Board of Supervisors Meeting Date:

Planning Commission 

May 14, 2009

Staff Lead:


Andrew Hushour, Assistant Zoning Administrator

Community Development 


A Zoning Ordinance Text Amendment to Article 2, General Regulations, Article 6, Accessory Uses, and Section 15-300, Definitions, to Establish the Height and Location Requirements for Accessory Wind Energy Systems


Topic Description:

This proposed text amendment seeks to establish Zoning Ordinance provisions regarding the use of private, non-commercial wind energy systems, such as windmills or wind turbines.


Requested Action of the Board of Supervisors:

Conduct a public hearing and consider adoption of the attached Ordinance.

Financial Impact Analysis:

No financial impact analysis has been conducted.


Summary Staff Report: 

There has been an increasing interest in the past year, both locally and statewide, in alternative energy sources. At a local level, and especially in rural counties, this idea has most recently manifested itself in the proliferation of wind energy systems such as small wind turbines, or windmills, as a viable independent energy source for personal (i.e., private and/or non-commercial) use. Since these systems are becoming more popular among citizens, local governments statewide have started to consider the land use policy questions that are presented by wind turbines, as well as the regulatory challenges they pose to both the Virginia Uniform Statewide Building Code and local zoning ordinances. Among local governments in Virginia, Rockingham County was the first to implement local zoning regulations for wind energy in 2004; more recently, Halifax County passed Zoning Ordinance language addressing the use of personal Wind Energy Systems.  Many other jurisdictions are in the process of reviewing the issue (See Attachment 1 for Ordinances/Articles related to other Jurisdictions).

In Fauquier County, staff has received several inquiries throughout 2008 regarding individuals seeking to erect wind turbines on their property for personal use and, in October 2008, approved the first two permits for personal windmills in the rural zoning districts. While there is no specific language regarding windmills in the current Zoning Ordinance regulations, the general provisions found in Article 2 and Article 6 do address accessory uses and structures in general terms. As a matter of interpretation, staff relied on language found in Section 2-506 of the Ordinance, which states that “the height limitations of this ordinance shall not apply to barns, silos, residential chimneys, spires, cupolas, elevator penthouses, domes, flagpoles, birdhouses, flues, monuments, radio towers, television antenna or aerials, water towers, water tanks, transmission towers and cables, smoke stacks, air conditioning units or other similar roof structures and mechanical appurtenances.”  With respect to setbacks, staff relied on the existing location regulations for accessory structures found in Section 6-105, requiring that any structure over seven (7) feet in height meet the required side yard setbacks for the zoning district in which it is located and a rear yard setback equal to the overall height of the structure.  In both cases, the subject properties were located in the Agricultural (RA) District and consist of more than five (5) acres. In addition, both applicants were applying for approval of the same structure, a Skystream windmill that is approximately 54 feet in height, measured from the lowest point of the finished grade to the uppermost projection of the arc of the blades on the turbine itself. Although the minimum side yard setback of the RA District is only 25 feet, in both cases the applicant agreed to staff’s request that the windmills be located a minimum of 55 feet from the side lot lines, which would provide a setback ratio of 1 foot for every 1 foot of height of the structure.

During the review of the two permits for private windmills that were approved in October 2008, staff identified the height and setbacks of the proposed structures as being the primary areas for concern. Given the interest in the application of these systems for private use and anticipating their more frequent application as a viable alternative energy source for citizens, staff has determined that a more comprehensive set of Ordinance provisions is warranted at this time to address wind energy systems that provide power for on-site users.

Staff would note that commercial Wind Energy Systems (i.e., systems installed for the purpose of generating power for sale) are currently being regulated under existing Zoning Ordinance provisions for public utilities (Category 20) and require special exception approval.   This text amendment makes no changes to these larger-scale types of facilities.

Proposed Amendment

The proposed text amendment would specifically establish on-site Wind Energy Systems as a permitted accessory use in Section 6-102.32, with specific limitations as further set forth in the proposed text.  The provisions establish lot size, setback, design, and maintenance standards related to such systems, as well as approval procedures.   For additional background information, staff is providing two detailed documents providing additional technical information as well as a review of local ordinances with this staff report: A Guide for State and Local Governments prepared by the American Wind Association and published in September 2008 (Attachment 2) and Local Ordinances to Regulate Wind Energy Projects prepared by John D. Hutchinson V of the Jennings Gap Partnership for the Shenandoah Valley Network and Rockingham Community Alliance in February 2009 (Attachment 3).


The text amendment is intended to address wind energy systems that are utilized for the generation of utility power for private consumption, as opposed to generation of utility power for commercial sale. The proposed definition makes it clear that the systems are for on-site consumption while still maintaining flexibility for net metering, or the selling of excess power back to a utility company: 

Wind Energy System: A wind energy conversion system consisting of a wind turbine, a tower and associated control or conversion electronics.   A system is considered an On-Site Wind Energy System only if it supplies electrical power solely for on-site use, except that when a parcel on which the system is installed also receives electrical power supplied by a utility company, excess electrical power generated and not presently needed for on-site use may be used by the utility company (i.e., net metering).

Permitted Zoning Districts

The proposed amendment limits on-site wind energy systems to the RA/Rural Agricultural and RC/Rural Conservation Districts.  

Lot Size and Setbacks

Staff originally drafted amendment language that limited wind energy systems to rurally zoned parcels containing a minimum of five acres. The intent was to discourage the use of such systems on smaller parcels where they may have increased impact on neighboring properties.  However, after some discussion with the Planning Commission, there was consensus that a setback requirement provided better protection than a lot size requirement, as the location of the facility on the lot would determine its impact on adjoining properties.  Therefore, the 5-acre minimum lot requirement was eliminated from the draft regulations.

The proposed setbacks are to be based on the proposed height of the overall structure.  The original setback proposed by staff was one foot for each foot of height.  However, based on discussion at the work sessions, the Planning Commission recommended additional setbacks to protect the surrounding community from potentially negative impacts of the use.    The provisions now contain a setback requirement from the property line of 110 percent of the height of the structure plus an additional setback requirement from existing residential units on adjoining properties of 150 percent of the height of the structure.  A waiver provision has been included for the 150 percent setback from a residential unit, based upon written consent and recordation of an easement from the affected, adjacent property owner.   The waiver provision is based on that utilized in Rockingham County. 


The majority of the local governments with existing standards for personal Wind Energy Systems do regulate height in some manner. Specific examples include: 


Height Limit

Clarke County

Allowed by-right up to 100 feet, maximum 2 units.

More units with special permit.

Halifax County

No height limit specified, but none allowed without special permit.

Highland County

Height limit of the Zoning District, greater height allowed with special permit.

Pulaski County

60 feet, with special permit (~70-80’ with turbine).

Rockingham County

65 feet on lots 1-5 acres, with special permit (~75-85’ w/turbine) and up to 80 feet on lots >5 acres, with special permit (~90-100’ w/turbine).

Rockbridge County

No height limit specified, but none allowed without special permit.

City of Suffolk

120 feet for a small system (output of 25kW or less) by-right and 250 feet for a large system (output of 26kW up to 999 kW) with a conditional use permit.


The review of other jurisdictions shows that regulations vary significantly, from allowing no systems, regardless of height, up to as high as 120 feet by-right or 240 feet with a special permit. The initial text amendment was drafted to include a maximum height limit of 80 feet, which is consistent with the by-right height of telecommunication towers in Article 11 of the Zoning Ordinance.  Staff has further researched the issue of height at the request of the Planning Commission in order to help clarify the minimum reasonable height for a standard, 10 kW output, wind energy system, which typifies those most commonly utilized for private use.

Generally, a wind energy system that is closer to the ground will receive more turbulence and will operate inefficiently, and overall wind speed decreases as you move closer to the ground.   An October 2005 issue of the Windletter, the monthly newsletter of the American Wind Energy Association, clearly describes the importance of height to a wind energy system (see Attachment 4 for the full document):

There are two things that can diminish the wind resource for a small wind turbine. The first is ground drag. Ground drag is the friction that occurs between the surface of the earth and air masses that flow over it. The more cluttered the landscape (with trees and buildings), the greater the ground drag will be in a given area. Ground drag reduces the wind’s speed, reducing its kinetic energy. The reason this is so important is because the output of a wind turbine is proportional to the cube of the wind speed. For example, increasing the wind speed from 10 miles per hour to 12 mile per hour results in a nearly 73% increase in the kinetic energy available in the wind.

The second thing that can reduce the output of a wind turbine is the turbulence caused by the obstacles that clutter the earth. Trees and buildings cause the wind to tumble and swirl rather than flow smoothly. Besides reducing the kinetic energy in the wind by slowing it down, turbulent winds also put undue stress and strain on the wind turbine and tower. Turbulence increases the maintenance on a wind generator, while it effectively reduces its life expectancy. Turbulence is the proverbial double whammy for small wind turbines!

A general ‘rule of thumb’ established by the American Wind Energy Association, and widely used by both local governments and industry related groups, is that the entire turbine itself must be a minimum of 30 feet above anything within 500 feet of the tower or the local tree line, whichever is greater. Since the turbine itself can be as large as 10-20 feet in diameter for a small Wind Energy System, this means the total height of the tower must be 40 feet above obstructions to be effective.

A review of many of the small energy systems available for purchase suggests that a height of 70-80 feet to the top of the blade is the typical height, which assumes that the system is adjacent to a home and tree line no more than 30 feet in height.  Typical house height is often slightly more, and while the height of tree lines varies substantially from site to site, it is not unusual to find tree stands more than 30 feet in height.

The issue of height was discussed by the Planning Commission at length.  An 80 foot by-right height limit was proposed in the original staff draft.  An alternative approach discussed was to allow a somewhat lower height, such as 60 feet by-right, and more height, up to 100 feet, with a special permit.  This approach would allow most proposals to be evaluated on a case-by-case basis, taking into consideration the constraints of the particular property, including potential impacts. A negative impact of the special use process is that it would add costs to prospective users, but the current $500 application fee for special permits is relatively minor compared to the typical $10,000 to $20,000 cost for these systems.   In addition, it introduces a public hearing process into the review and approval of such systems, which may be controversial.  

Ultimately, the Planning Commission recommended draft language allows 80 feet by-right and up to 100 feet with a special permit.

Visual Impacts

While the issue of visibility is based primarily on the height of a wind energy system, several other factors do contribute to its visual impact. As originally drafted, staff has included several other provisions aimed at reducing the visible obtrusiveness of Wind Energy Systems. 

Tower Type

There are three typical types of towers utilized for most wind energy systems:  guyed towers, lattice towers, and monopoles. According to industry sources, the lattice tower is the least expensive alternative for most systems, but the most utilized is the guyed tower, in part because these can be raised and lowered with a winch for maintenance.


     Guyed Tower (being raised)                   Lattice Tower                            Monopoleonopoleonopole

Staff is recommending that only guyed and monopole towers be allowed in cases where the tower is visible from adjoining property or the public street and/or public places, in order to reduce visual impact. 


A provision regulating the color of wind energy systems is also provided. A review of industry information indicates that most systems come in a galvanized steel finish or in an unobtrusive color such as white or gray; this is consistent with the regulatory practices in other communities. Staff has also included an alternative that would allow a property owner, with Zoning Administrator approval, to paint the system in order to further blend it into the surrounding environment.

Ridge Lines

Also related to the visibility of wind energy systems is the concern that a unit could be placed on a visually prominent steep slope. This is of particular concern since ridgelines typically would provide the best location for wind generation.  For this reason, the Commission recommended at its last work session that a ridgeline prohibition be drafted and staff has included this in the draft provisions.

Signage and Lighting

Additional standards are included that prohibit signage and lighting on wind energy systems.

Removal if Abandoned

With respect to the concern regarding the existence of abandoned systems, a provision has been included that will require the removal of any wind energy system that has been abandoned and/or is inoperable for a period of more than twelve (12) months.  


The Planning Commission initiated this proposal at the regularly scheduled meeting held on December 10, 2008.  Work sessions and public hearings were held on January 29, 2009, February 26, 2009, and March 26, 2009, with the Planning Commission voting 4-1 in March to recommend approval of the amendment to the Board of Supervisors, with Ms. McCarty voting against because of concerns about height.

Identify any other Departments, Organizations, or Individuals that would be affected by this request:

All Divisions, Department of Community Development, Fauquier County



1.      Examples of Zoning Ordinance Regulations/Articles on Wind Energy Systems from Other Virginia Jurisdictions

2.   A Guide for State and Local Governments prepared by the American Wind Association and Published in September 2008

3.   Local Ordinances to Regulate Wind Energy Projects prepared by John D. Hutchinson V of the Jennings Gap Partnership for the Shenandoah Valley Network and Rockingham Community Alliance in February 2009

4.   American Wind Energy Association Newsletter: Volume 24, Issue 10, October 2005

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