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Municipalities may adopt zoning regulations governing the installation and operation of solar and wind energy systems. This guide specifically examines zoning for non-commercial installations (for example, residential rooftop solar panels).
The benefits of alternative energy (i.e., solar and wind) systems are many and include
However, alternative energy uses can have negative impacts and concerns related to public safety, including:
If already otherwise permitted by a municipality, adding zoning regulations to address non-commercial alternative energy uses such as solar and wind systems will not necessarily increase the green benefits derived by the community by their use. However, regulating alternative energy uses through an established zoning ordinance will help minimize the adverse impacts these uses can cause.
A municipality with an adopted zoning ordinance in Pennsylvania essentially has a basic choice in accommodating non-commercial solar and wind energy systems. It may choose to allow such uses without the need for zoning purview. For example, the municipality may view a rooftop solar panel no differently from an electric heat pump. Both are accessory to a residential dwelling or commercial building, and both could be allowed by the municipality without being subject to local zoning regulation. Or, it may choose to regulate such uses through its zoning ordinance. Zoning regulations can reduce potential negative health, safety and aesthetic impacts associated with solar and wind energy systems such as excessive glare from solar panels and noise from wind turbines.
In using zoning regulations to govern the installation and operation of non-commercial solar and wind energy systems, a municipality has a number of regulatory options. For example, it may begin by defining in its zoning ordinance solar and wind energy systems as accessory uses, similar to sheds, swimming pools, fences, and garages. Or, it may specifically list solar and/or wind systems as a permitted accessory use in one or more base zoning districts included within the zoning ordinance. In either case, such uses would be subject to ordinance regulations that apply to all accessory uses and structures, such as setback requirements or height limitations.
Beyond these basic steps, the municipality can add supplemental regulations to its zoning ordinance that would specifically apply to accessory solar and/or wind energy uses. For example, supplemental regulations can be used to specify structural setbacks from roof edges or lot lines, establish impervious cover limitations, or require the removal of such structures when no longer in use. Where a non-commercial solar or wind energy system is proposed for a historic building or site, the system’s location on a building, or on the ground, or the materials used in its construction, may be specifically guided by supplemental regulations or performance standards included in the zoning ordinance.
Stepping up to a secondary level of regulatory options, municipalities may require in some instances that accessory solar and wind energy systems only be permitted when subject to discretionary approval by a Zoning Hearing Board or the elected officials. Or, in some instances, the establishment of such uses may even be prohibited. For example, the requirement for special exception approval and imposition of reasonable development conditions may be appropriate for mitigating the impacts of a modern solar panel when placed on a historic building.
Pennsylvania municipalities have little experience with regulating non-commercial solar and wind energy systems through municipal zoning, providing few opportunities to learn by example. Consequently, a municipal governing body’s decisions may have to be based largely on the municipality’s own experience with, and level of comfort with, these uses.
This guide addresses the regulation of alternative energy uses that are accessory to permitted principal uses on a building, lot or parcel, in other words, regulation of alternative energy systems that generate power utilized entirely or largely by a property’s principal use, which may be a home, business, or farm.
This guide does not provide guidance on the regulation of principal or utility scale alternative energy uses. However, it is advisable for municipal governing bodies to provide for such uses in their zoning ordinances. (Utility scale alternative energy systems have to be allowed in one or more locations in order to avoid an exclusionary zoning challenge.)
This guide is applicable to Pennsylvania municipalities that have enacted a zoning ordinance consistent with the Pennsylvania Municipalities Planning Code (MPC).
Regulating non-commercial alternative energy systems through the use of an existing zoning ordinance is accomplished by adopting an amendment to the ordinance that adds specific provisions to sections of the ordinance. Considerations in developing the content of these provisions are described below as well in the supplemental paper “Details Applicable to the Inclusion of Non-Commercial Solar and Wind Systems in the Municipal Zoning Ordinance.”
The following questions identify issues that may arise during the establishment of non-commercial alternative energy zoning regulations; these have arisen in similar ordinance development efforts and are provided to help develop a working outline of the draft regulations.
Many of these questions are addressed in the following sections. In addition, one or more of the individuals listed in the Experts area of the guide may be contacted for help in answering any remaining questions.
It is recommended that the zoning ordinance include a supporting statement of purpose, or a specific community development objective, in order to establish a foundation for the regulation of alternative energy systems. These statements need not name the solar and wind systems that are regulated, but should reflect the MPC’s purposes that include “…to promote the effective utilization of renewable energy sources… (§105).” Finally, the purpose statement or community development objective can be linked to the adopted comprehensive plan’s goals, policies, and/or objectives that encourage alternative energy use.
The meanings of new terms used in any new regulations should be included in the zoning ordinance’s definitions chapter or article. Definitions routinely used in the examples cited herein include the following:
Solar Access. The access of a Solar Energy System to direct sunlight.
Solar Easement. A legal agreement that protects access to sunlight on a property.
Solar Energy System. Any solar collector panel(s), film(s), shingle(s), or other solar energy device(s), or solar structural component(s), mounted on a building or on the ground and including other appurtenant structures and facilities, whose primary purpose is to provide for the collection, storage, and distribution of solar, or radiant, energy received from the sun and used for heating or cooling, for water heating, and/or for generation of electricity. A Solar Energy System may be ground-mounted (i.e., placed on top of the ground surface) or roof-mounted (i.e., placed on or as an integral part of a building).
Utility Scale Alternative Energy System. Any commercially-sized or -scaled Solar or Wind Energy System; e.g., the System is the principal use on the property and its operator has signed an official agreement of power purchase with a utility provider, or, it produces energy in excess of one-hundred-twenty-five (125) percent (%) of the energy needed by the property’s principal use.
Wind Energy System. Any electric generation facility, whose main purpose is to convert and store wind energy into usable forms of energy and that includes the wind turbine(s), structural supports, electrical infrastructure, and other appurtenant structures and facilities. A Wind Energy System may be freestanding (i.e., placed on top of the ground surface) or roof-mounted.
Each base district included in a zoning ordinance contains a list of uses permitted within the district. Often these are divided into uses permitted (by-right), uses permitted by special exception, uses permitted by conditional use, and accessory uses.
The proposed zoning regulations should clearly state that non-commercial alternative energy systems (solar and wind) are permitted as accessory uses to permitted principal uses, subject to any applicable zoning regulations. This can be accomplished in either of two ways. First, non-commercial solar and wind energy systems can be added to the list of accessory uses already defined and permitted, most often in the General Regulations part of the ordinance. Or, the proposed zoning provisions may add, and specifically list, “solar and wind energy systems when accessory to a permitted principal use,” to one or more of the existing base zoning districts, as determined appropriate by the municipal governing body. This second option is preferred, as most municipalities have a number of different zoning districts.
The proposed zoning regulations should also address whether non-commercial solar and wind energy systems are accessory only to residential uses, or whether they can also be accessory to commercial, institutional, agricultural, industrial, and other types of permitted uses. When addressing alternative energy systems for residential uses, the type of dwelling (e.g., single-family detached dwellings, townhouses, and apartments) approved for such use may also need to be identified. For example, will solar panels be permitted on a townhouse or duplex, or only on a single-family detached dwelling?
In some zoning districts, it may be appropriate to further specify the type and physical location of the alternative energy system (refer to following section). For example, townhouses and apartments are usually situated close to each other, so that roof-mounted, or freestanding, wind turbines may not be desirable from a safety standpoint or visual impact perspective. On the other hand, in an agricultural zoning district where the building lots may be 25 acres, 50 acres, or larger, wind turbines (again, with consideration to all other provisions of the zoning regulation) may be appropriate.
For non-commercial solar and wind energy systems, the proposed zoning regulations should differentiate between ground-mounted/freestanding and roof-mounted systems (See “Introduction to Solar and Wind Energy Technologies” for descriptions). In addition to addressing spacing concerns for higher-density residential and other uses, ground-mounted/freestanding systems should be required, at a minimum, to comply with minimum yard or setback requirements for accessory structures. A ground-mounted solar collector may be required to be located behind the building line, or to the side, or rear of the principal use or structure. This may be important in suburban or urban residential zoning districts with smaller lots where citizens would have strong aesthetic or other objections to ground-mounted collectors located in the front yard. This would be particularly true if more than one lot owner on a street chose to build in the front yard. The minimum required setback for a freestanding, accessory wind turbine may directly correspond to the proposed height of the turbine for safety purposes. That is, a 100-foot tall wind turbine may require a minimum setback of 100 feet from all property lines, so that no part of the turbine would encroach upon an adjoining lot or parcel if it were to fall or be lowered for maintenance, replacement, or abandonment. (See section on Sample Performance Standards.)
Accessory solar or wind energy systems mounted to principal structures should also be precluded through zoning provisions from over-hanging building roof edges. Some municipalities have required roof-mounted systems to be set back at least three feet from the roof edge, to allow ready access by firefighters or other personnel. (See section on Sample Performance Standards.)
Ground-mounted solar collectors may be limited in overall height by maximum height limitations within a zoning ordinance. They may be limited to the same maximum height limitation applied to all accessory structures, or limited through a separate provision. Freestanding wind turbines may be exempted by the zoning ordinance from complying with the maximum height limitation that applies to principal structures (e.g., 35 feet), similar to other accessory uses normally exempted, such as a radio antenna or grain silo.
It would be appropriate however to establish a maximum height limitation for wind turbines (e.g., 150 feet), or have more than one maximum height limitation depending on the character of the surrounding landscape. For example, a more densely developed residential area may have a 50 or 75-foot height limit for wind turbines, while an agricultural area might allow twice the height. How the maximum height limitation is measured should also be defined in the case of wind turbines, e.g., measured from the base of the pole or column (at average ground level) to the highest blade tip of the turbine.
Roof-mounted solar panels are often permitted to slightly exceed the building height limitation for the principal structure. This extra allowance provides for roofs already constructed at the maximum height limit allowed for principal structures. Normally a maximum height limit, or cap, is established to limit the height of the solar panel as well. (See section on Sample Performance Standards.)
With any solar energy system installation, whether ground- or building-mounted, the panel or collector placement should not result in offensive or harmful glare impacting adjoining uses or properties, or that creates dangerous driving conditions for passing motorists. Operating wind turbines should not result in excessive noise, light flicker, or radio interference, beyond the host property. Although many municipal zoning ordinances contain basic performance standards that generally address anticipated environmental issues such as noise, glare, odor, vibration, and other impacts for all listed uses, additional performance standards can be provided for non-commercial alternative energy systems that specifically address glare, noise, and other reported impacts. (See section on Sample Performance Standards.)
Whether a non-commercial solar or wind energy system, defined as an accessory use, is permitted “by-right”, or by special exception or conditional use, there are different decision-making procedures normally included in a zoning ordinance that must be followed.
Ministerial zoning permit approvals are those issued by a municipal staff person (or contracted consultant) once he or she has determined that a requested use is permitted by the zoning ordinance, and that it complies with all applicable zoning ordinance provisions. For example, when a non-commercial solar or wind energy system is defined as an accessory use either in the general regulations section of the zoning ordinance, or under appropriate base districts of the zoning ordinance, the Code Enforcement Official (CEO), Zoning Officer, or building official, must issue a zoning approval when an applicant for a building or zoning permit adequately demonstrates that the requested use is accessory to an existing or proposed principal use, and will meet all zoning ordinance provisions applicable to accessory uses, such as minimum structural setbacks from property lines, if freestanding, and maximum height limitations, if freestanding or structurally attached. Where included in the zoning ordinance, an applicant for a building or zoning permit may also have to demonstrate that the accessory use, whether a solar or wind energy system, will comply with any applicable supplemental regulations or performance standards.
Once the CEO, Zoning Officer, or building official makes such a determination, the use must be approved and the local building or zoning permit issued. The CEO, Zoning Officer, or building official is prevented by Pennsylvania zoning law to attach any conditions of approval not otherwise specified within the zoning ordinance, and the zoning ordinance language needs to allow for simple “yes it complies”, or “no it does not comply” determinations and avoid “gray-area” interpretations. Input by any property owner adjoining the parcel proposed for the use is also legally not relevant to the permit issuance determination. (An exception to this may be where an adjoining landowner or tenant has filed a complaint with the municipality over a possible ordinance violation on a pre-existing situation, resolution of which by the municipality is still pending.)
Discretionary zoning decisions are those made by an appointed body, or elected body, normally at an advertised public hearing, and after first considering all relevant information, taking public testimony, reviewing the zoning ordinance and other applicable documents, and ultimately reaching a decision on the request, whether favorable, or not, and if favorable, including any conditions deemed appropriate to further regulate the use. For example, prior to applying for local building or zoning permit approval to install a non-commercial solar or wind energy system, an applicant would be required to separately apply for special exception or conditional use approval to allow such system or use to be established on a lot or structure. The zoning district text must identify the need for either a special exception, or conditional use, in order to establish such a use, and the zoning ordinance will also include any procedural (and application submittal) requirements for obtaining the discretionary approval. An application fee for special exception or conditional use approvals typically applies (established by resolution), and application decisions can take several months to obtain due to application processing time and satisfying any legal requirements for advertising public meetings or hearings.
The zoning ordinance requirement for special exception or conditional use approval for a non-commercial solar or wind energy system may be appropriate for portions of a municipality which are historic in nature, such as a village, hamlet, or National Register Historic District. Prior to making a decision on a special exception or conditional use, an advertised public hearing is held by the Zoning Hearing Board (for special exception) or the municipality’s elected body (for conditional use). This hearing allows owners of property surrounding the proposed solar or wind energy system to learn more about the proposal, provide comments on the proposal, including voicing concerns with potential impacts. Potential adverse impacts identified through the review of a solar or wind energy system special exception or conditional use application could be addressed through the Zoning Hearing Board’s (or governing body’s) imposition of reasonable development conditions that would accompany the special exception (or conditional use) approval.
When discretionary approval options are being considered, use of the special exception option is preferred over the conditional use option, and avoids involving a municipality’s elected officials in relatively minor use approvals. By comparison, the conditional use tool would be quite appropriate where utility-scale alternative energy systems are being considered. Like other uses in the zoning ordinance that are subject to special exception approval, the Zoning Hearing Board should consider whether the alternative energy use would adversely or materially affect the health, safety, and general welfare of the municipality. The Hearing Board can impose reasonable conditions with an approval to prevent, or mitigate, anticipated adverse impacts of the solar or wind energy system, especially with respect to landscaping, lighting, aesthetics, and the harmonious design of buildings. Finally, when drafting alternative energy zoning regulations, the benefits gained by requiring discretionary approvals (i.e., where conditions for approval can be imposed to address potential impacts of such uses in sensitive areas such as an historic district) should be weighed with the possible disadvantages, which relate mainly to both an applicant’s, and the municipality’s time to process or obtain special exception approval, and the associated cost and perception of excess regulation.
Prohibiting the establishment of non-commercial solar or wind energy uses may be appropriate for portions of the municipality, where the installation of such uses may cause undue noise, glare, historic, or other visual impacts. Provided that such uses are permitted by zoning somewhere within the municipal boundaries, prohibiting them in one or more zoning districts based on a rational explanation should be legally defensible. The opinion of the municipal solicitor should always be consulted before enacting such prohibitions.
Combining procedural options within the zoning ordinance, depending on the alternative energy system’s type, physical location and site characteristics, is often a wise approach. For example, a roof-mounted solar energy system might be appropriate in residential zoning districts subject only to receipt of a building permit and adherence to the zoning regulation’s performance standards (refer to next section). Alternately, special exception approval from the municipality’s Zoning Hearing Board, with input by the HARB, may be required for a roof-mounted solar energy system on a property within a National Register Historic District recognized by the zoning ordinance. (See section on Alternative Energy Systems Accessory to Historic Resources.)
Performance standards (or supplemental regulations) are typically included in zoning ordinances to protect the health, safety, and general welfare, by limiting or mitigating the potentially negative impacts of a use or its operation, in this case, an accessory solar or wind energy system. Supplemental regulations can be tailored to a specific use, unlike general regulations, or a base district’s area and bulk regulations, that must apply to a number of different accessory uses permitted by zoning. This section offers sample performance standards categorized by solar, wind or both types of systems. All of these standards were developed based on Pennsylvania zoning ordinances that permit accessory solar and wind energy systems, and materials drafted by a Delaware Valley Regional Planning Council- (DVRPC) sponsored “Alternative Energy Ordinance Working Group, (AEOWG)”.
The following samples are intended to cover a wide range of issues. An ordinance regulating accessory solar or wind energy systems should not be considered incomplete or inadequate if it does not include all of these performance standards; how many the municipality decides to include depends largely on the extent to which the municipal governing body wishes to regulate such uses, and the complexity of issues that are anticipated.
Successful administration and enforcement of zoning regulations for alternative energy uses will best be accomplished by developing, enacting, and revising as needed, a succinct and unambiguous set of Performance Standards (Supplemental Regulations). In turn, these Performance Standards should be paired with clear and enforceable administrative procedures, and followed with consistent enforcement of zoning ordinance provisions. Where applicable, special exception or conditional use conditions of approval must also be consistently monitored and enforced for compliance.
Adding non-commercial solar systems (especially ground-mounted) and/or wind turbines (either roof-mounted or freestanding) to historic buildings or structures, or when placed within historic landscapes, will likely be a sensitive issue for municipal officials, their historic commissions, and property owners, who value historic resources. Some municipalities may require a more extensive review and approval process, as enabled through the local ordinance; some may add to their zoning ordinance’s performance standards to address these situations; and some may simply prohibit the establishment of accessory solar and wind systems for historic resources. This form of accessory use can present challenging policy questions for a municipality: Should an owner of a historic resource be able to benefit from the use of an alternative energy system similar to owners of non-historic resources who also choose to use such systems? Should these owners be required to protect the historic resource value of a structure or setting when installing such a system?
Although not required, a prudent prerequisite for a municipality that is interested in protecting historic resources through regulation is to first identify its historic resources. This can be achieved through the use of a formal site survey of all historic resources that are eligible for listing on the National Register of Historic Places; designating the land they fall upon as a Historic District as authorized by Pennsylvania’s Act 167, the Historic District Act; or by designating local historic resources through the completion of a County Historic Site Survey. Once identified by the municipality, several different forms of regulations are available to Pennsylvania municipalities to help retain the nationally or locally significant historic resource values. These identification and regulatory approaches are explained in the ConservationTools.org guide Local Regulation for Historic Preservation.
With a local resource inventory and supporting regulations in place at the municipal level, the historic resource value of buildings, structures, or lots can be far more effectively addressed when accessory solar and wind systems are proposed. For example, where a roof-mounted solar system or ground-mounted solar or wind system is proposed for a historic resource within an established Historic District, the municipality’s ordinance that established the District could require the procedural review of such proposal by its Historic Architectural Review Board (HARB). This Board would then forward its recommendation to the municipal governing body in regard to approval, denial, or conditional approval of a “Certificate of Appropriateness” (COA) for the proposed work.
Where a municipality has provided for the protection of historic resources through use of its zoning ordinance, approval of a special exception by the Zoning Hearing Board may be required in order to add a solar panel to a historic dwelling, for example. Comments on this addition could be requested from the municipality’s Historic Commission, if established, and forwarded to the Zoning Hearing Board for consideration during its hearing on the special exception request. The Zoning Hearing Board can impose reasonable conditions for special exception approval, and in this case, such conditions could be used to help minimize the impacts of the solar panel on the historic dwelling, for example, requiring that the solar panel be located outside the public view. (See discussion of discretionary approval in the “Permitting Process” subsection above.)
The National Trust for Historic Preservation’s “Design Guidelines for Solar Installations”, states that:
“Consideration should always be given to solutions that protect historic features, materials, and spatial relationships with the visibility of all solar energy installations – including solar panels – minimized to the greatest extent possible.” Ten design guidelines are offered by the Trust for consideration when planning to use solar panels on historic structures or on historic sites. Although not necessarily intended for such use, these helpful guidelines could be incorporated as an appendix, or special section of the ordinance text, and reviewed by the municipal governing body when considering a request for the use of solar panels on a historic building or structure.
Ten design guidelines are offered by the Trust for consideration when planning to use solar panels on historic structures or on historic sites. Although not necessarily intended for such use, these helpful guidelines could be incorporated as an appendix, or special section of the ordinance text, and reviewed by the municipal governing body when considering a request for the use of solar panels on a historic building or structure.
For additional electronic examples and context, see Delaware Valley Regional Planning Commission’s (DVRPC) “Alternative Energy Ordinance Work Group.” This ad-hoc committee of planning professionals from throughout the DVRPC region meets regularly to share information regarding a range of ordinance topics related to numerous alternative energy systems. Also, refer also to the zoning ordinances governing solar energy uses from the City of Erie, the Borough of Pottstown, and Manheim Township. For wind energy ordinances, refer to East Pennsboro and Manheim Township’s wind energy ordinances.
In a suburban Pennsylvania township, the Board of Supervisors directed its Planning Commission to work with a local consultant to develop zoning provisions that regulated non-commercial alternative energy uses, and propose such draft regulations as an amendment to the existing zoning ordinance. The consultant was directed by the Planning Commission to: (1) apply the new zoning provisions initially to the existing commercial and industrial zoning districts (portions of which include a National Register Historic District) and leave the residential zoning districts unregulated (for now) with regard to these uses; and, (2) require conditional use approval for these non-commercial systems. The Planning Commission and its consultant met for several months and drafted a set of provisions that were presented to the Board for review and possible adoption. However, the Board could not act on the Planning Commission’s proposed draft ordinance because of the following concerns: a) that non-commercial solar and wind energy systems proposed for residential zoning districts probably should be included after all with this amendment; b) the provisions for commercial and industrial use of such systems that more severely limited their use for historic structures within the National Register Historic District may unfairly restrict the owner of the historic structure; and c) the requirement for conditional use approval for all non-commercial solar and wind energy uses in the commercial and industrial districts was viewed to be too burdensome on township property owners. The Board decided instead to return the draft ordinance provisions to its Planning Commission so that it might reconcile the Board’s concerns.
Lessons learned: Although it is not uncommon for elected officials and their appointed commissions to hold differences of opinion, before drafting new zoning regulations, it would be wise for municipal officials (i.e., both elected and appointed) to be unified, if possible, on the task at hand. In this case, the Board and Planning Commission might have agreed from the start a) which areas of the municipality alternative energy ordinance provisions would initially be applied to; and b) based on their understanding of the procedural differences between “by-right” and discretionary approvals, conceptually agree upon when the requirement for conditional use would be appropriate, if at all. Admittedly, designing ordinance provisions for non-commercial solar and wind energy systems when involving historic buildings, landscapes, and National Register Historic Districts can be challenging, and few good examples or “go-by’s” exist to draw from. Municipalities will often find themselves weighing the historic value of a building or landscape with the environmental and other benefits of promoting alternative energy uses in their communities. Fortunately, as solar technology quickly advances and photovoltaic cells are incorporated into almost any building material (window glass, roofing shingles, aluminum siding), regulating non-commercial solar energy systems to avoid historic resource impacts should become less and less of a zoning concern.
Even though several residential solar installations in this suburban Pennsylvania township had been previously allowed to occur without the need for zoning regulation, its Board of Supervisors was in the process of pro-actively drafting an alternative energy zoning ordinance for solar energy uses. However, as the Board drafted its zoning ordinance amendment, a homeowner installed solar panels over virtually the entirety of his/her roof facing a public street, along with the installation of a ground-mounted solar array in the side yard and in clear view from the public street. Given that the houses in this neighborhood were spaced relatively close together, and sat on opposing sides of the street, complaints from abutting property owners of significant glare from the roof-mounted solar panels were filed with the township. The Board became extensively involved in the resolution of this neighborhood dispute as the township’s CEO had already approved the installation. Also while this same township was drafting its alternative energy zoning regulations, a request by a commercial water provider was filed with the township to establish a utility-scale solar energy array to help power their water treatment facility and sell surplus power to “the PECO grid”. Without sufficient zoning controls to prevent or minimize the potential impacts of this large solar array, the Board was essentially limited to negotiating basic site improvements with the applicant and issuing the zoning permit approval.
Lessons learned: 1) even non-commercial solar energy systems in suburban residential settings may not always be “harmless,” and therefore appropriate to regulate through a municipal zoning ordinance so that adverse impacts caused by such uses can be avoided or mitigated, and 2) municipal officials would be wise to proactively update their municipal ordinances to effectively regulate non-commercial and utility-scale (commercial) alternative energy uses as time, energy, and budget allow.
Tara Tracy, CPSS, Senior Planner, and John Theilacker, AICP, Associate Director, of the Brandywine Conservancy’s Environmental Management Center, were the primary authors of this guide. Andy Loza edited the guide.
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