(A) Zoning district allowance. Small wind turbine systems in accordance with the standards in this chapter are allowed as a permitted accessory use in all zoning districts.
(B) General standards. The following standards shall be applicable to small wind turbine systems in all zoning districts:
(1) Number. No more than 1 wind energy system is permitted per parcel.
(2) Setbacks. The base of the wind turbine tower shall be set back from all property lines a distance equal to the highest possible extension of the system apparatus.
(3) Roof mounting. Roof mounted wind turbines shall be permitted only when a determination is made by the City Building Official that the underlying roof structure will support such system and all applicable building standards are satisfied.
(4) Rotor clearance. No part of a rotor blade shall be located within 30 feet of the ground and within 20 feet of the nearest tree, structure or aboveground utility facility.
(5) Noise. Wind energy systems shall comply with Minnesota pollution control agency noise standards outlined in Minnesota Rules Ch. 7030 at all property lines.
(6) Screening. Wind energy systems shall be screened from view to the extent possible without impacting their function.
(7) Aesthetics. All portions of the wind energy system shall be a nonreflective, nonobtrusive color, subject to the approval of the zoning administrator. The appearance of the turbine, tower and any other related components shall be maintained throughout the life of the wind energy system pursuant to industry standards. Systems shall not be used for displaying any advertising. Systems shall not be illuminated.
(8) Feeder lines. The electrical collection system shall be placed underground within the interior of each parcel. The collection system may be placed overhead near substations or points of interconnection to the electric grid.
(9) Safety.
(a) Wind energy systems shall meet minimum standards such as International Electrotechnical Commission (IEC) 61400-2 or the American Wind Energy Association's (AWEA) small wind turbine performance and safety standard or other standards as determined by the City Building Official.
(b) Wind energy systems shall be certified by Underwriters Laboratories, Inc., and the National Renewable Energy Laboratory, the Small Wind Certification Council or other body as determined by the city. The city reserves the right to deny a building permit for proposed wind energy systems deemed to have inadequate certification or testing for operation in a severe winter climate.
(c) Wind energy systems shall be maintained under an agreement or contract by the manufacturer or other qualified entity.
(d) All grid connected systems shall have an agreement with the local utility prior to the issuance of a building permit. A visible external disconnect shall be provided if required by the utility.
(10) Abandonment. If a wind energy system remains nonfunctional or inoperative for a continuous period of 1 year, the system shall be deemed to be abandoned and shall constitute a public nuisance. The owner shall remove the abandoned system at their expense after a demolition permit has been obtained. Removal includes the entire structure including foundations to below natural grade and transmission equipment.
(11) Permits. A building permit, and conditional use permit if required, shall be obtained for any wind energy system prior to installation.
(C) Residential district standards.
(1) Mounting. All wind turbine systems shall be roof mounted. Ground mounted systems are not permitted.
(2) Height. Wind energy systems shall not extend more than 6 feet above the highest point of the roof.
(D) Commercial, industrial, and institutional district standards.
(1) Mounting. Subject to the requirements of this chapter, wind energy systems may either be roof mounted or ground mounted.
(2) Height.
(a) Except as may otherwise be allowed by conditional use permit, wind turbine systems shall conform to the maximum height requirements of the applicable commercial, industrial or institutional zoning district.
(b) Wind turbine system heights in excess of the maximum height requirement of the applicable zoning district may be permitted by conditional use permit provided that:
1. The system height, as measured from the base of the tower for ground mounted systems, or base of the building for roof mounted systems, to the highest possible extension of the system apparatus shall not exceed 75 feet.
2. The additional system height is required to allow for the improved operation of the wind energy system.
3. The additional wind energy system height results in a net energy gain.
4. The wind energy system does not adversely affect solar access to adjacent properties.
5. The wind energy system complies with all other engineering, building, safety, and fire regulations.
6. The wind energy system is found to not have any adverse impacts on the area, including the health, safety, and general welfare of occupants of neighboring properties and users of public rights-of-way.
7. The criteria and applicable standards of this section are considered and determined to be satisfied.
(3) Ground mounted systems.
(a) Ground mounted wind energy systems shall not be installed in the front yard of any lot or in the side yard of a corner lot adjacent to a public right-of-way.
(b) Only monopole towers are permitted.
(c) System height shall be measured from the base of the tower to the highest possible extension of the system apparatus.
(d) Ground located wind energy systems shall not encroach on public drainage, utility roadway or trail easements.
(4) Blade length. A maximum blade length of 15 feet is permitted.
(Ord. 2013-05, passed 5-20-2013)