Tag Archive for: Solar Grazing

By Asaf Maman and Avi Elkayam, Trigo Solar 

Declining precipitation levels and the associated reduction in arable land can negatively impact rural communities and pose a threat to food security. While utility-scale solar projects reduce greenhouse gas emissions, they can also encroach on arable lands and reduce the yield of rainfed crops. Wheat, barley, soy, corn, and other grains are cultivated in rainfed fields that are vital to food security. As precipitation levels decline and desertification spreads, arable land and farms that produce these crops are in peril.   

As solar energy is employed in the conversion from fossil fuels to renewable energy, hundreds of thousands of square miles of land will include solar development. According to the National Renewable Energy Laboratory, there will be roughly 22,000 square miles of solar in the U.S. by 2035i. It is important to understand that the actual land for solar development must be adjacent to grid or to power demand centers. The growing competition between farming, suburban development, and solar development highlights the potential for agrivoltaics.  

Agri-PV is a solution to this issue. It can significantly improve the cultivation of staple foods that substantially affect global food security by cracking the code and untying the water-land knot. By increasing the amount of water available for rainfed crops, we can increase the amount of arable land and avail a portion of it for sustainable solar development. 

In a series of field-controlled winter wheat experiments, Trigo has discovered an almost linear correlation between the amount of water supplied to cultivated area and the quantity of stem biomass and nutritional value. Based on these findings, Trigo designed an east-west solar array formation and solar table structure to both collect and regulate rainwater for redistribution into a cultivated row below. By increasing the rain capture area from both structures, enclosing, and effectively directing the rain, we managed to control the amount of water and increase it, countering the effects of declining precipitation over years.  

North-south solar array over winter wheat. Photo: Trigo Solar 

Design schematic. Source: Trigo Solar 

This design is focused on economic and efficient deployment of solar arrays that improve rain collection and redistribute water to boost crops growth, counter drought effects, and revive agricultural operations.  

Rainwater catchment design schedmatic. Source: Trigo Solar 

Benefits to this design include:  

  1. Maintaining the same yields from smaller cultivated surface area requires more limited farming operations and lower expenses, which can increase farm profitability. 
  1. Capturing more water and channeling it smartly reduces the risk of drought and the associated annual volatility and provides the farm with a drought shield. 
  1. Increased ground wetness, root growth, and wind shield from the solar rows reduces the erosion and carry away of the upper soil layer, which create irreversible damage to farms. 
  1. Preserved land under the Trigo structure can be used for future land reserve and land rotation. 
  1. The steady income from solar power generation can support farm economics and mitigate farming financial risks. 
  1. The availability of cheap, local, green power can further support many of the farm operations expected to undergo electrification in the coming decade. 
  1. The existence of a water-distribution and cheap-power system changes the economics of farming, potentially allowing the cultivation of second seasonal crop during the dry season.  

These benefits have the potential to create more win-win opportunities for effective cooperation between the agricultural and sustainable energy sectors. 

Trigo will continue its experiments to validate the benefits for major U.S. staple crops at U.S. farms to share the knowledge and promote sustainable mass Agri-PV development.  

Win for America’s Farmers: Harvesting Solar Energy 

“America’s solar industry has boomed in recent years, and is slated for a big boost from the Democrats’ recently passed climate bill. Yet solar still only accounts for about 3 percent of electricity flowing into America’s grid—less than one-seventh the share from coal. If we want to phase out fossil fuels and accommodate an electric vehicle revolution, the sun’s contribution has to rise dramatically—and fast. But where to put all the panles?

The best places for solar installations, according to a 2019 study from the University of Utah and Oregon State, tend to be the areas where we already grow our food. That’s because, just like sun-loving tomato plants that fare poorly when the mercury creeps north of 85 °F, photovoltaic (PV) panels lose their efficiency at higher temperatures. But that doesn’t mean we have to starve ourselves to keep lights on and cars humming. By elevating solar panels far enough above the ground so people, plants, and animals can operate underneath, we can “essentially harvest the sun twice,” says University of Arizona researcher Greg Barron-Gafford. Enough sunlight to grow crops gets past the panels, which also act as a shield against extreme heat, drought, and storms.” – Mother Jones  

5 Signs the US Agrisolar Revolution has Begun  

“An upswell of opposition to large-scale solar power plants on farms took shape in the U.S. last spring, partly fueled by conspiracy theories about climate change. Nevertheless, farmland is attractive to solar developers. Now they have a new support system on their side, in the form of agrivoltaics.” – Triplepundit.com  

Solar Energy Corporation of India Issues Tender to Install Agrisolar Pumps 

“New Delhi: The Solar Energy Corporation of India (SECI) on Monday issued a tender for setting up agricultural solar pumps in selected states pan-India under component-B of the PM-KUSUM scheme of the renewable energy ministry.  

‘Individual farmers will be supported to install standalone solar agriculture pumps of capacity up to 7.5 HP for replacement of existing diesel agriculture pumps and irrigation systems in off-grid areas, where grid supply is not available. Installation of new pumps will be permitted under this scheme except in dark zone areas,’ said the SECI tender document.” – Energyworld.com 

UC Davis Study Shows Harvesting Various Light Spectra Benefits Agrisolar  

“Scientists from the University of California, Davis, are investigating how to better harvest the sun — and its optimal light spectrum — to make agrivoltaic systems more efficient in arid agricultural regions like California. 

Their study, published in Earth’s Future, a journal of the American Geophysical Union, found that the red part of the light spectrum is more efficient for growing plants, while the blue part of the spectrum is better used for solar production.” UCDavis.com 

Massachusetts Sees Increase in Agrisolar Incentives 

“A Massachusetts incentive program for projects that blend solar energy and agricultural production shows signs of finally gaining momentum after a slow rollout that has at times frustrated solar developers and farmers alike. 

In 2018, Massachusetts became the first state to offer financial incentives for “dual-use” or “agrivoltaic” solar projects built above active agricultural land. Since the launch, however, just three projects have gotten up and running. Another eight have qualified for the incentive but not yet been built.” – Energynews.com  

This life cycle assessment study investigates the environmental performance of sheep-based agrivoltaic systems and concludes that agrivoltaic systems are superior to conventional ground-mounted PV systems because they have dual purposes and reduce the environmental impacts associated with producing food and electricity.

Written By: Alex Delworth, Clean Energy Policy Associate; Center for Rural Affairs

Just off the campus of Maharishi University in Fairfield Iowa, sits a 1.1-megawatt (MW) solar farm. Beneath the panels, a flock of sheep and their newborn lambs are grazing, while beginning rancher Emily Mauntel and her Australian Shepherd Ziggy stand back and admire their work.

Solar farms pose a considerable opportunity for multipurpose agricultural uses in rural spaces. Iowa has seen a rapid increase in solar project development the past two years. According to the Solar Energy Industries Association, the industry is expected to add another 1,304 MW—a 250% increase over current installed capacity—during the next five years. Depending on the type of technology installed, this could mean between 6,520 and 13,040 acres of land will be used for solar production. With proper local siting, these projects will be required to plant and maintain native vegetation underneath the panels. This increase in open pasture presents a unique opportunity to combine traditional land uses with renewable energy development, such as pollinator habitats or open grazing for livestock. An opportunity Emily has already begun benefiting from.

Originally from Michigan, Emily relocated to Fairfield to attend Maharishi International University. While completing a three-month internship at a goat farm in Oregon as part of the university’s Regenerative Organic Agriculture certificate program, her interest in livestock grew. After the internship, she remained in Oregon for another year, working for various livestock operations and gaining experience in the industry. In late 2021, she moved back to Fairfield to work on the university’s vegetable farm and help her peers in their respective livestock businesses.

Emily Mauntel holding a solar-grazing lamb. Photo: Emily Mauntel

One day she and a friend were driving past a large solar array in Minnesota and noticed how the infrastructure was perfect for sheep grazing. They knew about the array in Fairfield, which is owned by the university and operated by Ideal Energy, a local solar company. She contacted the solar company to pitch the idea first and gained their approval before approaching the university. Both parties were ecstatic because the university had been looking for somebody to graze livestock and Ideal Energy saw an opportunity to avoid spending about $5,000 for annual landscaping, according to the company. Emily said the two parties came to an agreement that she would graze the array, which provided her an opportunity to access pasture in exchange for landscaping the solar farm. With this agreement, Emily benefited by not having lease payments for the time her sheep were on the farm, saving her approximately $360 per month according to Iowa State University’s land lease estimates, or about $2,520 for 2022.

Sheep grazing under solar array. Photo: Emily Mauntel

Once Emily had approval, she and her friend went into business together and purchased a 30-head herd of sheep from an auction in Texas. In May 2022, 29 ewes and one ram were dropped off on the six-acre, 1.1-MW solar farm. Before purchasing the herd, she surveyed the land and determined that, given the amount of growth on the site, she would be able to graze five sheep per acre. That is two more than usual because of how lush the plant life was on the property. The site was planted with a mix of flowering prairie species, including clover, fescue, broad-leaf plantain, and others, which served as a good food source. The sheep were allowed to roam freely throughout the solar array, something Emily said worked well. Overall, she believes rotational grazing would have been more efficient but would have required a larger investment due to the cost of a moveable fence.

Emily with her herd. Photo: Emily Mauntel

What makes this story especially interesting is that the agribusiness model directly addresses two major issues beginning farmers face—access to land and infrastructure. A 2017 survey by the National Young Farmers Coalition found that land access was the number one issue their respondents faced. Young farmers, according to the survey, are also the most inclined to rent, which makes finding land with the right infrastructure more difficult.

The Fairfield solar site’s infrastructure made the land even more attractive to Emily. She said it had sufficient fencing to hold her sheep and keep out predators. Due to the required native vegetation management, it also had plenty of food for the sheep, which means she never had to supplement food for them, except a mineral feed mix for nutrition. A water source to fill up the livestock troughs and an access road straight up to the gate also proved beneficial. Considering all of these factors, Emily was able to cut a lot of costs throughout the process.

Newly energized by the experience she has gained through solar grazers and managing her own livestock, Emily is now looking to return to the West to continue ranching. She and her business partner plan to sell their herd. Emily hopes to see the solar grazing model continue on the site, saying it has been a perfect opportunity for her to gain experience in the industry, and she believes it will be a great opportunity for the next person, as well.

DOE Solar Energy Technologies Office Announces $8 Million in Projects for Agrivoltaics Research 

The U.S. Department of Energy (DOE) Solar Energy Technologies Office announced $8 million in new projects that will research agrivoltaics—agricultural production, such as crop production, livestock grazing, and pollinator habitat underneath solar panels and/or in between rows of solar panels. 

The Foundational Agrivoltaic Research for Megawatt Scale (FARMS) funding program will advance agrivoltaics practices and show how it can provide new economic opportunities to farmers, rural communities, and the solar industry. They explore different ways to implement agrivoltaics that will address concerns from the solar industry and farmers. Currently, less than 2% of solar systems utilize agrivoltaic practices.” – Energy.gov  

AgriSolar Clearinghouse partner Greg-Barren Gafford from The University of Arizona is among the award recipients. Learn more about award recipients, which also include Rutgers and Ohio State University, here.  

USDA Announces Climate Smart Commodity Awards 

USDA Announced 71 climate-smart commodity awards in round 2 of the initiative. Among the awardees is The University of Texas Rio Grande Valley (UT-RGV), with the project “Validating Agrivoltaic Technology with Underserved Agricultural Producers.”  

The AgriSolar Clearinghouse will serve as a technical assistance provider for this project.  This work will include the production of outreach materials, education, and workshops to promote benefits to potential agrivoltaic adopters in the Rio Grande Valley.

JUA Technologies Develops Solar-Powered Dehydrator 

“JUA Technologies, an agriculture technology start-up that manufactures solar-powered crop dehydrators, has received a two-year, $600,000 Phase II Small Business Innovation Research (SBIR) grant from the U.S. Department of Agriculture (USDA) to develop its technology.” – PV Magazine 

Italian Research Shows Benefits of Growing Soybeans Using Agrivoltaics

“Scientists from Università Cattolica del Sacro Cuore in Italy have investigated different shade depth treatments on soybeans grown under an elevated agrivoltaic system in Monticelli d’Ongina, Italy. ‘Our work confirmed that soybean is shade tolerant and can be grown in combination with solar power generation. Considering not only soy but more crops and extensive crops in a large scale agrivoltaics is useful for increasing the sustainability of the agrivoltaic system itself.’ researcher Eleonora Potenza told PV magazine. – PV Magazine

Meta Obtains 720MW of Solar from Silicon Ranch

“Facebook owner Meta Platforms will power additional data center operations around the Southeast with 720 MW of new solar developments in Georgia and Tennessee with Silicon Ranch. Silicon Ranch is partnering with the Walton Electric Membership Corporation and the Tennessee Valley Authority (TVA) to supply power from seven new solar facilities to power Meta’s data centers in the two Southeast states, respectively.” – PV Magazine

Emma W. Kampherbeek, Laura E. Webb, Beth J. Reynolds, Seeta A. Sistla,
Marc R. Horney, Raimon Ripoll-Bosch, Jason P. Dubowsky, Zachary D. McFarlane

A study led by Emma Kampherbeek (Wageningen University & Research, the Netherlands)  highlights multiple benefits of coupling solar energy production to sheep grazing in rangeland systems. This project investigated how sheep use solar arrays as a forage site and the impacts of solar array presence on forage quality in a California Central Coast site with a Mediterranean climate. Sheep with access to solar panels graze more than when they are on nearby native rangeland without an array.  This increased foraging behavior is likely driven by a combination of the protection that the array provides the sheep from weather conditions, which increases grazing time, as well as increased protein content and digestibility of forage with the array footprint.

For this November teatime, we were excited to have Tyler Swanson and Jessica Guarino from the University of Illinois join us to discuss the latest on agrivoltaic regulations (check out their discussion of zoning, for example), solar grazing contracts, the economic considerations around grazing, and best practices from the targeted grazing industry that solar graziers can use for insight when developing contractual agreements. Much of the discussion revolved around issues concerning farmland becoming solar sites and the local conflicts that can create.

We had a very interesting discussion during the Q&A, where graziers dug into issues surrounding scaling up solar grazing, expanding agrivoltaics into crop production, and optimizing land-use for grazing at solar sites.

This Teatime was hosted by Kevin Richardson of the American Solar Grazing Association and Dr. Stacie Peterson of the AgriSolar Clearinghouse.

In November, Sabrina Portner from the University of Minnesota presented on her exciting research into growing 14 different forage and grain crops at three different solar sites. The forages and grain were grown in the context of feeding them to the research farm dairy herd. Sabrina and her team looked at how different shade levels affected each crop’s biomass production, as well as the nutritional value of the crops.

This research addresses an important issue: as land availability pressures increase, especially with the expansion of solar in rural areas, the sustainable intensification of agriculture and the need for combining solar sites with agricultural production become more imperative. Their research works towards both goals of food production and clean energy production while providing flexible economic opportunities to farmers.

This Teatime was hosted by Kevin Richardson of the American Solar Grazing Association and Victorian Smart of the AgriSolar Clearinghouse.

Farmers in France are Beginning to Combine Solar Panels and Crops 

“In the Haute-Saône region, in the northeastern part of the country, an experiment is being conducted by solar-energy company TSE. It is hoping to find out whether solar energy can be generated without hindering large-scale cereal crops. Previous attempts to experiment with agrivoltaics have been through smaller-scale projects. But, keen to see if it can thrive on an industrial level, 5,500 solar panels are being spread over this farm in the commune town of Amance by TSE.”  – Euronews 

Solar Grazing Event Helps Kentucky Students Learn about Agrisolar 

“The event was made possible through a partnership between the Kentucky Sheep and Goat Development Office, LG&E/KU, University of Kentucky, Ohio State University, and solar development company Lightsource bp. Students learned about solar technology, seed mix establishment and meeting nutritional needs in solar grazing. Additionally, the release said students were able to tour the LG&E/KU E.W. Brown Generating Station’s solar array in Mercer County.” – The News Enterprise 

Cornell Researcher Hosts EarthTalks Agrisolar Series 

“Niko Kochendoerfer, a postdoctoral fellow in animal sciences at Cornell University, will deliver the talk ‘Effect of sheep stocking rate on ecosystem parameters in ground-mounted solar arrays’ at 4 p.m. on Monday, Nov. 14. The talk, which is free and open to the public, takes place in 112 Walker Building on the University Park campus and via Zoom.”  – PSU 

Rebecca A. Efroymson, Environmental Scientist, Oak Ridge National Laboratory); and Jonathan M. O. Scurlock, Chief Adviser for Renewable Energy & Climate Change, National Farmers’ Union of England and Wales

Solar photovoltaic (PV) power, the most popular form of renewable energy on farms, is being adopted all over the world. Growers and processors of food worldwide have a long history of using the sun’s energy to produce and dry their crops, and solar PV is adding a modern twist to our relationship with the sun. It is no surprise that some of the best locations on Earth for harnessing solar energy are often ideal places for agriculture and horticulture. However, intelligent design for multi-purpose land use can alleviate real or perceived conflicts between energy and food production. Solar modules can shade crops where light intensity is in excess of crop requirements, reducing water evaporation; they can be mounted on agricultural buildings to power farm business energy needs; and they can export low-carbon electricity to meet wider demands for “green” power and the transition to a “net zero” global economy.

We use the term agrivoltaics broadly to describe any combination of agricultural activity and solar electricity production, but outside the USA, the term usually refers more specifically to the intimate juxtaposition of solar modules and agricultural land use. Examples include PV modules mounted at a height of several meters to allow access to land below by farm machinery or large livestock, where they provide shelter from storms or excessive solar radiation, and the integration of solar PV into greenhouses for crop protection.

We caught up with a range of projects across three continents to report upon their objectives and their future prospects.

Around 30% of British farmers have either rooftop or ground-mounted solar energy. The National Farmers Union (NFU) aspires to the goal that every farmer and grower have the opportunity to become a net exporter of low-carbon energy. The falling capital cost of both solar and battery electricity storage has resulted in a growing pipeline of solar installations across a range of sizes, including large 100-hectare (ha) and 1,000-ha solar farm projects, largely independent of government policy support. The NFU advises farmers that solar PV can be deployed across entire fields, as small, ground-mounted installations around field margins or adjacent to farmyards, on farm buildings, and on domestic rooftops. Developers of solar farms are encouraged by the NFU to follow best practice guidelines for multi-purpose land use, combining energy production, continued agricultural management such as grazing, and creation of wildlife habitat. NFU’s strong preference is for large-scale solar farm development to be located on lower-quality agricultural land, avoiding as much as possible the most productive and versatile soils. Roof-mounted solar systems in Britain continue to offer a sound investment, making between 10% and 25% simple return on capital annually at current electricity prices, depending on how much of the generated power is used on-site. At of the end of 2021, about 70% of the United Kingdom’s 14 gigawatts of solar power generation capacity was located in the agricultural sector.

In the Netherlands, the Symbizon project at Almere, near Amsterdam, has brought together a Swedish energy company with Dutch researchers and a private organic farm to construct a 700-kilowatt solar park with alternating strips of PV modules and rows of crops. Starting in spring 2023, the production of herbs will be investigated, and potatoes, beans, beetroot, broccoli, and grains may be included in this pilot study. Pivoting double-sided (bifacial) solar modules will catch the reflected light from soil and crops.

Nearby in Germany, Goldbeck Solar is an innovator in solar agrivoltaic structures. The company has developed a system of solar PV arches that slide on side rails, allowing farmers to shelter or expose various crops. Typically oriented east to west for maximum solar energy yield, the arches span up to 9 meters, at a height of 2.5 to 3 meters, allowing a degree of control over temperature, humidity, and light. These agrivoltaic modules can also provide shelter for livestock from extreme weather, such as high temperatures and hail. The modules are currently undergoing trials in the four-year Sunbiose project in the Netherlands, which had already succeeded in growing raspberries under the partial shelter of solar PV modules. 

Agrivoltaics are being tested in East Africa, where their shade can reduce heat stress and water loss, and farmer incomes in disadvantaged rural communities may be improved. An experimental facility opened in 2022 in Insinya, Kenya, through partnership with Universities of Sheffield, York and Teesside in the United Kingdom, the Stockholm Environment Institute, World Agroforestry, the Centre for Research in Energy and Energy Conservation, and the African Centre for Technology Studies. Some 180 PV modules, each 345 watts, have been installed about 3 meters above the ground, allowing a variety of crops to be grown under the shade from the strong equatorial sun. Geoffrey Kamadi of The Guardian reports that benefits include improved yields of cabbage, eggplant, and lettuce; a reduction in water loss; and a reduction in high daytime temperatures and UV damage.

Small-scale agrivoltaic development (less than 0.1 ha) has progressed rapidly in Japan, producing 0.8% of the total solar power generated in the country in 2019. Japan has perhaps the greatest number of agrivoltaic farms to date, with more than 120 plant species being cultivated on agrivoltaic farms. The Solarsharing Network provides a catalog of 27 agricultural crops (Solar Sharing for FUN | SOLAR SHARING NETWORK| Solar Sharing Association of Japan (solar-sharing.org) and their light needs. Innovative crop systems include tea, according to Makoto Tajima and Tetsunari Lida of the Institute for Sustainable Energy Policies.

One pilot agrivoltaic project in New Zealand is seeking low-growing flowering plants like alyssum to attract bees and reflect light up to rows of bifacial PV modules. The high energy demand of irrigation systems can benefit from on-farm solar energy. In New Zealand, as in the U.S., UK, and Australia, sheep and other small livestock graze under solar modules, avoiding the need for mowing. As New Zealand reporter Delwyn Dickey notes, the success of such large-scale agrivoltaic systems (i.e., solar farms) may be determined by an insistence upon dual land use during the consenting process and the willingness of solar energy development companies to adopt dual land use.

Clearly, from small-scale intimate mingling of solar PV with agricultural production to multi-purpose land use in the largest of solar farms, the merits of harvesting the sun’s energy twice are appreciated the world over. The outlook for agrivoltaics is bright indeed.