(A) WT-01 small wind turbine systems. This wind turbine system standards division (A) applies to the following zoning districts: PR; AG; IA; R1; R2; R3; M1; M2; MP; UV; IS; NC; LC; GC; OC; CB; HC; EP; IC; I1; I2; and HI. The following standards apply to small wind turbine systems.
(1) Permitted systems.
(a) Horizontal axis wind turbine. A horizontal axis small wind turbine system shall be permitted as per the standards in this division (A).
(b) Vertical axis wind turbine. A vertical axis small wind turbine system shall be permitted as per the standards in this division (A).
(2) Prerequisites.
(a) Energy production purpose. Small wind turbine systems shall be primarily sized and installed for the purpose of generating energy for an on-site use (i.e., residence, small business or farmstead). The small wind turbine system shall be sized to not produce more than 150% of the annual on-site electricity needs.
(b) Lot size. A minimum three-quarter acre lot shall be required for a small wind turbine system to be installed.
(c) Manufacturer installation specifications. Any permitted small wind turbine system shall be installed according to the manufacturer’s specifications unless in conflict with applicable standards in this unified development chapter. When conflicts exist, the following standards apply.
1. Manufacturer specifications are more strict. When the manufacturer’s specifications are more strict than this chapter, the manufacturer’s specifications shall be followed.
2. Zoning standards are more strict. When this chapter is more strict than the manufacturer’s specifications, this chapter shall prevail, and that particular small wind turbine system shall be considered not permitted.
(3) Turbine system limitations.
(a) Minimum ratings. A small wind turbine system shall be Underwriters Laboratories (UL) listed, have Conformite Europeenne marking (CE Mark) for Europe-based manufacturers, be certified by the Canadian Standards Association (CSA) for Canada-based manufacturers or otherwise approved by an equivalent region-based or county-based standards association recognized as equivalent to the Underwriters Laboratories (UL).
(b) Experimental turbines. Any small wind turbine system that does not meet the minimum ratings shall be considered experimental and shall not be permitted.
(c) Connection to the grid. Any small wind turbine system that is intended to be connected to the power grid shall be IEEE 1547 compliant (Institute of Electrical and Electronics Engineers Standard for Interconnecting Distributed Resources with Electric Power Systems).
(4) Supporting structure.
(a) Tower-mounted. A horizontal axis small wind turbine system designed for tower mounting may be mounted on a monopole, pole with guy wires, lattice tower or lattice tower with guy wires.
(b) Roof-mounted. A horizontal or vertical axis small wind turbine system designed for roof mounting may be mounted to the roof of a primary or accessory building.
(c) Ground-mounted. A vertical axis small wind turbine system designed for ground mounting shall be mounted on the ground.
(5) Height limitations.
(a) Tower-mounted. The maximum tower height for a small wind turbine system shall be 80 feet for lots under five acres, and 110 feet for lots five acres or greater.
(b) Roof-mounted. The maximum height of all components of a roof-mounted small wind turbine system shall be six feet above the highest point of the roof for residential buildings and ten feet above the highest point on the roof for agricultural, commercial, institutional and industrial uses.
(c) Ground-mounted. The maximum height of all components of a ground-mounted small wind turbine system shall be 40 feet.
(6) Maximum number of turbine systems.
(a) Small lot. A lot with two acres or less shall be restricted to one horizontal axis small wind turbine system and one vertical axis roof- mounted small wind turbine system.
(b) Large lots. A lot with more than two acres may have:
1. Up to two tower-mounted horizontal axis or ground-mounted vertical axis small wind turbine systems; and
2. Up to three roof-mounted vertical axis small wind turbine systems.
(7) Wind load. A small wind turbine system shall be engineered to survive a 100 mph wind load or greater.
(8) Rotor diameter. The maximum rotor diameter shall be 20 feet for a small wind turbine system with a maximum rated power of less than 11 kilowatts (kW); and 40 feet for a small wind turbine system with a maximum rated power of 11 kilowatt (kW) or greater.
(9) Location restrictions.
(a) Setback from property line. A small wind turbine system, not including guy wires, shall be a minimum of 25 feet from the property line or 110% of the height of the tower, whichever is greater.
(b) Setback from buildings. A small wind turbine system, not including guy wires, shall not be required to be setback from any on-site building.
(c) Setback from utilities. A small wind turbine system, not including guy wires, shall be a minimum of 50 feet from any above-ground utility line or 120% of the height of the tower, whichever is greater.
(d) Setback for guy wires. Guy wire anchors shall be at least 15 feet from all property lines.
(10) Safety.
(a) Roof-mounted systems. The rotors (i.e., blades) of a horizontal axis turbine mounted on a roof shall not extend horizontally beyond the roof line of the building to which it is attached.
(b) Ground clearance. The rotors (i.e., blades) of a horizontal axis wind turbine mounted on a tower shall not extend vertically to within 20 feet of the ground.
(c) Overspeed protection. A small wind turbine system shall have a fail-safe breaking system, auto-furling system or similar system to prevent structural failure due to excessive revolutions per minute (rpm). Overspeed protection shall be a proven industry standard.
(11) Nuisance prevention.
(a) Noise. A small wind turbine system shall not generate more than 40 decibels (db) at any point 100 feet from the small wind turbine system.
(b) Illumination. A small wind turbine system shall not be illuminated in any way unless required by FAA regulations.
(12) Abandoned systems. A small wind turbine system shall be considered abandoned if its use as a wind turbine system is discontinued for more than six months. The small wind turbine system shall be removed within six months after being abandoned.
(13) Appurtenances. A small wind turbine system shall not have any appurtenances (e.g., lighting, flags, signs or decorations) attached to it except for meteorological measuring equipment.
(Ord. 10-2010, passed - -2010, § 5.96)
(B) WT-02: large wind turbine systems. This wind turbine system standards division (B) applies to the following zoning districts: PR; AG; IA; M2; UV; IS; LC; GC; OC; HC; EP; IC; I1; I2; and HI. The following standards apply to large wind turbine systems.
(1) Permitted systems.
(a) Horizontal axis wind turbine. A horizontal axis large wind turbine system shall be permitted as per the standards in this division (B).
(b) Vertical axis wind turbine. A vertical axis large wind turbine system shall be permitted as per the standards in this division (B).
(2) Prerequisites.
(a) Energy production purpose. Large wind turbine systems shall be primarily sized and installed for the purpose of generating energy for an on-site use (e.g., a school, industry or office building). The large wind turbine system shall be sized to not produce more than 200% of the annual on-site electricity needs.
(b) Lot size. A minimum two acre lot shall be required for a large wind turbine system to be installed.
(c) Manufacturer installation specifications. Any permitted large wind turbine system shall be installed according to the manufacturer’s specifications unless in conflict with applicable standards in this unified development chapter. When conflicts exist, the following standards apply.
1. Manufacturer specifications are more strict. When the manufacturer’s specifications are more strict than this chapter, the manufacturer’s specifications shall be followed.
2. Zoning standards are more strict. When this chapter is more strict than the manufacturer’s specifications, this chapter shall prevail and that particular large wind turbine system shall be considered not permitted.
(3) Turbine system limitations.
(a) Minimum ratings. A large wind turbine system shall be manufactured to meet all applicable industry standards for manufacturing practices and safety.
(b) Experimental turbines. A large wind turbine system that does not meet the applicable minimum ratings shall be considered experimental and shall not be permitted.
(c) Connection to the grid. A large wind turbine system that is intended to be connected to the power grid shall be IEEE 1547 compliant (Institute of Electrical and Electronics Engineers Standard for Interconnecting Distributed Resources with Electric Power Systems).
(4) Supporting structure.
(a) Tower-mounted systems. A horizontal axis large wind turbine system designed for tower mounting shall be mounted on a monopole. Lattice towers and towers with guy wires shall not be permitted.
(b) Roof-mounted. A large wind turbine system shall not be permitted to be mounted on a roof.
(c) Ground-mounted systems. A vertical axis large wind turbine system designed for ground mounting shall be mounted on the ground.
(5) Height limitations.
(a) Tower-mounted. The maximum tower height for a large wind turbine system shall be 120 feet for lots under five acres, and 140 feet for lots five acres or greater.
(b) Roof-mounted. Large wind turbine systems are not permitted to be mounted on a roof.
(c) Ground-mounted. The maximum height of all components of a ground mounted large wind turbine system shall be 60 feet.
(6) Maximum number of turbine systems.
(a) Small lot. A lot with 15 acres or less shall be restricted to one horizontal axis or vertical axis large wind turbine system.
(b) Large lots. A lot with more than 15 acres may have up to two horizontal axis or vertical axis large wind turbine systems.
(7) Wind load. A large wind turbine system shall be engineered to survive a 110 mph wind load or greater.
(8) Rotor diameter. The maximum rotor diameter shall be 200 feet for a large wind turbine system.
(9) Location restrictions.
(a) Setback from property line. A large wind turbine system shall be a minimum of 100 feet or 200% of the hub height from the property line, whichever is greater.
(b) Setback from on-site buildings. A large wind turbine system shall be required to be setback 100 feet from any on-site primary building. There is no required setback from accessory structures.
(c) Setback from off-site land uses. A large wind turbine system shall be a minimum of 1,000 feet from a platted residential subdivision, multiple-family residential development, institutional use (e.g., school or church), land zoned single-family residential, land zoned multiple-residential or land zoned institutional. These standards only apply to off-site properties and should not be construed as restricting any of the above listed types of development (e.g., school or multiple-family development) from choosing to have an on-site large wind turbine system.
(d) Setback from utilities. A large wind turbine system shall be a minimum of 200 feet or 200% of the hub height from above ground transmission lines, utility lines or substations, whichever is greater.
(10) Safety.
(a) Ground clearance. The rotors (i.e., blades) of a horizontal axis large wind turbine system mounted on a tower shall not extend vertically to within 30 feet of the ground.
(b) Anti-icing technology. A large wind turbine system shall be equipped with technology able to detect icing on rotors that causes the system to shut down when experiencing a significant icing event; or shall utilize another industry accepted standard for protecting against shedding of significant pieces of ice capable of damaging nearby buildings and/or injuring persons or animals on the ground.
(c) Controls and brakes. A large wind turbine system shall be equipped with a redundant braking system that includes both aerodynamic overspeed controls (i.e., variable pitch, tip and other similar systems) and mechanical brakes.
(11) Nuisance prevention.
(a) Noise. A large wind turbine system shall not generate more than 40 decibels (db) at 1,000 feet from the large wind turbine system.
(b) Illumination. A large wind turbine system shall not be illuminated in any way unless required by or Federal Aviation Administration (FAA) regulations. Federal Aviation Administration (FAA) regulations shall be demonstrated to the Zoning Administrator prior to installation. If signal lighting is required on the top of a large wind turbine system, then it shall be shielded to prevent light below the horizontal plain.
(c) Shadow flicker. The flickering effect caused by an Federal Aviation Administration (FAA) required signal light and the turning of the rotor shall be mitigated to the extent possible with the best known technology or practice.
(d) Color. A large wind turbine system shall be a non-obtrusive color such as white, off-white, gray, earth tones or similar non-reflective colors.
(e) Signs. No large wind turbine system shall be used to display a commercial message.
(f) Signal interference. The owner shall make reasonable efforts to avoid any disruption or loss of radio, telephone, television or similar signals, and shall mitigate any harm caused by the large wind turbine system.
(12) Abandoned systems. A large wind turbine system shall be considered abandoned if its use as a wind turbine system is discontinued for more than six months. The large wind turbine system shall be removed within nine months after being abandoned.
(13) Appurtenances. A large wind turbine system shall not have any appurtenances (e.g., exterior lighting, wireless communication antennas or ornamentation). Weather monitoring devices and safety equipment shall not be considered appurtenances.
(Ord. 10-2010, passed - -2010, § 5.97)