary from six feet to thirty feet, depending on the composition of the land, and can be forty to fifty feet wide.
This platform will support the steel towers which weigh between 140 to 225 tons- depending on their height, nacelles that weigh between 50 and 70 tons, and the rotor or blade assembly which weighs between 35 and 50 tons, for a total weight of 200 to 345 tons.   
Developers will rarely agree to remove all of the foundation when the turbines re decomissioned. Most will not remove more than four feet of below-ground concrete and rebar, and only if this was agreed to prior to construction or is required in a town or county ordinance.
Each turbine requires high voltage electrical cables trenched into the ground and connected to a substation and then the electrical grid. The turbine will use these high voltage connections to draw power in order to operate the machinery and also to send power when there is sufficient wind.
Each wind turbine also requires its own access road. These roads will vary in length and location across a landowner's property depending on the wind developer's needs and wishes unless the landowner makes sure the preferred location of the turbine, the road, and the trenches are spelled out clearly in the contract.
The photos below show the first steps of the turbine construction phase. (Unless otherwise noted, all construction photos by Gerry Meyer, Fond du Lac County, WI, 2007 and 2008)
Above: Landowner's field being prepared for turbine construction
Industrial scale wind turbines require high voltage cables to be trenched into the soil. These cables appear to be laid in without conduit.
Below: Gravel access road and high voltage electrical cable trench cut diagonally through landowner's field.
In the right-hand corner of the image above, you can see the substation where good crop land used to be.
Landowners should expect the inevitable damage to their fields from the size and weight of the machinery required for industrial wind turbine construction. Torn up fields, severely compacted soil and careless removal and treatment of topsoil are frequent complaints from landowners hosting turbines. How the land will be restored and how a landowner will be compensated for this kind of damage is another thing which must be clearly addressed in the contract.
NOTE FROM THE BPWI RESEARCH NERD--We thank Gerry Meyer for sharing these construction photos with us. Next, turbine anatomy from the ground, up.
Source: GE Energy Wind Turbines