In 2007 Ashe County adopted a wind ordinance to regulate the use of wind-energy systems in unincorporated areas of the county and to describe the conditions by which a permit for installing such a system may be obtained. This policy was adopted in the context of an ongoing debate over the legal interpretation of the 1983 Ridge Protection Act.
For the purposes of this ordinance, wind-energy systems are classified as “large” if they consist of one or more turbines with a rated generating capacity of more than 20 kilowatts (kW) and “small” if a project consists of a single turbine rated at less than 20 kW.* A site permit is required to establish, place, operate, maintain, expand or enlarge a wind energy system.
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 turbines are restricted to a 135-foot height limit and large systems to a 199-foot height limit. This latter height is based on Federal Aviation Administration regulations requiring lighting to warn aircraft of air space hazards. Large wind energy systems are also prohibited from rising above the vegetative canopy of protected mountain ridges by more than 35 feet. Protected ridges are defined as those on mountains rising more than 500 feet above adjacent valley floors.
Clearance: Rotor blades on wind turbines must maintain at least 24 feet of clearance between their lowest point and the ground.
Visual Appearance: Towers and rotor blades must be painted or finished so as to conform to their surroundings and reduce visual obtrusiveness. Wind systems must also remain free from signage, advertising, flags, streamers, and other decorative items. Electric wiring for the turbines, “insofar as possible,” must be placed underground.
Setbacks: The ordinance generally requires that large wind systems must be set back at least 1,000 feet from neighboring property lines. Wind systems must also be set back from public and private roads a distance of at least 1.5 times the height of the tallest turbine on the property. Large wind-energy systems must comply with state and federal requirements for setbacks from streams, creeks, branches, rivers and other surface waters.
Noise Requirements: The aggregate noise or audible sound of a large wind system must not exceed five decibels above the existing average noise level of the surrounding area and is restricted to a maximum of 45 decibels measured outside the property lines that contain the wind system.
Building Permit Requirements: A building permit is required, and building permit applications for wind-energy systems must be accompanied by standard drawings of the turbine structure, including the tower, base and footings. An engineering analysis of the tower certified by a licensed professional engineer, including standards for ice/wind loading, must also be submitted. (This analysis may be supplied by the manufacturer.)
Impact Analysis, Mitigation, and Planning: Applications for large wind-energy projects must include the following: building and electrical permits; site and design information; construction, operation, maintenance and insurance information; decommissioning information; a comprehensive third-party impact analysis and all other relevant permits and approvals. All applicants must also undergo a public hearing so that the county planning board may receive comments and other information pertinent to the application.
* Multiple small wind energy systems located on farms are considered to be separate small wind-energy systems even if the aggregate rated capacity exceeds 20 kW, provided that the primary intent is to generate power to reduce on-site consumption.