Solar installations are becoming more frequent as individuals, communities, companies and utilities look for renewable energy solutions. The information on this page is provided to help explore early planning opportunities, permitting requirements, long-term land use, life cycle analysis and equity-based evaluations for developing your solar infrastructure project. The focus is on ground-mounted projects as they have a broader impact on the environment than building mounted or home installations.
While solar projects can benefit the environment as well as the community in which they are installed, they can have undesirable outcomes when not carefully planned. The planning phase is the time to establish which installation and management practices can have the most beneficial outcomes, often at the lowest costs. It is particularly important for these environmental factors to be taken into consideration during the permitting of these large-scale projects prior to their construction. Retrofitting those practices later may increase costs.
Solar-related permits are typically reviewed in DNR's Office of Energy, rather than in the individual programs or regional offices. Contact the individuals listed on this page for additional questions.
How Can I Get Solar on My Property?
Whether you are an individual landowner, a municipality, or are representing a property owner, consider the following before initiating a solar project:
- Review definitions and explanations about different options in solar installations. Scroll down to the "How Do Solar Panels and Solar Farms Work?" section on Utility Scale Solar Farms in Wisconsin.
- For information on installers, pricing guides and information on incentives and rebates: Wisconsin Solar.
- There are legal considerations when installing solar: Here Comes the Sun: Solar Development in Wisconsin.
- Communities can obtain technical assistance through Solsmart – a national organization for communities fostering solar markets, supported by U.S. Department of Energy
Solar installations can often be considered 'short-lived' infrastructure projects. Your upfront choice of sites can make the best use of available land.
- Consider aspects for siting on marginal, rather than prime farmland. Maps that show these distinctions are available through the National Resources Resources Service or your local Land Conservation Department.
- If the site selected is farmland, establish siting steps proactively reduce soil disturbance.
- The Wisconsin Department of Agriculture, Trade and Consumer Protection has guidelines for wind and solar installations and protecting the land for future production: Agricultural Impact Statements: Wind Farms.
- Some areas may be included in Farmland Preservation zoning or under Farmland Preservation Agreements that could affect siting of solar installations. Learn about the Farmland Preservation Program.
- Floodplain and shoreland zoning setbacks and requirements are another important factor to consider for solar siting. Please connect with your local zoning administrator to determine specific requirements in your area.
- Municipalities may need to update zoning to allow for solar installations. Read an article from Capital Area Regional Planning Commission on zoning issues.
- One article suggests considering open land around US interstate highways.
- Avoid siting on environmentally sensitive land: forest, wetland, rare species habitat.
- A report on siting solar by the Great Plains Institute: Siting Utility-Scale Solar and Wind in Wisconsin.
Public Input on Solar Projects
Those living near a proposed solar project may have concerns about the impact on their surrounding area, whether environmental or economic or other. There may be opportunities to provide comments to the regulatory agencies on proposed projects. The exact agency or agencies will depend on whether it is large enough to be reviewed by the Public Service Commission (PSC) and the DNR.
Joint PSC/DNR Regulated Projects: Large-scale solar projects are reviewed by the PSC and DNR. The PSC reviews all projects over 100 Megawatts in size, and many projects submitted by public utilities. The public input stage for those projects happens through the joint PSC/DNR review process. You can review proposed projects and provide input at PSC Major Cases. For more information on the PSC role in siting solar installations please also see the “Large Project Requirements” tab of this webpage.
The public is encouraged to provide comments on construction applications that come to the PSC. Find out more about how to participate in the PSC project reviews at:
Projects limited to DNR authority: Projects under 100 megawatts in size may still involve construction activities. that require DNR permits. The procedure to obtain DNR permit coverage follows the established statutory public involvement requirements.
- Public notice is a required step in the individual water permits; however, general permits only have a public notice period when they are reissued every five years.
- Wetland and waterway permits and storm water permits can be reviewed from ePermit tracking.
There may be additional public input review as part of any local permit review process.
Proactive Steps to Community Engagement
US Department of Energy has released a new edition of the Solar Power in Your Community guidebook to help local governments unlock environmental and economic benefits of increased solar deployment in their communities. This latest edition contains nearly 40 case studies from around the country that show field-tested approaches to reduce solar market barriers, highlights new technologies and strategies to maximize the benefits of solar, such as combining solar with energy storage to improve resilience, and emphasizes strategies for improving the equity of solar deployment at the local level. Wisconsin Clean Energy Toolkit offers ideas and resources to help local communities interested in building renewable energy.
- Before siting, meet with stakeholders, and local government leaders to fully explain the project.
- Review the community planning documents to understand how this project supports local goals.
- Articulate how this project will benefit the community and its residents. This may include some of the following:
- Factors such as public health/safety/equity, environmental sustainability, community resilience and improved economic prosperity.
- Consider hiring local residents for the site preparation, construction and maintenance of the project.
- Are you considering prevailing wages?
- Through the development of this project, are you helping build the skills and capabilities of the local labor force?
- Do you have a clear end-of-use/decommissioning plan?
The initial reviews needed for a solar project will include a simultaneous review of endangered resources, wetlands and waterways and site contamination. Keep in mind that project timing can be critical to managing multiple permit requirements.
All projects must avoid impacts to state and federally listed species. To ensure your project is in compliance with these laws, please visit Endangered Resources Review.
Wisconsin Historical Society
Applicants for utility construction projects must assess potential impacts to historic resources in order to be considered for PSC approval. Historic resources include archaeological sites, historic structures, and other sites of cultural significance. The Wisconsin Historical Society (WHS) maintains an inventory of these historical resources in the Wisconsin Historic Preservation Database (WHPD).
Most wetland impacts require authorization from the DNR through s. 281.36, Wis. Stat. Applicants must determine if wetlands are present within the project area and if present, site project components to avoid wetland impact. If wetland impact cannot be avoided, wetland impacts must be minimized to the maximum extent practicable and authorized by the DNR.
The DNR's Surface Water Data Viewer can be used as a starting point in determining if wetlands are potentially present within the project area. When conducting this desktop review, the Wisconsin Wetland Inventory Layer and Mapped Indicator Soils layer can be conservatively assumed wetland. A wetland field delineation must be conducted in all project areas where project infrastructure is proposed (i.e., arrays, fence lines, driveways, collector lines, transmission lines, substation, etc.) and any other areas where land will be disturbed. Information on wetland field delineation can be found on the DNR's Wetland Boundary Delineation webpage. Wetland delineations for solar projects must be reviewed and approved by the DNR's Office of Energy. However, wetland delineations conducted by consultants who are assured by the DNR do not require wetland boundary confirmation.
Activities in and adjacent to navigable waterways may require authorization from the DNR through Chapter 30, Wis. Stat. Activities that may trigger Chapter 30 permit coverage include, but are not limited to, culvert and bridge crossings for permanent access roads and driveways, temporary clear span bridges for temporary access roads, storm water pond within 500-feet of a waterway, open cut trenching a collection line, etc. Applicants must determine if regulated waterways are present within the project area and if present, attempt to site project components to avoid and minimize impacts to waterways and attain applicable permits if necessary.
The DNR's Surface Water Data Viewer is used to identify navigable (regulated) waterways within a project area. All waterways identified in the Surface Water layer are assumed navigable along with any other field identified waterways. The Waterways page of the DNR website provides information on activities regulated near waterways and provides links to applicable permit applications.
Floodplain and Shoreland Zoning
Floodplain and shoreland zoning setbacks and requirements are another important factor to consider for solar siting. Please connect with your local zoning administrator to determine specific requirements in your area. Electrical components should generally be places above the Flood Protection Elevation (FPE). Please be aware that H&H (hydrologic and hydraulic) studies may be required, depending on post placement, density and electrical components in relation to the floodplain and floodway. This is important to ensure solar panels can withstand flood events should they occur.
Prior to property changing hands, all parties involved should conduct a thorough review to learn of any issues with its environmental condition. The first step is to check the Bureau of Remediation and Redevelopment's tracking system, also known as the BRRTS database or the RR sites map to see if there is any record of contamination on or near the property you intend to purchase. If any contamination is present on the property, learn more about clean up requirements.
Information on restricted and prohibited invasive species can be found on the DNR website. Projects should survey construction areas and inventory invasive species present in the project area. Best Management Practices to avoid introduction and spread of invasive species should be used and can be found for different land types or activities.
Good project management can be critical for a successful installation. Don't let the enthusiasm for a great project get ahead of the permitting and environmental protection needs. Some DNR reviews have seasonal restrictions that can delay construction, as can the presence of important resources. State and federal application processes can have different schedules that impact the project. And of course, in Wisconsin, weather can limit construction schedules.
Other elements to consider include site clearing, land stabilization and initial vegetation management, including:
- Construction can extend full year for large scale projects, so erosion control overwintering needs are different.
- Consider phasing construction to minimize the bare soil area at any one time.
- When clearing trees, consider how to reuse wood rather than burn.
- Connect with community building projects - local parks may be interested in mulch.
- Chips from grinding/stump removal can be used as biomass fuel.
- Local technical college may have use for the wood in construction programs.
- Local jurisdictions may have different schedules for how soon disturbed areas must be temporarily stabilized.
Lifecycle Disposal/Preparation of Land and Equipment
Land use plans and your selection of equipment should also consider the long-term end of life disposition of the project. Things to consider in your planning process include:
- As you select equipment, how are you factoring in longevity of infrastructure, ability to recycle components and other 'end-of-life' parameters?
- Are you selecting equipment that is durable for Wisconsin?
- Does your design allow for array flexibility and expansion?
- Long term lease considerations
- Will your management plans accommodate working with landowners?
- How flexible will your plans be for the property if you find you are not using sections for panels right away?
- How does your design facilitate post decommissioning land use?
If a solar project has more than 1 acre of total land disturbance planned during construction activities, then storm water permit coverage is needed.
Results of initial reviews will need to be submitted with an electronic Notice of Intent (NOI) application:
- Upload Endangered Resource review information as an attachment in the ePermit tracking system.
- Upload wetland concurrence email with attachments in the ePermit tracking system.
- If files sizes are > 20 MB, please break files up into smaller pieces for upload. Give smaller files names that reflect the contents.
What Is >1 Acre of Land Disturbance for Solar Projects?
Per s. NR 216.002 (14), Wis. Adm. Code, "Land disturbing construction activity means any man-made alteration of the land surface resulting in a change in the topography or existing vegetative or non-vegetative soil cover that may result in storm water runoff and lead to increased soil erosion and movement of sediment into waters of the state. Land disturbing construction activity includes clearing and grubbing, demolition, excavating, pit trench dewatering, filling and grading activities."
As the definition implies, both temporary and permanent changes to the land are included. One often overlooked source of land disturbance is rutting due to vehicle access—both construction equipment and worker vehicles. Generally, the ruts are removed using fine grading equipment, which also creates ground disturbance. Unless there are measures in place to prevent it, it is likely that the entire site will be disturbed during construction due to staging, access and grading activities.
Erosion And Sediment Control Considerations For Solar Array Construction
Solar construction often involves the disturbance of large land areas and therefore carries with it the potential for environmental impacts due to erosion occurring during construction activities. The following items should be considered during development of an erosion and sediment control plan for solar projects:
- Pre-seeding: Many solar projects are developed in areas that were previously cultivated for row crops. Establishing a cover crop of oats, alfalfa or other grasses prior to the start of construction can help reduce the potential for erosion during the early phases of construction.
- Drain Tile: Many solar projects are developed in areas that are served by drain tile. Damaged drain tile can result in sediment discharge or flooding in unexpected locations. Locating and showing the drain tile locations on the erosion control map can help the contractor avoid damage to existing drain tile. Where grading or excavation is proposed, drain tile may need to be replaced where there would be insufficient cover over the tile to avoid damage due to construction equipment. A plan for repairing damaged drain tile should be included in the construction documents.
- Off-site drainage: One way to limit the potential for erosion and sediment discharge is to limit the flow of drainage from areas draining onto the construction site from areas outside the limits of construction. Diversion swales or berms can be used to route this water around, rather than through, the construction site.
- Existing topography: The initial stages of construction are often the ones with the highest potential for erosion and sediment discharge. Therefore, erosion and sediment control that is designed for the topography that is present on the first day of construction is needed, but often overlooked during erosion and sediment control design.
- Construction sequencing: The amount of disturbed area at any one time should be limited. For multi-block sites, work should be staged so that land disturbing activities progress one block at a time with subsequent crews following to stabilize areas.
- Concentrated flow: Sheet flow is generally limited to a maximum distance of 300 feet in ideal conditions. After that it begins to channelize, especially in soils with low infiltration capacity, such as clay. For long flow lengths often present in solar projects, it is recommended that cues be taken from existing topography on the location of swales and proposed grading should be considered accordingly. Ditch checks, sediment traps and sediment basins are appropriate sediment control practices for concentrated flow areas.
- Soil handling: Crop production often relies on thick layers of topsoil. When excavating trenches or stripping topsoil in preparation for grading, care should be taken to separate topsoil from subsoil and then replace the material with the topsoil at the surface.
- Module installation: During module installation the traffic between the rows of piles can damage the vegetation and compact the soil. Best practices for this stage include installation from every other row to preserve vegetation in the alternative rows, use of tracked equipment, routing traffic around damaged areas and limiting vehicle access during wet conditions.
- Minimum erosion control requirements: Erosion and sediment control practices must be designed to address all of the items in s. NR 151.11 (6m)(a), Wis. Adm. Code. Soil loss and sediment discharge calculations may not be used to justify providing less treatment than is required by paragraph (a) in that section.
- Winter construction: Many projects are continuing construction through the winter months. While the ground is frozen at times, there are generally several thaw cycles during the winter. Erosion and sediment control inspections must continue through the winter months so that erosion and sediment controls are maintained in functional condition prior to snowmelt events. It is important to plan ahead for spring as the ground is often soft, making access more challenging. Plowing of snow in vegetated areas is not recommended, as it often results in damage or removal of vegetation. Instead of plowing, lightly compacting or grooming the snow may facilitate access without damaging vegetation.
Post-construction Storm Water Management for Solar Projects
Post-construction storm water management practices must satisfy the performance standards in ss. NR 151.121 to 151.128, Wis. Adm. Code. The DNR has developed technical standards to assist in the design of practices that meet those performance standards. For most ground-mounted solar array installations, the following clarifications are provided:
- Solar panels, other above-ground equipment and gravel or paved access roads are considered impervious surfaces. Therefore, most solar installations do not meet the exemption in s. NR 151.121 (2) (a).
- The vegetation under the arrays and the vegetated buffers around the arrays may be considered a best management practice adequate to meet the performance standards in s. NR 151.121-124, Wis. Adm. Code for the array and buffer areas only under the following conditions:
- Flow from the panels is delivered as sheet flow from the solar panels to a well vegetated area. Where the rows are perpendicular to the topographic contours, measures are provided to prevent formation of concentrated flow and eroded channels at the dripline.
- The aisles between the panels is at least as wide as the flow length over the panels and is maintained as vegetated in good condition. Soil compaction in the aisles is addressed as described in Technical Standard 1005 section V.G.
- The distance between the lowest point of the panel and the ground is less than 10 feet
- Hydrologic modeling that assumes the panels are disconnected impervious surfaces demonstrates that the post-construction peak flow condition from the array area is less than the pre-construction peak flow condition for the 1-and 2-year 24-hour storms. Pre-development runoff curve numbers must not exceed the maximums provided in s. NR 151.123, Wis. Adm. Code.
- The array area is sloped at 8% or less and is not receiving runoff from areas outside of the array area.
- The following information is included in the materials submitted with the NOI: Panel length, width, and spacing of solar panels, mounting height, and orientation. For panels on tracking systems, please indicate the range of positions, night stow position nd storm stow position.
- The vegetation under and around the arrays is included as a storm water best management practice in a long-term maintenance agreement per s. NR 216.47(5), Wis. Adm. Code. The maintenance agreement should specify the actions needed to maintain the vegetation is good condition during facility operation.
- Compliance with post-construction performance standards must be demonstrated for all areas not included in item 2 above. Compliance with the total suspended solids performance standard is typically demonstrated using WinSLAMM or P8. Compliance with the peak discharge performance standard is typically demonstrated using TR-55 methodology developed by the Natural Resource Conservation Service. The DNR has developed post-construction technical standards and post construction modeling guidance to assist applicants in demonstrating compliance with post-construction performance standards.
It is important to know that large solar projects will be reviewed by the Public Service Commission (PSC) in addition to DNR. All applicants must follow the solar application filing requirements when submitting an application to the PSC.
There are generally two sizes of projects that come before the PSC.
- 100 Megawatts or larger in size require a Certificate of Public Convenience and Necessity. These projects are often submitted by independent companies, or developers, of solar projects. These large projects require a hearing and rounds of testimony from the applicant and technical staff.
- Smaller utility scale projects, between 7 and 50 Megawatts in size, submitted by regulated public utilities. These require Certificates of Authority, and usually do not require a hearing.
PSC's assessment will include a review of project siting and environmental impacts on all solar projects. In addition, PSC will conduct an evaluation of the cost, engineering, and need of projects submitted by public utilities.
- Application Filing Requirements
- Noise Measurement Protocol
- Electric and Natural Gas Filing Requirements and Related Environmental Topics
- Transmission Line Review Process
Reviewed materials will include:
- noise pre-construction modeling and post-construction verification;
- endangered resources reviews;
- cultural and historic resource reviews;
- land use plans;
- review of impacts to wetlands, waterways or other sensitive habitats;
- geotechnical information;
- aesthetic impacts, including requirements for photo simulations in parts of the project area; and
- electromagnetic fields and stray voltage measurements.
Best Practices and Beyond Compliance Ideas
As you develop an installation such as a solar farm, it is important to consider how the infrastructure can benefit as many as possible. While there are many positive benefits to installing solar projects, there are still impacts on the environment and community to be weighed. The information provided is intended to help developers and installers consider how to integrate more positive actions into the development and long-term operation of solar sites. We encourage you to consider how your development can contribute to both the environment as well as the community in which it is being installed.
Renewable energy can support local interests in energy resilience, cost management and reducing climatic impacts in communities that have populations of vulnerable, low-income or people of color.
- Implement a construction sequencing plan that minimizes the amount of land disturbed or exposed (susceptible to erosion) at any given time across the project.
- Vegetate disturbed areas and areas of exposed soil as soon as possible and seed with a cover crop and/or native seed mix to minimize erosion potential and prevent the establishment of invasive species.
- Prepare and implement an invasive species management plan that identifies known areas of invasive species populations and includes specific protocols to minimize the spread of invasive species.
- Leave existing vegetative buffers in place.
- Avoid the use of herbicide in wetlands and near waterways, or utilize herbicides approved for use in aquatic environments.
- Prior to construction, install signage or fencing at wetland and waterway boundaries to alert construction crews to not work within or access across these areas.
- Post copies of all plans and environmental documents on a project website and distribute to construction crews and inspectors. Plans should clearly label the locations of wetlands and waterways and include language stating vehicle access, storage of materials, grading, and all other construction activities are not permissible within these areas. Plans should also clearly label where sediment and erosion control practices need to be installed if working adjacent to wetlands and waterways.
- Solar and Agricultural Land Use
- Farmer's Guide to Going Solar
- U.S. Department of Energy InSPIRE Project Overview
- Benefits of mixed use of sites for solar installations. Bees, sheep, crops: Solar developers tout multiple benefits | AP News
Creating Pollinator Habitat
- DATCP Pollinator Plan
- The Center for Pollinators in Energy - a national clearinghouse and catalyzer of pollinator-friendly solar information, standards, best practices, and state-based initiatives
- How solar developers plant pollinator friendly habitat – examples from Minnesota which can be applied in Wisconsin
- Restoring Native Prairie at Solar Facilities
- Bee and Butterfly Fund: Solar Synergy - solar project pollinator support
- Reducing Visual Impacts of Alternative Energy Facilities
- Potential Impacts of Solar Arrays on Highway Environment, Safety and Operation
Vegetation Under Panels
- Nature Conservancy – Wildlife Friendly Solar
- PSC approved projects have required deer/agricultural fencing (not chain link) around arrays, without the use of barbed wire, to avoid wildlife entanglement. Barbed wire may be used on substation fencing.
- Consider placing wildlife corridors through larger sites, not just placing fences all along roadways or parcel lines. Finding routes between panel sections or features like waterways can decrease impacts to wildlife.
- Dual-use solar farms welcome nature back to the land
When solar panels, which typically have a lifespan of more than 25 years, reach the end of their lives and become a waste stream, they must be managed safely. U.S. EPA provides information about different types of solar panels and how they are regulated at end of life.
- Regulation and management of solar panel waste
- Solar panel recycling
- Frequent questions on solar panel waste
- PSC noise protocol. Projects that come to the Commission for review will have noise impacts evaluated as part of the project review. Applicants should contact PSC staff and follow the suggested noise study protocol.
Resources From Other States
- Minnesota PCA storm water manual for solar farms
- Maryland design guide
- Pennsylvania storm water/solar FAQ