§ 152.102. ALTERNATIVE ENERGY SYSTEMS.

(A) Purpose. The purpose of this section is to establish standards for alternative energy systems within the city.

(B) Ground source heat pump systems.

(1) Accessory use.

(a) Ground source heat pump systems shall be allowed as a permitted accessory use in all zoning districts in accordance with the standards in this section.

(b) Ground source heat pump systems in public water bodies or water bodies owned or managed by the City of Mayer shall be prohibited except for stormwater ponds managed by the City of Mayer and when accessory to a City of Mayer facility.

(2) System requirements.

(a) All ground source heat pump systems shall be closed loop systems that circulate heat transfer fluids as allowed by this section through pipes or coils buried beneath the land surface.

(b) Heat transfer fluids shall be limited to Minnesota Department of Health approved nontoxic, food grade fluids such as potable water, aqueous solutions of propylene glycol not to exceed 20% by weight or aqueous solutions of potassium acetate not to exceed 20% by weight.

(3) Location.

(a) Ground source heat pump systems shall only be located in the rear yard as defined by the City of Mayer zoning ordinance.

(b) All components of ground source heat pump systems shall be set back a minimum of five feet from interior side lot lines and ten feet from rear lot lines.

(c) Ground source heat pump systems shall not encroach upon drainage and utility easements or any other easement.

(4) Screening. Ground source heat pump systems installed for use in a commercial, industrial or institutional uses are considered mechanical equipment and shall be screened in accordance with the requirements of the city’s zoning ordinance, if required. Ground source heat pumps installed for residential use shall be exempt from the screening requirement.

(5) Noise. Ground source heat pump systems shall comply with Minnesota Pollution Control Agency standards outlined in Minnesota Rules Chapter 7030.

(6) Certification. The ground source heat pump system shall be certified by Underwriters Laboratories, Inc., and comply with the requirements of the international building code.

(7) Abandonment. Any ground source heat pump system which is inoperable for 12 successive months shall be deemed to be abandoned and shall be deemed a public nuisance. The owner shall remove the abandoned system at their expense after obtaining a demolition permit as follows:

(a) The heat pump and any external or aboveground mechanical equipment shall be removed.

(b) Pipes or coils below the land surface shall be filled with grout to displace the heat transfer fluid, which is to be captured and disposed of in accordance with state and federal regulations.

(c) The top of the pipe, coil or boring shall be uncovered and sealed.

(8) Building permit.

(a) A building permit shall be obtained for any ground source heat pump system prior to installation.

(b) Borings for ground source heat pump system where the pipes or coils are installed vertically below the land shall also be subject to approval by the Minnesota Department of Health.

(C) Solar energy systems (SES).

(1) Purpose and intent. Mayer finds that it is in the public interest to encourage the use and development of renewable energy systems that have a positive impact on energy conservation with limited adverse impact on nearby properties. As such, the city supports the use of solar energy systems and the development of solar farms. Mayer also finds that the development of solar farms should be balanced with the protection of the public health, safety and welfare. The city intends the following standards will ensure that solar farms can be constructed within the city while also protecting public safety and the natural resources of the city. Consistent with the Comprehensive Plan, it is the intent of the city, with this section, to create standards for the reasonable capture and use, by households, businesses and property owners, of their solar energy resource and encourage the development and use of solar energy.

(2) Severability. The provisions of this section shall be severable and the invalidity of any paragraph, subparagraph or subdivision thereof shall not make void any other paragraph, subparagraph or subdivision of this section.

(3) Applicability. These regulations are for all SES and solar farms on properties and structures under the jurisdiction of the zoning ordinance except that the city requires the owner or operator of solar farms that would generate more than 50 megawatts of power to get approval for such a system from the Minnesota Public Utilities Commission (PUC).

(4) Types of SES.

(a) Roof or building mounted SES. Accessory to the primary land use, designed to supply energy for the primary use.

1. Roof or building mounted SES are permitted accessory uses in all districts in which buildings are permitted.

2. All roof or building mounted SES shall meet the standards of the Minnesota Building Code and the owner or contractor shall receive a building or mechanical permit before installing a roof or building mounted SES.

3. Color. All roof or building mounted SES shall use colors that are the same or similar with the color of the building or roof material of the building on which the system is mounted.

4. Roof or building mounted SES shall not exceed the maximum allowed height in any zoning district and shall not extend beyond the perimeter of the roof line of the building on which it is mounted. For purposes of height measurement, roof or building mounted SES other than building-integrated systems shall be considered to be mechanical devices and are restricted consistent with other building mounted mechanical devices for the zoning district in which the system is being installed.

5. Roof mounted SES shall be placed on the roof to limit visibility from the public right-of-way or to blend into the roof design, provided that minimizing visibility still allows the property owner to reasonably capture solar energy.

(b) Ground mounted SES. Accessory to the primary land use, designed to supply energy for the primary use.

1. Ground mounted SES are permitted accessory uses in all districts in which buildings are permitted and shall be limited to a maximum area of 200 square feet in residential districts and shall not encompass more than 10% of the total property area or lot size in all other districts.

2. Ground mounted SES require a city building permit and is subject to the accessory use standards for the district in which it is located, including setback, height and impervious surface coverage limits.

3. The city does not consider the collector surface of a ground mounted SES that is not in a DNR designated Shoreland District as impervious surface. Any collector surface of a ground mounted SES foundation that is in a DNR designated Shoreland District and compacted soil or other component of the solar installation that rests on the ground is considered impervious surface.

4. The height of a ground mounted SES shall not exceed 20 feet at maximum tilt.

5. Ground mounted SES shall only be located in the rear yard as defined by this Chapter.

6. Ground mounted SES shall not encroach upon drainage and utility easements.

(c) Community SES. Community SES shall be accessory to the primary land use and designed to supply energy for off-site uses on the distribution grid, but not for export to the wholesale market or connection to the electric transmission grid. These systems shall be subject to the following conditions:

1. Community SES are permitted accessory uses in all districts in which buildings are permitted except for residential districts.

2. Prohibitions. The city prohibits community SES within:

i. Shoreland districts as designated by the Department of Natural Resources (DNR) and the Mayer Zoning Map.

ii. Wetlands to the extent required by the Minnesota Wetland Conservation Act.

iii. The Floodplain Management Area as approved by ordinance by the city.

iv. Residential districts.

3. An interconnection agreement must be submitted to the utility company and proof be provided to the city that the utility company has deemed the agreement “complete”.

4. All structures must meet the setback, height and coverage limitations for the zoning district in which the system is located, except as otherwise stated in this section.

5. Ground mounted community SES must meet all required standards for structures in the district in which the system is located.

6. Site plan required. The owner or operator shall submit to the city a detailed site plan for both existing and proposed conditions. These plans shall show the location of all areas where solar arrays would be placed, the existing and proposed structures, property lines, access points, fencing, landscaping, surface water drainage patterns, floodplains, wetlands, the ordinary high water mark for all water bodies, any other protected resources, topography, electric equipment and all other characteristics requested by the city.

7. Power and communication lines. Power and communication lines running between banks of solar panels and to electric substations or interconnections with buildings shall be buried underground. The city may grant exemptions to this requirement in instances where shallow bedrock, water courses or other elements of the natural landscape interfere with the ability to bury lines.

8. Decommissioning plan. The city requires the owner or operator to submit a decommissioning plan for community SES to ensure that the owner or operator properly removes the equipment and facilities upon the end of project life or after their useful life. The owner or operator shall decommission the solar panels in the event they are not in use for 12 consecutive months. The plan shall include provisions for the removal of all structures and foundations, the removal of all electrical transmission components, the restoration of soil and vegetation and a soundly-based plan ensuring financial resources will be available to fully decommission the site. The disposal of structures and/or foundations shall meet all city requirements. The city also may require the owner or operator to post a bond, letter of credit or establish an escrow account to ensure property decommissioning.

(d) Solar farms. Solar farms shall be ground mounted SES arrays that are the primary use on parcel on which it is located and are designed for providing energy to off-site uses or export to the wholesale market. Solar farms, including those that are not permitted or regulated by the State of Minnesota Public Utilities Commission (PUC), shall be subject to the following conditions:

1. Solar farms shall be permitted as an interim use in the C/I Commercial/Industrial and P/I Public/Institutional zoning districts, and shall be processed according to the standards of Chapter 1006 of the Zoning Ordinance.

2. Shall be on properties of at least five acres in size.

3. Stormwater management and erosion and sediment control shall meet the requirements of the city and best management practices.

4. Prohibitions. The city prohibits solar farms within:

i. Shoreland districts as designated by the Department of Natural Resources (DNR) and the Mayer Zoning Map.

ii. Wetlands to the extent required by the Minnesota Wetland Conservation Act.

iii. The Floodplain Management Area as approved by ordinance by the city.

5. Foundations. The manufacturer’s engineer or another qualified engineer shall certify that the foundation and design of the solar panels meets the accepted professional standards, given local soil and climate conditions.

6. Other standards and codes. All solar farms shall meet all applicable local, state and federal regulatory standards, including the State of Minnesota Building Code, as amended; and the National Electric Code, as amended.

7. Power and communication lines. All power and communication lines running between banks of solar panels and to electric substations or interconnections with buildings shall be buried underground. The city may grant exemptions to this requirement in instances where shallow bedrock, water courses or other elements of the natural landscape interfere with the ability to bury lines.

8. Interconnection. The owner or operator of the solar farm must complete an interconnection agreement with the electric utility in whose service territory the system is located.

9. Site plan required. The owner or operator of the solar farm must submit to the City a detailed site plan for both existing and proposed conditions. These plans shall show the location of all areas where solar arrays would be placed, the existing and proposed structures, property lines, access points to the site, fencing, landscaping, surface water drainage patterns, floodplains, wetlands, the ordinary high water mark for all water bodies, any other protected resources, topography, electric equipment and all other characteristics requested by the city. The plan shall be reviewed and approved by the city’s Emergency Management Director.

10. The owner or operator of the solar farm must submit to the city a detailed emergency shutdown plan as part of the review process.

11. The city allows the installation of small operations, security and equipment buildings on the site of solar farms as permitted accessory uses to the solar farm.

12. The owner or operator shall contain all unenclosed electrical conductors located above ground within structures that control access. In addition solar farms shall be protected from entry by a minimum six foot tall fence. Razor wire is prohibited on all fences. All electrical connections to the utility system must meet or exceed the National Electrical Safety Code.

13. Signage shall be posted at all entrance points to the property the solar farm is located on that includes at a minimum, the owner and operator’s name, contact information and emergency phone numbers.

14. The solar farm owner or operator shall provide access to the Mayer Fire Department either in the form of a lock or key to all access points to the property the solar farm is located on.

15. Solar farms that have panels that are ten megawatts or more shall meet the review and design standards of the MN Department of Commerce and/or MM Public Utilities Commission (PUC) for solar farms, as applicable.

16. Decommissioning plan. The city requires the owner or operator to submit a decommissioning plan for solar farms to ensure that the owner or operator properly removes the equipment and facilities upon the end of project life or after their useful life. The owner or operator shall decommission the solar panels in the event they are not in use for 12 consecutive months. The plan shall include provisions for the removal of ail structures and foundations, the removal of all electrical transmission components, the restoration of soil and vegetation and a soundly-based plan ensuring financial resources will be available to fully decommission the site. The disposal of structures and/or foundations shall meet all city requirements. The city also may require the owner or operator to post a bond, letter of credit or establish an escrow account to ensure property decommissioning.

(e) Additional standards. In addition to the standards allowed above, all SES shall meet the following standards.

1. The owners or operators of SES that are connected to the electric distribution or transmission system, either directly or through the existing service of the primary use on the site, shall obtain an interconnection agreement with the electric utility in whose service territory the system is located. Off-grid systems are exempt from this requirement.

2. Electric SES components that are connected to a building electric system must have an Underwriters Laboratory (UL) listing.

3. All SES shall meet the standards of the Minnesota and National Electric Code.

4. All SES using a reflector to enhance solar production shall minimize glare from the reflector that affects adjacent or nearby properties. Steps to minimize glare nuisance may include selective placement of the system, screening on the north side of the solar array, reducing use of the reflector system or other remedies that limit glare.

5. Setbacks. All SES structures and equipment shall meet the setback and coverage limitations for the zoning district in which the system is located, except that solar farms shall be setback from all property lines at least 100 feet. In addition, solar farms shall be screened from adjacent residential uses in accordance with § 152.091 Screening.

6. Abandonment. Any SES which is inoperable for 12 successive months shall be deemed to be abandoned and shall be deemed a public nuisance. The owner shall remove the abandoned system at their expense after obtaining a demolition permit.

7. Building permit. A building permit shall be obtained for any SES prior to installation.

8. All SES shall meet ail federal and state requirements including the Public Utilities Commission (PUC) including size requirements.

(D) Wind energy conversion systems (WECS).

(1) Purpose. The purpose of this section is to establish standards and procedures by which the installation and operation of wind energy conversion systems (WECS) shall be governed within the city.

(2) Application.

(a) Conditional use permit required.

1. The erection of a wind energy conversion system shall require approval of a conditional use permit, according to § 152.155 of this chapter.

2. Commercial wind energy conversion systems shall only be allowed as conditional uses within the A Agriculture zoning district on lots at least ten acres in area. The acreage restriction is required to protect WECS from encroachment by other uses or structures and to accommodate required setback between the WECS and property lines.

3. Non-commercial, tower-mounted WECS shall be allowed as conditional uses within A Agriculture, C-1 General Commerce, C/I Commercial/ Industrial, and P/I Public/Institutional zoning districts of the city, subject to the regulations and requirements of this section, provided the property upon which the system is to be located is constructed and maintained on any parcel of at least two and one-half acres In size. The acreage restriction is required to protect WECS from encroachment by other uses or structures and to accommodate required setback between the WECS and property lines.

4. Non-commercial, roof-mounted WECS shall be allowed as an accessory use on all properties within all zoning districts in the City of Mayer, subject to the regulations and requirements of this section. Only one roof-mounted WECS shall be allowed per lot.

5. Site plan drawing. All applications for a WECS conditional use permit shall be accompanied by a detailed site plan drawn to scale and dimensioned, displaying the information as specified in § 152.031 of this chapter, including the following:

i. Location and height of all buildings, structures, aboveground utilities and trees on the lot, including both existing and proposed structures and guy wire anchors.

ii. Location and height of all adjacent buildings, structures, aboveground utilities and trees located within 350 feet of the exterior boundaries of the property in question.

iii. Sketch elevation drawing of the premises accurately depicting the proposed WECS and its relationship to structures on the subject site and adjacent lots.

iv. A description of the project including: nameplate generating capacity, proposed tower height, and proposed rotor diameter.

v. Engineer’s certification of structure design, electrical design, and fall zone.

vi. An elevation drawing of the premises accurately depicting the proposed WECS and its relationship to structures on the subject site and adjacent lots.

vii. In addition, applications for commercial WECS shall include:

a. An FAA permit application, if required.

b. A decommissioning plan.

6. Declaration of conditions. The Planning Commission may recommend and the City Council may impose such conditions on the granting of a WECS conditional use permit as may be necessary to carry out the purpose and provisions of this section.

(3) Code compliance.

(a) Compliance with State Building Code. Standard drawings of the structural components of the wind energy conversion system and support structures, including base and footings shall be provided along with engineering data and calculations to demonstrate compliance with the structural design provisions of the State Building Code. Drawings and engineering calculations shall be certified by a Minnesota licensed engineer.

(b) Compliance with National Electrical Code. WECS electrical equipment and connections shall be designed and installed in adherence to the National Electrical Code as adopted by the city.

(4) Warranty. Applicant shall provide documentation or other evidence from the dealer or manufacturer that the WECS has been successfully operated in atmospheric conditions similar to the conditions within Mayer. The WECS shall be warranted against any system failures reasonably expected in severe weather operation conditions.

(5) Design standards.

(a) Height of tower-mounted WECS.

1. The permitted maximum height of a tower mounted WECS shall be determined in one of two ways. In determining the height of the WECS the total height of the system shall be included. System height shall be measured from the base of the tower to the highest possible extension of the rotor blades.

i. A ratio of one foot to one foot (1:1) between the distance of the closest property line to the base of the WECS to the height of the system. If the property the WECS is located on is adjacent to a residential zoned property an additional setback of ten feet shall be added.

ii. A maximum system height of 175 feet.

2. The shortest height of the two above mentioned methods shall be used in determining the maximum allowable height of a WECS system. The height of a WECS must also comply with FAA regulation part 77 “Objects Affecting Navigable Air Space” and/or MNDOT Rule 14, MCAR 1.3015 “Criteria for Determining Obstruction to Air Navigation”.

(b) Height of roof-mounted WECS. A roof-mounted WECS shall only be allowed a maximum six feet above the roof line of the building or structure.

(c) Setbacks. No part of a WECS (including guy wire anchors) shall be located within or above any required front, side or rear yard setback. WECS towers shall be setback from the closest property line one foot for every one foot of system height. WECS shall not be located within 30 feet of an aboveground utility line.

(d) Rotor size. All WECS rotors shall not have rotor diameters greater than 26 feet, except that roof-mounted WECS shall not have a rotor diameter greater than three feet.

(e) Rotor clearance. Blade arcs created by the WECS shall have a minimum of 30 feet of clearance over any structure or tree within a 200 foot radius.

(f) Rotor safety. Each WECS shall be equipped with both a manual and automatic braking device capable of stopping the WECS operation in high winds (40 miles per hour or greater).

(g) Lightning protection. Each WECS shall be grounded to protect against natural lightning strikes in conformance with the National Electrical Code as adopted by the city.

(h) Tower access. To prevent unauthorized climbing, WECS towers must comply with one of the following provisions:

1. Tower climbing apparatus shall not be located within 12 feet of the ground.

2. A locked anti-climb device shall be installed on the tower.

3. Towers capable of being climbed shall be enclosed by a locked, protective fence at least six feet high.

(i) Signs. WECS shall have one sign, not to exceed two square feet posted at the base of the tower and said sign shall contain the following information.

1. Warning high voltage.

2. Manufacturer’s name.

3. Emergency phone number.

4. Emergency shutdown procedures.

(j) Lighting. WECS shall not have affixed or attached any lights, reflectors, flasher or any other illumination, except for illumination devices required by FAA regulations part 77 “Objects Affecting Navigable Air Space” and FAA Advisory circular 70/7460-1F, September 1978 “Obstruction Marking and Lighting”.

(k) Electromagnetic interference. WECS shall be designed and constructed so as not to cause radio and television interference.

(l) Noise emission. Noises emanating from the operation of WECS shall be in compliance with and regulated by the State of Minnesota Pollution Control Standards, Minnesota Regulations NPC 1 and 2, as amended.

(m) Utility company interconnection. No WECS shall be interconnected with a local electrical utility company until the utility company has reviewed and commented upon it. The interconnection of the WECS with the utility company shall adhere to the National Electrical Code as adopted by the city.

(6) Ornamental wind devices. Ornamental wind devices that are not a WECS shall be exempt from the provisions of this chapter and shall conform to other applicable provisions of this title.

(7) Inspection. The city hereby reserves the right upon issuing any WECS conditional use permit to inspect the premises on which the WECS is located. If a WECS is not maintained in operational condition and poses a potential safety hazard, the owner shall take expeditious action to correct the situation.

(8) Abandonment. Any WECS or tower which is not used for 12 successive months shall be deemed abandoned and shall be dismantled and removed from the. property at the expense of the property owner.

(E) Outdoor hydronic furnaces.

(1) Purpose. To promote the public health, safety and welfare and to safeguard the health, comfort, living conditions, safety and welfare of the citizens of the City of Mayer due to air pollution and human health impacts caused by the use of outdoor hydronic furnaces and similar devices.

(2) Prohibited use. No outdoor hydronic furnace or similar device shall be permitted within any zoning district of the city.

(Ord. 201, passed 8-24-15; Am. Ord. 225, passed 10-8-18)