1. Permitted Accessory Use. Active solar energy systems shall be allowed as an accessory use in all zoning classifications where structures of any sort are allowed, subject to certain requirements as set forth below. Active solar energy systems that do not meet the visibility standards in C. below will require a special use permit, except as provided in Section 170.31(2)(B).
A. Height. Active solar energy systems must meet the following height requirements:
(1) Building- or roof- mounted solar energy systems shall not exceed the maximum allowed height in any zoning district. For purposes for height measurement, solar energy systems other than building-integrated systems shall be given an equivalent exception to height standards as building mounted mechanical devices or equipment.
(2) Ground- or pole-mounted solar energy systems shall not exceed 20 feet in height when oriented at maximum tilt.
B. Set Back. Active solar energy systems must meet the accessory structure setback for the zoning district and primary land use associated with the lot on which the system is located.
(1) Roof-mounted Solar energy systems. In addition to the building setback, the collector surface and mounting devices for roof-mounted solar energy systems shall not extend beyond the exterior perimeter of the building on which the system is mounted or built, unless the collector and mounting system has been explicitly engineered to safely extend beyond the edge, and setback standards are not violated. Exterior piping for solar hot water systems shall be allowed to extend beyond the perimeter of the building on a side yard exposure.
(2) Ground-mounted Solar energy systems. Ground-mounted solar energy systems may not extend into the side-yard or rear setback when oriented at minimum design tilt.
C. Visibility. Active solar energy systems shall be designed to blend into the architecture of the building or be screened from routine view from public right-of-ways other than alleys. The color of the solar collector is required to be consistent with other roofing materials.
(1) Building Integrated Photovoltaic Systems. Building integrated photovoltaic solar energy systems shall be allowed regardless of whether the system is visible from the public right-of-way, provided the building component in which the system is integrated meets all required setback, land use or performance standards for the district in which the building is located.
(2) Solar Energy Systems with Mounting Devices. Solar energy systems using roof mounting devices or ground-mount solar energy systems shall not be restricted if the system is not visible from the closest edge of any public right-of-way other than an alley. However roof-mount systems that are visible from the nearest edge of the street frontage right-of-way shall not have a highest finished pitch steeper than the roof pitch on which the system is mounted, and shall be no higher than twelve (12) inches above the roof.
(3) Coverage. Roof or building mounted solar energy systems, excluding building-integrated systems, shall allow for adequate roof access to the south-facing or flat roof upon which the panels are mounted. The surface area of pole or ground mount systems shall not exceed half the building footprint of the principal structure.
(4) Historic Buildings. Solar energy systems on buildings within designated historic districts or on locally designated historic buildings (exclusive of State or Federal historic designation) will require a special use permit.
D. Approved Solar Components. Electric solar energy system components must have a UL listing and solar hot water systems must have an SRCC rating.
E. Plan Approval Required. All solar energy systems shall require administrative plan approval by the zoning official.
(1) Plan Applications. Plan applications for solar energy systems shall be accompanied by to-scale horizontal and vertical (elevation) drawings. The drawings must show the location of the system on the building or on the property for a ground-mount system, including the property lines.
a. Pitched Roof Mounted Solar Energy Systems. For all roof-mounted systems other than a flat roof the elevation must show the highest finished slope of the solar collector and the slope of the finished roof surface on which it is mounted.
b. Flat Roof Mounted Solar Energy Systems. For flat roof applications a drawing shall be submitted showing the distance to the roof edge and any parapets on the building and shall identify the height of the building on the street frontage side, the shortest distance of the system from the street frontage edge of the building, and the highest finished height of the solar collector above the finished surface of the roof.
(2) Plan Approvals. Applications that meet the design requirements of this ordinance, and do not require a special use permit, shall be granted administrative approval by the zoning official. Plan approval does not indicate compliance with Building Code or Electric Code.
F. Compliance with Building Code. All active solar energy systems shall meet approval of local building code officials, consistent with the State of Iowa Building Code and solar thermal systems shall comply with HVAC-related requirements of the Electric Code.
G. Compliance with State Electric Code. All photovoltaic systems shall comply with the Iowa State Electric Code.
H. Compliance with State Plumbing Code. Solar thermal systems shall comply with applicable Iowa State Plumbing Code requirements.
I. Utility Notification. All grid-intertie solar energy systems shall comply with the interconnection requirements of the electric utility. Off-grid systems are exempt from this requirement.
2. Special Use. The city encourages the installation of productive solar energy systems and recognizes that a balance must be achieved between character and aesthetic considerations and the reasonable desire of building owners to harvest their renewable energy resources. Where the standards in 170.31(1)(A), 170.31(1)(B), or 170.31(1)(C) cannot be met without diminishing the minimum reasonable performance of the solar energy system, a special use permit may be sought from the Board of Adjustment. A special use permit shall be granted if the standards set out in paragraph B, below are met.
A. Minimum Performance Design Standards. The following design thresholds are necessary for efficient operation of a solar energy system:
(1) Fixed-Mount Active Solar Energy Systems. Solar energy systems must be mounted to face within 45 degrees of south (180 degrees azimuth).
(2) Solar Electric (photovoltaic) Systems. Solar collectors must have a pitch of between 20 and 65 degrees.
(3) Solar Hot Water Systems. Solar collectors need to be mounted at a pitch between 40 and 60 degrees.
(4) System Location. The system is located where the lot or building has a solar resource.
B. Standards for a Special Use Permit. A special use permit shall be granted by the Board of Adjustment if the applicant meets the following safety, performance and aesthetic conditions:
(1) Aesthetic Conditions. The solar energy system must be designed to blend into the architecture of the building or be screened from routine view from public right-of-ways other than alleys to the maximum extent possible while still allowing the system to be mounted for efficient performance.
(2) Safety Conditions. All applicable health and safety standards are met.
(3) Non-Tracking Ground-Mounted Systems. Pole-mounted or ground-mounted active solar energy systems must meet set-back requirements.
3. Renewable Energy Conditions for Certain Permits
A. Condition for Rezoning or Special Use Permit. The City may, in an area where the local electric distribution system was installed more than twenty years ago, or where the local electric utility has documented a near-term need for additional distribution substation or conductor capacity, require on-site renewable energy systems as a condition for a rezoning or a special use permit.
(1) The renewable energy condition may only be exercised for new construction or major reconstruction projects.
(2) The renewable energy condition may only be exercised for sites that have 90% unimpeded solar or wind energy access, and for which the renewable energy system can reasonably meet all performance standards and building code requirements.
B. Condition for Planned Unit Development (PUD) Approval. The City may require onsite renewable energy systems as a condition for approval of a PUD permit, in order to mitigate for:
(1) Risk to the performance of the local electric distribution system,
(2) Increased emissions of greenhouse gases,
(3) Other risks or effects inconsistent with the City’s Comprehensive Plan.