The purpose of this chapter is to establish standards for alternative energy systems within the city. (Ord. 867, sec. 81, 5-17-2010)

   A.   Application:

      1.   Accessory Use:

         a.   Administrative Permit: Installation of one wind energy conversion system that conforms to the height limits of the respective zoning district may be allowed as a permitted accessory use subject to approval of an administrative permit within any zoning district of the city and subject to the regulations and requirements of this section.

         b.   Interim Use: Installation of one wind energy conversion system exceeding the height limit of the respective zoning district may be allowed as an accessory use subject to approval of an interim use permit within any zoning district of the city, subject to the regulations and requirements of this chapter, provided the property upon which the system is to be located is zoned agricultural, commercial, industrial or public-open space district or is constructed and maintained on any parcel of at least two and one-half (21/2) acres in size.

      2.   Declaration Of Conditions: The planning commission may recommend and the city council may impose such conditions on the granting of a WECS interim use permit as may be necessary to carry out the purpose and provisions of this section.

      3.   Site Plan Drawing: All applications for a WECS interim use permit shall be accompanied by a detailed site plan drawn to scale and dimensioned, displaying the information as specified in chapter 9 of this title and the following:

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

         b.   Location and height of all adjacent buildings, structures, aboveground utilities and trees located within three hundred fifty feet (350') of the exterior boundaries of the property in question.

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

      4.   Studies: Applications for an interim use permit under this section shall include studies documenting sufficient access to unobstructed wind necessary for operation of the proposed turbine.

   B.   Code Compliance:

      1.   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.

      2.   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.

   C.   Manufacturing 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 Lakeville. The WECS shall be warranted against any system failures reasonably expected in severe weather operation conditions.

   D.   Design Standards:

      1.   Height:

         a.   The permitted maximum height of a WECS shall be determined in one of two (2) 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.

            (1)   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.

            (2)   A maximum system height of one hundred seventy five feet (175').

         b.   The shortest height of the two (2) 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 regulations.

      2.   Setbacks: No part of a WECS shall be located within or above any required front, side or rear yard setback. WECS towers shall be set back from the closest property line one foot (1') for every one foot (1') of system height. WECS shall not be located within thirty feet (30') of an aboveground utility line.

      3.   Installation:

         a.   All towers used to support a WECS shall be a monopole design certified by a structural engineer or manufacturer that the pole is capable of supporting the WECS.

         b.   WECS installed on an existing structure shall require certification of a structural engineer that the existing structure is capable of supporting the WECS.

      4.   Rotor Clearance: Blade arcs created by the WECS shall have a minimum of thirty feet (30') of clearance over any structure or tree within a five hundred foot (500') radius.

      5.   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).

      6.   Electrical:

         a.   All utilities shall be installed underground.

         b.   An exterior utility disconnect switch shall be installed at the electric meter serving the property.

         c.   Each WECS shall be grounded to protect against natural lightning strikes in conformance with the national electrical code as adopted by the city.

      7.   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 twelve feet (12') of the ground.

         b.   A locked anticlimb device shall be installed on the tower.

         c.   Towers capable of being climbed shall be enclosed by a locked, protective fence at least six feet (6') high.

      8.   Signs: WECS shall have one sign, not to exceed two (2) square feet posted at the base of the tower and said sign shall contain the following information:

         a.   Warning high voltage.

         b.   Manufacturer's name.

         c.   Emergency phone number.

         d.   Emergency shutdown procedures.

      9.   Color/Lighting:

         a.   WECS under one hundred seventy five feet (175') in height shall be painted a noncontrasting color consistent with the surrounding area such as: sky blue, gray, or brown, and have a galvanized or oxidized finish to reduce visual impact.

         b.   WECS shall not have affixed or attached any lights, reflectors, flasher or any other illumination, except for illumination devices required by FAA regulations.

      10.   Electromagnetic Interference: WECS shall be designed and constructed so as not to cause radio and television interference.

      11.   Noise Emission:

         a.   Within residential districts, noises emanating from the operation of WECS shall not exceed ten decibels (10 dB) above ambient area noise levels.

         b.   In all other districts, 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.

      12.   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.

   E.   Ornamental Wind Devices: Ornamental wind devices that are not a WECS shall be exempt from the provisions of this section and shall conform to other applicable provisions of this title.

   F.   Inspection: The city hereby reserves the right upon issuing any WECS interim 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.

   G.   Abandonment:

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

      2.   An interim use permit allowing for installation of a WECS under this section shall terminate upon the occurrence of any of the following events, whichever occurs first:

         a.   The property on which the WECS is located is zoned to other than an agricultural, commercial, industrial or public-open space district.

         b.   The property on which the WECS is located is subdivided and the resulting lot area is less than 2.5 acres.

         c.   Any of the events outlined by section 11-5-7 of this title. (Ord. 867, sec. 81, 5-17-2010)

   A.   Accessory Use:

      1.   Solar energy systems shall be allowed as a permitted accessory use in all zoning districts in accordance with the standards in this section.

      2.   The following systems shall be exempt from the requirements of this section and shall be regulated as any other building element:

         a.   Building integrated solar energy systems that are an integral part of a principal or accessory building, rather than a separate mechanical device, replacing or substituting for an architectural element or structural component including, but not limited to, photovoltaic or hot water solar energy systems contained within roofing materials, windows, skylights and awnings.

         b.   Passive solar energy systems that capture solar light or heat without transforming it into another form of energy or transferring the heat via a heat exchanger.

   B.   System Standards:

      1.   Electrical:

         a.   All utilities shall be installed underground.

         b.   An exterior utility disconnect switch shall be installed at the electric meter serving the property.

         c.   Solar energy systems shall be grounded to protect against natural lightning strikes in conformance with the national electrical code as adopted by the city.

         d.   No solar energy system shall be interconnected with a local electrical utility company until the utility company has reviewed and commented upon it. The interconnection of the solar energy system with the utility company shall adhere to the national electrical code as adopted by the city.

      2.   Accessory Structure: Ground mounted solar energy systems shall be regulated as an accessory structure in accordance with section 11-18-7 or 11-18-9 of this title, as applicable, as to the number allowed, setbacks, building coverage, and height.

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

   C.   Location:

      1.   Roof mounting:

         a.   The solar energy system shall comply with the maximum height requirements of the applicable zoning district.

         b.   TThe solar energy system shall not extend beyond the perimeter of the exterior walls of the building on which it is mounted.

         c.   Use of solar panels as a canopy or affixed to a canopy above off-street parking stalls for multiple family, commercial, industrial, and institutional uses shall be permitted in addition to accessory structures allowed by chapter 18 of this title, subject to the following provisions:

            (1)   The edge of the canopy shall be thirty feet (30') or more from the front and/or side lot line, provided that adequate visibility both on site and off site is maintained.

            (2)   The canopy, including solar panels, shall not exceed twenty four feet (24') in height and must provide fourteen feet (14') of clearance.

            (3)   The canopy fascia shall not exceed three feet (3') in vertical height.

            (4)   Canopy lighting shall consist of canister spotlights recessed into the canopy with no portion of the light source or fixture extending below the bottom face of the canopy. Total canopy illumination may not exceed the limits established by section 11-16-17.A of this title. The fascia of the canopy shall not be illuminated.

            (5)   The architectural design, colors, and character of the canopy shall be consistent with the principal building on the site.

            (6)   Signage shall not be allowed on a detached canopy.

            (7)   Canopy posts shall not obstruct traffic within the off-street parking area.

      2.   Ground mounting:

         a.   The solar energy system shall only be located in the rear yard as defined by this title.

         b.   The solar energy system shall comply with the maximum height requirements for accessory buildings for the applicable zoning district.

         c.   All components of the solar energy system shall be set back a minimum of five feet (5') from interior side lot lines and ten feet (10') from rear lot lines.

         d.   Solar energy systems shall not encroach upon drainage and utility easements.

   D.   Screening: Solar energy systems shall be screened in accordance with the requirements of section 11-21-13 of this title to the extent possible without affecting their function.

   E.   Certification: The solar energy system shall be certified by Underwriters Laboratories, Inc., and comply to the requirements of the international building code.

   F.   Abandonment: Any solar energy system which is inoperable for twelve (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.

   G.   Building Permit: A building permit shall be obtained for any solar energy system prior to installation. (Ord. 867, sec. 81, 5-17-2010; Ord. 1031, 6-1-2020; Ord. 1078, 6-5-2023; Ord. 1080, 6-5-2023)

   A.   Accessory Use:

      1.   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.

      2.   Ground source heat systems in public water bodies or water bodies owned or managed by the city of Lakeville shall be prohibited except when accessory to a city of Lakeville facility.

   B.   System Requirements:

      1.   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.

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

   C.   Location:

      1.   Ground source heat pump systems shall only be located in the rear yard as defined by this title.

      2.   All components of ground source heat pump systems shall be set back a minimum of five feet (5') from interior side lot lines and ten feet (10') from rear lot lines.

      3.   Ground source heat pump systems shall not encroach upon drainage and utility easements.

   D.   Screening: Ground source heat pump systems shall be screened in accordance with the requirements of section 11-21-13 of this title.

   E.   Certification: The ground source heat pump system shall be certified by Underwriters Laboratories, Inc., and comply to the requirements of the international building code.

   F.   Abandonment: Any ground source heat pump system which is inoperable for twelve (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:

      1.   The heat pump and any external or aboveground mechanical equipment shall be removed.

      2.   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.

      3.   The top of the pipe, coil or boring shall be uncovered and sealed.

   G.   Building Permit:

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

      2.   Borings for ground source heat pump systems where the pipes or coils are installed vertically below the land shall also be subject to approval by the Minnesota department of health. (Ord. 867, sec. 81, 5-17-2010)

Accessory use of a wood fired furnace, stove or boiler not located within a building intended for habitation by humans or animals shall be allowed as an interim use only within agricultural/rural districts, subject to the following provisions:

   A.   Minimum Lot Area: The minimum lot area for use of an accessory hydronic furnace shall be ten (10) acres.

   B.   Setbacks: Hydronic furnaces shall be set back a minimum of one hundred feet (100') from all property lines.

   C.   Burning Material: Material to be burned shall be limited to corn, pellet materials or natural, dry wood that has not been painted, varnished or coated in any way, has not been pressure treated with preservatives and does not contain resins or glues as in plywood or other composite wood products.

   D.   Exterior Storage: Outdoor storage of burning material shall be in accordance with subsection 11-18-7G of this title.

   E.   Other Requirements: All requirements for installation and maintenance shall be met including, but not limited to, local, state and federal regulations and manufacturer's specifications and shall be EPA phase II qualified.

   F.   Permit Termination: The interim use permit shall terminate upon the occurrence of any of the following events, whichever occurs first:

      1.   The property on which the hydronic furnace is located is zoned to other than an agricultural/rural district.

      2.   The property on which the hydronic furnace is located is subdivided and the resulting lot area is less than ten (10) acres.

      3.   Any of the events outlined by section 11-5-7 of this title. (Ord. 867, sec. 81, 5-17-2010)