Determining Setback Distances and Height for Small Wind Turbines
To balance against the need for tall towers, good practice requires that a small wind turbine in a residential district be “set back” from a property line some given distance. (For commercial or other zones, this distance is often considerably less, even zero, since in these areas affected parties seldom exist immediately outside a property line.)
The mandated distance in residential zones should reflect valid concerns for property rights of abutting neighbors, as well as those of the wind turbine owner. This most commonly translates to the tower height plus the length of one blade (or the turbine’s “total extended height”) from the property line, inhabited neighboring structures, utility lines, and/or road right-of-ways. This distance should suffice so long as the tower is professionally engineered and/or the installer provides engineered plans of the tower, the foundation, and the system does not exceed the definition of nuisance noise as established in the zoning code.
Independent structural analyses of a tower and its foundation are readily available from the manufacturer, so requiring additional studies is unnecessary and also prohibitively expensive for a wind turbine owner. For their own protection and insurance considerations, the manufacturer conducts these studies for reasons of economics, responsibility, and – even if for no other reason – self-preservation.
However, in residential zones, some argue that a turbine’s setback should be no different than that of a house, cellular tower, flag pole, street lights,
or any other engineered structure, and that height should not be expressly limited nor specified in zoning regulations. Instead, they argue that in residential zones small wind turbine heights are already self-regulated based on sound level restrictions at the property line.
Also keep in mind that:
- Small wind turbines on the market are engineered to withstand hurricane force winds (110 -130 mph).
- Allowing abutting property owners to submit signed easements may be an alternative form of compliance should roads and utility lines be absent in the immediate vicinity.
- A manufacturer’s engineering specifications should be an acceptable means of ensuring safety and practicality.