Case Study: Winston Cone Optics and Dairy Processing 

Winston Cone Optics’ installed pilot system on the roof of a dairy barn in California.

By Anna Adair, NCAT Energy Program Assistant

Thanks to the increase of solar photovoltaic sites in recent years, agrivoltaics has started to work its way into the public eye as a means of bridging the gap between land use for agricultural and energy production. By co-locating energy production with sustainable agriculture, the land that solar arrays occupy can continue to produce crops, provide forage for grazing animals, or even serve as a pollinator habitat for bees. Beyond photovoltaics, the broader umbrella of “agrisolar” also encompasses concentrated solar-thermal power (CSP), which can help decarbonize the agricultural processing space. Winston Cone Optics (WCO) in Merced, California, is at the forefront of this effort, helping dairy farmers reduce their propane consumption by using CSP to heat water for equipment sterilization.  

WCO’s CSP system was developed at University of California, Merced under the guidance of Dr. Roland Winston. The technology utilizes nonimaging optics, which allows the system to function in a stationary position. Compared to photovoltaic tracking systems – which adjust the solar panel’s angle throughout the day to follow the path of the sun – WCO’s system requires less upkeep and fewer parts, while simultaneously achieving 50 to 60% efficiency. The solar collectors pair nonimaging reflectors with evacuated tube receivers. These receiver tubes house a selectively coated fin that absorbs the concentrated thermal energy. As the fin increases in temperature, pressurized water is circulated through the tube and into a heat exchanger where the hot water can be passed into the hot water system. 

Schematic drawing of the dairy’s system. 

When WCO was looking for a pilot site, they learned of a local dairy building a fully automated freestall barn just down the road from their headquarters. They reached out to the farmer and offered to install their system in an effort to cut down the farm’s propane costs. Funding from California Energy Commission helped finance the project, which totaled around $50,000 not including labor. In October 2022, a 91-square-meter array mounted on the roof of the barn began pre-heating water for milking equipment sterilization. The system preheats 1,000 gallons of well water from 70 to 180 degrees Fahrenheit each day and collects it for use at any time in a hot water storage tank. It integrates seamlessly into the existing propane-fueled heating system, which now acts as a backup system to heat the water on cloudy days when the solar system can’t fully handle the demand. The system’s cost per kilowatt is almost half of what the farmer currently pays for propane, and it has reduced on-farm consumption for water heating by 70%. 

Close-up of the concentrated solar system on the barn roof. 

As farmers continue to search for ways to lower their operating costs and decrease their reliance on fossil fuels, WCO’s robust and uncomplicated system is an attractive solution showing great promise. The team emphasizes the adaptability of the system, as the modular collectors can easily be scaled up or down to meet the needs of a wide variety of processes. The modules are able to be installed on both flat and angled surfaces, making them easy to place on almost any rooftop and avoid taking up valuable ground space. The installation time is also impressively quick. The team first recommends conducting a thermal energy audit to ensure the building is properly insulated, followed by a period of time tracking the energy needs of the building’s current system. Once an understanding of the energy load has been established, the team knows how to size the CSP system properly for the process’s demands. Then, it may take as little as a few weeks to install the new system. Looking forward, the WCO team is excited to continue their work in the dairy space and hopes to expand their portfolio of sites across a variety of farms both big and small.  

Photos courtesy of: Winston Cone Optics 

Solar Shepherd in Massachusetts: Solar Grazing 

By Allen Puckett, NCAT Technical Writer 

July 2023 

The Solar Shepherd provides grazing services in Brookfield, Massachusetts, with 75 sheep that graze a solar array site owned by SWEB Development, a European clean energy firm. This beneficial partnership was born when SWEB reached out to Solar Shepherd for grazing services after seeing their solar-grazing sites on social media. Learn more about the partnership in the AgriSolar Clearinghouse’s video How a Shepherd and Solar Developer are Joining Forces to Grow Sheep, Clean Energy. 

Solar Shepherd’s founder and owner Dan Finnegan is a third- generation sheep farmer in eastern Massachusetts. His history working in a corporate environment led him to think more about what was important to him—the land, local farming, and clean energy. While he likes raising sheep, there wasn’t enough acreage for it to be profitable without agrisolar sites. 

“It wouldn’t be enough to produce a living for a family,” he said. “This is more than a hobby-farming operation. With solar grazing, we dramatically expand our flock. We work hard to be competitive with landscapers on these sites. The grazing fees mitigate the costs and pay down the investment to take the show on the road (transporting sheep to solar sites). We’re used to farming out the back door, and now we have sites spread hundreds of miles apart. The grazing fees make that cost affordable.”  

“I saw a solar array built on a lambing pasture, and a landscaper showed up with a tractor and started mowing up the solar arrays. He was going about 30 mph with a batwing sprayer and was mowing the rows and hosing down the panels around the arrays. I was thinking, they should just put the sheep down there and let them graze,” Dan recalled. 

Solar Grazing Site Specifications and Management  

The site is in a 15-acre array that produces 5 MW of DC and 3.375 MW of AC, enough to power approximately 1,100 homes. A landowner leases the land to SWEB, and SWEB hires Dan to graze the solar arrays with the sheep. The pricing is relatively the same as traditional mowing and gas-powered landscapers, but grazing sheep comes with many environmental benefits, such as enhanced landscape stabilization that directly benefits the solar companies. This stabilization includes deeper root systems on previously rocky terrain, improved turf health, and significant runoff reduction. 

Solar Shepherd practices rotational grazing on their sites, which allows more carbon in the soil and retains more moisture. “We see that impact very rapidly. There are some sites we had that, in just one year, the customer came to us and said, ‘I can’t believe the impact the sheep had on the vegetation sustainability. It was rocky before, and now there are deeper root systems, stabilized soil.’ Erosion is a big concern at the base of the panels. A direct benefit to the solar companies is stabilizing that ground,” Dan added. 

There’s also the “Fuzz and Buzz” – a solar seed blend used at the Brookfield site that benefits pollinators and sheep. It’s not as robust of a floral bloom, but the bees and sheep benefit greatly from this blend. A gas-powered mower removes all the vegetation on an array in a single day. The sheep take around a month to “mow” the same array. This allows valuable pollinator habitat to be left for the bees and birds. There’s good seed-to-solar contact, and the imprints from the sheep hooves allow the seeds to be captured in the soil. The sheep help the effectiveness of reseeding a site and some graziers will run the sheep back over the seeds to help stomp them down into the earth. 

Solar grazing includes running three main operations: a sheep farm, a trucking company (as you move the animals), and a commercial landscaping business. “It’s more than just opening the gate, throwing the sheep in there, and driving away. There are always some sites that require things outside the lines,” said Dan.  

Dan’s partner, border collie Reggie, has been vitally important in effectively managing the sheep on solar sites. In the trucking operation, sheep are loaded in and out of trucks over and over, and that requires collecting them from one site to another to be loaded into the trucks.  

Reggie is immensely valuable in this process. She rounds up the sheep quickly, whereas it would take multiple human workers significantly more time. She is vital to effective time management (and cost, if you consider paying multiple workers to round up sheep all the time). Reggie moves the sheep around the array in accordance with rotational grazing practices. 

Grant Incentives in Massachusetts 

Massachusetts does have a grant program for dual use of solar (Massachusetts SMART Initiative), but it is “written in such a fashion that it can be difficult to be profitable,” said Dan. The grant does not apply to sites that already exist, and it requires panels to be built 10 feet off the ground. Solar Shepherd has not received this grant and has also not yet grazed an array that fits the 10-foot grant requirement.  

Livestock production is diminishing in Massachusetts and what’s left is small-scale vegetable farming. Dan speculates that the state is writing laws for solar development incentives with this in mind instead of grazing sheep under solar panels. 

Community Response 

“The community loves what we’re up to,” said Dan. “We had about 500 comments (on the recent video featured on CBS) and all of them were loving what we are doing. There are a few political comments. So, grazing sheep on solar might bring some unification from a political perspective.”  

He also added that, “At least half the time I show up, there is a family there outside the gate at the fence watching the sheep. People are wanting to bring kids out to the sites to see the sheep. I’d like to do a program where people can come see them. We would love to host a solar event. We’re going to bring some sheep to town off the hill in Brookfield so people can see them and interact with them. I have a dream of bringing a bus load of kids out here to see how bees, sheep, and everything all come together.” 

Since the Brookfield location is an ancient hay site where indigenous peoples managed the land when colonists first arrived, not damaging the vegetation or compacting the soil during the solar array installation was very important. This priority to minimize damage to the land could have a positive impact on community support for a solar site, particularly on ancient farmland or similarly valued sites. Communities like to see that a (solar) development company cares about the land and the process of development. 

Considerations for New Sheep Graziers 

New sheep graziers or those thinking about getting into sheep grazing on solar sites should consider a couple of things throughout the process. Educating themselves on what’s happening on the solar array is very important. “They don’t have to be engineers,” says Dan, “but they should understand what’s happening and what the potential dangers are and keep themselves and animals away from those areas. Stay out of areas where you might think ‘I should have an electrician in there.’ These are areas that contain things like cable trays and equipment pads.”  

Don’t move forward with grazing a solar site if you haven’t walked the location and examined it for suitable conditions for your sheep. If construction techniques did not leave a space where you would feel comfortable leaving the sheep, such as poor wire management or dangerous or sharp edges on array components, it may be a good decision to decline grazing in that location.  Dan says the sites he turns down are for animal welfare reasons. There might not be enough nutrition on the site, but it is usually wiring management. A good perimeter fence can also make a site more ideal for sheep.  

Operating a grazing operation on your own property requires having a plan for food and water delivery, as well as for avoiding predation. A plan should be in place for responding to issues that may arise on the site and with little notice. Solar Shepherd has a 24-7 hotline for such issues. 

For fencing, Dan prefers to use electric netting, which provides effective  protection from predators. Coyotes prefer to go under the fence rather than over it, and considering such nuances in predator-prevention strategies can help design a fencing system that is most effective for your area and your circumstances. Hiring people who think from the sheep’s perspective is important, says Dan. Fortunately, he has not had any issues with predation to his sheep.  

The Future of Solar Shepherd and Solar Grazing 

The future of Solar Shepherd is looking bright. It originally took the company approximately one year to get hooves on the ground at a solar site. Now it only takes about a week or two. “I feel great about the solar grazing future and Solar Shepherd. The sales pitches are getting shorter and shorter. The world is becoming aware of this subject. Five years ago, it was, ‘You’re doing what?!’ The last pitch I gave was an hour-long presentation. I got 15 minutes into the meeting, and people said, ‘It’s great; we are ready to sign.’” 

Maces Pond: Agrisolar Wild Blueberries

By Chris Lent, NCAT Agriculture Specialist

Not far from the town of Rockport, Maine, Paul Sweetland of Sweetland Farms, LLC has been tending wild blueberries since he was a young boy. On one field that he has been farming since the late 1990s, there is more than blueberries being produced. Solar panels have been installed over about 11 acres of wild blueberry plants in the first project in Maine to collocate solar electric production with wild blueberry cultivation. The project was developed by BlueWave, a Boston-based solar development company, and installed by CS Energy in the spring and summer of 2021.  

When the owner of this land, David Dicky, started receiving solicitations from solar companies to lease his land for solar development, he was interested. However, he didn’t want to see acres of wild blueberries destroyed in the process of constructing a solar array. After consulting with several solar developers, he began working with BlueWave because of their experience and openness to developing dual land use solar installations. Dual-use solar, also called agrisolar or agrivoltaics, pairs agricultural production and solar electric production on the same land. BlueWave, with input from Mr. Sweetland and Dr. Lily Calderwood, a horticulturalist at the University of Maine, developed a solar site plan that would protect the berry plants and research the impacts of the solar installation on wild blueberry production. After a nearly two-year permitting process, Bluewave and CS Energy began installation in early 2021, aiming to have the project finished by late spring to allow time over the summer for the blueberry plants to recover. 

Navisun, a Boston-based solar independent power producer, purchased the solar project from Bluewave in early 2021. They worked closely with the installer, the landowner, and Sweetland Farms to ensure that this agrisolar project was financially viable for everyone. Both Navisun and Bluewave have made a commitment to innovation and land stewardship in solar development and have actively pursued agrisolar projects like this one to fulfill that commitment. 

Bluewave funded research by Dr. Calderwood to study the effects of solar construction on the established blueberry plants. To do this, the construction area was divided into three sections. In one section, panels were installed using standard practices and equipment. In the second section, the crew was mindful of reducing passes with heavy equipment, sharp turns, and other practices that can rip and damage the ground and plants. In the third section, they used polyethylene ground-protection mats and were very careful about using the same access paths and minimizing equipment passes through planning and efficiencies. The construction crew went through training on these low impact techniques before construction began.  

Commercially managed low bush or wild blueberries are harvested in July and August and then the farmer either burns off or mows the plants in the fall. The following year, the plants are in a vegetative cycle building new growth. It isn’t until the following year that the plants enter a cropping cycle, the berries are harvested, and the cycles start over again. Construction on this project took longer than planned, leaving a shorter time for the plants to recover in the first year. Despite this, the blueberries in all three sections rebounded, with the section containing the most protected plants rebounding more quickly and with better vegetative growth in the first year. The plants produced almost no berries in the harvest year of 2022. Dr. Calderwood attributes this to the short time the plants had to recover in the year of construction and the shade from the solar panels. More will be known about how well the berries will produce under the panels as the study continues through the 2024 harvest . 

The solar array covers nearly 11 acres of land plus an access road and is sized to produce 4.7 megawatts of DC power. To date, power production from the system is higher than was estimated. The system consists of a combination of one-sided (monofacial) and two-sided (bifacial) panels on a fixed-tilt racking system. The height and row spacing of the panels follow conventional solar development design, with the upper height at about 8 feet and the space between the rows of panels also about 8 feet. To accommodate for deep snow in the winter, the height of the drip edge, which is the distance from the front edge of the lower panels to the ground, was increased from a typical 30 inches to 5 feet. This additional height slightly increased the cost of the system but is standard procedure for Navisun on projects located in high snow areas and had the benefit of creating some extra height for working the blueberry crop under the panels. Navisun indicated that the installation costs were slightly above market cost for this size system. 

Through Maine’s Net Energy Billing Program, the local power company allows Navison to create energy credits based on the solar energy generated at the site. Navison then offers and sells those credits to small commercial customers in the area. Navisun pays the landowner a lease payment for the acreage the solar array occupies and subleases the land under the panels to Mr. Sweetland, agreeing to pay him a stipend as the caretaker of those grounds for at least the first five years the system is operating. This stipend can help offset any losses to Sweetland Farms if there is a reduction in blueberry production under the panels and isn’t an extra expense for Navisun, as they would need to arrange and pay for grounds maintenance in any solar development. Sweetland Farms also has an agreement to pay the landowner a percentage of the gross income from the cultivation and harvest of wild blueberries on the site. This creative arrangement of leases, subleases, and payments is a way to ensure everyone involved is treated fairly and is happy with the financial aspects of the project. 

One challenge in dual-use agrisolar projects like Maces Pond is finding the balance between energy production of the panels and crop production under the panels. The partners involved in developing this project knew that energy production would be a focus but also wanted to protect and track the production of wild blueberries under the panels. The data collected from this research and lessons learned could inform future projects and open the door for other wild blueberry landowners in Maine to diversify their income from their property.  

Because the panel height and width between the rows of the array were not designed to allow for traditional farming equipment adjustments have been made to help work the blueberries under the panels. For example, an ATV is now used for any spray applications and a walk behind harvester will be used under the panels instead of tractor-pulled harvest equipment. Mr. Sweetland and others working under the panels learned to always wear a hard hat to avoid the risk of hitting their heads on the solar racking.  

Trialing different levels of care for the protection of the ground and berry plants during installation has shown that with the right methods the natural state of a site can be protected during the construction phase. With some planning and simple techniques, damage to a site’s ecology can be minimized. 75% of the wild blueberry plant is below ground in the root system so the tops can be damaged without killing the plant. All the berry plants rebounded after the construction phase, but those that were protected the most did the best. 

There is some concern among communities in Maine that solar development will destroy wild blueberry fields which can take 10 or more years to establish. When the landowner in this project decided to move forward with a solar development project on his land, he visited his neighbors to talk to them and they all have been supportive of the project. Mr. Sweetland believes that support was bolstered by proactively approaching the neighbors and by the agrisolar nature of the project, which allowed for the preservation and continued production of blueberries under and around the solar panels. 

Dr. Calderwood will continue to collect data on shade levels, soil temperatures, plant density, insect and weed pressures, blueberry bud and fruit counts, crop yield, berry size, and more through 2024. That research is funded through a Northeast SARE Novel Approach grant and more information on Dr. Calderwood’s research on this project can be found at the University of Maine Cooperative Extension: Wild Blueberry page.

Case Study: Boulder Housing Partners Triangle Solar Array

Written for the AgriSolar Clearinghouse by Allison Jackson, Colorado Agrivoltaic Learning Center

The Boulder Housing Partners Triangle Solar Array is one of the first solar arrays in the Boulder, Colorado, area that is solely dedicated to offsetting energy use for low-income residents. The array is a south-facing fixed array with the leading edge of the solar panels about two feet off the ground. Construction was completed in 2021, and the array will generate over 19 GWh of solar energy in the next 10 years.

This solar array was built on 3.8 acres of degraded, rocky soils with prairie dog burrows and overgrown weeds. It was not an ideal spot for agrivoltaics (co-location of photovoltaics and agricultural activities), but that is what makes the possibility of rehabilitating solar land so appealing. Byron Kominek, owner of Jack’s Solar Garden and executive director of Colorado Agrivoltaic Learning Center, and Duncan Gilchrist of The Nature Conservancy had ideas about repurposing the land around these panels. “If we can demonstrate the ability to grow vegetation in a south-facing fixed solar array built on some of the worst terrain you can imagine for agricultural activities, then we will know that agrivoltaics can work within any solar array site,” stated Byron Kominek. According to Duncan Gilchrist, “The Nature Conservancy’s interest in this project is to demonstrate a replicable model for agroecological land restoration within solar arrays that weren’t originally designed for agrivoltaics.”

Area that has not been altered. Photo: Colorado Agrivoltaic Learning Center

Area of the solar array with swales and perennial plantings. Photo: Colorado Agrivoltaic Learning Center

With no water source at this site, integrating agriculture into the semi-arid climate of Colorado is extremely difficult. So, in conjunction with the Drylands Agroecology Research, the landscape was altered utilizing permaculture ideas of slowing, spreading, and sinking rainfall to aid in water retention. A series of basins were dug and amended with compost at the leading edge of the solar panels to capture moist running off of the solar panels to sink the water deep within the soil’s profile. Having planted hundreds of hardy, drought-tolerant perennials, these basins will hopefully provide a repository of soil moisture for these plants during the driest months of the year. Utilizing the shade from the solar panels will also help slow evaporation from the soil and maintain a more even soil moisture.  

The land was terraformed in November of 2022 with a mini-excavator and shovels. Perennial herbs were purchased and planted within the basins at the leading edge of the solar panels in April 2023. Irrigation was provided only at the time of planting for the perennials to get established. Herbs that were planted include fennel, lavender, lemon balm, oregano, rhubarb, thyme, and wild licorice. These plants will be monitored by researchers from the Dryland Agroecology Research group to assess their survivability and vigorousness.  

Terraforming the land in November of 2022 with a mini-excavator. Photo: Duncan Gilchrist, The Nature Conservancy

One benefit of having people within solar arrays stewarding the land is that they can catch system problems before the solar array asset owner does. Be it damaged panels, unsecured wires, or inverter errors, these issues can be easily monitored and relayed to the asset owner. In the long run, this can save asset owners money in operations and maintenance costs and potentially reduce the chances of lost revenues. During an initial site assessment for the viability of this agrivoltaics research project, consultants noted that the system’s inverters were offline followed by a discovery that the entire system was. The solar array asset owner was rapidly notified to alert their O&M team only to find out that the O&M company no longer serviced this site. The team also noticed that a small tree had grown up between two panels, shading their solar cells. These findings by the assessment team helped the solar array asset owner get their system back online, helped avoid future lost revenues, and kept their system running effectively. 

With the wet spring and summer this year in Colorado, the perennials are growing and thriving. Hopefully, this project can be a model for retrofitting solar arrays and incorporating agriculture under the microclimates that solar panels provide. 

Planting perennial herbs within the basins. Photo: Duncan Gilchrist, The Nature Conservancy  

Bronze fennel plant thriving in the solar array. Photo: Colorado Agrivoltaic Learning Center

Reducing Post-Harvest Losses Through the Use of Innovative Solar-Powered Refrigeration Systems 

Written for the AgriSolar Clearinghouse by Ridge to Reefs staff Emma Verlinden, Paul Sturm, and Phal Mantha

In 2017, the devastation following Hurricane Maria was catastrophic for countless coastal communities. The archipelago of Puerto Rico experienced mass power loss and severe food-supply shortages, leaving many rural communities without power for extended periods of time (in some cases for as long as 6 to 12 months). Agricultural lands became unusable, with crop fields devastated by high winds, extreme rainfall, and incessant flooding. Following the catastrophe, the only seed producer in the archipelago lost nearly their entire supply due to a lack of refrigeration caused by the extended power outage. Meanwhile, shelves were empty at stores due to nearly 90% of Puerto Rico’s food being imported and food spoiling during the power outage.

In response to this challenge, Ridge to Reefs designed a Mobile Solar Walk-In Refrigeration System to help farms reduce post-harvest losses and bring high-quality produce and refrigerated farm goods to market. Additionally, Ridge to Reefs led and assisted in the construction of numerous stationary iterations of this design at various locations throughout Puerto Rico. The mobile system design is constructed around a 6’x14’ single-axle enclosed trailer, with six (280-watt) photovoltaic panels mounted on the rooftop. CoolBot technology is paired with a 10,000 BTU window air-conditioning unit, 2,000-watt Pure Sine Wave inverter, 210 amp-hours of batteries, and a charge controller to maintain temperatures between 40and 55°F per the farmers’ needs. The panels atop the trailer provide 1.68kW of power with ample battery storage, reducing the risk of crop loss in the event of a major power outage. The trailer is fully insulated (to above R-20) throughout the walls, roof, and floor, allowing for heat resistance in even tropical climates. In all, approximately 275 cubic feet of storage is available inside the unit to allow farmers to efficiently store and transport their agricultural goods. Because the power systems are grid-tied in Puerto Rico, and with such high risk of natural disaster occurrences, Ridge to Reefs designed this highly agile system to be grid-independent, using commercial, off-the-shelf technologies as dictated by community need.

Design diagram of the solar-powered refrigerated trailer system.
Aerial view diagram of the solar-powered refrigerated trailer system.

The construction and deployment of a mobile refrigeration system presents a viable solution for producers to more efficiently transport and store their goods throughout tropical regions, especially those that are susceptible to natural disasters. The entire system was constructed for approximately $10,000 USD, but potential grant and funding opportunities for farmers seeking to transition to solar operations could allow technology of this sort to become more available. Additionally, this option may allow island communities to cultivate greater market portions of locally sourced foods by increasing the sales reach of small-scale agricultural operations. Many producers do not have access to refrigerated shipping methods, and having on-site cold storage and transport for their goods can prove very economically stimulating.

Costs of electricity in island regions such as Puerto Rico and Hawai’i are on average four times higher than in mainland communities, which can prove detrimental to the capabilities of local farms in these regions. By providing farmers with the capacity to store and distribute their produce independently, they are able to reinvest the saved costs and increased profits into their own operations and increase overall productivity. In this way, the solar-powered refrigeration systems also promote local circular economies.

Completed construction of the mobile solar-powered refrigeration prototype that was donated by Ridge to Reefs. 

The deployment of the mobile solar cold-storage system also taught our team and partners numerous valuable lessons. First, in mountainous regions, maneuvering a towed trailer system can be less than ideal and a task not every driver is comfortable with. It may be worth exploring integrating this sort of system into a “Sprinter” van or similar large van. Furthermore, the utilization of lithium iron phosphate or even lithium ion battery banks may offer significant advantages and may prove to be feasible improvements. With our system, an increase in battery bank capacity would have significantly improved standalone time and a battery bank capacity of closer to 300 or 350 amp-hours would have provided three to four days of standalone time. Additionally, with improvements in solar panel technology, many higher-output panels are available with the same dimensions. For example, 330-watt panels could be used for the next generation, allowing for higher power output. The Ridge to Reefs Team plans on first upgrading the existing mobile trailer with these improvements and is also seeking opportunities to construct and deploy similar systems in the future. 

The implications of solar integration into agricultural operations are vastly important, especially considering the global call for an increase in the utilization of renewable energy sources. While this system is a small-scale mobile refrigeration unit, Ridge to Reefs has also constructed numerous other stationary solar refrigeration systems throughout Puerto Rico to ensure the security of crops for farmers during times of distress. Systems such as these could create opportunities for producers in other tropical regions such as Hawai’i by allowing them to reduce crop wastage, reach new markets, recirculate money in their community, and address concerns  related to sustainability, food security, and developing local economies.

Photos courtesy of Ridge to Reefs

Case Study: Cozy Cove Farm

By Anna Adair, NCAT Energy Program Assistant

Just outside of Gurley, Alabama, a herd of grazing llamas and alpacas find refuge from the sun underneath a solar array. Tony and Cozette O’Neil, owners of Cozy Cove Farm, have been raising the animals since 1995, shearing their fleece to make yarn and felt. Today, the O’Neils are also proud renewable energy producers for their community, thanks to the 50-kW solar system that has been generating electricity since February 2013.

A retired NASA engineer, Tony has believed in the power of solar technology since his work on the solar-powered space station Skylab in the 1970s. In 2012, with an electric bill sometimes reaching $500 a month, he learned that he could generate and sell renewable energy to the Tennessee Valley Authority (TVA). The cost of solar equipment was decreasing around this time as well, making it the ideal time to install solar on their 54-acre farm. Working with Outpost Solar, the O’Neils planned a photovoltaic system consisting of 208 fixed-tilt panels in a 100-by-100-foot area, tucked away on a corner of their pastureland next to the Flint River. Because the array was built on a floodplain, the panels had to be elevated to seven feet above ground level. The unexpected change to the design had an upside: shade for more than 100 llamas and alpacas that call Cozy Cove Farm home.

The O’Neils took advantage of several incentives to build their solar array, which totaled $160,000 upon completion. The majority of the cost was covered by a 30% federal tax credit and a 25% USDA REAP grant. Smaller grants from state and local programs brought the out-of-pocket cost to just under $48,000. Alabama Farm Credit provided the O’Neils with a loan for the remaining amount, which they were able to pay back completely in October of 2017. In just under five years, the array paid for itself thanks to a 10-year contract with the TVA that paid them 22 cents per kWh of electricity generated.

Today, 10 years after the solar system’s completion, the O’Neils continue to benefit from its installation. Service and repair costs have been low, with only one panel needing replacement from damage in the first year. At the end of their initial contract, the O’Neils signed a subsequent contract for an additional 10 years that allows the TVA to purchase the electricity they produce at the same rate their utility charges them for their energy consumption. “This provides us with approximately $3,500 a year after all of our farm energy needs are paid for,” says Tony. He also encourages other farmers considering installing solar on their property to think long-term. “Electricity cost is only going to increase in the future, and the cost of solar panels and inverters are at an all-time low at present.” While many agrisolar projects are still in the first few years of operation, Cozy Cove Farm stands as a shining example for how agrivoltaic installations can benefit their owners for over a decade.

Photo credit: Scott Sklar, George Washington University

Case Study: Mustang Two Solar Facility

Indart sheep between rows of solar panels.

By Anna Adair, NCAT Energy Program Assistant

Just outside of Stratford, California, hundreds of sheep spend their days grazing between rows of solar panels at the Mustang Two solar park. The site, owned by Idemitsu Renewables, sits on 1,160 acres and produces enough clean energy to power over 50,000 homes. The 150-megawatt facility was constructed in 2020, with the sheep taking up residence shortly after. Courtesy of Indart Solar Sheep Grazing, the herd helps maintain the vegetation growing around the solar panels while also working to improve the biodiversity of the plants on site.

Indart Solar Sheep Grazing owner Ryan Indart had grazed several sites prior to adding Mustang Two to the list, building positive relationships within the solar community along the way. When a friend at SOLV Energy, the operators of the site, informed him that the conditional use permit required grazing, Ryan jumped at the opportunity. Mustang Two was the first site Ryan had to compete for, but he successfully won the bid to be the grazier on site. In 2021, he unloaded his sheep onto what was, at the time, the largest site in his portfolio.

Two years later, the Indart sheep continue to do their part in maintaining a safe, well-managed solar site. Despite not being the easiest location to graze, Ryan and his sheep have received great feedback from both SOLV and Idemitsu. The facility has a dense foxtail barley population, and the sheep can be selective about when they choose to eat the plant. Although the foxtail may not be ideal, grazing has many environmental benefits when done under the watchful eye of a knowledgeable rancher. Over time, Ryan’s sheep will help diversify the plant life and improve the soil quality at Mustang Two, as well.

Photo by NCAT

Case Study: Slate Solar PV Park

Indart sheep grazing around solar panels.

By Anna Adair, NCAT Energy Program Assistant

Located in Kings County, the Slate Solar PV Park produces power for hundreds of thousands of California citizens, while simultaneously providing food and shade for its resident sheep herd. The 390-megawatt site, owned by MN8 Solar and operated by Canadian Solar, rests on 2,120 acres and consists of almost 951,000 bifacial solar panels. Rather than relying solely on mowing, the operators count on Ryan Indart and his company Indart Solar Sheep Grazing to provide anywhere from 1,150 to 2,000 sheep to keep most of the site’s vegetation under control.

Ryan credits his solid relationships with his clients for the opportunity to graze at the site. The Slate facility is adjacent to another PV park, known as Mustang 2, where Ryan’s sheep were already grazing during Slate’s construction phase. He reached out to his contacts at Mustang 2 to see if anyone had connections at Canadian Solar and was given the number of the asset manager for Slate. One phone call and a positive reputation amongst the solar operators in his area later, Ryan signed a three-year contract to graze his sheep as part of Slate’s vegetation management plan.

Today, Ryan says he believes both Canadian Solar and MN8 Solar are happy with the partnership. Grazing animals can help lower the operations and management costs at a solar site, which is a high priority for the businesses involved. Although Slate does mow some sections of the facility as needed, the Indart sheep significantly reduce the area that needs mowing, all while finding respite from the hot California sun underneath the panels.

Photo by NCAT

Case Study: Indart Solar Sheep Grazing

Indart sheep between rows of solar panels.

By Anna Adair, NCAT Energy Program Assistant

As the average age of the American farmer continues to rise, the question of how to transition an agricultural operation to the next generation is a concern for current farmers. Can agrisolar offer a solution to help keep multi-generational farms and ranching operations profitable and in family hands? For Ryan Indart and his family in Clovis, California, solar grazing has given them the opportunity to not only keep their sheep operation up and running, but also to expand the business to include multiple partners and grazing sites across state lines.

The Indarts have been ranching and farming in California for generations. Ryan’s grandfather first introduced the family to ranching when he purchased 1,000 sheep in 1937, later selling the wool to the U.S. government to clothe American soldiers in World War II. His parents bought the operation in 1970 and ran the business for nearly 40 years before it was his turn to carry on the family legacy. However, his parents didn’t simply hand over the operation, and Ryan worked tirelessly to reach his goal of taking over the business.

Although he had moved away from his family land after college, Ryan always loved the sheep and wanted to return to raising them eventually. He knew he needed to earn enough money to either purchase his family’s operation or start one of his own. After earning his MBA from Notre Dame in 2002, he worked in commercial real estate for several years before he and his wife Beatriz moved back to Frenso County and purchased all aspects of the family business, from equipment to the sheep themselves.

The early years were far from stress-free, however. Like many farming families in America today, the Indarts struggled to turn a profit year after year. In addition to raising sheep for wool and lamb, they did tractor work and dry farmed a variety of crops, but none of their hard work reliably produced a consistent profit. Rising wages and the increased cost of living in California led them to seriously consider moving out of the area Ryan’s family has called home for generations. Thankfully, a single phone call set the family on a new course and opened the door for the creation of Indart Solar Sheep Grazing.

In 2018, Ryan received a call from a solar developer with a 1,600-acre solar facility in western Fresno County. Large solar systems were just beginning to pepper the Central California landscape, and the developer was looking for a local sheep grazier to help manage vegetation at the site. They reached out to the California Wool Growers Association, where Ryan was serving as President, and were directed to the Indarts’ operation. When the developer offered to compensate the family for their grazing services, Ryan thought “This could be a gamechanger.” He signed his first solar grazing contract just a few short months later and spent the rest of 2018 and 2019 expanding Indart Solar Sheep Grazing.

Comparison of land grazed (right) versus not grazed by Indart sheep at the Slate Solar Facility in Kings County, California.

Today, Indart Solar Sheep Grazing includes multiple grazing partners that share the Indarts’ high degree of professionalism, and Ryan takes a lot of pride in setting a value standard for the solar grazing industry. “We run an organized business. Whenever there’s a problem we’re always there to help solve it,” he says. Including partnerships, Indart Solar Sheep Grazing has over 10,000 sheep grazing over 15,000 acres from northern California to Arizona. 

Ryan is a wealth of knowledge but has one particular piece of advice for established farmers considering venturing into solar grazing: get comfortable with being uncomfortable. After his first contract in 2018, he regularly cold called solar companies whose facilities he saw in the area, offering them his services as an experienced grazier. “You’ve got to be willing to challenge your fears. Try something new. Make a phone call,” he says. “The worst thing that can happen is they say no.” He emphasizes that farmers must be willing to try new things and adapt to the current state of agriculture in the United States. “That’s what’s made us successful.”

Ryan Indart discussing solar grazing during the Central California Follow the Sun Tour with the AgriSolar Clearinghouse.

For new farmers trying to break into the agricultural industry, Ryan believes the barriers of entry to solar grazing are fewer than those encountered in traditional farming scenarios. Land access is a common hurdle for first generation farmers, but solar grazing provides immediate access to acres of land, often with quality forage for grazing animals. Contracts with site owners also mean farmers are making money throughout the year, rather than just during lambing season. “You have instant access to revenue,” Ryan says.

Looking to the future, the Indarts plan to continue expanding their business. With just over 3,500 sheep in their personal flock, the family’s goal is to reach about 5,000 animals total. Ryan says they may be more strategic about what clients they take on as well, and subcontract with other sheep graziers who share their business values as they reach the limit of where they can graze themselves. “It’s a huge blessing to be able to stay in business in California,” Ryan says. “But I couldn’t do this without a support system.”

When speaking about his company’s success, Ryan credits his family and team members that have been with him for years. Many of the team members are originally from Peru, and employment with the Indarts’ business has provided them with the opportunity to send their children to school or buy a home for their family. “I’m very grateful I can provide jobs for these guys, and help them better their lives,” Ryan says. “That’s what makes me happy.”

Finally, Ryan states that it’s wonderful to be a part of the renewable energy movement but emphasizes that “We’ve been doing this for generations.” With proper grazing techniques, graziers have helped improve plant diversity and soil health for years before solar grazing entered the scene. Ryan says he’s proud to continue what his grandfather started, and thankful for the chance to create jobs and opportunities for his employees that have become a part of his family.

All photos by NCAT.

Case Study: James River Grazing

Sheep grazing at the Mechanicsville site.

By Anna Adair, NCAT Energy Program Assistant

Located near Richmond, Virginia, the Mechanicsville solar park is one of the state’s first utility-scale solar sites. Covering over 220 acres, the 28-megawatt, single-axis tracking site provides a source of clean power to thousands of homes in the state. More than just a solar site, though, the location is also the home base for hundreds of sheep under the care of Eric Bronson and Sam Perkins at James River Grazing. 

James River Grazing started in 2016 when founder Eric Bronson noticed the solar industry beginning to take off in Virginia. A Virginia native, Bronson attended college at Montana State University and worked for several years on large, range-based livestock operations before returning to his home state. He knew he wanted to stay involved in agriculture, but without already owning land, he realized the upfront costs were prohibitive. Compared to raising cattle or growing crops, the lower initial investment needed to successfully farm sheep gave Bronson the chance to farm in a traditional production environment before the company received its first solar grazing contract in 2019.  

For solar sites without grazing plans, mowing must be brought in for vegetation management, a difficult task for many solar developers in recent years due to labor shortages. “The grazing came along at the perfect time,” Bronson says. He explains that the Mechanicsville site was being mowed about once a month, but with the integration of livestock, it was reduced to a “clean up” mow in the fall and smaller mows in early spring. Even then, “they’re not mowing one hundred percent of the site,” Bronson explains. Only about a quarter of the site is mowed at these times, significantly lowering the time and labor cost required to control the vegetation. 

Sheep grazing under the solar panels.

Operating on the Mechanicsville site didn’t come without its challenges, however. The site hosts between 100 and 300 ewes at a time, depending on the time of year and vegetation growth. While smaller operations will move flocks on and off location seasonally, James River Grazing operates on the site year-round. Not having facilities on-site and the expansive costs to move the sheep off-site is an added layer of difficulty that comes with grazing sheep on utility-scale sites. “Everything has to be portable,” Bronson points out. Nonetheless, James River Grazing’s efforts have been so successful that SunEnergy1, the solar developer for the site, hired Bronson as Director of Livestock for the entire company and has implemented solar grazing on a number of other sites, as well. 

With a total of six grazing sites and around 1,500 sheep, Bronson says James River Grazing is looking to continue its success by creating additional partnerships with developers across the region. While being one of the first to embrace solar grazing comes with some advantages, it also means that learning involved a significant amount of trial and error. “That was one of the biggest roadblocks,” Bronson says, referring to the lack of available resources to help guide them in the early days. Their knowledge and experience also put them in an ideal place to help solar developers create construction plans with solar grazing in mind, making it much easier for grazers to care for the sheep on site. James River Grazing is still working out the details for exactly how they plan on moving into the consulting space, but their track record of success will undoubtedly make them a valuable resource for solar developers and new grazers alike.  

All photos courtesy of James River Grazing.