Model Ordinance
Small Wind Energy Systems (SWES) Ordinance
Kennebec Valley Council of Governments
Introduction
Concern about rising energy costs is generating a lot of interest in renewable energy alternatives particularly small wind power. Increasing numbers of homeowners are purchasing small wind energy systems (SWES) to lower their electric bills, become more independent of the electric grid, to avoid the unpredictability of traditional energy prices and to reduce their carbon footprint. Commercial and municipal applications of small wind energy systems (SWES) are also growing in popularity.
While wind power has obvious benefits small wind energy systems (SWES) are a land use with a potential for negative and sometimes controversial impacts on neighborhoods and the environment. Opinions about the aesthetics of small wind systems in particular are often divided. To be effective small wind systems need good access to wind, which is dependent on proper siting and adequate height. Adequate height means that usually such systems will be noticeable in the community.
Many municipalities have no or inadequate provisions in their land use ordinance(s) to address siting and constructing SWES. Many towns have maximum height restrictions for structures of typically 35 feet, which would not allow an SWES. Some communities may have a generic site plan review ordinance but lack standards specific to SWES.
The attached Model SWES Ordinance addresses the needs stated above by establishing set standards to protect the public’s interest while allowing the effective use of SWES. The ordinance is designed to fit into an existing local land use ordinance, which has a review structure. Administrative and procedural sections would need to be added in order for this model to be a stand-alone ordinance. This ordinance is the product of reviewing numerous ordinances and reports related to small wind energy. Commentary is included for some provisions with a particular focus on how to address the visual impacts of SWES. This model ordinance will ultimately be a part of a model ordinance of aerial structures.
For further information or assistance in establishing SWES standards in your community please contact KVCOG at 207-453-4258 Ext. 27 or
MODEL ORDINANCE
Small Wind Energy Systems (SWES) Ordinance
Kennebec Valley Council of Governments
1.0 Purpose
The intent of this ordinance is to regulate the placement, construction, and modification of small wind energy systems (SWES) while minimizing adverse visual, safety, and environmental impacts.
2.0 Authority
2.1 The ______Code Enforcement Officer is vested with authority to review and approve or reject a building permit application for a SWES 60 feet or less in height.
2.2 The ______Planning Board is vested with the authority to review and approve, conditionally approve or reject any application for a SWES taller than 60 feet. A public hearing is required.
3.0 Application Submission Requirements
3.1 Applicant and landowner’s name and contact information
3.2 Address of SWES location including tax map and lot number, existing use, and parcel acreage
3.3 Description of the project including specific information on the type, size, rotor material, rated power output, performance, safety and noise characteristics of the system including name and address of the manufacturer, model and serial number.
3.4 A Site Plan showing the planned location of the SWES and location of and distance to setback lines, property lines, roads, driveways, ROWs and any overhead utility lines and on the subject property and adjacent properties within 300 feet any buildings including their purpose and tree cover and average height of trees.
3.5 A survey map at an appropriate scale showing within 2500’ of the proposed SWES any parks and other designated areas considered locally important in an open space plan, recognized historic sites, and important bird areas as identified in state Beginning With Habitat data.
3.6 Proposal for landscaping and screening.
3.7 A scaled representation of the SWES showing system height and evidence the proposed height does not exceed the height recommended by the manufacturer of the system.
3.8 Structural drawings from manufacturer or engineer showing foundation and anchor design along with specifications for soil conditions at the site.
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3.9 A line drawing of the electrical components of the system in sufficient detail to establish that the installation conforms to all applicable electrical codes.
3.10 Emergency and normal shutdown procedures
3.11 If a roof-mounted system is proposed evidence by a structural engineer that the applicant’s roof is sufficiently sturdy to hold a roof-mounted wind generator in winds 100 miles per hour for an hour.
3.12 Evidence that the provider of electrical service of the property has been notified of the intent to install an interconnected electricity generator unless the system will not be connected to the electricity grid
3.13 Photographs of the proposed site
Commentary: These requirements would supplement other application submittal requirements in an existing land use ordinance.
4.0 Definitions
Habitable Building (structure): Structures likely to be occupied on a continuous or temporary basis.
Small Wind Energy System (SWES): A wind energy conversion system consisting of a wind turbine, a tower, and associated control or conversion electronics, which has a rated capacity of not more than 100kW and which is intended to primarily reduce on-site consumption of utility power.
Commentary: To provide context to the capacity rating system, typically sized turbines are listed below:
2 - 10kW: Residential
10 –20kW: Agricultural, Farm
50kW: Small Municipal Operation (e.g. Kittery, ME) or Commercial
100kW: Municipal or Commercial
System Height: The height above grade to the tip of the turbine blade when it reaches its highest elevation.
Tower: The structure on which the small wind energy system is mounted.
Wind Turbine: Parts of the small wind energy system including blades, generator and tail.
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5.0 Dimensional Requirements
5.1 Minimum Site Area
Minimum site area for a SWES shall be one half acre unless roof mounted. Each additional freestanding SWES will require an additional two acres. No more than 3 SWES are allowed on any one site regardless of acreage.
Commentary: Many communities have a minimum lot size of one acre for SWES. This often severely limits their use in a residential or village district. Establishing a larger minimum site area when there is more than one SWES allows more room for reducing the added visual impact (see appendix B) from multiple SWES. Many municipalities opt to allow only one SWES per site.
5.2 Height and Capacity/Zoning Restrictions
In residential and village districts maximum system height is 60 feet and maximum capacity is 10kW. In commercial and rural districts maximum system height is _____feet and maximum capacity is 100kW.
Commentary: See commentary about height and visual impacts in Appendix B.
5.3 Safety Setbacks
5.3.1 SWES shall be setback a distance equal to one hundred ten (110) percent of the system height from adjoining property lines.
5.3.2 SWES shall be setback a distance equal to one hundred fifty (150) percent of the system height from any habitable building on adjoining properties.
5.4 Other Setbacks
5.4.1 An SWES exceeding 60 feet tall must be setback 2500 feet from any park or designated area of local importance indicated in an open space plan, any historic site, or any important bird area as indicated in the State’s Beginning With Habitat data.
6.0 Design Requirements
6.1 Access
6.1.1 All ground mounted electrical and control equipment shall be labeled and secured to prevent unauthorized access.
6.1.2 The tower shall be designed and installed such that public access via step bolts or a ladder is prevented for a minimum of 12 feet above the ground.
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6.2 Blade Clearance
The minimum distance between the ground and any protruding wind turbine blades of a free standing SWES shall be 25 feet as measured at the lowest arc of the blades.
6.3 Electrical Interconnections
All on-site electrical wires associated with the SWES shall be installed underground except for “tie-ins” to public utility company transmission poles, towers and lines. A licensed electrician must connect the SWES to the residence or other structure.
6.4 Noise
The small wind energy system shall not exceed 55 dBA, as measured at the property line, except during short-term events such as severe wind storms and utility outages.
Commentary: The ambient noise level of most SWES turbines is around 52 to 55 decibels. This means that while the sound of the wind turbine can sometimes be picked out of surrounding noise if a conscious effort is made to hear it a SWES is typically no noisier than an average refrigerator.
6.5 Over-speed Controls
SWES shall be equipped with both manual and automatic over-speed controls.
6.6 Signal Interference
The system shall be operated and located such that no disruptive electromagnetic interference with signal transmission or reception is caused beyond the site. If it has been demonstrated that the system is causing disruptive interference beyond the site, the system operator shall promptly eliminate the disruptive interference or cease operation of the system.
6.7 Structure Type
The tower shall be a monopole without guy wires.
Commentary: The sleeker profiles of monopoles make them generally less visible than lattice or guyed towers. Since visibility is often the most contentious issue concerning SWES a monopole tower is recommended.
6.8 Visual Appearance
6.8.1 SWES shall be painted in non-reflective, light gray color.
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6.8.2 All signs, both temporary and permanent, or any graphic representation are prohibited on the SWES except appropriate manufacturers or installers identification and warning signs.
6.8.3 No tower shall be lighted unless required by the FAA.
Commentary: See commentary about visual impacts in Appendix B.
7.0 Abandonment of Use
A SWES which is not generating electricity for twelve (12) consecutive months shall be deemed abandoned and shall be dismantled and resolved from the property by the owner within 120 days of receipt of notice from the town.
Commentary: Some municipalities allow eighteen (18) consecutive months.
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SWES Model Ordinance
Appendix A
Ordinance Provisions Assessing and Mitigating Visual Impacts
Note: The following application and regulation ordinance provisions concern determining and reducing visual impacts. These provisions should be considered for SWES exceeding 80 feet and could be added to the model SWES ordinance. For the rationale behind these provisions and additional tools see Appendix B with techniques assessing and mitigating visual impact and commentary about visual impacts.
Additional Application Submission Requirements
3.14 Sight lines and photographs
3.14.1 Sight line representation. A sight line representation shall be drawn from representative locations that show the lowest point of the tower visible from each location. These locations shall include a sight line representation from the closest residence and/or occupied building to the SWES and any public road or public area within 300 feet. Each sight line shall be depicted in profile, drawn at one inch equals 40 feet. The profiles shall show all intervening trees and buildings. There shall be at least two sight lines from the closest habitable structures or public roads or areas included in the application.
3.14.2 Existing (before condition) photographs. Each sight line shall be illustrated by one four-inch by six-inch color photograph of the current view.
3.14.3 Proposed (after condition). Each of the existing condition photographs shall have the proposed SWES superimposed on it to accurately simulate the SWES when built.
3.15 Elevations
3.15.1 Any and all structures on the subject property.
3.15.2 Existing trees and shrubs at current height and proposed trees and shrubs at proposed height at time of installation, with approximate elevations dimensioned.
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8.0 Visibility
8.1 Screening and buffering
8.11Wherever possible, SWES shall be located to make maximum use of existing vegetation and structures for the purpose of screening the turbine from off-site views. To the greatest extent possible, SWES shall be sited such that mature
vegetation and/or existing structures are located between the SWES and public and private viewpoints.
8.1.2 A year-round vegetated buffer of sufficient height and depth to screen the SWES shall be provided. Height and depth of the required buffer may vary in accordance with the specific project and site conditions. Trees and vegetation may be existing on the subject property or installed as part of the proposed SWES or a combination of both. Consideration should be given to providing vegetated buffers nearer to the viewer to get maximum benefit from the screening, while limiting any turbulence that could affect the efficiency of the SWES.
8.2 Scenic Landscapes and Vistas
8.2.1 SWES shall be located toward the edge of any defined scenic and open view-sheds.
8.2.2 Any SWES that is located within 300 feet of a scenic vista, scenic landscape, or scenic road as designated by the town shall not exceed the height of vegetation at the proposed location.
8.3 Siting
8.3.1 SWES shall be located as far away as possible from important views in order to diminish the visual impact of the structure.
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SWES Model Ordinance
Appendix B
Commentary About Height and Visual Impacts
Techniques Assessing and Mitigating Visual Impacts
Commentary: To work effectively SWES must be visible which sometimes invites controversy concerning aesthetics. According to a Technology Assessment Group which assisted the Cape Cod Commission in developing a model medium to large wind power ordinance the bottom of a turbine rotor blade should be at least 10 feet above any obstacle (trees or buildings ) within 300 feet to avoid turbulence in the air column. Other sources claim that the rotor blade needs to be 25 to 35 feet above such obstacles. An American Planning Association publication points out that SWES must be 50 to 120 feet high to be effective.
Some municipalities have responded to the tension of aesthetics and effectiveness by limiting height from 50 to 60 feet in residential and village areas and from 60 to 80 feet in commercial and rural districts. Some wind power advocates argue that such height limits prevent SWES from working as effectively as they would if they were much taller. In New York SWES heights typically range from 80 to 120 feet outside of dense residential areas.
As SWES heights approach 80 feet and higher it becomes much more difficult to blend a wind tower into the community landscape. It’s recommended that where SWES are allowed to exceed 80 feet that some of the following tools and approaches below and in Appendix B be employed (and required).