The Benefits of Agrivoltaics

The Benefits of Agrivoltaics

Here, we explore the numerous benefits of combining solar with agriculture and sheep, i.e.,

sheep agrivoltaics. This idea involves rotational sheep grazing on farmland alongside solar

photovoltaics arrays and is a concept that has been practiced in New York, California, North Carolina, Europe, and other locations17 . Through a literature review of agrivoltaics projects and

case studies and an interview with a leading sheep agrivoltaics expert, our team researched the

key considerations for integrating agriculture into the Dibe’ Ni Tsaa Energy project.

Cultural Value. The Navajo Nation has a long history of agriculture, especially so in the Four

Corners area. Before NAPI and the Navajo Mine were established, the land was used for grazing

of livestock for Navajo farmers such as Lucinda’s grandfather. Nonabah herself comes from a

family that maintains an educational farm in the Four Corners area, Navajo Ethno-Agriculture,

which provides education on traditional Navajo farming. NAPI land is located in San Juan

County, New Mexico, which has 2,091 farms operated by Native producers, representing the third highest number across the United States.18 Agriculture in the Navajo Nation has been

maintained despite a variety of challenges, and has become an increasingly important theme in establishing food sovereignty on the reservation.19 In our meetings with Nonabah, she expressed

that an agricultural component of the project could provide a unique way to appeal to the board

of NAPI.

17 Gimlet Media. Sheep + Solar, A Love Story, 2021. https://gimletmedia.com/shows/howtosaveaplanet/39hgkba

18 Census ofAgriculture. American Indian/Alaska Native Producers, 2017. . https://www.nass.usda.gov/Publications/Highlights/2019/2017Census _ AmericanIndianAlaskaNative _ Producers.pdf 19 Earth Refuge. The Navajo Nation: A Case Study on Food Colonialism and Environmental Justice, 2021. https://earthrefuge.org/the-navajo-nation-a-case-study-on-food-colonialism-and-environmental-justice/

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Sheep grazing is an especially appealing aspect from a cultural standpoint. Nonabah proposed a

rotational grazing model in which the land could be grazed twice a year with Suffolk and Navajo

Churro sheep in rotation. Sheep are the most prominent form of livestock in Navajo agriculture,

and are an integral part of Navajo culture and identity. The Churro sheep in particular has faced

extinction during the internment of Navajos in the 1860s and “livestock reduction” campaigns by

the federal government in the 1930s; the efforts of the Navajo people to maintain and restore the breed have allowed the sheep to survive today. 20 Churro sheep are valuable both as a healthy

food source and for their wool, which is used in traditional Navajo blanket weaving. Flocks of

Churro sheep are still being maintained in an effort to further revitalize the breed and its value as a form of healing from the attempts of the US government to exterminate the breed.21 The sheep

have been described as another way that the Navajo are achieving sovereignty because of its

ability to provide both food and income for Navajo people.

Additionally, because the New Mexico State University Agricultural Science Center (NMSU

ASC) at Farmington is located near NAPI land, there is an opportunity for Navajo students to

engage in research and training in the growing field of agrivoltaics. NMSU has launched an

initiative specifically focused on the food, energy, and water nexus, which provides a unique

opportunity for NMSU ASC and NAPI to engage in a mutually beneficial partnership through educational programs for students.22

20 Slow Food Foundation for Biodiversity. Navajo-Churro Sheep. https://www.fondazioneslowfood.com/en/slow-food-presidia/navajo-churro-sheep/ 21 The Christian Science Monitor. Reviving Navajo identity, one sheep at a time, 2022. https://www.csmonitor.com/USA/Society/2022/0407/Reviving-Navajo-identity-one-sheep-at-a-time 22New Mexico State University. Nexus program taps into NMSU expertise to solve food, energy and water challenges, 2021. https://news.nmsu.edu/2021/06/nexus-program-taps-into-nmsu-expertise-to-solve-food-energy-and-water-challenges .html

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Logistical and Financial Value. Our research centered around the added benefit of agrivoltaics in

logistical and financial planning of the Dibe’ Ni Tsaa Energy project. A study performed by the

National Renewable Energy Laboratory in the Arizona drylands found that growing crops under solar panels can provide mutual benefits between food, energy, and water. 23 Through the shading

provided by solar panels, soil moisture was increased by 5% to 15%, ensuring that irrigation was

more efficient. Overall water use efficiency and food production increases varied by crop type;

compared to control treatment, chiltepin fruit production was tripled, jalapeño water use

efficiency was 157% greater, and cherry tomato production was doubled with 65% greater

water-use efficiency. Additionally, crops were able to keep solar panels cooler: solar panels located above crops were about 9℃ cooler than the control group, which reduces the amount of

energy lost by solar panels to heat. Increased energy efficiency can result in up to 10% more

overall energy output, which could provide substantial revenue through the sale of surplus energy. 24 These findings have been supported by other studies performed in a variety of

environments, but the similarity in climate makes the NREL study particularly relevant to

consider. 25,26,27,28

Growing crops on NAPI land could involve the leasing of land to independent growers, which

would provide an additional revenue stream through land lease agreements; alternatively, NAPI

23 Nature. Agrivoltaics provide mutual benefits across the food–energy–water nexus in drylands, 2019. https://www.nature.com/articles/s41893-019-0364-5#Sec6 24 Oregon State University. Sustainable Farm Agrivoltaic. https://agsci.oregonstate.edu/newsroom/sustainable-farm-agrivoltaic 25 PV Magazine. Novel plant design for agrivoltaics, 2021. https://www.pv-magazine.com/2021/08/05/novel-plant-design-for-agrivoltaics/ 26 PV Tech. The yin and yang of Agri-PV: Bringing together the best of both worlds, 2021. https://www.pv-tech.org/the-yin-and-yang-of-agri-pv-bringing-together-the-best-of-both-worlds/ 27 One Earth. A town in India is using solar panels to protect crops, 2022. https://www.oneearth.org/town-in-india-using-solar-panels-to-protect-crops/ 28 Plos One. Remarkable agrivoltaic influence on soil moisture, micrometeorology and water-use efficiency, 2018. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0203256

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could grow additional crops on the land and produce revenue by selling the crops grown under

solar panels.

Alternatively, some land on the project area can be used for rotational grazing of sheep.

Depending on the climate, sheep grazing offers different benefits to solar projects; for example,

in areas with high plant growth, sheep grazing can reduce operation and maintenance costs by up to 75% and increase solar output by preventing the shading of panels by vegetation.29 Not only

would such grazing be beneficial for solar generation, but it can improve the health of the sheep as well as the soil.30 In drier climates such as New Mexico, sheep can play critical roles in

reducing wildfire risk, as discussed more below. A study performed by Temple University

researchers found that a site grazed by 500 to 700 sheep can increase nutrient fixation of soil, in addition to sequestering up to one ton of carbon per year. 31 Once sheep have sufficiently grazed a

certain patch of vegetation, shepherds can rotate them to more overgrown sections, providing a

steady food source for the sheep and continual maintenance for the solar panels. Solutions exist to protect sheep from predators, such as solar powered electric fences.32

Meeting with Lewis Fox. Lewis is the Founder and Partner at Agrivoltaic Solutions, LLC,

providing sheep grazing and other vegetation maintenance services throughout the Northeastern

US. He was able to share about his work and how it might apply to the NAPI project, as well as

how considerations around grazing might be different in these different regions. By the end of

our call, Nonabah and Lewis both expressed interest in continuing through a potential

29 Town of Mount Morris. Mount MOrris Agrivoltaic Study, 2021. https://townofmtmorris.com/wp-content/uploads/2021/11/MountMorris-AgrivoltaicReport2021-WEB.pdf 30 Gimlet Media. Sheep + Solar, A Love Story, 2021. 31 Temple University. Managed sheep grazing can improve soil quality and carbon sequestration at solar photovoltaic sites, 2022. https://scholarshare.temple.edu/handle/20.500.12613/7254 32 Gimlet Media. Sheep + Solar, A Love Story, 2021.

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partnership with Agrivoltaic Solutions, and we hope that we have established the beginning of a

working partnership. Lewis also knows of several people doing similar work in the southwestern

US (particularly around Tucson, Arizona), and plans to send potential contacts in the region to

Nonabah.

Through our meeting with Lewis, we were able to determine some key considerations based on

his experience with consulting in projects around California and West Texas. In the southwestern

climate, sheep grazing can generate $100 to $200 per acre annually, with about 1 sheep per acre,

which is lower than rates in the Eastern United States due to the drier climate. In terms of capital

costs for investment, operation and maintenance would range from $50 to $150 per acre

annually, with additional investment needed to prepare the area for grazing. Lewis identified four

areas needed for planning of the project: (1) water supply and transport, which would be

significantly reduced by NAPI’s existing water supply, (2) perimeter fencing, which would

require a “predator wrap” to be applied to the bottom of the fence to prevent predators to dig into

the site, (3) interior dividing fences for rotational grazing, which would be most cost effective

when installed permanently rather than through temporary fencing installed yearly, and (4) wire

control, which would be organized through collector lines and racking in order to prevent sheep

from being caught in cables on the site. Overall, Lewis estimated less than $100,000 capital

investment, which is much less than the $216,000,000 in capital costs already associated with the

project.

Lewis also offered insight into the logistical benefits of solar grazing: overgrowth and

maintenance savings may not be as significant given the drier climate; instead, the primary

benefit of sheep grazing would be reduced risk of wildfire by consuming dried vegetation, which

could be appealing given the increasing risk of wildfire in the Western United States.

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Potential Contacts

In addition to our review of agrivoltaics, we have identified potentially useful contacts working

on agrivoltaics projects in the region.

Greg Barron-Gafford. Dr. Barron-Gafford is a professor at University of Arizona, and the

leading author of the previously referenced National Renewables Energy Laboratory study on

agrivoltaics in Arizona. Currently, he is leading the SCAPES project with research sites in

Arizona, Colorado, and Illinois to identify optimal agrivoltaics designs for crop growth across different climates.33

Chad Higgins. Dr. Higgins is a professor at Oregon State University, where he is studying the economic benefits of agrivoltaics to rural communities.34 His research includes savings

associated with on-site energy, revenue due to the sale of surplus energy, as well as the

generation of jobs, which is especially relevant to Navajo Power’s values.

American Solar Grazing Association. The American Solar Grazing Association (ASGA) is a

national organization seeking to organize those interested in grazing sheep on solar energy sites by facilitating connections, research, and support.35 Their website provides a helpful map of

existing solar grazing sites, relevant research initiatives, and guides for solar developers seeking

to establish agrivoltaics projects. Lewis Fox is a founding board member, providing Navajo

Power an immediate connection.

33University ofArizona. UArizona Partners on $10M USDA Grant to Expand Research on Growing Crops Under Solar Panels, 2021. https://news.arizona.edu/story/uarizona-partners-10m-usda-grant-expand-research-growing-crops-under-solar-panels 34 Engineering.com. Agrivoltaics Provide Food, Power and Money: A Triple Win, 2021. https://www.engineering.com/story/agrivoltaics-provide-food-power-and-money-a-triple-win 35 American Solar GrazingAssociation. Recommendations. https://solargrazing.org/recommendations/

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