Farmland Solar Policy Design Toolkit

Regulatory Categories for Solar Development & Farmland


Defining Farmland and Agriculture

States and local governments are seeking new ways to regulate solar development on certain agricultural lands. In specific cases, solar installations on farmland might be prohibited, restricted, subject to certain conditions, or even promoted and incentivized.

State and local governments will benefit from reviewing relevant legal definitions of farmland when establishing new solar development laws. This review should consider the interaction of new and existing regulatory categories for farmland with new and existing regulatory categories for solar development, as well with other applicable state and municipal laws governing land use and environmental permits.

Carefully crafted legal and regulatory definitions for different types of farmland can help protect agricultural land uses and ensure farmer access to clean energy. 

When creating new definitions or categories for types of farmland, lawmakers may begin by looking at federal definitions, which can be incorporated by reference into new laws and regulations. Lawmakers can also design their own categories of important farmland based on a variety of land use characteristics, including the farmlands’ acreage, income, crops grown, specific agricultural uses, or even suitability for solar development.

Federal Definitions of Farmland

Farmland Protection Policy Act 

The Code of Federal Regulations (CFR) at 7 CFR § 657.5 defines several categories of important farmland in the United States under the Farmland Protection Policy Act (FPPA), including 1) prime farmland, 2) unique farmland, 3) additional farmland of statewide importance, and, 4) additional farmland of local importance.  FPPA is administered by the Natural Resources Conservation Service, and its purpose is to minimize federal contributions to farmland conversion and ensure federal programs are compatible with state, local, and private farmland protection programs and policies. However, the FPPA definitions for farmland are often borrowed for other statutory purposes, including rules for solar development.

Prime Farmland

“…land that has the best combination of physical and chemical characteristics for producing food, feed, forage, fiber, and oilseed crops, and is also available for these uses (the land could be cropland, pastureland, rangeland, forest land, or other land, but not urban built-up land or water). It has the soil quality, growing season, and moisture supply needed to economically produce sustained high yields of crops when treated and managed, including water management, according to acceptable farming methods. In general, prime farmlands have an adequate and dependable water supply from precipitation or irrigation, a favorable temperature and growing season, acceptable acidity or alkalinity, acceptable salt and sodium content, and few or no rocks. They are permeable to water and air. Prime farmlands are not excessively erodible or saturated with water for a long period of time, and they either do not flood frequently or are protected from flooding. Examples of soils that qualify as prime farmland are Palouse silt loam, 0 to 7 percent slopes; Brookston silty clay loam, drained; and Tama silty clay loam, 0 to 5 percent slopes.”
To qualify as “prime,” farmland must also meet specific criteria relating to soil moisture and irrigation, soil temperature, pH, flooding, erosion, and permeability, as set out in 7 CFR § 657.5(a)(2).

Note: This definition does not necessarily include all land that is currently being farmed; rather, it identifies productive soils that are suitable to be farmed.

Unique Farmland

“…land other than prime farmland that is used to produce specific high value food and fiber crops. It has the special combination of soil quality, location, growing season, and moisture supply needed to economically produce sustained high quality and/or high yields of a specific crop when treated and managed according to acceptable farming methods. Examples of such crops are citrus, tree nuts, olives, cranberries, fruit, and vegetables.” 7 CFR § 657.5(b)(1).
The definition further requires the land have “a moisture supply that is adequate for the specific crop,” and a “combination of favorable factors” that “favor the growth of a specific food or fiber crop.” 7 CFR § 657.5(b(2).

Note: This category focuses on the land’s productivity and economic potential, capturing farmland that might escape regulatory attention under the soil quality characteristics analyzed in the “prime” definition.

Additional Farmland of Statewide Importance

“…those that are nearly prime farmland and that economically produce high yields of crops when treated and managed according to acceptable farming methods. Some may produce as high a yield as prime farmlands if conditions are favorable. In some States, additional farmlands of statewide importance may include tracts of land that have been designated for agriculture by State law.” 7 CFR § 657.5(c). It up to relevant state agencies to develop “criteria for defining and delineating this land.”

Note: When “additional farmland of statewide importance” is defined, that land is treated as important farmland under the federal definition.

Additional Farmland of Local Importance

“In some local areas there is concern for certain additional farmlands for the production of food, feed, fiber, forage, and oilseed crops, even though these lands are not identified as having national or statewide importance.” 7 CFR § 657.5(d).

Note: Like the state-identified farmland, identification of locally-important farmland is left up to relevant local agencies and ordinances.

USDA Census of Agriculture

The Census of Agriculture collects data on all farmland and active farms in the United States, and the U.S.D.A ‘s Economic Research Service has developed extensive definitions in pursuit of accurate data collection. The categories of “land in farms” and “other farmland” may be useful to policymakers attempting to target certain types of farmland for solar development restrictions or incentives, respectively.

Land in Farms

“The acreage designated as ‘’land in farms’’ consists primarily of agricultural land used for crops, pasture, or grazing. It also includes woodland and wasteland not actually under cultivation or used for pasture or grazing, provided it was part of the farm producer’s total operation. Large acreages of woodland or wasteland held for nonagricultural purposes were deleted from individual reports during the edit process. Land in farms includes CRP, WRP, FWP, and CREP acres. Land in farms is an operating unit concept and includes land owned and operated as well as land rented from others. Land used rent free was reported as land rented from others. All grazing land, except land used under government permits on a per-head basis, was included as ‘‘land in farms’’ provided it was part of a farm or ranch. Land under the exclusive use of a grazing association was reported by the grazing association and included as land in farms. All land in American Indian reservations used for growing crops, grazing livestock, or with the potential of grazing livestock was included as land in farms. Land in reservations not reported by reservation, individual American Indians, or non-Native Americans was reported in the name of the cooperative group that used the land. In a few instances, an entire American Indian reservation was reported as one farm.”

“Other" land

“This category includes land in house lots, barn lots, ponds, roads, ditches, wasteland, etc. It includes those acres in the farm operation not classified as cropland, pastureland, or woodland.”

State Definitions of Farmland 

Lawmakers may choose to incorporate federal definitions of farmland by reference, or may define one or several meanings for the words “farm,” “farmer,” “farmland,” “agriculture,” “agricultural use,” or “land in agricultural production” to serve different purposes in different laws and regulations. Definitions may be based on a list of crops or specific agricultural uses, the suitability of certain lands for farming, or on the farm’s acreage or income generated from farm products.


Del. Code Ann. tit. 9 § 8330 (2019)

“Land shall be deemed to be in agricultural use when devoted to the production for sale of plants and animals useful to man, including but not limited to: forages and sod crops; grains and feed crops; dairy animals and dairy products; poultry and poultry products; livestock, including beef cattle, sheep, swine, horses, ponies, mules or goats, including the breeding and grazing of any or all of such animals; bees and apiary products; fur animals; trees and forest products; or when devoted to and meeting the requirements and qualifications for payments or other compensation pursuant to a soil conservation program under an agreement with an agency of the federal government.”


Fla. Stat. § 193.461 (2019)

“In determining whether the use of the land for agricultural purposes is bona fide, the following factors may be taken into consideration:

  1. The length of time the land has been so used.
  2. Whether the use has been continuous.
  3. The purchase price paid.
  4. Size, as it relates to specific agricultural use, but a minimum acreage may not be required for agricultural assessment.
  5. Whether an indicated effort has been made to care sufficiently and adequately for the land in accordance with accepted commercial agricultural practices, including, without limitation, fertilizing, liming, tilling, mowing, reforesting, and other accepted agricultural practices.
  6. Whether the land is under lease and, if so, the effective length, terms, and conditions of the lease.
  7. Such other factors as may become applicable.”

New York

N.Y Agric. & Mkts. Law § 301 (Consol. 2019).

“Land used in agricultural production” means not less than seven acres of land used as a single operation in the preceding two years for the production for sale of crops, livestock or livestock products of an average gross sales value of ten thousand dollars or more; or, not less than seven acres of land used in the preceding two years to support a commercial horse boarding operation or a commercial equine operation with annual gross receipts of ten thousand dollars or more. Land used in agricultural production shall not include land or portions thereof used for processing or retail merchandising of such crops, livestock or livestock products. Land used in agricultural production shall also include: [omitted]”

Energy-specific Definitions of Farmland and Agricultural Use

Lawmakers can also define types of farmland or agricultural uses within the chapter or title of state code applicable to public utilities, or within specific rate incentive programs. This provides clarity as to the definition of certain lands within the energy development context.

Refers to the agency of agriculture’s soil definition in the criteria for obtaining a certificate of public good:

“(i) In any proceeding regarding an electric generation facility that will have a capacity greater than 500 kilowatts and will be sited on a tract containing primary agricultural soils as defined in 10 V.S.A. § 6001, the Agency shall appear as a party and provide evidence and recommendations concerning any findings to be made under subdivision (b)(5) of this section on those soils, and may provide evidence and recommendations concerning any other matters to be determined by the Commission in such a proceeding. (emphasis added).”

30 V.S.A. § 248(F) (2019)

Defines “agricultural activities” within the general definitions section applicable to the Public Utilities Commission:

“‘Agricultural activities’ means a commercial agricultural, silvicultural, or aquacultural facility or pursuit conducted, in whole or in part, including the care and production of livestock and livestock products, poultry and poultry products, apiary products, and plant and animal production for nonfood uses;  the planting, cultivating, harvesting, and processing of crops;  and the farming or ranching of any plant or animal species in a controlled salt, brackish, or freshwater environment.”

HI Rev. Stat. § 269-1 (2010 through Reg. Sess.)

Specially defines “agricultural producers” as eligible for time-of-use rate incentives for off-peak electricity use:

“As used in this section, “agricultural producer” means any person or corporation whose principal purpose is the agrarian production of food or fiber.”

Cal. Pub. Util. Code § 744 (2017)

Additional References
  1. Farmland Protection Policy Act (FPPA) (Public Law 97-98, December 22, 1981). The FPPA does not authorize the federal government to regulate the use of private or nonfederal land or affect the property rights of owners of such land.
  2. FPPA definitions: 7 CFR § 657.5
  3. United States Department of Agriculture, Economic Research Service, 2017 Census of Agriculture


Defining Solar Development

States often regulate solar development by defining categories of solar projects that are treated differently. Categories based on specific characteristics of a proposed solar array are useful for drawing boundaries around solar development regardless of where in state or local law solar policies are found or which entity is charged with their implementation. Regulatory categories can help incentivize solar arrays that are low-impact, uncontroversial, and clearly in the public interest, while ensuring oversight of projects that may lead to the loss of important farmland and other natural resources, or significant community conflict.

Regulatory Categories Based Size, Location, or Design

Regulatory categories for solar systems across states can seem somewhat arbitrary, as states and utilities vary remarkably in their categorization of solar arrays as “small-scale” or “utility-scale,” as well as “residential,” “commercial,” or “industrial.” These terms do not have consistent definitions in law or policy across states and depend in part on whether an array is set up “behind the meter.” Fundamentally, policy-makers should consider creating regulatory categories for solar development based on the proposed the array’s size, location, or design.

Regulations based on Solar Array Size

State and local laws can categorize solar projects by size using characteristics like the capacity of the array, its land use footprint, or an electric load associated with the array, all of which can loosely define the “size” of a given solar project. Size-based restrictions are the most common regulatory strategy used in state solar development laws. The overall size of an array may affect nearly every aspect of project development including its land use impacts, aesthetic significance, effect on electric reliability, permitting requirements, and interconnection costs, as well as its economic potential.

Regulatory categories based on solar array “size” allow states and localities to offer a fast-track permitting process, lower fees, or higher rates for smaller arrays and those associated with specific electric loads, and to require additional oversight of large-scale solar development. The questions of “how small?” and “how large?” are a matter of local decision-making and have no single correct answer. Regulations based on array capacity, land use footprint, or associated electric load are relatively simple and blunt policy instruments. They draw bright lines useful for establishing basic program eligibility or the imposition of relaxed or special compliance obligations in law. They also come with a relatively low administrative burden and give regulators a simple yes-or-no answer for many development applications.

Array Capacity

Regulatory categories based on array capacity are the most common policy design states use to treat solar projects differently. The capacity of a solar array refers to how much power or electricity it can be expected to generate. Generally, solar panels are classified by their rated output power, defined in watts. This rating is the amount of power that a single solar panel could produce in one peak hour of sunlight. A solar array consists of multiple panels put together. The installed capacity of a solar array is the wattage rating of the individual panels in the array added together, usually expressed in kilowatts. The installed capacity of a solar array, or “nameplate capacity,” represents the maximum amount of power the array could generate. In reality, solar arrays only generate electricity when the sun is shining and they are free from obstruction. The capacity factor of solar compares its nameplate capacity to its actual net generation of electricity and may range from approximately 10-20%. Array capacity is often used to limit the size of qualifying projects in net-metering programs, which may also include a cap on total program capacity.

A solar array’s panel capacity is usually reported in direct current (DC), while operating capacity is reported as it is delivered to the grid in alternating current (AC). Capacity values reported in DC are typically 10% to 30% higher than those reported in AC. This ratio may be referred to as the “inverter loading ratio” (ILR).

Land Use Footprint

A solar array’s land use footprint measures the acreage of land underlying the array and provides another easy way to identify projects within laws and regulations. Higher capacity arrays are likely to have a larger land use footprint. However, this generalization may be misleading as to some agrivoltaic projects. The land use footprint of smaller capacity arrays is likely to increase when designed to accommodate agricultural land uses.

Regulating solar arrays based on acreage may be useful when total acreage is a concern. Limitations on an array’s land use footprint can also be tied to the total parcel size, restricting solar to a certain percentage of the total land area.

Associated Electric Load

Regulations may require solar arrays to be sized to meet the needs of a specific electric load, like an on-site or other identified business, residence, or farm. The allowed capacity might be calculated using the average electric load over a prior time period. While renewable energy resources in general are desperately needed and under-developed in the United States, putting too many distributed energy resources in one place can overload the electric grid without careful planning. Using a specific electric load as a regulatory limit on solar development allows beneficial solar arrays to be matched more closely with the needs of the electric grid and can reduce over-sized net-metered arrays.

Customer type

Solar policies may distinguish between arrays serving residential, commercial, or industrial customers. While any individual customer may differ from the average, these categories are loosely aligned with project size. In 2015 the average U.S. Residential system was five kilowatts, while the average commercial system was two-hundred kilowatts in capacity.

Regulations based on customer type identify the end-use entity consuming the electricity and how that end user is classified in a utilities’ established electric rate structures for different customer classes. Regulatory categories based on customer type can align new renewable energy development rules with existing utility practices. They may be particularly useful when a utility is delegated the task of designing and implementing a net-metering program.

Agricultural User

Some states put solar projects into a special regulatory category when the electricity will be used by a farm or other agricultural consumer. Solar arrays that meet a farm’s on-site electricity needs should be encouraged so that agricultural landowners can benefit from renewable energy.

FOCUS: Rhode Island

Rhode Island defines a variety of regulatory categories for solar development across its renewable energy policies depending on the purpose of regulation. Click the tabs below to see the variety of definitions RI uses.

For residential customers and small-scale solar projects, the Renewable Energy Growth tariff applies to projects ≤ 25 kW.

Allows solar on farmland enrolled in current use taxation when energy is sited on up to 20% of the acreage of the farm, and further allows farmers to site dual use projects on the total farmland acreage.

RI Gen Laws § 44-27-10.1(a).

Net-metering is available for customer-sited systems sized to meet on-site loads, based on a three-year average of electricity consumption. Systems must be on-site with “virtual net metering” exceptions for public sector projects, farms, affordable housing, and residential projects.

RI Gen Laws § 39-26.4-2(8) and § 39-26.4 3(a)(1)(ii).

Separate tariffs are established for medium and commercial scale solar, using competitive bidding under a ceiling price.

All buildings associated with farms are eligible for net-metering credits if they meet basic “farm building” criteria. RI Gen Laws § 39-26.4-2(8). RI Gen Laws § 39-26.4-3(a)(1)(ii).

Categories based on Solar Array Location: Identifying “Preferred Sites”

Lawmakers can categorize solar projects based on their proposed location to steer development toward or away from certain lands, or to require that projects in sensitive locations meet protective conditions for array construction and operation. Some states are working to direct solar development away from farmland and other “greenfields” by providing an incentive or requirement for locating projects on “preferred sites,” such as roofs, landfills, carports and other alternative structures.

States and local governments will benefit from creating lists of “preferred sites” and “ineligible locations” for solar development that can be integrated into solar policy via siting and permitting processes and rate mechanisms.

States and local governments may desire to create lists of lands falling into a variety of categories (preferred sites, eligible but not preferred, ineligible) to meet their own purposes.

The advantages of creating a preferred siting policy include conservation of farmland and other greenfields, lowering of development costs by using existing infrastructure, incentivizing remediation of previously developed properties and brownfields, supporting the grid by siting solar arrays close to electric load, and increased community consensus that eases project development. Common preferred and ineligible locations for solar development are discussed below.

Creating a regulatory category for roof-mounted solar arrays is low-hanging fruit for farmland solar policy. Lawmakers can make it easier for consumers to mount solar on their homes and businesses by easing land use and energy permitting requirements for roof-mounted arrays. By creating “fast-track” approval processes, lawmakers can expedite clean energy deployment while reducing development costs for solar projects sited on roofs and existing structures. These projects are almost always in the public interest, and every kilowatt of solar energy placed on a roof relieves pressure on farmland, open space, and other natural resources. One of the benefits of solar energy is that it can be integrated into existing infrastructure to convert unused space to energy production. A 2018 study found eight-billion square meters roof space in the U.S. suitable for solar development.

Solar canopies and solar carports describe an alternative to roof-mounted solar in which panels are not mounted on a pre-existing structure or roof, but rather are located on a new overhead canopy built to hold the arrays without interfering with the underlying land. Parking lots make up almost seven percent of urban footprint within cities. Of that, only one percent of available parking spaces are affected by shading from surrounding obstructions. Coupling electric car charging stations with parking lot solar supports beneficial electrification goals by encouraging the switch to electric vehicles and increasing their convenience. Further, canopy solar is a particularly useful option for building solar arrays over open space and agricultural land in ways that allow for dual land uses.

Several states are incentivizing development of solar on closed brownfields, landfills and superfund sites. Since most landfills and previously contaminated sites remain empty and undeveloped for years, solar presents an opportunity to revitalize land and bring value to local communities surrounding these sites. Solar siting on closed landfills is occurring in diverse states, including Massachusetts, California, New York, New Jersey, Maryland, and Michigan.

There are an estimated 10,000 closed landfills in the U.S., presenting thousands of acres of property with the potential for solar development.  Of course, landfill and brownfield sites are likely subject to a number of regulatory requirements before solar development is possible. Some landfills are subject to a five-year review process by the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). In addition, local or state post-closure permits may be required. Establishing financial incentives for solar projects on these sites can help defray the higher cost of project development. 

Floating solar involves mounting panels onto rigid pontoon structures that can withstand harsh conditions on open water. This idea not only saves space on land, but also reduces water evaporation from reservoirs and may increase solar efficiency. As of 2017, there were over one-hundred floating solar projects around the world, with only seven located in the United States. The National Renewable Energy Laboratory estimates that if floating solar were installed on bodies of water throughout the United States, as much as two million hectares of land could be saved, while meeting ten percent of the United States’ electricity needs.

Some states and local governments establish a process through which sites not already included on a regulatory list of “preferred sites” may be added to the list and receive the same regulatory benefits. For example, Vermont’s Act 174 requires local and regional planning commissions to complete energy planning and provides incentives to solar sited in locations designated in “duly adopted” municipal plans. Further, specific projects may gain “preferred site” status by obtaining joint letters of support from a municipality and relevant municipal and regional planning commissions. See, VT Energy Planning Standards.

In addition to identifying specific sites or site-types that states or localities prefer for solar development, lawmakers may find it useful to identify sites that are ineligible for solar development. Ineligible sites might include identified greenfields, prime farmland, land subject to conservation in perpetuity, historic sites, or other protected lands. Policy makers are encouraged to use restrictions on sensitive lands, and only establish prohibitions on solar where absolutely necessary, so as to avoid excluding residents from the benefits of clean energy.

Categories based on Solar Array Design

Lawmakers can regulate solar projects based on their proposed design or create specific design standards for array construction and operation. Deciding on design standards for new solar installations is “higher-level” policy creation, likely to occur after states have put basic size and location regulations in place. Policymakers should consider the regulation of array design as a tool in writing comprehensive farmland solar policy.

Agrivoltaics and Dual Use

An “agrivoltaic” or “dual use” policy allows, incentivizes, or requires a solar array on farmland to exist alongside agricultural uses, so that the land is used both for energy generation and farming concurrently. For example, a solar array may be designed to permit animal grazing or vegetable production below or beside the solar panels. Layering land uses can be both efficient and profitable for an agricultural landowner, as well as good development policy. Lawmakers should consider a dual use policy to allow solar siting on agricultural land enrolled in state “current use” taxation programs, without triggering tax penalties for land conversion.  Dual use of land for both agriculture and solar energy may also be referred to as “multiple use” or “colocation.”

Agrivoltaic systems have increased in popularity as farmers and large-scale industries try to maximize use of their land and find that solar can complement crop production or livestock grazing without overly compromising the efficiency of either land use. However, agrivoltaic systems do require compromise.  It is not as simple as putting out panels and letting livestock or machinery work without adjustment. For example, a solar array usually must be raised at least four meters to allow space for farm machinery to safely maneuver under it compared to two meters for grazing cattle. While some land area is lost to the solar array, successful systems have managed only a 10% loss of space, and the benefits realized from electricity generation support both farm viability and sustainability.

Incentives for dual use or agrivoltaic projects may be structured within rates paid for energy under state net metering programs or feed-in tariffs, or may be stand-alone incentives. Lawmakers may define a specific set of agricultural dual use practice, like sheep grazing or crop production, that are eligible for incentive programs, or they can establish flexible design standards for project qualification, like incentivizing solar arrays that achieve less than 50% shading of the underlying land.

Voluntary Performance Standards 

Voluntary standards can incentivize performance by creating a marketable project certification, such as “pollinator friendly” or “agriculture friendly.”

FOCUS: Vermont

Vermont created a voluntary standard for establishing pollinator-friendly habitat on solar sites. To be labeled “pollinator friendly,” solar installers must complete and abide by a “solar site pollinator scorecard.” Sites can either be built to the voluntary standards or retrofitted after construction.

Mandatory Performance Standards 

States can regulate the design of solar arrays by establishing mandatory design requirements for new installations, requiring that arrays are able to meet outcome-based standards, or by creating a process to develop array-specific or site-specific design requirements or performance standards.

FOCUS: Massachusetts

The Massachusetts SMART tariff establishes an “Agricultural Solar Tariff Generation Unit,” or ASTGU, which receives a six-cent rate adder for solar arrays designed to coexist with agricultural production. To qualify as an AGSTU, project applicants must submit documentation about the underlying agricultural land and characteristics of the proposed solar array, including the dual-use system type, the total gross acres of open farmland to be integrated with the project, the type of crops to be grown and harvested, animals to be grazed with herd sizes, and design drawings. The SMART tariff AGSTU regulations include a mix of narrative standards, mandatory design parameters, performance standards, and site-specific requirements. Use the tabs below to compare performance standards and design requirements found in the Massachusetts SMART tariff for dual use arrays qualifying for a special six-cent rate adder.

See, 225 CMR 20 (SMART), Agricultural Solar Tariff Generation Unit Guideline and Agricultural STGU Pre-Determination Letter Form.

Narrative standards describe the purpose or outcome intended by a regulation without mandating the method of achieving the standard.

For example,

  • “The solar array must not interfere with the continued use of the land beneath the canopy for agricultural purposes;
  • The solar array must be designed to optimize a balance between the generation of electricity and the agricultural productive capacity of the soils beneath; and,
  • The solar array must be a raised structure allowing for continuous growth of crops underneath the solar photovoltaic modules, with height enough for labor and/or machinery as it relates to tilling, cultivating, soil amendments, harvesting, etc. and grazing animals.”

Mandatory performance standards may require a specific process or construction technique for solar development projects.

For example,

  • “No removal of all field soils;
  • Existing leveled field areas left as is without disturbance;
  • Where soils need to be leveled and smoothed, such as filling potholes or leveling, this shall be done with minimal overall impact with all displaced soils returned to the areas affected;
  • Ballasts, screw-type, or post driven pilings and other acceptable minimal soil impact methods that do not require footings or other permanent penetration of soils for mounting are required, unless the need for such can be demonstrated;
  • Any soil penetrations that may be required for providing system foundations necessary for additional structural loading or for providing system trenching necessary for electrical routing shall be done with minimal soils disturbance, with any displaced soils to be temporary and recovered and returned after penetration and trenching work is completed;
  • No concrete or asphalt in the mounting area other than ballasts or other code required surfaces, such as transformer or electric gear pads;
  • Address existing soil and water resource concerns that may be impacted to ensure the installation does not disturb an existing soil and water conservation plan or to avoid creating a negative impact to soil and water conservation best management practices, such as stimulating erosion or water run-off conditions;
  • Limit use of geotextile fabrics; and maintain vegetative cover to prevent soil erosion.”

Solar policies can mandate extremely specific design parameters for new solar installations, but policymakers should consider leaving room for site-specific adjustments.

For example,

  • “Panel Height Requirements. For fixed tilt ASTGUs, the minimum height of the lowest panel point shall be eight (8) feet above ground. For tracking ASTGUs, the minimum height of the panel at its horizontal position shall be 10 feet above ground;
  • Maximum Direct Sunlight Reduction Requirements. All ASTGUs must demonstrate that the maximum sunlight reduction from the panel shading on every square foot of land directly beneath, behind and in the areas adjacent to and within the ASTGU’s design shall not be more than 50% of baseline field conditions;
  • Growing Season/Time of Day Considerations. The typical growing season shall be considered to be March through October, with sunlight hour conditions with maximum 50% sunlight reduction to be between 10AM and 5PM for March and October, and from 9AM to 6PM from April through September;
  • Maximum Size. The maximum AC rated capacity of an ASTGU shall be two MW in the first two Capacity Blocks of each Distribution Company’s service territory. The Department, in consultation with MDAR, will make an evaluation as to whether or not this provision shall be adjusted in subsequent Capacity Blocks.”

Solar policies can require or allow site-specific consultations, analyses, or conditions for solar project development.

For example,

  • “To qualify as an Agricultural Solar Tariff Generation Unit, project applicants must submit documentation about the underlying agricultural land and characteristics of the proposed solar array, including the dual-use system type (ground-mounted racking, pole towers, tracking, etc.), the total gross acres of open farmland to be integrated with the project, the type of crops to be grown and harvested, animals to be grazed with herd sizes, and design drawings.”
  • In addition, applicants must, in consultation with UMass Amherst agricultural extension services, document the crops to be grown and compatibility with the design of the agricultural solar system, and provide detailed reports annually to the Department of Energy Resources and the Department of Agricultural Resources regarding the productivity of the crops and herds after project implementation and throughout the SMART incentive period.
Additional References
  1. Jacob Marsh, Behind-the-meter: What you Need to Know, Energy Sage, September 12, 2019,
  2. Energy Information Administration, Solar plants usually install more panel capacity relative to their inverter capacity, Mar. 16, 2018 (
  3. Sean Ong at el., National Renewable Energy Laboratory, Land-Use Requirements for Solar Power Plants in the United States, June 2013 (
  4. Fred Mayes, U.S. EIA, Today in Energy, More than Half of Small-scale Photovoltaic Generation comes from Residential Rooftops, June 1, 2017 (
  5. RI Gen Laws §§ 44-27-10.1(a), 39-26.4-2(8), and 39-26.4-3(a)(1)(ii).
  6. Pieter Gagnon et al., Rooftop Solar Photovoltaic Technical Potential in the United States: A Detailed Assessment, Jan. 2016(
  7. Abdulsalam Alghamdi, et. al. Assessment of Large-Scale Photovoltaic Power Generation from Carport Canopies, Energies, May 13, 2017, at 1-2
  8. Cody Boteler, Are capped landfills and solar panels a natural match?, Waste Dive, Dec. 5, 2017 (
  9. Gabriel Sampson, Solar Power Installation on Closed Landfills: Technical and Regulatory Considerations, Sept. 2009 (
  10. Kerry Thoubboron, Energy Sage, Floating Solar: What you Need to Know, Nov. 17, 2018 (
  11. Kim Trapani & Miguel Redón-Santafé, A review of floating photovoltaic installations: 2007-2013, Progress in Photovoltaics, at 524-532 (
  12. Robert S. Spencer, et al, Floating Photovoltaic Systems: Assessing the Technical Potential of Photovoltaic Systems on Man-Made Water Bodies in the Continental United States, Environmental Science & Technology 2019 53 (3), at 1680-1689 (
  13. Adeh, E.H., Good, S.P., Calaf, M. et al., Solar PV Power Potential is Greatest Over Croplands. Sci .Rep . 9, 11442 (2019). (
  14. University of Vermont, Pollinator Solar Scorecard Form, (Accessed: Feb. 7, 2020).
  15. See also, Massachusetts’ administrative regulations and guidances: 225 CMR 20 (SMART), Agricultural Solar Tariff Generation Unit Guideline and Agricultural STGU Pre-Determination Letter Form.

Using Regulatory Categories in Policy Design

 Improve Clarity of Law and Policy

States and local governments are seeking new ways to regulate solar development on certain agricultural lands. In specific cases, solar installations on farmland might be prohibited, restricted, subject to certain conditions, or even promoted and incentivized. Defining the land and projects subject to regulation is crucial to creating clear and effective policy.

Carefully crafted legal and regulatory definitions for different types of farmland and agricultural use can streamline regulators’ implementation of solar development laws.

Regulatory categories for farmland, agricultural use, and solar development can be established by referencing existing definitions within state and municipal policy, or by creating new definitions for inclusion in solar development laws.

→ Improve Flexibility of Law and Policy

Establishing smart regulatory categories allows different types of farmland to be regulated differently, allowing farmers and agricultural landowners to benefit from solar development, while protecting prime and productive farmlands– both of which support important climate and energy goals. Regulatory categories can also be used to ensure additional oversight of solar arrays likely to have adverse impacts or proposed for sensitive lands.

→ Promote both farmland protection and farmer access to clean energy 

  • Distinguish between prime farmland, land in agricultural use, and marginal or “other” farmland in creating solar siting policy.
  • Adopt different criteria for reviewing and permitting solar projects located on primary agricultural soils, land in agricultural use, and marginal farmland.
  • Require applicants to submit information about potential impacts of a solar development project on farmland or existing agricultural uses.
  • Require solar installations to meet specific performance standards if located on prime or important farmland.
  • Require agency or third-party certification of farmland impacts or compliance with farmland protection criteria for projects in designated locations.
  • Incentivize solar arrays located on marginal land or unproductive portions of established farms.
  • Increase rates paid for energy from solar arrays located on marginal land or unproductive portions of established farms.
  • Increase rates paid tor energy from solar arrays located on “preferred sites.”
  • Incentivize solar arrays sited on farmland that primarily benefit the farm, rather than other off-site entities.

→ Promote Agrivoltaic or Dual Use Solar Arrays

State and local policymakers should consider the following strategies to increase the number of solar arrays specifically designed to allow for dual land uses or a minimal impact on agriculture. Many of these strategies are described in more detail in later sections of this Toolkit.

  • Create voluntary dual use standards or recommendations.
  • Certify dual use projects as pollinator, agriculture, or farmland friendly.
  • Engage agencies of agriculture to develop evidence-based criteria for dual use qualification.
  • Establish narrative and specific performance standards for dual use projects.
  • Provide rate-based incentives for dual use arrays.
  • Enable farmland enrolled in current use taxation programs to install dual use solar arrays.
  • Require monitoring and reporting of agricultural uses under and around solar arrays.