A Geologists Digs For Setback Rationale

 Tony Fleming searched for a rationale to the setbacks in his area, and his resulting article shows there isn't a coherent rationale for the setbacks.
Wind Ordinance Debate: The 1,000-foot Set-Back Standard (Are environmentalists underregulating themselves?) — MasterResource

In Indiana and elsewhere, many counties are falling all over themselves to adopt the so-called “1,000-foot voluntary industry setback” between large wind turbines and residences.¹ In some states, it has become part of “model” wind ordinances created by wind developers and energy agencies.

This buffer zone (who said these structures were environmental?) is starkly smaller than those mandated in several countries widely touted by industry proponents as wind “success” stories. InDenmark, for example, the setback is four times total turbine height (or about 2,000 feet for a large turbine), along with a built-in mechanism for compensating abutters for property-value losses.

In Holland, it is 1 km (3,314 ft). Germany’s noise-based setback ranges up to a full mile (1.6 km).

 Read the full, referenced, article at MasterResource