Responsible Community Integration
As with any new development, wind projects have the potential for impacts on the surrounding community. The following section outlines the most common siting considerations for wind projects to ensure the responsible and appropriate incorporation of wind power into a community. For a complete guide to wind siting, see the AWEA Siting Handbook.
Wind turbine visibility
The visual impact of turbines is often a concern for communities, though this is a very subjective issue. While some people may find the turbines to be intrusive, others see them as elegant features. Local conditions of the project site have significant influence on the visibility of wind turbines and the degree to which area residents will be impacted. The local topography (e.g. hilly, flat agricultural, etc.) can impact visibility, as can the land cover (e.g. forest, grassland, cropland, etc.). Turbine size can have a mixed influence on the visual impact, as a project with larger turbines will have fewer, but more visible towers and rotors.
Due to the multitude of variables that affect visibility, wind developers perform visual impact assessments for proposed locations. Using digital imagery, the appearance of the proposed project in various seasons and at various times of day can be modeled and presented to community members prior to construction.
Another potential visual impact is known as shadow flicker, which occurs when the sun is at such an angle that the shadow of the rotating turbine blades is cast on a building, road, or other area occupied by people. Wind siting software can model the exact dates and times that shadow flicker will occur at a specific site and, if necessary, this can be mitigated by setbacks or vegetative screening.
Wind Turbine Sound
The sounds heard by wind turbines can vary based on many factors including the meteorological conditions in the area, whether the receptor is upwind or downwind from the turbines, distance from the turbines, and vegetation or other obstructions near the receptor. The sound commonly heard from utility scale wind turbines is a “whooshing” sound that is created as the wind turns the turbine blades. The sound impacts from wind projects can also be modeled as the project is being planned to ensure that the sound levels will fall within the limits set by local ordinance.
Wind turbines can have an impact on radar systems, including weather radar, military radar and aviation radar. As with other large objects, wind turbines can appear on radar screens as “clutter,” which is a reflected signal that can make the identification of targets of interest more difficult. The Federal Aviation Administration (FAA) performs an obstruction evaluation for structures over 200 feet tall, including wind turbines. Once a developer submits the required 7460-1 form, other agencies are informed of the location of proposed wind turbine and they provide feedback to the FAA on potential impacts as well. The Department of Defense Siting Clearinghouse evaluates the impact of energy projects on its military test, training, and operational missions and has found over 20 Gigawatts of projects to be mission-compatible.
North Carolina Model Wind Ordinance
The North Carolina Wind Working Group developed the Model Wind Ordinance for Wind Energy Facilities in North Carolina (include link to document) in 2008 as a resource for communities considering wind energy development. The ordinance was developed in a collaborative effort that included federal and state agencies, wind industry professionals, non- profit organizations, and other stakeholders interested in responsible wind energy development.
The model ordinance is intended to provide assistance to communities designing a local wind ordinance. The North Carolina Wind Working Group encourages each community to modify the model ordinance to meet their needs. However, it is important to note that the setbacks are minimum requirements, designed to protect public safety and mitigate the impacts of noise and shadow flicker. By addressing these concerns through minimum setback requirements, the model wind ordinance omits lot size requirements and height restrictions – which can be found in several North Carolina ordinances.
While North Carolina’s primary wind resources are located in mountain and coastal counties, the model ordinance does not consider or account for regional variations – such as hurricanes. Therefore, the Wind Working Group encourages communities to consider important local factors when crafting a wind ordinance. Finally, communities should also understand that the adoption of a local wind ordinance will not preclude a wind energy facility from the requirements of applicable state and federal regulations.
As of early 2013, over 10 local wind ordinances are in place in North Carolina – including several counties that have wind projects proposed. See the Database of State Incentives for Renewables and Efficiency for more information.
 NYSERDA. Power Naturally – Wind Energy Toolkit: Other Potential Environmental Impacts. October 2005. http://www.powernaturally.org/programs/wind/toolkit/5_otherpotenviroimpactsrevised.pdf