Wait, Who Approves Large-Scale Solar Siting?
Imagine this. You are a planner for a rural county in Western Minnesota. One day, community members start flooding your inbox and voicemail with their concerns about a proposed solar project in an agricultural district. While you had a brief conversation with the prospective developer, you didn't realize they had already submitted their application to the state's public utility commission, completely bypassing local zoning.
The project has a rated capacity of 51 MW, triggering automatic preemption of local siting authority. When you call your friend who works as a planner in South Dakota, they share your surprise; the project would need to be nearly twice as big to trigger preemption in their state. Your former classmate who works in North Dakota is surprised, too. Their state requires a state siting permit, but that wouldn't preempt local zoning.
Determining which agency ultimately has the authority to approve the siting of a new large-scale solar facility can be complicated. Some of this complexity is because authorities are trying to fit the square peg of a field of solar arrays through the round hole of decision-making processes initially developed to coordinate the siting of conventional power plants. And some are due to state-by-state differences inherent to our federalist system of government.
Generally, federal agencies retain the sole authority to approve projects on federal lands. Meanwhile, most states, through their planning and zoning enabling laws, have granted local agencies the power to approve many (if not most) large-scale solar projects on private lands. However, as highlighted in Module 2 of the Solar@Scale guidebook, about half of all states have established explicit limits on local siting authority, offer certain developers a way to bypass that authority, or maintain a parallel siting process.
Automatic Preemption (We'll Take It from Here)
Most states require all wholesale power plants to obtain certificates of public convenience and necessity, but these certificates don't, typically, confer final siting approval. That is, local jurisdictions usually retain that authority. However, as the Solar@Scale guidebook notes, some states do preempt local control for certain types of large-scale photovoltaic (PV) projects, either by treating their public convenience and necessity certification process as a final land use approval or by requiring developers to obtain a siting permit from a special-purpose siting board.
In these states, the trigger for preemption is project size, but the relevant size thresholds vary widely from state to state (Table 1). Fourteen states use the rated power capacity of the proposed facility as a trigger, with thresholds ranging from an extreme low of 15 kW in Vermont up to 300 MW in New Mexico. Two states, Maine and Oregon, use the site area of the proposed facility as a trigger, and Wyoming preempts local authority for all proposed facilities with rated capacities over 30 MW or site areas greater than or equal to 100 acres.
In most states, these thresholds apply to all wholesale power facilities. In a few, though, the thresholds apply more narrowly to renewable energy facilities or, in the case of Oregon and Wyoming, are solar-specific.
For proposals for preempted facilities, local jurisdictions can still participate in state decision-making processes as special parties of interest. This means planners and local officials can testify whether proposed facilities meet local zoning requirements, but generally, the state siting authority can approve projects even if they fail to meet local standards. The one noteworthy exception is Ohio, which effectively offers counties a preemptive veto by allowing them to designate "restricted areas" that prohibit the construction of large-scale solar facilities (§303.58; §4906.101).
While Vermont has the lowest size threshold for preemption, it does authorize local jurisdictions to establish (reasonable) screening requirements for solar facilities (24 VSA §4414(15); §2291(28)). Then, applicants must demonstrate compliance with these local requirements to state officials (30 VSA §248(b)(1)(B)).
Table 1. States With Thresholds for Automatic Preemption of PV Project Siting Decisions
| State | Threshold(s) for Automatic Preemption | Applicability | Siting Authority |
|---|---|---|---|
| Connecticut | ≥ 1 MW | Renewable energy facilities | Connecticut Siting Council |
| Florida | ≥ 75 MW | Steam or solar electrical generating facilities | Florida Siting Board |
| Iowa | ≥ 25 MW | Electric power-generating plants | Iowa Utilities Commission |
| Maine | ≥ 20 acres | Any site development project | Maine Department of Environmental Protection |
| Maryland | ≥ 2 MW | Electric power generating stations | Maryland Public Service Commission |
| Massachusetts | ≥ 100 MW | Electric power-generating units | Massachusetts Energy Facilities Siting Board |
| Minnesota | ≥ 50 MW | Electric power-generating plants | Minnesota Public Utilities Commission |
| New Hampshire | ≥ 30 MW | Electric power generating stations | New Hampshire Site Evaluation Committee |
| New Mexico | ≥ 300 MW | Electric power-generating plants | New Mexico Public Regulations Commission |
| New York | ≥ 25 MW | Renewable energy systems | New York Office of Renewable Energy Siting and Electric Transmission |
| Ohio | ≥ 50 MW (subject to a county "veto" power) | Large solar or wind facilities | Ohio Power Siting Board |
| Oregon | ≥ 160 acres if sited on high-value farmland; ≥ 1,280 acres if sited on cultivated land or land composed of National Cooperative Soil Survey soils in capability classes I–IV; ≥ 1,920 acres on any other land | PV power generation facilities | Oregon Energy Facilities Siting Council |
| Rhode Island | ≥ 40 MW | Electric power-generating facilities | Rhode Island Energy Facility Siting Board |
| South Dakota | ≥ 100 MW | Solar and wind energy facilities | South Dakota Public Utilities Commission |
| Vermont | ≥ 15 kW | Electric power-generating facilities | Vermont Public Utility Commission |
| Virginia | > 150 MW | Electric power-generating facilities | Virginia State Corporation Commission |
| Wyoming | > 30 MW or ≥ 100 acres | Solar power facilities | Wyoming Industrial Siting Council |
Developer's Choice Preemption (I'll Choose That One)
Three states designate local jurisdictions as the default final siting authority for all large-scale solar facilities but give developers the option of submitting their proposals to state authorities instead (Table 2). In Washington, developers can submit their proposals for any large-scale solar project for review by the Washington Energy Facility Site Evaluation Council. Meanwhile, in California and Michigan, developers of proposed solar facilities with rated capacities of 50 MW or more can bypass local land use approvals in favor of a state decision-making process.
While state-siting decisions often take longer, on average, than local decisions, experienced developers may view state authorities as more predictable than local officials. Once a developer has successfully navigated the state review process, they may feel as though they have a good understanding of how to do it again. In contrast, every local land use review and approval process can have unique features, and every potential host community may have distinct concerns that developers need to address before local officials feel comfortable saying "yes."
In California and Washington, once a developer opts into the state's siting process, planners and local officials are relegated to the role of interested parties. State authorities will likely often give serious consideration to well-founded local concerns, but they aren't obligated to reject a project just because it doesn't meet local zoning requirements.
In Michigan, developers must still submit site plans to local jurisdictions that have ordinances that are fully compliant with the state's maximally restrictive standards (§460.1223; see Maximally or Minimally Restrictive Standards). If a local jurisdiction does not have a fully compatible ordinance, the developer can bypass local approvals and apply directly to the state. Developers can also opt into the state siting process if local authorities don't issue a decision within 120 days or if they deny an application that complies with state standards.
Table 2. States That Allow Developers to Bypass Local Siting Authority for PV Projects
| State | Threshold for Developer's Choice | Applicability | Siting Authority |
|---|---|---|---|
| California | ≥ 50 MW | Renewable energy and energy storage facilities | California State Energy Resources and Conservation Commission |
| Michigan | ≥ 50 MW | Solar, wind, and energy storage facilities | Michigan Public Service Commission |
| Washington | None | Renewable energy facilities | Washington Energy Facility Site Evaluation Council |
Maximally or Minimally Restrictive Standards (You Can't Do That)
Three states have placed limits on local zoning standards for certain large-scale solar facilities (Table 3). In Illinois and Michigan, state law establishes maximally restrictive standards for certain projects. Meanwhile, Wyoming state law has a small set of minimally restrictive standards.
Counties in Illinois retain final siting authority for projects proposed within their land use jurisdiction (i.e., unincorporated areas). However, they cannot impose stricter standards than those spelled out in state law (55 ILCS §5/5-12020). These standards establish maximum setbacks, minimum height limits, and maximum and minimum fencing requirements. They also prohibit unreasonable application fees and specify that county regulations must otherwise conform to the mitigation requirements included in the Illinois Department of Agriculture's standard wind farm agricultural impact agreement.
Similarly, cities and counties in Michigan cannot hold projects with rated capacities greater than or equal to 50 MW to more restrictive standards than those included in state law (PA 233 of 2023). Like in Illinois, these standards limit setback, height, and fencing requirements. In both states, state legislators adopted maximally restrictive standards to give greater certainty to developers.
Wyoming's limits on county zoning authority work in the other direction. Cities and counties must impose setbacks greater than or equal to those specified in state law (§18-5-504). Here, state legislators prioritized certainty for nonparticipating adjacent landowners.
Table 3. States With Maximally or Minimally Restrictive Standards for PV Projects
| State | Applicability | Type of Standards |
|---|---|---|
| Illinois | Any PV project under the county land use authority | Maximally restrictive |
| Michigan | PV projects ≥ 50 MW under local land use authority | Maximally restrictive |
| Wyoming | Any PV project ≤ 30 MW or 100 acres under county land use authority | Minimally restrictive |
Parallel Siting Processes (Yes, And)
Finally, it's worth highlighting that four states have established siting processes that don't preempt local authority (Table 4). Instead, these processes run in parallel to local land use approvals. Developers must secure approval from state and local authorities before they can proceed to construction.
The thresholds for these parallel state siting processes are all based on the rated capacity of the proposed facility. At the low end, Virginia requires all projects with rated capacities greater than 5 MW and 10 acres of site area (but rated capacities less than or equal to 150 MW) to go through a Department of Environmental Quality "permit-by-rule" process that is less stringent than the state's preemptive process for projects with rated capacities greater than 150 MW (9 VAC §15-60-130). At the high end, Wisconsin only requires projects with rated capacities of at least 100 MW to go through a parallel state siting process.
One other state, Louisiana, has authorized a parallel siting process for all solar facilities with a footprint of 10 or more acres (§30-1154(D)). However, as of late February 2025, implementation is pending the Louisiana Department of Energy and Natural Resources' final rulemaking.
Table 4. States With Parallel Siting Processes for PV Projects
| State | Threshold(s) for Parallel Siting | Applicability | Parallel Siting Authority |
|---|---|---|---|
| Kentucky | ≥ 10 MW | Non-utility-owned electric power generating facilities | Kentucky State Board on Electric Generation and Transmission Siting |
| Louisiana | ≥ 10 acres | Solar power-generating facilities | Louisiana Department of Energy and Natural Resources |
| North Dakota | ≥ 50 MW | Electric power-generating facilities | North Dakota Public Service Commission |
| Virginia | > 5 MW and 10 acres ≤ 150 MW | PV projects | Virginia Department of Environmental Quality |
| Wisconsin | ≥ 100 MW | Electric power-generating facilities | Wisconsin Public Service Commission |
Conclusions
While there have been some recent efforts to limit local siting authority for large-scale solar facilities, it is not clear the extent to which momentum is building for similar efforts in other states. Furthermore, the average size of new large-scale solar facilities is increasing, but this does not necessarily mean that most new projects are bypassing local land use decision-making processes. Automatic preemption and developer's choice states are generally clustered in the Northeast and Midwest. Many of the hottest markets for solar development are in the Sunbelt and Midwestern states, without limits on local control.
The current default condition of local control over most solar siting decisions can have unintended consequences. Developers may gravitate to more permissive jurisdictions, but this doesn't necessarily correspond to optimal siting decisions.
The lumpy distribution of facilities could, in some regions, stress transmission infrastructure or severely slow down the pace at which new facilities can be connected to the grid. Even with local siting approvals, developers must separately navigate a patchwork of utility interconnection rules before bringing projects online. In extreme cases, a local approval could time out before a developer can start construction, resetting the entire process.
Furthermore, the potential land use impacts of solar facilities don't stop at jurisdictional boundaries. A large project may have several adjacent property owners in other jurisdictions.
As of now, it is hard to predict whether softening support for large-scale solar development at the federal level will translate into more action at the state level. And if it does, will this mean more limits on local control in the name of speeding a transition to clean energy? Or will more states take their cues from Ohio and broaden local authority over siting decisions?
Solar@Scale is a partnership between the International City/County Management Association (ICMA) and the American Planning Association (APA) that aims to help cities, towns, counties, and special districts understand and realize the potential benefits of large-scale solar development.
Have a question about Solar@Scale or want to share your experiences with planning and zoning for large-scale solar development? Contact solar@planning.org.
upcoming and Recent Solar@Scale activities
- Siting Solar on Brownfields and Underutilized Lands (Live webinar; March 19, 2025)
- Breaking Through the Pro-Solar/Anti-Solar Binary (NPC 25 in Denver)
- Best Practices in Planning for Large-Scale Solar (recorded webinar)
Top image: John Touscany / iStock Editorial / Getty Images Plus