Tyrrell County, located in northeastern North Carolina, adopted a wind ordinance in 2009 to regulate the use of wind energy facilities in the unincorporated areas of the county. The ordinance is substantially similar to the [http://www.dsireusa.org/library/includes/incentive2.cfm?Incentive_Code=N... model wind ordinance] drafted by the North Carolina Wind Working Group, and establishes parameters for the permitting process, height restrictions, minimum setbacks, noise and shadow flicker, installation and design, and decommissioning of retired systems.
For the purposes of this ordinance, wind energy facilities are classified as "small" if they consist of a single wind turbine with a rated generating capacity of 20 kilowatts (kW) or less, "medium" if one or more wind energy facilities have a total rated capacity of more than 20 kW but not greater than 100 kW, "large" if they have a total rated capacity of more than 100 kW but less than 999 kW, utility scale if they have a rated capacity of 1 MW or greater.
'''Permitting Process:''' All new wind energy facilities, or expansions of existing facilities must receive a permit from the County Planning Board prior to construction. A permit application must include a narrative describing the facility; approximate generating capacity; the proposed number and height of all wind turbines to be built; location of the proposed site and names and addresses of all adjoining property owners; a detailed site plan; certification of compliance with Federal Aviation Administration (FAA) regulations; decommissioning plans; and financial assurance that the owner can pay for decommissioning.
'''Height Requirements:''' The total height of a wind turbine is determined by the height above grade to the tip of the turbine blade as it reaches its highest elevation. Small wind systems are restricted to a 120-foot height limit, whereas medium and large systems are restricted to a 250-foot height limit, and utility scale systems are restricted to a 500-foot limit.
'''Setbacks:''' The setback is calculated by multiplying the required setback number by the wind turbine height and measured from the center of the wind turbine base to the property line, building or road. Setbacks are generally determined by the following table:
|Wind Energy Facility Type||Occupied Buildings on System Owner's Property||Occupied Buildings on Adjacent Property||Property Lines and Right-of-Ways||Highway 64|
'''Noise and Shadow Flicker:''' Noise and shadow flicker issues for small and medium wind energy facilities are addressed by setbacks, or will be addressed by existing noise ordinances. Audible sound from a large or utility scale wind energy facility should not exceed fifty-five dBA, as measured at any occupied building of a non-participating landowner. Shadow flicker at any occupied building on an adjacent property caused by a large or utility scale wind energy facility located within 2,500 ft of the building shall not exceed thirty hours per year. These restrictions may be waived under certain conditions.
'''Installation and Design:''' The installation of wind energy facilities must conform to all applicable industrial standards, including those of the American National Standards Institute. All structural, electrical and mechanical components for the facility must conform to relevant local, state and federal codes. Towers and rotor blades must be of a non-obtrusive color approved by the County Planning Board. Wind energy facilities must also remain free from advertising, including flags, streamers and other decorative items, as well as artificial lighting, except that which is required by the Federal Aviation Administration (FAA). Any on-site transmission or power lines must, to the extent possible, be placed underground.