Opportunities and Barriers for Agrivoltaics on Tribal Lands

Abstract

Recent federal legislation, like the 2021 Infrastructure Investment and Jobs Act and 2022 Inflation Reduction Act, has led to a push for more solar energy on Tribal lands, increasing competition for already limited agricultural land. Agrivoltaics is an innovative technology with the potential to lessen the tradeoffs between agriculture production and solar energy generation. This study investigates the opportunities and barriers for agrivoltaics on Tribal lands through expert qualitative interviews with Tribal agriculture professionals that inform geospatial suitability analysis of physical characteristics. Qualitative results indicate agrivoltaics on Tribal lands could contribute positively to food sovereignty, energy sovereignty, and economic development goals for Tribes; on the other hand, Tribal agriculture professionals have technical, economic, siting, and socioecological concerns that should be addressed through future work. Quantitatively, we find up to 15 million acres of Tribal agricultural land may be feasible for micro-grid agrivoltaics, with 7 million acres in sufficient proximity to existing transmission lines to tie into the grid. The leading states for Tribal agrivoltaics by land area are South Dakota, Montana, and Arizona, each home to Tribes with large land bases and a strong agricultural economy. This work aims to inform Tribal land managers, policymakers, and researchers on the opportunities and barriers for agrivoltaics on Tribal lands.

1. Introduction

In recent years, the U.S. Congress passed the Infrastructure Investment and Jobs Act (2021) and Inflation Reduction Act (2022), marking a historic investment in clean energy development and climate change action for the nation [1]. Among other initiatives, this landmark legislation included hundreds of millions of dollars for clean energy programs for Tribal communities and increased the Tribal Energy Loan Guarantee Program available loan authority to $20 billion [2]. This is significant because Tribal lands account for more than 5% of solar photovoltaic potential in the US, even though they only represent approximately 2% of the United States’ total landmass [3]. In the last ten years, there have been concerted efforts to increase renewable energy projects on Tribal lands: utility-scale examples include the 250 MW Moapa Southern Paiute Solar Project in Nevada (2016) and the 55 MW Navajo Nation Kayenta Solar Program (2017–2019) [4].

While enthusiasm for solar energy in Indian Country is growing, one drawback is the land intensity of solar developments. The U.S. Department of Energy Sunshot Vision Study estimates approximately 1.8 million acres of land will be dedicated to solar energy generation by 2030 (DOE), covering more than the area of Delaware which claims only 1.2 million acres of land [5]. Studies show agricultural lands (cropland and grassland utilized for pasture) are prime targets for conversion to solar energy infrastructure because they usually meet the most favorable productivity conditions for solar panels (i.e., plentiful insolation, light winds, moderate temperatures, and low humidity) [6]. Furthermore, it is unlikely that a site used for conventional solar energy generation will be converted back to agricultural production due to long-term implications from typical management causing soil compaction and decreased soil health [7]. This forces Tribal leaders to make difficult decisions about land-use priorities between agriculture and energy.

Agrivoltaics (AV)—the co-location of solar photovoltaic panels and crops or livestock for increased land productivity—minimizes the severity of this tradeoff by incorporating dual-use land strategies. Integrating agriculture and energy through agrivoltaic schemes may increase land productivity by 35–73% depending on intercropping density [8]. Researchers posit that agrivoltaic systems can lead to increased photovoltaic panel efficiency [9], increased water use efficiency [10], and increased yield resiliency [11]. Estimates show that global energy demand could be fully met if only 1% of global agricultural land was converted to agrivoltaics [6]. Researchers have studied the potential of agrivoltaic technology in various contexts. Field experiments in animal agrivoltaics extend to sheep [12], rabbits [13], and dairy cattle [14] while modeling exercises cover perennial pasture performance for livestock grazing in species such as ryegrass [15]. Row crop projects include in-field assessments of wheat [16], maize [17], potatoes [18], and rice [19], as well as modeling schemes of cotton [20] and aloe vera [21]. Researchers worked with horticultural crops such as lettuce [22], peppers [9], and tomatoes [23], and modelled scenarios for grapes [24]. Most agrivoltaics research installations are in the Northern Hemisphere with concentrations in the United States, European Union, and East Asia [25].

Studies concerning the social decision-making processes that facilitate agrivoltaics implementation have been more limited. Investigators out of Michigan interviewed agriculturalists [26] and solar industry professionals [27] to better understand the diffusion of agrivoltaics technology and its impact on social acceptance of solar siting. Their results indicate farmers are concerned about long-term land productivity and economic viability while solar developers are interested in the potential for dual-use systems to increase community acceptance. Researchers in Japan explored the social impact of existing agrivoltaics systems [28], finding improved energy security for local stakeholders. A California-based research team assessed landowner attitudes to proposed utility-scale solar energy with agriculture co-location as an option [29]. They found widespread interest in solar on farms but noted the current feasibility for agrivoltaics in the area was low.

Our research extends previous qualitative work to Tribal lands in the United States, where, to the best of our knowledge, there are no ground-mounted agrivoltaics installations to date. The closest application of agrivoltaics on Tribal lands is a greenhouse-mounted project on the Colville Indian Reservation constructed in 2022, the first of its kind in the state of Washington [30]. We pair that interview work with geospatial analysis to assess the degree to which agrivoltaics is an appropriate technology for Tribal lands. The following sections present the research methods, results, implications, and conclusions.

2. Materials and Methods

This research is divided into three phases conducted in the following order: (1) a scoping study to identify the potential for agrivoltaics on Tribal lands; (2) a series of qualitative expert interviews to uncover perceived opportunities and barriers for adoption; and (3) a suitability study to suggest locales for priority exploration.

2.1. Scoping Study

This scoping study uses Google Earth Engine, a cloud-based geospatial analysis platform [31], to outline AV potential. We rely on the U.S. Census Bureau’s AIANNH (American Indian, Alaska Native, Native Hawaiian) Areas dataset to narrowly define Tribal lands as only the ~73 million acres of federally recognized American Indian reservations, off-reservation trust land, and joint-use areas located within the boundaries of the continental United States, using the vector map published in 2022. Agricultural land use classifications are derived from the U.S. Department of Agriculture’s Cropland Data Layer dataset for 2022 and divided into three categories: non-agricultural lands (70% of Tribal land area), grassland pasture (21%), and cultivated cropland (9%) like small grains, hay, corn, and soybeans (Figure 1). We consider agrivoltaics in the context of existing agricultural land and thus exclude non-agricultural land from the sum of potential land. Parcels with tall crops, defined as trees and other crops with an average mature height over 13 feet tall (i.e., sugar cane), are excluded to accommodate the maximum clearance for existing raised AV systems [25]. Tribal agricultural land with a slope greater than 5% is deemed too steep for solar implementation and is excluded from the potential footprint for AV [32].

Table 1. Data sources for scoping parameters.

Parameter	Dataset
Tribal land base	US Census Bureau AIANNH Areas
Agricultural land use	USDA Cropland Data Layer
Slope	SRTM Digital Elevation Data V4

shows parameter data sources and Scheme 1 shows the cartographic model. The scoping study results informed the questions deployed in the qualitative expert interviews described in the next section.

2.2. Qualitative Data Collection and Analysis

The second phase of this research—expert interviews—uses qualitative methods to generate knowledge grounded in human experience [33]. After completing the scoping study, the lead author conducted 21 semi-structured interviews in March 2023 to investigate the opportunities and barriers for agrivoltaics on Tribal lands as perceived by Tribal agriculture professionals (see Appendix A for interview protocol). Sampling was purposive, employing a method of data collection where the guiding logic is to find relevant participants who can bring rich insights to the research topic [34].

Participant recruitment was conducted in partnership with the Intertribal Agriculture Council, a national non-profit with staff throughout the nation. We aimed to contact diverse professionals with extensive knowledge in agriculture on Tribal lands. We targeted a mixture of participants from Indian Country at large and from geographic areas with high agrivoltaics potential according to the scoping study results. Participants included technical assistance specialists, academic researchers, and other industry experts, and more than half of the participants (n = 12) identified themselves as current or former agricultural producers with decision-making authority for farms/ranches.

Table 2. Selected interview participant demographics.

Sector	Location	Gender	Age	Producer Status
Nonprofit: 15	Eastern US: 3	Female: 11	18–29: 7	Current: 10
Academia: 3	Great Plains: 4	Male: 10	30–49: 10	Former: 2
Private: 2	Rocky Mountains: 3		50–69: 3	Never: 9
Public: 1	Southwest US: 6		70+: 1
	Pacific Coast: 5

details the demographics of interview participants.

All participants provided informed consent prior to the interview, and transcripts were anonymized for privacy. The interview protocol was organized according to the following themes: (1) experience in Tribal agriculture; (2) knowledge of local energy production; (3) perceptions of agrivoltaics (e.g., opportunities and barriers); and (4) reflections on the Tribal AV scoping map. The semi-structured nature of the interviewing process allowed for refinement of the protocol over time. Interviews lasted between 30 min and 1 h, were conducted and recorded via Zoom (version 5.17.11), and were transcribed by a trained research assistant using Otter.ai transcription service. The interview campaign concluded once it reached saturation, a point when surfaced concepts are well defined and no new themes are emerging [35].

Transcripts were analyzed in Dedoose (version 9.0.107)—a qualitative research software—using inductive thematic analysis [36], a process that involves familiarizing oneself with the data, coding it line-by-line, interpreting the themes that emerge, and developing hypotheses iteratively. To analyze the data, the lead author worked with two trained research assistants to review the initial transcripts and develop a preliminary codebook based on themes raised by those participants. That codebook was used by the lead author to analyze the remaining interview transcripts; amendments and additions were made to the codebook as required by the emergence of new topics or intricacies. Direct quotations presented in the results are italicized and attributed anonymously by an identifying number.

2.3. Suitability Study

The suitability study followed the interviews and considered three parts of a prospective agrivoltaics system: types of agriculture production, solar energy generation potential, and distance between PV panels and the electrical grid (Scheme 2). Assessment of agriculture potential incorporates the views of interview participants who advocated for prioritizing less productive lands for co-location of solar: “I’ve got no problem with taking less productive grazing land, but I don’t agree with a field full of solar panels on beautifully productive cropland”. (P12). Grassland pasture acres were assigned a value from the range 0–1 based on the calculated productivity using 2013–2022 median summer NDVI (normalized difference vegetation index) from Landsat 8 imaging. Assessing grassland productivity via remote sensing is challenging due to lack of information about management and grazing intensity [37], but NDVI has been shown to be the most widely used index for that purpose [38]. The least productive grazing lands (first interval; minimum to lower quartile) received a value of 1, highest priority, while areas in the second, third, and fourth intervals received values of 0.75, 0.50, and 0.25, respectively. Cropland acres were assigned a value of 0.50 to represent medium priority for AV development.

A precise accounting of solar energy generation potential is place-based and technology-specific, and there are limited studies showing power output in an agrivoltaic configuration. A generalized metric used here is daily photovoltaic power potential (PVOUT) from the World Bank Group’s Global Solar Atlas. PVOUT is an assessment of power generation potential for a site with free-standing fixed-mounted c-Si modules mounted at the optimum tilt to maximize yearly solar energy generation [39]. PVOUT pixel values are normalized from 0 to 1 (lowest to highest) and used as an indicator of relative solar energy generation potential at each location. Agrivoltaics potential is the sum of agriculture potential and solar potential; this value represents the relative suitability of each pixel for agrivoltaics application.

Suitability for agrivoltaics projects seeking to tie into the grid must also consider proximity to existing power delivery infrastructure. Building transmission lines to connect a site can be time-intensive and costly: it can take up to 10 years for planning, permitting, and construction at costs ranging from USD 50,000 to USD 180,000 per mile [40]. Transmission potential is calculated here by creating a raster of each pixel’s distance to the nearest high voltage (100 kV) electric power transmission line as detailed in the U.S. Department of Homeland Security’s Homeland Infrastructure Foundation-Level Database. This research adopts the scheme from Majumdar’s work [40] of partitioning sites into four distance-to-transmission categories: (1) land within 1 mile is assigned a value of 1, the highest potential; (2) land within 1–3 miles is assigned 0.66; (3) land within 3–6 miles is assigned 0.33; and (4) land more than 6 miles away is excluded. Grid-tied agrivoltaics potential is the sum of agrivoltaics potential (standardized from 0 to 1) and transmission potential.

3. Results

3.1. Scoping Study Findings

This scoping study sought to narrow down the Tribal areas across the United States to Tribal lands feasible for agrivoltaics (Figure 2). The findings show that ~15.2 million acres of Tribal land (21% of Tribal land nationally) are feasible for agrivoltaics given land use, crop type, and slope (

Table 3. Total Tribal agricultural land and Tribal agricultural land with agrivoltaics potential.

		Area (1000 Acres)	% of Subtotal
Tribal agricultural area	Cropland	6790	31%
	Pastureland	15,415	69%
	Subtotal	22,205	-
Tribal agrivoltaics potential	Cropland	5920	39%
	Pastureland	9297	61%
	Subtotal	15,217	-

).

3.2. Interview Findings: Opportunities for Adoption

In interviews, participants anticipated benefits from agrivoltaics spanning from farm or ranch operations to the tribal community. Many participants stated that the concepts behind agrivoltaics were intuitive: “When you think about keeping the land productive while generating energy, it makes complete sense to do multiple things on one piece of land”. (P2) and matched their cultural approach to land management: “I think the intention of it aligns with our traditional ways of land management which is to stack function on function. I think about the three sisters garden and how our value as humans is to understand how to work in the system”. (P11). Findings that arose most frequently are detailed below.

3.2.1. Food Sovereignty Benefits

Many participants shared that Indigenous food sovereignty was of paramount importance to their communities, and they would support adoption of agrivoltaics if the technology could contribute to a stronger Native food system: “We have to be open to trying these things out. It’s worth the risk if it’s going to benefit our ability to feed our people”. (P8). Participants noted that Native agriculture is on a growth trajectory, and solar energy integration is a logical next step: “You know, we’ve got 4 million Indian people in the US, and that number is growing 4% per year. We need access to more energy to quickly scale up food production and processing. Why not look at clean energy?” (P13). They also saw the supply chain shocks brought on by the COVID-19 pandemic as a sign for tribes to double down on increasing their food production: “This pandemic should have opened so many eyes to see that you cannot be totally sovereign when the grocery stores are running out of food. The good news is a lot of tribes still have a land base and have the capability to produce food to sustain themselves”. (P12).

One frequent observation was the utility of shade in agricultural operations. Even though agriculture is powered by the sun, participants shared that there are many situations where producers can benefit from the shade provided by panels. One respondent from a desert region underlined the need for protection from the sun: “We have very, very hot summers. Sometimes plants get burned and having that shade would provide much needed relief for the plants”. (P20). Another person from a hot, arid climate thought agrivoltaics could expand the variety of food cultivated in their area: “The shade from agrivoltaics could allow producers to grow foods like lettuce that they couldn’t grow in the desert before”. (P1). Someone familiar with greenhouse operations shared the following: “Solar panels on a greenhouse would be perfect because you can block out the hot afternoon sun while generating energy. That seems like a win-win”. (P19). Shade also has productivity implications for livestock, as evidenced by a cow-calf operator who pointed out that shade can increase animal growth: “A lot of our cattle ranchers are grazing on open pasture and the direct heat from the sun can hinder calf growth. It would be a benefit if they can get some shade and put on more pounds quicker”. (P3). Other participants brought up the possibility of constructing agrivoltaic installations over waterways with special significance for commercial fishing: “Our waters are getting so shallow that salmon are dealing with lethal temperatures. If we could create shade and also capture energy, that would be cool”. (P11).

Adding solar panels to the farm or ranch can bring electricity to more Native agriculture operations, opening opportunities for sustainable intensification and value-added processing: “If you’re going to do any kind of agriculture, you have to have that energy. I just can’t see doing anything without it”. (P17). Participants reflected on ways that access to electricity could help producers tap into other natural resources on the land: “There are some places where there’s enough water, but no energy for an irrigation system. In those cases, agrivoltaics could be used to run the pumps and get higher production”. (P12). They also pictured agrivoltaics as a pathway for mitigating the energy-intensity of controlled environment agriculture technology like greenhouses: “There is a tribe with a 40,000 square foot greenhouse and they are looking to mount solar panels on it to provide power for the cooling units. There’s a lot of benefit to agrivoltaics”. (P2). Participants also saw space for electricity access to impact food sovereignty beyond production: “One predominant issue across many tribal communities is a need for refrigeration and cooling to mitigate spoilage. If agrivoltaics could power that type of equipment, the community would be able to make greater use of the food it is producing”. (P4).

3.2.2. Energy Sovereignty Benefits

For many participants, discussion of agrivoltaics went hand in hand with the goal of energy sovereignty for their communities: “To be energy sovereign would be really quite incredible”. (P1). Some people saw the technology as a chance to shift the energy network in Native communities toward more tribal control: “It’s inspiring to see tribes managing their own energy because tribal governments know how to serve their communities best”. (P4). They also pointed out that the current political landscape is prime for solar energy development on Tribal lands: “The prospects for solar energy in Indian Country look really good. There will be more projects coming online with the Department of Energy Guaranteed Loan Program increasing from $2 billion to $20 billion for tribes”. (P13). Increased power accessibility and a more equitable energy transition were a few ways participants envisioned agrivoltaics contributing to more energy sovereignty.

Participants talked about the anticipated increase in power accessibility that would accompany agrivoltaic development. Their visions for greater energy access sit against a backdrop of poor service to Tribal areas: “Energy access can be quite limited in rural tribal communities; there are thousands of homes without electricity. If you have an agrivoltaics system, you can support yourself and your family in a more robust way”. (P5). One participant shared that the power access burden fell disproportionately on younger people in their Tribal reservation: “Our younger generations are in a tough position because they are starting to get plots that are farther out, and it can cost up to $60,000 or $80,000 to run power to their plots. Adopting a solar system like agrivoltaics could allow them to utilize their land better”. (P18). Another participant drew upon previous experience when discussing how a tribal solar farm buoyed the community after a natural disaster: “There was a big earthquake, and a lot of the county was out of power, but the Tribe had power from their sustainable energy system”. (P1). Finally, many participants mentioned that greater power accessibility from agrivoltaics can lay the foundation for greater economic investment in the community: “We can’t have economic development without affordable, reliable electricity”. (P13).

Many Native agriculture professionals thought agrivoltaics could be a part of a just energy transition for tribes. Participants referenced the legacy of fossil fuel extraction on their lands and envisioned a different energy pathway for their communities: “We have a unique, sometimes devastating history of extraction with fossil fuels. We really need alternative energy”. (P8). They pointed out that having the solar option from agrivoltaics could allow them to switch away from other forms of energy that damage critical habitat for traditional foods: “It’s about weighing the pros and cons. If we can get energy in a different way (agrivoltaics), then we wouldn’t be so dependent on hydroelectricity and a lot of these dams could come down for our salmon”. (P14). One participant expressed that their community may be more willing to embrace electrification as a climate mitigation strategy if they knew their energy was coming from a system that matched their stewardship values: “Even though we are concerned about carbon and climate change, Native people around here aren’t excited about electric vehicles because we don’t know where the electricity is going to come from. We want to be part of addressing climate change, but the offerings don’t align with our values”. (P11). Another person thought that agrivoltaics could be part of a broader charging network for the expansion of electric vehicles to rural areas: “People are trying to drive Teslas around here now, and there are very few options to charge them. If you had agrivoltaics, there would be more access to recharge in rural areas”. (P20).

3.2.3. Economic Development Benefits

Participants saw increased revenue diversity as a significant benefit of agrivoltaics. At the tribal scale, the energy revenue from agrivoltaics could provide consistent income to fund vital governmental functions: “Tribal agricultural organizations are always underfunded, but you could set this [agrivoltaics] up in a way to have a continual operating fund”. (P6). The same concept can be applied to the finances of agricultural producers, affording them additional cash flow to help weather volatile markets: “The way ag markets are right now you’re barely making it by, so having an extra source of income is something to look at”. (P6). Participants shared that the new income stream could free up producers to spend more time investing in their agricultural operations: “Another level of productivity is to decrease the amount of time that Native farmers and ranchers need to spend off of their operation. Many producers across Indian Country have to work off-farm jobs to cover costs”. (P4). Some participants speculated consumers would be willing to pay a price premium for products grown in an agrivoltaic system: “Consumers are looking for sustainability as a justification for where they put their dollars. So, if a farmer is able to say that they incorporate agrivoltaics, that only reinforces their ability to sell a differentiated product”. (P4). Other respondents imagined that proceeds from solar energy generation could alleviate enough financial pressure to allow room for regenerative practices, increasing the potential for climate resilience: “So, if tribes are going to do this, do it with consideration as to what you can do to make that soil healthy again while the solar panels generate an income”. (P12).

While they thought agrivoltaics would likely be profitable, many participants expressed concern over who exactly would reap the monetary benefit. One participant surmised that producers would be excluded from agrivoltaics energy revenue: “To this day, individuals on the ground have never had any rights to revenue from any sort of business venture the tribe introduced on their lands because they only have a farmland use permit. If that’s the case with agrivoltaics, producers will have a very negative opinion of it because they wouldn’t be able to make any money off of it”. (P20). Another participant expressed concern that the economic benefit could go primarily to non-Native individuals living on Tribal lands: “A lot of the non-Native producers farm along those fertile ridges, while the Native producers run cattle on the hilly parts not suitable for farming. Because of that, you see a lot of rich, non-Native farmers on the rez [reservation] and a lot of poor Native ranchers. The agrivoltaics company would likely end up working with the non-Native farmers on Tribal lands, so I’m not a big fan”. (P19).

3.3. Interview Findings: Barriers to Adoption

Participants also voiced many concerns about agrivoltaic technology and its suitability for Tribal lands. The perceived barriers ranged in magnitude and scope, existing on a spectrum from inconveniences to fatal flaws. The concerns that surfaced most are detailed below, grouped into four themes that emerged from the data: technical and operational; financial, market, and labor; siting; and social and ecological (

Table 4. Participants (n = 21) who cited concerns across the summary themes.

Concern	Count
Technical	15
Economic	19
Siting	18
Socio-ecological	15

).

3.3.1. Technical Concerns

When asked about their prior knowledge of agrivoltaics, most participants stated that they had not encountered the concept before being recruited to the study: “I never heard of it until I was contacted by you”. (P12). Given the novelty of agrivoltaics, many participants shared concerns about the functionality of the system. Several people were concerned about the durability of solar installations on a working farm or ranch. A cattle producer expressed this concern: “Cows are large mammals and they like to rub against stuff. Can these panels handle a 2000-pound cow rubbing and pushing against it constantly?” (P7). Others brought up the risk from extreme weather conditions: “The wind is strong out here. Can solar panels withstand the kind of wind that blows barns apart and flips travel trailers over?” (P12). Another recurring concern was safety for people and animals interacting with the solar equipment: “What are the safety measures to keep the cattle safe or to keep water from getting in the wiring? Is the individual working on it going to risk death each time something goes wrong out in the field?” (P9) and “When you’re working with electricity, there’s just that hazardous component to it”. (P5).

Concerns about increased operational complexity and impaired agricultural productivity came up often. Participants discussed agrivoltaics as existing on a spectrum from full agricultural production to total energy generation and were cognizant of the changes necessary to find a configuration that prioritized agricultural efforts: “If you are balancing your solar farm against your actual farm, you need to make sure you are raising plants that can handle the anticipated shade”. (P4). Another participant was less optimistic about the ability to combine agriculture with solar energy production without sacrificing productivity: “Well, that’s something we’ve already looked at and the yield is going to go down. These plants are photosynthetic and they’re not going to get the energy they need to maximize their output”. (P10). Participants also said they foresee challenges with how producers carry out ranch tasks like rounding up the herd: “It would be difficult for a rancher on horseback to gather up their cattle if they’re hanging out under the shade under the panels”. (P3).

3.3.2. Economic Concerns

Along with considering technical barriers, many participants worried about finding the financial resources to implement agrivoltaics on Tribal lands. There are many approaches to closing the capital gap, and respondents highlighted challenges with financing by the tribe, producer, and solar developer. Those participants envisioning a tribal entity-led project pointed out that many tribes have tight balance sheets and would have difficulty getting loans to cover a project of this size: “Our tribal government doesn’t have a lot of moneymaking opportunities, so I think the lack of capital in Indian Country could be a barrier to putting these [agrivoltaic systems] up”. (P14). Interviewees who considered a producer-owned endeavor worried about trouble securing financing based on difficulty collateralizing trust land: “Most of our producers are working on trust land, and on paper your operation is worth nothing. If I cross the river onto non-tribal lands, they have the same thing I do, but they look fantastic on paper”. (P15). Finally, there was hesitancy around working with solar developers, a sentiment shared here by a Tribal ag financer: “I would be worried about the producer negotiating with the energy company because the energy company has all the resources and good lawyers, and producers might not get an equitable contract”. (P19).

Many participants relayed concerns about successfully entering the energy market. First, a large portion of Indian Country is remote, with much of the current agricultural land located far from existing transmission infrastructure. Participants worried that this lack of connectivity could preclude them from agrivoltaics arrangements that include offloading energy to the grid: “Tribes may be left out of agrivoltaics because we don’t have the power lines to take up the energy and sell it”. (P1). Respondents were also concerned that local utilities would be hesitant to partner with them in a meaningful way. One person said they knew of a tribe seeking to implement agrivoltaics, and that tribe had already encountered a barrier finding a buyer for their future energy generation: “The utility company said they already had enough green energy and they weren’t going to take anymore. That’s strange, and it limited the Tribe’s interest in wanting to do agrivoltaics because who are they going to sell the energy to?” (P1). Another respondent was in the process of inquiring about grid-tied solar on their allotted land but had already been given the cold shoulder by their local utility: “If we do this, we want to market our solar to the electric co-op, but they don’t want to work with us. They didn’t tell me that directly, but they shared it with one of our non-Native partners. So, we’re going to tell them that we feel there is some discrimination happening, and it’s probably going to get pretty political”. (P17).

Another set of constraints raised by participants was about the lack of a skilled local workforce to manage, install, and maintain agrivoltaics on Tribal lands. The reflections of one tribal farmer gives voice to the concern that it is too risky to rely on outside labor to propel a project: “I can’t tell you how many times I’ve seen new technology come to reservations, and our people don’t know how to fix it, so it just sits there while the people who brought it are nowhere to be found”. (P10). Participants saw the remoteness of many Tribal nations as a contributing factor to the shallow labor market: “One of the problems we have in rural communities is finding qualified staff”. (P17). The human resource concern covered both on-the-ground jobs and management positions: “It comes down to education and the lack of skilled labor is a limiting factor. We just need more trained people who can install these [agrivoltaics systems]”. (P5). Participants acknowledged that training would be an ongoing challenge given the high levels of job turnover in some Tribal communities: “It would be challenging to keep the technical knowledge constant if there’s quite a bit of turnover. There needs to be a center where Tribes could send their staff to train”. (P1).

3.3.3. Siting Concerns

When it comes to siting agrivoltaics, participants emphasized there are unique challenges like checkerboarding, fractionation, and leasing when working on Tribal agricultural land. Checkerboarding refers to the mixing of tribal land designations and ownerships on adjacent tracts of land, creating a highly heterogeneous landscape: “I think you have to get into the land statuses. It’s pretty checkerboarded on my reservation. It’s kind of all over; we have fee and trust and allotted and non-Native land”. (P3). The checkerboard nature of the layout impedes the ability of tribes or tribal members to carry out activities that require large, contiguous sections of land and the jurisdictional complexity can make permitting a hardship. Fractionated ownership describes lands whose title ownership is divided among heirs without any pathway for division of the land. Participants noted that implementing agrivoltaics would require permission from titleholders: “There are instances of land with fractionated ownership, and in those cases, you have to get majority approval of all owners to change the land use”. (P2). Over time, the number of owners grows exponentially, making it increasingly difficult for a person seeking to work on the land to coordinate property decisions with heirs who often live far away from the land at hand: “I talked to one producer who was required to get the allotees to sign off on a right-of-way to access his grazing unit. He had to send out 560 letters and hope that at least 51% responded saying, “Yes, you can do that”.” (P6).

Due to the levels of checkerboarding and fractionation, many Tribal agricultural operations rely on leasing additional acreage through the Bureau of Indian Affairs (BIA), a process that comes with its own bureaucratic challenges: “With tribal communities, a lot of people are using leased land, and there’s a bunch of paperwork that you have to go through before you can get approved to do something else”. (P15). Among other issues, lengthy wait times for BIA review plague farmers and ranchers looking to make material changes like agrivoltaics to their operations: “I was working with one producer who wanted to do a spring development. He was approved by NRCS, approved by the tribe, and then it went to BIA and sat on their desk for two years”. (P6). On top of that, the nature of leasing inherently disincentivizes capital improvements to the land and raises questions about the energy revenue from agrivoltaics: “The investments you make in the property go toward the actual titleholders, so essentially anything you put in is going to cost you more money the next time you try to get that lease. And if we’re producing energy, who gets the dividends? Does it go to the landowners or the producer leasing the land? I don’t know”. (P6).

Participant reflections on siting informed the suitability study, particularly on the topic of the optimal location for dual-use solar infrastructure on Tribal lands. As referenced in Section 2, participants shared disappointment with seeing what they perceived to be the most productive agricultural land transitioned to single-use solar: “Farmers aren’t the biggest fans of solar due to solar [developers] taking the best part of the land instead of the weaker land”. (P7). The opportunity cost of fertile land led participants to express a feeling of wastefulness: “When you see a large solar field, I feel like the land below those panels is a wasted resource”. (P2).

3.3.4. Social-Ecological Concerns

Many of the concerns raised by participants highlight how the cultural values of the community factor into the adoption of agrivoltaics. Participants pointed out the breadth of the stakeholder ecosystem, encouraging decision-makers to include the full community in cost-benefit analyses: “Something that is true in our Native communities is that we’re not individuals, we’re a community and you can’t prosper on your own. If we do this project, it has to benefit everybody as a tribe, not just the individual”. (P18). They were also circumspect about the complicated history of energy development on Tribal lands and wondered if agrivoltaics could be implemented in more socially responsible ways: “A lot of times these energy projects create a layer of separation and don’t provide a direct community connection. I’m wondering if it is possible to coexist and not be so intrusive and extractive?” (P8). In the same vein, participants worried opening the door to solar energy generation on working lands would inevitably cause agricultural interests to suffer: “If the energy companies get a hold of it, they will be a lot better off than agriculturalists, so I kind of lean towards leaving things alone”. (P10).

Participants were also concerned about how agrivoltaics would impact the environment and non-human creatures. Several people shared that they expected local climate implications from solar installations: “Once you have a big field of solar, from just the reflective light alone, it’s going to change the weather patterns and bird patterns and there will be consequences”. (P5). Others were worried about the long-term soil impacts, as summarized by a soil science researcher who fields these kind of questions from the public: “People always ask me how will solar panels impact the soil and surrounding ecology. Some people say the metals that you’re putting in the ground to hold up the panels will have a negative effect, but we don’t know because there are limited studies looking at long-term impacts”. (P16). Many participants brought up impacts on wildlife, sharing concerns about habitat displacement: “How are we impacting our wildlife? Are we taking advantage by putting up our own facilities in their homes?” (P14).

3.4. Suitability Study Findings

The suitability study introduces weighted criteria (agricultural potential, solar potential, and transmission potential) to find priority areas for agrivoltaics exploration. Figure 3 shows calculated agrivoltaics potential and grid-tied agrivoltaics potential in panels (a) and (b). Priority AV land is defined as pixels with agrivoltaics potential scores in the top 50% of the study region.

Table 5. Ranking of states with Tribal lands based on AV feasibility and priority. Feasibility incorporates all the Tribal land with some level of suitability for agrivoltaics. Priority contains only the top 50% of suitability scores.

AV Feasible Land
Top states	100,000 acres
(1) South Dakota	63.8
(2) Montana	33.8
(3) Arizona	10.9
(4) North Dakota	10.8
(5) Oklahoma	6.6
(6) New Mexico	4.5
(7) Idaho	3.0
(8) Minnesota	2.7
(9) Washington	2.6
(10) Utah	2.5
Grid-tied AV feasible land
Top states	100,000 acres
(1) South Dakota	23.1
(2) Montana	17.9
(3) Arizona	4.7
(4) Oklahoma	4.5
(5) North Dakota	4.1
(6) New Mexico	3.7
(7) Washington	2.3
(8) Idaho	2.0
(9) Minnesota	1.9
(10) Nebraska	1.6
AV priority land
Top states	100,000 acres
(1) South Dakota	29.0
(2) Montana	18.1
(3) Arizona	10.9
(4) New Mexico	4.5
(5) Oklahoma	3.5
(6) Utah	2.5
(7) Wyoming	1.8
(8) Washington	1.1
(9) North Dakota	1.0
(10) Oregon	0.9
Grid-tied AV priority land
Top states	100,000 acres
(1) South Dakota	11.1
(2) Montana	9.1
(3) Arizona	4.0
(4) New Mexico	3.5
(5) Oklahoma	2.4
(6) Minnesota	1.8
(7) North Dakota	1.5
(8) Washington	1.2
(9) Idaho	1.1
(10) Utah	1.0

shows the top ten states by land area with agrivoltaics feasibility and prime suitability for both micro-grid and grid-tied applications. South Dakota, Montana, and Arizona capture first, second, and third place across all four categories; this result mirrors the amount of agricultural land relative to each state. Notably, while Arizona and North Dakota have nearly identical amounts of agrivoltaics feasible land, all of Arizona’s land is considered prime suitability while only one-tenth of North Dakota’s area has the same classification.

For grid-tied applications, a little less than half of Tribal land suitable for agrivoltaics–7.3 million acres—is within six miles of existing high-voltage transmission lines. This finding corroborates participant concerns about limited transmission infrastructure. State area rankings remain the same as for micro-grid applications (Figure 4). While pastureland is the most predominant land use on Tribal lands, the share of land attributed to croplands increases from 31% of Tribal agricultural area to 50% of the area deemed suitable for grid-tied applications. This outcome indicates that pasturelands are more likely than croplands to be situated in areas that are ruled out by exclusion criteria like slope and proximity to electric power lines.

4. Discussion

The results on opportunities indicate participants believe agrivoltaics on Tribal lands could positively contribute to existing movements for equity and self-determination in Native communities. Participants linked agrivoltaics to food sovereignty, the idea that Tribes have the inherent right to control their own food systems and the responsibility to eliminate food insecurity in their territory. The idea that agrivoltaics can lead to better agricultural outcomes is supported by findings in the literature, including a study showing higher yields for peppers and cherry tomatoes in Arizona [9], increased resilience to climatic extremes for wheat in Germany [11], and higher water efficiency for lambs in Oregon [41]. Beyond production, the electric power derived from agrivoltaics could help Tribal producers more effectively store and process their harvest, reducing food loss and increasing value-added agriculture endeavors.

Participants connected the adoption of agrivoltaics to the pursuit of energy sovereignty, the right of Tribes to determine their own energy policies and practices. Agrivoltaics could create decentralized networks of renewable energy generation to address chronic energy poverty in Indian Country, a notion supported by Tribal energy researchers who found residential solar units in the Navajo Nation helped close the electrification gap for many residents beyond the reach of traditional utilities [42]. It could also alleviate dependence on controversial energy sources like coal and hydropower; decades of Tribal-led advocacy against the latter have contributed to the ongoing decommissioning and removal of dams in the United States [43].

Participants envisioned agrivoltaics as a sustainable economic development strategy, a perennial priority for many Tribal nations. While electricity revenue projections depend on power production and levelized cost of energy, considerations unique to each agrivoltaic system, the literature supports the notion that agrivoltaics can significantly increase income from the land. One researcher [8] used the Land Equivalent Ratio (LER), a method for comparing outcomes from an intercropping system to a single-crop system [44], to show land productivity increases up to 70%. A case study in India found a 30% increase in economic value for farms employing agrivoltaics technology [45]. Design decisions like array density, panel height, and sun-tracking features impact both the expected solar returns and growing conditions for plants or livestock, leading to inherent tradeoffs between agriculture and energy productivity. Most studies show energy contributing more to the total income; a limited review of financial data from agrivoltaic systems found that revenue from solar electricity accounted for 82.5–98% of the total income [25]. Depending on ownership status and operating contracts, Tribal agrivoltaics could be a viable investment for Native communities.

The results on barriers indicate participants have technical, economic, siting, and socio-ecological concerns with agrivoltaic implementation on Tribal lands.

Table 6. Summary of concerns about agrivoltaic development on Tribal lands across four categories.

Theme	Findings	Sample Quote	Recommendation
Durability	Participants questioned the durability of AV infrastructure given various hazards on working lands.	“How tough is the agrivoltaics equipment? Because someone is totally backing a tractor into it at some point”. (P6)	Sponsor pilot projects to test AV infrastructure in a variety of production systems.
Complexity	Participants expressed concerns about increased knowledge and management burdens for producers.	“Your practices will have to adapt. Understanding what you can and can’t do versus having a wide-open piece of land is going to be a major thing”. (P2)	Scale up extension services to provide evidenced-based recommendations to producers.
Productivity	Participants worried that AV installations would hinder their land productivity.	“I would be worried that the rain isn’t going to hit parts of the field and the panels would cause runoff to pool into one spot”. (P15)	Invest in robust research programs to measure and mitigate impacts to productivity.
Financing	Participants anticipated challenges raising large sums of capital for AV given the socio-economic landscape in Tribal areas.	“I like the idea, but I think the upfront cost will turn a lot of people off. It’s really expensive to do solar”. (P16)	Explore opportunities to fund AV through existing set-asides for clean energy development on Tribal lands.
Market	Participants did not think utility companies would want to purchase energy from AV.	“You have all this excess energy, but who is going to buy it? Will the utility commission even allow us to sell surplus energy to other people?” (P10)	Consider incentives for utility companies to cooperate with AV operators in their service area.
Labor	Participants shared how the acute shortage of trained workers in Tribal areas could constrain AV implementation.	“We have a human resources capacity problem in Tribal areas”. (P13)	Develop comprehensive training material that can be delivered to interested parties in rural areas.
Land tenure	Participants saw land tenure complexities as a major hurdle for AV implementation.	“Land restrictions would probably be the number one issue that we would run up against”. (P2)	Partner with Tribes on proposals to streamline land use and development.
Leasing	Participants expected challenges implementing AV on land leased through the Bureau of Indian Affairs (BIA).	“It’s a big, big hurdle with BIA land management to put in infrastructure, or even just to generally operate”. (P6)	Direct resources to alleviate bureaucratic backlogs and increase responsiveness to Tribal clients.
People	Participants emphasized that potential AV projects would need to benefit the whole community, not just interested parties.	“What are the community’s likes, the community’s passions? How can it benefit the community beyond the money sense?” (P18)	Make space for stakeholder input and create a holistic framework for assessing community benefit.
Nature	Participants voiced concerns about the well-being of plants, animals and water in proximity to AV systems.	“How will wildlife be impacted by this? I feel like people don’t consider that many tribes are very respectful of all wildlife, even animals that may be thought of as vermin by others”. (P16)	Prioritize technology and design solutions that minimize disruption to the ecosystem.

below provides an overview of key findings that emerged from the interviews and author recommendations aimed at a broad coalition of stakeholders interested in agrivoltaics. These themes are reflective of the experiences of interview participants and are informative for charting a path toward agrivoltaic adoption on Tribal lands. The findings on infrastructure durability and operation complexity build on the existing evidence of the agricultural industry’s perspective of agrivoltaics [26], while participant statements about the possible siting challenges in store for agrivoltaics development on Tribal lands are corroborated by findings in previous work on Indian land tenure [46]. Concerns about solar displacing prime agricultural land match findings that show producers are more willing to adopt utility-scale solar energy on low-productivity tracts [29].

The results from the geospatial analysis indicate approximately 15 million acres of Tribal land are suitable for agrivoltaics, with up to 7 million acres of that land located in reach of existing transmission infrastructure for grid-tied applications. This figure is considerable given a study that found the United States would only need 8.3 million acres of agrivoltaics to meet 20% of 2019 US electricity generation [47]. Our analysis found South Dakota, Montana, and Arizona were the leading states for Tribal agrivoltaics suitability. While Arizona has long been thought of as a solar leader due to its southwestern locale, land in South Dakota and Montana has not been prioritized for solar development. If Tribes and Tribal producers in these states so choose, they could join premier agrivoltaics research stations around the world located in similar latitudes, including France [8], Germany [11], and Italy [17].

Limitations

Due to non-random interview sampling, this research does not aim to make generalizable claims based on representativeness, but rather to reveal the nuanced perceptions, opinions, and attitudes of the people interviewed. Through this theory-generating work, future research can utilize other methodological approaches that allow for broader, generalized claims about Tribal agrivoltaics potential. Since the results are based on what was shared in interviews, it is possible that some important opportunities and barriers were not surfaced through this work due to the knowledge bases of the interview participants. For example, we expect agricultural and energy policy to have a significant impact on the suitability of agrivoltaics for Tribal lands, but the participants did not spend time discussing those implications. Future work can ask tailored questions to uncover more information in that domain.

The geospatial analysis is limited to a first approximation of where agrivoltaics is suitable on Tribal lands. Future work can work directly with tribes to create maps that account for land tenure, zoning, and cultural values, extend the physical parameters assessed (e.g., proximity to substations, road access, land aspect, water availability), and incorporate land use ground-truth data. A more complex exercise to define agrivoltaics potential in Indian Country would also include parameters around photovoltaic technology used in agrivoltaics. The state of the art is improving rapidly, and future innovation may impact the energy generation estimates significantly. Finally, it is important to note that development potential on Tribal lands is dependent on financial capacity and political will. While this study identifies priority areas for exploration based on physical factors, a prudent step forward would be to assess the economic, policy, and governance landscape for investment in agrivoltaics on Tribal lands. This may include intertribal partnerships that pair financial capacity with natural resource endowment across geographies.

5. Conclusions

Agrivoltaic systems can increase land productivity by integrating agriculture production and solar energy generation, and the potential for increased utilization of agrivoltaic technology on Tribal lands is high given the push for solar energy development across Indian Country. This study investigates opportunities, barriers, and geospatial suitability for agrivoltaics on Tribal lands. The interview results indicate participants can see agrivoltaics contributing positively to existing movements for food sovereignty, energy sovereignty, and sustainable economic development if their concerns about technical, economic, siting, and socio-ecological barriers are addressed. The spatial analysis results show up to 15 million acres of existing Tribal agricultural land could meet minimum suitability requirements for agrivoltaics, with 7 million acres of that land in close enough proximity to existing energy infrastructure to connect to the electric grid. The findings from Tribal agriculture professionals can be used to inform further research, future policy, and Tribal land-use decisions. Ultimately, agrivoltaics can minimize the loss of agricultural land, increase the supply of renewable energy, and create pathways to economic diversification for Tribes and Tribal producers. Additional research and extension efforts are needed to fully explore the potential for agrivoltaics in Indian Country and the broader social decision-making processes that facilitate agrivoltaics implementation.