How Solar-Friendly is Your Zoning Code?

Mirroring a nationwide uptick in solar development, Wisconsin is projected to install an additional 4,630 MW in the next five years, enough to power 754,450 homes. This represents a 280% increase from current installations, putting our state in 11^th for growth.

If recent trends are any indication, we can expect the Dane County solar market to continue growing as well. This means local planning and zoning departments are likely to receive many more solar applications in the coming years. Are our zoning and permitting processes ready to accommodate the increased demand for solar?

CARPC will be considering this question as we examine how solar development is addressed in local zoning codes through our code assessment project and SolSmart designation process. In addition to making things easier for staff, local zoning codes that establish clear expectations, a streamlined process, and minimal barriers can drive solar development costs down by as much as 10%.

If these are current priorities for your community, there’s no need to wait for the findings of our review. Read on for some tips on assessing your local code today.

First, start with a quick search for key terms:

• Photovoltaic
• Solar
• Renewable energy
• Clean energy
• Energy storage

Next, check for best practices. If your code does discuss solar development, determine whether it’s a permitted use in most zoning districts or requires additional review. You can also look for inclusion of best practices such as:

• Include statement of purpose or intent regarding solar energy regulations that outlines the goals of including solar energy systems in the zoning code and provides an opportunity to link solar energy development to specific community goals and plans.
• Include definitions for solar energy: distinguish between solar energy system type (roof-mounted vs ground-mounted) and use (accessory vs primary) to provide clarity and a foundation on which to specify permissible uses in specific zoning districts and provide development standards.
• Explicitly permit accessory use roof-mounted solar PV systems as a by-right or allowed use in all major zoning districts.
• Exempt roof-mounted solar PV from height restrictions or allow r​oof-mounted solar PV to exceed height restrictions by a defined number.​
• Explicitly permit accessory use ground-mounted solar PV systems as a by-right or allowed use in at least one zoning district.
• Explicitly permit accessory use energy storage systems in all major zones.
• Include setback standards for accessory use ground-mounted solar PV similar to those for other residential accessory use structures. These setbacks generally allow accessory structures to be built closer to a property line than primary structures. Rural communities or those with large lots can be less restrictive and allow solar energy systems to encroach into established residential accessory use setbacks.
• Include placement standards for accessory use ground-mounted solar PV. Depending on the character and typical lot size of the community, it may be appropriate to encourage the siting of accessory use ground-mounted PV systems in the side or rear yard of a property. Rural communities or those with large lots can be less restrictive and allow solar energy systems in front yards.
• Exempt accessory use ground-mounted solar PV from lot coverage and/or impervious surface standards as long as the area beneath the system is pervious.
• If your community has enough usable land that could be developed for a large-scale solar energy system, include standards for primary use ground-mounted solar PV.​ This could be of particular interest if there is a brownfield site such as a landfill available for development.

Look for opportunities to modernize dated language. Today’s solar projects are much more uniform and regulated than in the past, with most using standard equipment and designs. Older, highly customized review processes are typically no longer necessary. If your code’s solar provisions were developed in the early days of PV, consider removing, reducing, or modifying unnecessary requirements such as:

• Screening requirements for roof-mounted solar PV systems
• Standards to limit system visibility (e.g. not visible from public rights of way)
• Aesthetic standards for solar PV systems
• Glare, glint, and/or noise standards for PV systems (PV panels are already designed with anti-reflective glass, and roof-mounted systems produce very minimal noise.)
• Limitations to solar PV system coverage to a percentage/part of available roof space
• Prohibitions on solar PV systems on flat or low sloped roofs (Many buildings with flat roofs like warehouses, data centers, distribution centers, and big box retail stores are excellent candidates for roof-mounted solar energy systems.)
• Limits on how much electricity a solar PV system can produce
• Limits on where a solar PV system’s energy is consumed
• Discretionary review processes for accessory use solar PV

Once you have an idea of where your code stands, learn more about best practices and review ordinance examples. SolSmart’s Best Practices Guidance for Solar and Zoning highlights the key components for organized, transparent, and consistent accessory use solar energy regulations. It also gives examples of model zoning ordinances from around the country, including the 2020 Wisconsin Solar Model Ordinance created by the Great Plains Institute.

Ready to go above and beyond? Consider developing solar-ready building guidelines like the City of La Crosse. Solar-ready buildings are engineered and designed for solar installation, whether it occurs at the time of construction or in the future. This makes it easier to install solar on new builds and cuts the cost of future retrofits. The U.S. Department of Energy’s 2023 Solar Power in Your Community guidebook provides additional ideas for local governments looking to increase access to and deployment of solar PV.

In the coming months, CARPC will be compiling our findings to see how extensively zoning codes address solar development and get a feel for the regional regulatory landscape. We’re also planning a training for planning and zoning staff on the technical implementation of solar best practices through local comprehensive plans, zoning codes, and land use decisions. Stay tuned for more information!