Lattice towers are the cheapest to manufacture, since they typically require about half the amount of steel used for a tubular steel tower. Generally, it is an advantage to have a tall tower in areas with high terrain roughness, since the wind speeds increases farther away from the ground, as we learned on the page about wind shear . Lattice towers and guyed pole towers have the advantage of giving less wind shade than a massive tower. Clearly, we cannot sensibly fit a 60 metre rotor to a tower of less than 30 metres. But if we consider the cost of a large rotor and a large generator and gearbox, it would surely be a waste to put it on a small tower, because we get much higher wind speeds and thus more energy with a tall tower.
Manufacturers often deliver machines where the tower height is equal to the rotor diameter.
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