Frequently Asked Questions

Planning and Zoning for Solar Energy

How do other communities encourage the use of solar energy systems through their comprehensive plans?

The local comprehensive plan presents a future vision of the physical, social, and economic characteristics of an entire city or county, and it specifies goals and policies intended to implement that vision. Because it is the most expansive official policy statement of a city council or county board, it is an ideal tool to support the deployment of solar energy systems on both public and private property.

There are two primary mechanisms by which comprehensive plans can support solar energy system deployment: (1) documenting the solar resource and (2) articulating policies to guide decision making.

First, comprehensive plans can provide information about the solar resource available in different parts of the community. This may be in the form a solar resource map showing which areas receive the most sunlight annually, or it may be a text description of site characteristics that maximize solar potential.

Second, comprehensive plans can articulate specific policies to guide decision making about solar energy system deployment on public and private land. These policies may address solar access protection, street and building orientation, or preferential locations for new solar energy systems.

Examples from PAS Essential Info Packet 30: Planning and Zoning for Solar Energy

How do other communities use development regulations to protect solar access?

The most effective point in the development process to protect solar access is when a parcel is being subdivided into lots for sale. Some communities have development regulations that require developers to orient and design lots so that structures of a certain height at certain location on each lot will not block solar access to adjacent lots. In effect, each lot then has a permissible building envelope where a structure can be built while still allowing the adjacent lot to the north access to the solar resource.

There is no single default method for protecting solar access in areas that have already been developed. A number of development regulations include a process for obtaining solar access permits or recording solar easements, which establish a right to solar access for an existing or planned solar energy system on a specific lot.

Beyond enabling solar access permits for a specific solar energy system, some development regulations require new structures on existing lots to conform to "solar setbacks" in order to protect solar access more generally. These setbacks are determined by a formula that factors in the height of the structure, the angle of light when the sun is at its highest point on December 21 (i.e., the winter solstice), and the slope of the lot.

As an alternative, a few communities use the concept of a "solar fence" in their development regulations to protect solar access for existing lots. A solar fence is a hypothetical opaque fence of a specific height encircling a lot. New structures must not create more shade than would be created by this solar fence.

Examples from PAS Essential Info Packet 30: Planning and Zoning for Solar Energy

How do other communities use development regulations to encourage appropriate solar orientation for new development?

The most effective point in the development process to encourage solar orientation is when a parcel is being subdivided into lots for sale. Some communities have development regulations that require streets and lots to be oriented to maximize the solar resource available to each lot or to a minimum percentage of lots.

Typically, development regulations do not specify a rigid site plan for all new development. Instead, the regulations set a goal for the minimum percentage of houses that will have an east-west orientation for their longest side. In practice, this might be achieved through a wide range of street and lot design options.

Examples from PAS Essential Info Packet 30: Planning and Zoning for Solar Energy

Do any communities require developers to build "solar-ready" homes?

A growing number of communities are either requiring or incentivizing the construction of "solar-ready" homes. In essence, the phrase "solar ready" means that the home is constructed in such a way that installing and connecting a solar energy system (whether photovoltaic or solar thermal) does not require additional wiring, plumbing, or building modification.

Typically, when communities elect to require solar-ready homes, they add provisions to the local building code. Alternately, some communities use their development regulations to incentivize solar-ready homes by making solar-ready construction eligible for a density bonus.

Examples from PAS Essential Info Packet 30: Planning and Zoning for Solar Energy

How do other communities use development regulations to encourage the installation of small-scale solar energy systems?

When communities address solar energy systems (i.e., photovoltaic, solar thermal, and building integrated) in their development regulations, they may define these systems as accessory structures, accessory uses, or primary uses. The major tension in this issue is potential tradeoffs between system optimization and aesthetic effects on surrounding properties.

Some communities permit accessory solar energy systems by right in all districts while others have special permitting processes that take into account site design and impacts to adjacent property owners. Over the past few years it has become increasingly common for communities to adopt specific standards for accessory solar energy systems to address placement issues without requiring a discretionary review.

Examples from PAS Essential Info Packet 30: Planning and Zoning for Solar Energy

How do other communities regulate large-scale solar installations?

Relatively few local governments address large-scale solar installations (i.e., solar farms) in their development regulations. Because utility-scale solar projects are typically subject to state or federal review as part of the permitting process, local codes that list development standards for these uses are rare. However, a growing number of communities are acknowledging large-scale solar installations as a legitimate land use.

When development regulations do address large-scale solar installations, they are typically permitted as conditional uses in a limited number of industrial or agricultural zoning districts and may be subject to specific use standards to address aesthetics or minimize environmental impacts.

Examples from PAS Essential Info Packet 30: Planning and Zoning for Solar Energy

What do other communities do to mitigate the effects of glare from solar panels on surrounding properties?

One of the major tensions in regulating solar energy systems is the potential tradeoff between system optimization and aesthetic effects on surrounding properties. In practice, the amount of glare depends not just on the angle of installation but also on the specific product installed. Different types of solar panels absorb different amounts of light. Newer panels generally include at least one anti-reflective layer to maximize absorption and minimize glare. In fact, the reflectivity of solar panels is often much lower than that of other nearby materials (e.g., standard glass, snow, or steel).

When communities address glare in their development standards for either rooftop or freestanding panels, the language is typically subjective. In other words, the standards usually say that systems must be designed and sited to avoid glare on adjacent properties or roadways without going so far as to require a glare study or specific glare mitigation techniques or technologies.

Examples of Development Standards that Address Glare

Albany (New York), City of. 2011. City Code. Chapter 375. Zoning. Article XIV. Specific Use Regulations. Section 375-93. Solar energy equipment. Available at www.ecode360.com/?custId=AL0934.

Calabasas (California), City of. 2011. Municipal Code. Title 17. Land Use and Development. Chapter 17.20. General Property Development and Use Standards. Section 17.20.190. Solar Energy Development Standards. Available at http://library.municode.com/index.aspx?clientId=16235&stateId=5&stateName=California.

Dundee (Michigan), Township of. 2010. Ordinance No. 09-10-01: Solar Panel Zoning Ordinance Amendment. Available at www.dundeetownship.info/zoning_ordinance.asp.

Lincolnshire (Illinois), Village of. 2011. Municipal Code. Title 6. Zoning. Chapter 17. Alternative Energy Collection Systems. Section 6-17-6. Solar Energy Systems (SES). Available at www.village.lincolnshire.il.us/code/code0617.pdf.

Shoreham (Vermont), Town of. 2004. Zoning Bylaws. Section 341. Conditional Use Review. Subsection G. Performance Standards. Section 527. Solar and Wind Energy Systems. Available at www.shorehamvt.org/town/docs/Shoreham-Zoning.pdf.

How do other communities address solar energy systems in historic districts?

In many cases solar energy systems are not visually compatible with historic structures or districts. However, many planners, preservationists, and solar advocates recognize the value of adding solar energy systems to historic structures and are eager to find solutions to this tension between aesthetics and historic preservation. A recent report, Implementing Solar PV Projects on Historic Buildings and in Historic Districts, co-authored by the National Renewable Energy Laboratory and the National Trust for Historic Preservation includes a series of guidelines for siting solar energy systems on historic properties.

Though some communities prohibit solar energy systems on historic structures altogether, many others do make accommodations for solar installations. The typical solution is to allow roof-mounted systems as long as they are not visible from the street, are restricted to rear sections of the roof or located on non-historic additions, lie flush with the roof pitch, and do not protrude above the roofline. Given these restrictions, ground-mounted systems are often preferable, provided that they can be sited out of sight from the public right-of-way and in a location that receives adequate sunlight.

Examples of Historic District Design Guidelines that Address Solar Energy Systems

Aurora (Illinois), City of. n.d. Rehabilitation and Restoration Guidelines. Available at www.aurora-il.org/documents/historicpreservation/HistoricPropertyGuidelines.pdf.

Boulder (Colorado), City of. 1994. Mapleton Hill Historic District Design Guidelines. Part VI, Section V. Solar Additions. Available at www.bouldercolorado.gov/files/PDS/historicpres/pdfs/maplhill.pdf.

Montgomery (Maryland), County of. 2011. Design Guidelines for Historic Sites and Districts in Montgomery County, MD. Chapter 3, Part 9.0. Solar Panels. Available at www.montgomeryplanning.org/historic/designguidelines.shtm.

St. Cloud (Minnesota), City of. 2011. Land Development Code. Article 13, Section 13.4.B.5. Commercial Historic District Design Guidelines - Accessory Structures and Appurtenances. Available at www.ci.stcloud.mn.us/planning/LandDevCode.aspx.


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