§ 11.83  WIND ENERGY CONVERSION SYSTEMS (WECS).
   Subd. 1.   Purpose.  The purpose of this section is to provide for the regulation of the construction and operation of wind energy conversion systems in the city, subject to reasonable conditions that will protect the environment, public health, safety, and welfare.
   Subd. 2.   Definitions.  For the purpose of this section, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
      A.     FACILITY OPERATOR.  The entity responsible for the day-to-day operation and maintenance of the wind energy conversion system.
      B.     FACILITY OWNER.  The entity or entities having controlling or majority equity interest in the wind energy conversion system, including their respective successors and assigns.
      C.     SUBSTATION.  The apparatus that connects the electrical collection system of the WECS(s) and increases the voltage for connection with the utility's transmission lines.
      D.     WECS, LARGE.  A wind energy conversion system consisting of one or more wind turbine(s), a tower(s), and associated control or conversion electronics, which has a total rated capacity of 50 or more kW.
      E.     WECS, SMALL.  A single system designed to supplement other electricity sources as an accessory use to existing buildings or facilities, wherein the power generated is used primarily for on-site consumption.  A small wind energy conversion system consists of a single wind turbine, a tower or roof mounted system, and associated control or conversion electronics, which has a total rated capacity less than 50 kW.
      F.     WIND POWER.  The conversion of wind energy into another form of energy.
      G.     WIND TURBINE HEIGHT.  The distance measured from grade at the center of the tower to the highest point of the turbine rotor or tip of the turbine blade when it reaches its highest elevation.
   Subd. 3.   Conditional use.  Wind energy conversion systems shall be allowed as a conditional use in districts as follows:
 
District
Small WECs
Large WECs
A-1
CUP
CUP
R-1, R-2, R-O & R-M
See Footnote No. 1
B-2
CUP
Not permitted
B-1 & B-3
CUP
Not permitted
 
 
District
Small WECs
Large WECs
I-1
CUP
CUP
I-2 & I-3
CUP
CUP
PUD
Site plan approval pursuant to City Code § 11.65
Not permitted
Footnote No 1:  Only wind energy conversion systems located on Austin Public School District 492 and Minnesota State College and University System properties shall be allowed as conditional uses.
   Subd. 4.   Permit application.  Application for a WECS permit shall be accompanied by drawings that show the following:
      A.     Location of the proposed WECS, and any other auxiliary equipment;
      B.     Property lines and physical dimensions of the lot;
      C.     A photograph or detailed drawing of the WECS, including the tower;
      D.     Specific information on the WECS, including type, size, rated power output, rotor material and performance, safety and noise characteristics;
      E.     Specific information on the type, height and material of the tower;
      F.     Clearance distances between the farthest extension of the WECS blades to property lines;
      G.     Location, dimensions and types of existing structures and uses on the lot;
      H.     Location of all above ground utility lines within distance equivalent to the total height of the WECS; and
      I.     Location and size of structures, trees and other objects within 300 feet which are taller than the lowest extent of the blades of the proposed WECS.
   Subd. 5.     Size regulations; compliance.
      A.     Rotors:
         1.     No WECS in a residential or commercial district shall have rotors that are longer than 35 feet in diameter.
         2.     No WECS in an industrial or agricultural district shall have rotors that are longer than 50 feet in diameter.
         3.     The minimum height of the lowest extent of any WECS rotor shall be 30 feet above the ground.
      B.    Height:  Free-standing wind turbine height limits:
 
District
Small WECs
Large WECs
A-1
150 feet
250 feet
R-1, R-2, R-O, & R-M
75 feet
150
B-1 & B-3
75 feet
N/A
B-2
150 feet
N/A
I-1
150 feet
150 feet
I-2 & I-3
150 feet
250 feet
PUD
150 feet
N/A
 
      C.     Compliance with regulations:  All WECS shall comply with federal aviation administration notification requirements and any other applicable regulations.
   Subd. 6.     Installation and design.
      A.   Towers:
         1.     All WECS tower structures shall be designed and constructed to be in compliance with pertinent provisions of the Minnesota State Building Code.  Indication of compliance may be obtained from the manufacturer's engineering staff or a state registered professional engineer.
         2.    The compatibility of the tower structure with the rotors and other components of the WECS shall be certified by a state registered professional engineer.
         3.     WECS towers shall either have tower climbing apparatus located not closer than 12 feet to the ground or be unclimbable by design for the first 12 feet.
      B.     Guy wire tower design shall not be permitted.
      C.     Over-speed control:  Every WECS shall be equipped with manual and automatic over-speed controls.  The conformance of rotor and over-speed control design and fabrication with good engineering practices shall be certified by a state registered professional engineer.
      D.     Electrical requirements:
         1.     All electrical components of the WECS shall be in compliance with the applicable requirements of the National Electrical Code as currently adopted by the Minnesota State Building Code Division and shall be inspected by a qualified electrical inspector.  The interconnection between the WECS and the electric utility shall be in compliance with the most recent edition of the National Electrical Code.  Certification will be supplied in writing that the WECS will automatically disconnect from the utility when there is no power input from the utility.  This certification can be supplied by the manufacturer of the WECS.
         2.     The interconnection of the WECS with the local electrical utility shall comply with all applicable federal and state regulations.  Every applicant for a WECS permit should notify his/her electrical utility in advance of his/her installation plans.
         3.     Every battery storage unit associated with a WECS shall be in compliance with the National Electrical Code as currently adopted by the Minnesota State Building Code Division and shall be inspected by a qualified electrical inspector.
         4.     The WECS, including the blades, shall be grounded and shielded to protect against natural lightning strikes in conformance with the current adopted version of the National Electrical Code.
         5.     No WECS shall have affixed or attached lights, reflectors, flashers or any other illumination, except for those devices required by the Federal Aviation Administration.
      E.     Structural components:
         1.     The safety of structural components of every WECS and the compatibility of the rotors with the towers of WECS shall be certified by a state registered professional engineer.  The safety of electrical components of every WECS shall be certified by a state registered professional electrical engineer.
         2.     The safety of all modifications to any WECS shall be certified by a state registered professional engineer.  Certification of safety is required before the building permit is granted for modifications made prior to installation.  Certification of the safety of modifications made after the WECS is installed and the permit is granted is also required.  Failure to have the safety of modifications certified after the permit has been granted shall result in revocation of the permit until certification has been obtained.
      F.     Signs required:  At least one sign shall be posted at the base of the WECS tower and shall contain the following information:
         1.     Notice of no trespassing;
         2.     Warning of high voltage; and
         3.     The visual appearance of WECS shall at a minimum:
            a.     Be a non-obtrusive color such as white, off-white or gray; and
            b.     Not display advertising (including flags, streamers or decorative items), except for identification of the turbine manufacturer, facility owner and operator.
   Subd. 7.   Siting.
      A.     The base of the tower of any WECS shall be set back from any property line a minimum of:
 
District
Small WECs
Large WECs
A-1
1.1 times the WECS's height
1,000 feet
R-1, R-2, R-O & R-M
1.1 times the WECS's height
1.1 times the WECS's height
B-1 & B-3
1.1 times the WECS's height
N/A
B-2
1.1 times the WECS's height
N/A
I-1
1.1 times the WECS's height
1.1 times the WECS's height
I-2 & I-3
1.1 times the WECS's height
1,000 feet
PUD
1.1 times the WECS's height
N/A
 
      B.     No part of a WECS shall be located within or over drainage, utility or other established easements.
      C.     No part of a WECS shall be located on or over property lines.
      D.     The base of a WECS tower shall not be on any required minimum front, side or rear yards as defined in § 11.01, Subd. 92, 93, 94, and 95 for their respective zoning district.
      E.     Efforts should be made when siting a WECS and any related equipment to avoid locations that may be vulnerable to vehicular accidents.
      F.     Clearance between a WECS and electrical lines shall be in compliance with the requirements outlined in the most recent edition of the National Electrical Code.
      G.     A wind turbine must not be within any conservation easement.
      H.     Siting on top of buildings:  Every WECS sited on top of a building shall comply with applicable provisions of the Minnesota State Building Code.  Certification of compliance by a state registered professional engineer is required.  The WECS must be less than ten kW and not extend higher than 15 feet above the maximum height allowed for the structure the WECS is mounted on.
   Subd. 8.   Nuisance concerns.
      A.     Noise setbacks:  The Planning Commission may impose a noise setback that exceeds the other setbacks set out in this section if it deems that such greater setbacks are necessary to protect the public health and safety of the community.
      B.     Audible noise standard:  The audible noise standard due to wind turbine operations shall not be created which causes the noise level at the boundary of the proposed project site to exceed 45 dB(A) for more than five minutes out of any one hour time period or to exceed 50 dB(A) for any time period.
      C.     Low frequency noise or infrasound noise:  Low frequency noise or infrasound noise from wind turbine operations shall not be created which causes the noise level at the boundary of the proposed project site to exceed the following limits:
 
1/3 Octave Band Center Frequency (Hz)
Sound Pressure Level (dB)
2 to 1
70 (each band)
20
68
25
67
31.5
65
40
62
50
60
63
57
80
55
100
52
125
50
 
      D.     Pure tone penalty:  In the event audible noise due to wind turbine operations contains a steady pure tone, such as a whine, screech, or hum, the standards for audible noise shall be reduced by five dB(A).  A pure tone is defined to exist when: the one-third octave band sound pressure level in the band, including the tone, exceeds the arithmetic average of the sound pressure levels on the two contiguous one-third octave bands by five dB(A) for center frequencies of 500 Hz and above, and eight dB(A) for center frequencies less than or equal to 125 Hz.
      E.     Repetitive, impulsive sound penalty:  In the event the audible noise due to wind turbine operations contains repetitive impulsive sounds, the standards for audible noise shall be reduced by five dB(A).
      F.     Pure tone and repetitive, impulsive tone penalty:  In the event the audible noise due to wind turbine operation contains both a pure tone and repetitive impulsive sounds, the standards for audible noise shall be reduced by a total of five dB)A).
      G.     Operations – low frequency noise:  A commercial wind energy facility shall not be operated so that impulsive sound below 20 Hz adversely affects the habitability or use of any dwelling unit, hospital, school, library, nursing home, or other sensitive noise receptor.
      H.     Noise complaint and investigation process required:  Applicant shall submit a noise complaint and investigation process based on the requirements set out in the application section.  The Planning Commission shall determine the adequacy of the noise complaint and investigation process.
      I.     Any noise level falling between two whole decibels shall be the lower of the two.
      J.     In the event the noise levels resulting from the wind energy conversion system exceed the criteria listed above, a waiver to said levels may be granted by the Planning Commission provided that the following has been accomplished:
         1.     Written consent from the non-applicant, affected property owners has been obtained stating that they are aware of the wind energy conversion system and the noise limitations imposed by this section, and that consent is granted to allow noise levels to exceed the maximum limits otherwise allowed; and
         2.     If the applicant wishes the waiver to apply to succeeding owners of the property, a permanent noise impact easement has been recorded in the Office of the Mower County Recorder which describes the benefitted and burdened properties and which advises all subsequent owners of the burdened property that noise levels in excess of those permitted by this section may exist on or at the burdened property.
   Subd. 9.   Other regulations.
      A.     Supplying more than one structure:  A WECS that supplies energy to two or more structures shall be allowed as long as the proposed WECS complies with all applicable zoning regulations and current adopted electrical codes
      B.     Wind access:  Adequate wind access is essential to the safe and efficient operation of a WECS, and the city encourages the use of private and restrictive covenants to protect wind access.
      C.     Maintenance requirements; abandonment; nuisance:
         1.     It shall be a public nuisance if any of the following conditions exist:
            a.     A WECS is not maintained in operational condition and poses a potential safety hazard;
            b.     A WECS is not maintained and operated in compliance with applicable zoning provisions and state and federal laws; or
            c.     A WECS has not generated electricity for a period of 12 consecutive months and the wind energy facility owner has failed to remove the WECS or make it operational within 30 days after the city has given written notice to remove the WECS.
      D.     Exemptions from provisions:  Any WECS that is by nature ornamental, rather than functional, shall be exempt from this section if total height is less than 25 feet.
      E.     Inspections:  Each WECS shall be inspected yearly by the Building Official, to verify that the WECS is operational and that all requirements of installation continue to be met.
      F.     All wind turbines shall comply with all applicable state and federal regulatory standards, including the Minnesota State Building Code as adopted by the State of Minnesota; National Electrical Code as adopted by the State of Minnesota; and Federal Aviation Administration (FAA) requirements; and Minnesota Pollution Control Agency (MPCA)/Environmental Protection Agency (EPA) regulation (hazardous waste, construction, storm water, etc.)
(Ord. 585, passed 6-7-10)