At most locations, wind energy is less consistent than PV, and usually peaks at different times. The generator must be placed higher than all obstructions within 500 feet in all directions, by at least 30 feet plus the blade radius. For a tower structure, budget 1 to 2 times the cost of the generator. Turbulence is greatly reduced with height.
Turbulence is the equivalent of rocks on a highway.
Sudden shifts in wind direction cause vibrations and stresses that greatly reduce reliability as well as energy output. The AIR 403 Wind Module by Southwest Windpower can be mounted onto a building in some cases, because it is very small and specially designed, and is vibration-dampened. Consider this only if the building's roof clears surrounding obstacles by at least 15 feet, and gets high exposure to steady, not gusty, prevailing winds. In some cases, there can be an acceleration of prevailing wind over the rooftop that can add to the wind energy potential. For more about AIR 403, ask Dankoff Solar Products for information.