(A) Zoning districts.
(1) Utility wind turbines shall be allowed as an accessory use in the I and BP districts.
(2) Small wind turbines shall be allowed as an accessory use in all business districts, and non residential uses in commercial districts.
(3) Residential wind turbines (only vertical axis style permitted) shall be allowed as an accessory use in all residential districts.
(B) Number. No more than one WECS is allowed per parcel.
(C) Design standards.
(1) Height. The permitted maximum height of a WECS shall be determined on the type of system proposed.
(a) Utility wind turbines. The height of a freestanding WECS located in a BP or I district shall not exceed 100 feet.
(b) Small wind turbines. The height of a freestanding WECS located in a business district shall not exceed 75 feet.
(c) Residential wind turbines. Residential wind turbines can be either building mounted a maximum height of 15 feet above the roofline of the principal structure; or mounted on a tower a maximum height of 20 feet above the roof line of the principal structure. Poles must be connected to the principal structure and cannot be freestanding. All residential wind turbines shall be of the vertical axis style.
(d) The structure upon which the proposed WECS is to be mounted shall have the structural integrity to carry the weight and wind loads of the WECS and have minimal vibration impacts on the structure.
(e) Poles shall match the color of the principal structure.
(2) Blade length. A maximum blade length of 15 feet is permitted.
(3) Setbacks for building mounted. A building or roof mounted vertical axis style WECS shall be located only on the side or rear rooflines.
(4) Easements. Wind energy systems shall not encroach on public drainage, utility roadway or trail easements.
(5) Rotor clearance. Blade-arcs created by the WECS shall have a minimum of 30 feet of clearance over any structure or tree within a 300 foot radius.
(6) 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.
(7) Aesthetics. All portions of the wind energy system shall be a nonreflective, non-obtrusive color, subject to the approval of the City Planner. Only monopole towers are permitted. 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, except for applicable warning and equipment information required by the manufacturer or by federal, state or local regulations. Systems shall not be illuminated.
(G) Noise. Wind energy systems shall comply with Minnesota Pollution Control Agency standards, as outlined in Minn. Rules Chapter 7030, at all property lines.
(I) Safety.
(1) Standards. 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 community development director.
(2) Maintenance. Wind energy systems shall be maintained under an agreement or contract by the manufacturer or other qualified entity.
(3) The WECS shall be equipped with both a manual and an automatic braking device capable of stopping the WECS operation in high winds.
(4) Tower access. To prevent unauthorized climbing, WECS towers must comply with one of the following provisions:
(a) Tower climbing apparatus shall not be located within 12 feet off the ground.
(b) A located anti-climb device shall be installed on the tower.
(c) Tower capable of being climbed shall be enclosed by a locked, protective fence at least eight feet high.
(J) Utility connection. All grid connected systems shall have an agreement with the local utility prior to the issuance of a building permit. A visible external disconnect must be provided if required by the utility.
(K) Abandonment. If the wind energy system remains nonfunctional or inoperative for a continuous period of one 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.
(L) Permits. A building permit shall be obtained for any wind energy system prior to installation. All applications shall be accompanied by detailed plans and specifications including, but not limited to, the following information:
(1) Site Plan showing:
(a) Lot lines and dimensions.
(b) Location and height of all buildings, structures, above ground utilities and trees on the lot, including both existing and proposed structures and guy wires anchors.
(c) Locations and height of all adjacent buildings, structures, above ground utilities and trees located within 300 feet of the exterior boundary of the property in question.
(d) Existing and proposed setbacks of all structures located on the property in question.
(2) Scaled drawings and photographic perspectives accurately depicting the structure the proposed location of the WECS and its relationship to structures on adjacent lots.
(3) A written certification from a licensed structural engineer that the structure has the structural integrity to carry the weight and wind loads of the WECS and have minimal vibration impacts on the structure.
(4) An analysis from a licensed engineer showing how the WECS shall be designed, constructed and operated in compliance with all applicable federal, state and local laws, codes, standards and ordinances.
(5) A written certification from a licensed engineer confirming that the WECS is designed to not cause electrical, radio frequency, television and other communication signal interference.
(6) Roof mounted WECS shall include detailed plans illustrating roof construction, mounting techniques and wind load capacity.
(Ord. 2012-1133, passed 3-5-12)