Tag Archive for: AgriSolar

By Dr. Stacie Peterson

The interdisciplinary research at Biosphere 2 and Manzo Elementary School in Tucson, Arizona is foundational for agrivoltaics in the United States.  My first introduction to agrivoltaics came from research at these sites, in the article Agrivoltaics Provide Mutual Benefits Across the Food-Energy-Water Nexus in Drylands. The opportunity to tour these sites, meet the researchers, and provide the AgriSolar Clearinghouse network with a way to connect was exciting indeed.

The tour started at the Biosphere 2 site, where Dr. Greg Barron-Gafford and graduate students Kai Lepley, Alyssa Salazar, Nesrine Rouini, and Caleb Ortega described their research, findings, and future projects. Greg provided a background of Biosphere 2, research conducted at the site, its application to agrivoltaics throughout the country, and its correlation to work at the Manzo Agrivoltaic site.    

Kai Lepley and Nesrine Rousini then described their work employing classic plant physiological instruments and novel ground-based remote sensing tools for tracking plant phenology and growth.  Alyssa Salazar described her studies on agrivoltaics impacts to the phenology and growing season patterns of different crops across our growing seasons and how this research can help determine how this approach might extend the growing seasons of certain crops.  Caleb Ortega described his planting approach as well as efficient and creative ways of collecting data.  They then asked the tour to help plant seeds for next years’ agrivoltaic experiments.

After a tour of the Biosphere 2 complex, the group travelled to Manzo Elementary Agrivoltaic site, where Mariah Rogers, Mira Kaibara, Stacy Evans, and Dr. Andrea Gerlak led a lunch-and-learn about the food science, social science, citizen science, student activities, and agrivoltaic food programs.  Mariah’s research involves blind taste tests of agrivoltaic and traditionally grown crops to determine if there are detectable differences in preference.

Dr. Andrea Gerlak, professor of Public Policy at the University of Arizona with extensive experience working on water resource policy and management issues, described her research, and its correlation to work by Alexis Pascaris, and their collaboration on the USDA-NIFA grant for agrivoltaics research (SCAPES project). Alexis is a social scientist whose research involves engaging key stakeholders – including farmers and solar industry professionals – to understand their perspectives about opportunities and barriers to agrivoltaics, which helps inform policy innovation and identify pathways to advance dual-use development responsibly. 

We were lucky enough to be joined by Alexis Pascaris of AgriSolar Consulting, Thomas Hickey of Sandbox Solar, Gema Martinez of BayWa r.e., Brian Naughton of Circle Two and Sandia National Laboratories, Mark Peterson of the Montana Department of Environmental Quality, and AgriSolar Clearinghouse Partner Coordinator, Danielle Miska. In coming months, we will lead tours to Minnesota, Colorado, Oregon, California, Massachusetts, Idaho, New York, and Texas. We hope you’ll join us! 

Stanford University engineers have announced that they have developed a new type of solar cell capable of generating electricity not just during the day but also at night, according to a recent report by National Public Radio.  

The new technology includes a device that incorporates a thermoelectric generator, pulling electricity from “the small difference in temperature between the ambient air and the solar cell itself,” according to the report.  

A recent study published by the journal Applied Physics Letters states that the new solar device serves as “continuous renewable power source for both day- and nighttime, and the approach can provide nighttime standby lighting and power in off-grid and mini-grid applications, where solar-cell installations are gaining popularity.” 

To learn more about the new technology, read the NPR report here

By Lindsay Mouw, Center for Rural Affairs

What’s the latest buzz about solar energy? It’s likely the thousands of honey bees that call solar fields home.

Commonly referred to as “agrisolar beekeeping,” the practice of placing beehives on or near solar fields is a burgeoning industry. While photovoltaic panels are generating energy from the sun, bees are busy at work making honey and pollinating the native and non-invasive plant species below the panels.

This business model creates a multi-stacking of benefits by using the land for multiple purposes simultaneously. When solar panel fields are planted with native and non-invasive plant species, not only is that land generating carbon-free energy, but also providing critical habitat for bees, monarch butterflies, and other insects, birds, and animals. It also creates new economic opportunities for local beekeepers and for the community in the form of energy generation tax payments.

As solar developers become aware of these benefits and strive to demonstrate responsible land stewardship, they are reaching out to beekeepers, such as Dustin Vanasse, CEO of Bare Honey based in Minneapolis, Minnesota, who may be interested in this practice. When a developer reaches out, Dustin says it is best that the two parties draft a contract that outlines expectations and responsibilities in order to establish a sound relationship with no surprises before moving forward with a project.

August 30, 2018 – Minnesota bee keeper, Jim Degiovanni, inspects “BareHoney” hives outside IMS Solar, a pollinator friendly PV array site in St. Joseph, MN. Early in growth, IMS Solar site uses a diverse mix of pollinator-friendly native flowers and grasses, and is co-located with a collection of beehives. (Photo by Dennis Schroeder / NREL)

According to Vanasse, the most common practice is to place hives just outside the fence of the solar field for liability and insurance reasons. Therefore, the beekeeper will need to ensure there is enough right-of-way space for the hives and to maneuver any necessary equipment. The responsibility of managing the pollinator species should be outlined in the contract as well but is typically the responsibility of a vegetation management service contracted with the project developer.

Vanasse also noted that it is helpful to obtain the seed mix of the site and management calendar from the developer to inform handling of the bee colonies. To meet pollinator goals, a vegetation management calendar should accommodate bloom seasons to ensure the bees have access to the diversity of species at the site.

Joel Fassbinder, a solar beekeeper in Decorah, Iowa, and owner of Highlandville Honey Farm, suggests waiting to place hives on agrisolar locations until the second or third year after the groundcover has been seeded to allow time for the seed to take hold and develop bountiful flowers.

“I also register my bees on Field Watch, a tool that communicates between beekeepers and pesticide applicators,” Fassbinder said.

Joel Fassbinder

Solar beekeepers are seeing an increasing opportunity in the market for their solar-grown honey products.

“Anymore, customers want more than just a good tasting product, they also want to support environmental work,” Vanasse said.

However, as the demand for environmentally responsible products has grown, so has the concern of greenwashing tactics employed by companies that make green claims or use misleading marketing and labeling without actually taking meaningful steps to generate a sustainable or environmentally responsible product. Vanasse said transparency in their operations is key. He frequently brings people out to his agrisolar beekeeping sites so they can see the multi-use purposes of the facilities and provides education services about the industry to project developers, county elected officials, schools, and beekeeper groups.

Vanasse noted that the state of Minnesota requires all ground-mounted installations to complete a solar pollinator scorecard  during the planning stage and after the establishment period of three years. This scorecard ensures the quality of pollinator habitat at the site is reported to the Minnesota Board of Water and Soil Resources. The scorecard is part of Minnesota’s Habitat Friendly Solar Program, a result of state policy that requires verification of adhering to the standards set by the Board of Water and Soil Resources.

Planting solar sites with pollinator species is quickly becoming the norm, in part because of policies like those in Minnesota and New York. In 2018, New York passed a bill that established a vegetation standard for ground-mounted solar arrays. Such policies are promoting numerous environmental benefits and new opportunities for beekeepers.

“Consistently our best performing hives are located on the agrisolar pollinator sites,” Vanasse said. “These hives have a more diverse source of pollen as opposed to a monocrop site; the abundance and diversity of plants lead to a more balanced and diverse diet for the bees, making the hives stronger.”

Fassbinder agrees and says “overall agrisolar beekeeping has been a very positive experience.”

Nearby farmers also benefit from the hives through increased pollination of their crops, especially those that are pollinator-dependent, such as berries, apples, squash, and pumpkins. Researchers at Argonne National Laboratory found in a case study that there are 1.1 million hectares of land designated as proposed or potential solar sites in the U.S. The estimated value of pollinator habitats on the hectares of land that are suitable for pollinator habitat is between $1.5 billion and $3.2 billion.

For beekeepers interested in getting into the photovoltaic beekeeping industry, Vanasse and Fassbinder recommend reaching out to Bare Honey or the solar project developer, whose information is usually available on a fence sign surrounding the project.

Vermont Farm Shows Benefits of Grazing Sheep on Solar Farms 

A report by North American Clean Energy reveals the benefits of grazing sheep on solar farms. The sheep are small enough to graze under the panels, which are sometimes hard to reach with maintenance equipment and often damaged by cows. Unlike goats, sheep are unlikely to chew on wiring and more likely to search for vegetation that other animals may not reach. Many solar farms in the nation are utilizing sheep for Agrisolar operations due to the natural behavior of the sheep as well as reducing carbon emissions and operation costs, according to the report.   

New Solar Filters May Enhance Crop Production 

Researchers from North Carolina State University have discovered that a variety of filters in greenhouses may enhance the production of crops such as lettuce, according to a news release by PV Magazine. Researchers used what is known as transcriptomic analysis to assess variations of crops grown in greenhouses equipped with organic solar cells coated with filters that may be adjusted in order to fine-tune characteristics of the crops being grown. In this study, Red Leaf Lettuce was used, according to the news release. 

Illinois Study Aims to Discover Which Crops Pair Well with Solar  

An Illinois project was recently approved for funding by the U.S. Department of Agriculture’s National Institute of Food and Agriculture to study agrivoltaic designs and variations of crop species, according to a report by PV Magazine. The project, Sustainably Collocating Agricultural and Photovoltaic Electricity Systems (SCAPES), will study specialty crops, row crops and foraging crops in three biophysically diverse environments in Arizona, Colorado and Illinois, according to the report.  

Guest blog post by Monarch Joint Venture

Up to 99% of native northern tallgrass prairie in the U.S. has disappeared since European settlement (Samson and Knopf, 1994). This loss of habitat is devastating for pollinators including the iconic monarch butterfly, which depends on native milkweed species and a variety of nectar plants to survive. Given this stark situation, one of the most impactful conservation actions any of us can take is to plant and maintain native habitat, whether it’s a backyard pocket prairie or a large-scale restoration. Many sectors, from agriculture to managed public lands to transportation rights-of-way, are exploring the benefits of pollinator-friendly habitat. Renewable energy is no different; in fact this sector has been a pioneer in the field…the solar field, that is.

In recent years, pollinator-friendly habitat creation on photovoltaic (PV) solar sites has gained momentum across the country, with Minnesota among the earliest adopters. In 2016, Minnesota became the first state to incentivize pollinator-friendly ground cover on its solar energy sites through Minnesota Statute 216B.1642. This development came on the heels of the 2015 National Strategy to Promote the Health of Honey Bees and other Pollinators, which catalyzed new conservation strategies across the nation.

“Minnesotans value conservation and pollinator health, so it’s natural that Minnesota is a leader in this area. You also see this in the preferences expressed by leading electric utilities like Connexus and Xcel,” says Rob Davis of Connexus Energy, which participated in the short documentary, “Pollinators, Prairie, and Power,” last year. “Whether a co-op like Connexus or a private or investor-owned company, energy buyers of all kinds can use the standards published by the state’s leading pollinator experts to express preferences in their renewable energy purchasing. It’s never been easier for energy buyers to ask for high-quality habitat as a ground cover for PV solar—there are numerous developers competing to win these projects.” 

This increasing interest is timely: Between 300,000 and 400,000 acres or land in the U.S. are currently being used for ground-mounted PV solar, and studies predict that 3-5 million acres of large-scale solar will be added to the landscape by 2035. According to the Solar Energy Industries Association, solar accounted for 54% of all new electricity-generating capacity added in the U.S. in the first three quarters of 2021, with projections for growth holding steady. Now is definitely the time to quantify the benefits of habitat-friendly landscaping among solar arrays, and that’s where the Monarch Joint Venture comes in.

During the summer of 2021, MJV partnered with Minnesota-based nonprofit Fresh Energy to monitor pollinator-friendly habitat on Minnesota solar developments. Founded in 1990, Fresh Energy works to shape and drive policy solutions to achieve equitable carbon-neutral economies, including habitat-friendly solar.

“We wanted to begin quantifying the impacts of pollinator-friendly solar on Minnesota’s pollinator populations,” says Michael Noble, executive director at Fresh Energy. “Habitat plantings under solar arrays can add a small amount to the cost of a solar development project, but this study shows that it’s an investment well worth making for the benefit of Minnesota’s critical pollinators.”

Using data collected during the study, MJV and Fresh Energy have released the Monitoring Pollinators on Minnesota Solar Installations report to demonstrate the potential benefits of using pollinator-friendly ground cover with solar arrays in Minnesota—as well as areas that need further research. Fresh Energy will be hosting a deeper dive into the report’s findings in a webinar on May 18th. Learn more and register here.

For the study, MJV National Monitoring Coordinator Laura Lukens surveyed four PV solar installations during June, July, and August 2021 to measure the abundance and species composition of milkweeds and flowering plants, as well as use by monarch butterflies and other pollinators. Survey and sampling protocols were designed in consultation with Argonne National Laboratory, which, in partnership with NREL’s InSPIRE study, has published research on use of native plants as solar array ground cover. The sites were located in Anoka and Ramsey counties, ranged in size from 18-68 acres, and were seeded with a native pollinator mix in either 2017 or 2018. A completed copy of Minnesota’s Habitat Friendly Solar Scorecard was available for each site. This monitoring provides essential information for solar site operators and other stakeholders to create long-term management plans to keep native ground cover thriving, and contributes to a growing amount of evidence that habitat-friendly solar sites can provide significant benefits to pollinators.

“Monitoring this habitat is important for many reasons,” says Laura. “Field surveys allow us to investigate potential impacts of solar array canopies on plant and pollinator communities and provide empirical evidence to back up what we suspect as being benefits of habitat in these spaces. With solar projected to grow by millions of acres in the next 15 years, this presents an exciting opportunity for the renewable energy sector to contribute to national pollinator and habitat conservation goals.” With more and more energy companies adopting habitat-friendly solar, this is good news indeed for pollinator conservation.

While surveying, Laura utilized a variety of monitoring protocols, including the Integrated Monarch Monitoring Program (IMMP), the MJV-administered national program that collects milkweed, flowering plant, and monarch use data from a variety of land-cover types and regions. Utilized by researchers and land managers, the IMMP also is a robust community science program designed for public participation. IMMP community and professional scientists contribute important data that are then utilized by monarch and pollinator conservationists and policymakers. 

In a nutshell, over the course of the monitoring project, Laura observed a high number of flowering plant species and an abundance of bees, butterflies, moths, flies, and wasps flourishing within and adjacent to the solar arrays. “These results indicate that pollinators utilized habitat regardless of solar panel presence,” Laura shares. “And this suggests that solar installations in Minnesota can indeed provide quality breeding and foraging habitat for monarchs and other pollinators.” 

At the same time, the project was limited in scope, and represents preliminary findings. Continued long-term data collection is critical for monitoring the status and trends of pollinator populations, investigating other co-benefits of solar habitat, and to ensure that pollinator-friendly practices achieve and maintain desired outcomes. Management of these sites will also be key to ensuring that habitat quality does not degrade through time.

Other researchers are studying additional co-benefits of habitat-friendly solar. For instance, PV-SMaRT, a collaborative project by the Department of Energy’s National Renewable Energy Laboratory, Great Plains Institute, Fresh Energy, and the University of Minnesota, is studying stormwater infiltration and runoff at PV solar sites across the U.S. Additionally, the U.S. Department of Energy (DOE) Solar Energy Technology Office is funding a four-year study investigating the impacts of co-location of pollinator plantings at large-scale solar installations (>10 MW), led by the University of Illinois, Chicago, in partnership with Argonne National Laboratory, the National Renewable Energy Laboratory, University of Illinois Urbana-Champaign, and Cardno (now Stantec). One of this project’s goals is to create tangible guidance and tools for industry use (e.g. pollinator planting implementation manual, solar site seed selection tool, pollinator solar field assessment tool, and cost-benefit calculator).

In addition to benefits for pollinators and other organisms, native ground cover on PV solar sites can also promote soil health, improve water quality, reduce runoff, and may even boost electrical output, especially on warmer days, by keeping the microclimate near the ground cooler. 

“Overall, habitat on solar arrays by itself will not solve the biodiversity crisis or arrest the decline in the monarch or other species,” Rob Davis adds. “However, solar with pollinator-friendly ground cover is setting a beneficial example for other developments to follow. All these things together with additional actions to conserve previously undisturbed lands and set more acres aside dedicated to conservation, through the USDA’s CRP and other programs, will benefit biodiversity and overall human health.”

In this paper, the researchers applied the InVEST modeling framework to investigate the potential response of four ecosystem services (carbon storage, pollinator supply, sediment retention, and water retention) to native grassland habitat restoration at 30 solar facilities across the Midwest United States.

The AgriSolar Clearinghouse, developed by the National Center for Appropriate Technology (NCAT) is launching a series of hands-on field trips to see firsthand the benefits of co-locating sustainable agriculture and solar energy. The Follow the Sun Tour’s first stop is April 5 at Biosphere 2 in Oracle, Arizona.

“AgriSolar allows us to harvest the sun twice. As America’s appetite for sustainably grown products and renewable energy continues to increase, agrisolar has the potential to provide both resources,” says NCAT Energy Program Director Dr. Stacie Peterson. “The Follow the Sun Tour will visit agrivoltaic sites around the country that are seeing success with things like co-located grazing, habitat rehabilitation, crop production, and cutting-edge research. Our national network of partners includes the world’s leading agrivoltaic experts and we are excited to connect the public with partners like Dr. Greg Barron-Gafford and provide the opportunity to tour his research sites.”  

Join Peterson and leading agrivoltaic researcher Dr. Barron-Gafford on a tour of the agrisolar research underway at Biosphere 2. Biosphere 2 is the world’s largest controlled environment dedicated to understanding the impacts of climate change. Operated by the University of Arizona, the facility includes 3.14 acres, with 7.2 million cubic feet sealed underneath glass domes. Barron-Gafford and his team are investigating the potential for reintroducing vegetation into the typical PV power plant installation in drylands. His research shows that this approach may lead to increased renewable energy production, increased food production, and reduced water use. For interested participants, the tour will continue to the Manzo Elementary School Agrivoltaic site in Tucson.

Space is limited. RSVP is required.

NCAT created the nation’s first AgriSolar Clearinghouse to connect farmers, ranchers, land managers, solar developers, and researchers with trusted, practical information to increase the appropriate co-location of solar and agriculture. It’s funded by the U.S. Department of Energy. The AgriSolar Clearinghouse features a library of more than 400 peer-reviewed articles, a media hub featuring videos, podcasts, and relevant news, and a user forum to directly connect people interested in agrivoltaic development in real-time. Partner organizations include leading universities, the Smithsonian, sustainable agriculture and energy advocates, the Center for Rural Affairs, and the national energy laboratories.

The benefits of co-locating solar with appropriate agricultural land include producing food, conserving ecosystems, creating renewable energy, increasing pollinator habitat, and maximizing farm revenue.

The AgriSolar Clearinghouse’s free Follow the Sun Tour will stop at about a dozen agrivoltaic sites over the next two years. Future field trips will include visits to sites in Colorado, Massachusetts, Minnesota, Oregon, New York and more. Sign up for the AgriSolar Extra to be sure you know about upcoming Follow the Sun Tour stops.

Indiana communities can now voluntarily adopt regulations qualifying them as solar and wind-ready communities, according to a recent news story by PV Magazine. This change is expected to create thousands of jobs in the clean energy industry, cut development times, and lower overall costs. 

Sean Brady, Clean Grid Alliance’s State Policy Manager, told PV Magazine, “We hope that counties in Indiana will use these new standards, but if not, we look forward to continuing to work with stakeholders to explore ways to grow the state’s energy economy.” Indiana is expected to increase its solar capacity to 6.75 GWs in the next five years, according to the story. Roughly 4,657 MW of clean energy is in the advanced stages of development in Indiana, and 1,218 MW under construction, according to the American Clean Power Association. 

To learn more about Indiana’s clean power development and the new law it passed to support renewable development, read the PV Magazine  here.  

Decomposition models of solar irradiance estimate the magnitude of diffuse horizontal irradiance from global horizontal irradiance. These two radiation components are well-known to be essential for the prediction of solar photovoltaic systems performance. In open-field agrivoltaic systems, that is the dual use of land for both agricultural activities and solar power conversion, cultivated crops receive an unequal amount of direct, diffuse and reflected photosynthetically active radiation (PAR) depending on the area they are growing due to the non-homogenously shadings caused by the solar panels installed (above the crops or vertically mounted). It is known that PAR is more efficient for canopy photosynthesis under conditions of diffuse PAR than direct PAR per unit of total PAR. For this reason, it is fundamental to estimate the diffuse PAR component in agrivoltaic systems studies to properly predict the crop yield.

Solar electricity from solar parks in rural areas are cost effective and can be deployed fast therefore play an important role in the energy transition. The optimal design of a solar park is largely affected by income scheme, electricity transport capacity, and land lease costs. Important design parameters for utility-scale solar parks that may affect landscape, biodiversity, and soil quality are ground coverage ratio, size, and tilt of the PV tables. Particularly, low tilt PV at high coverage reduces the amount of sunlight on the ground strongly and leads to deterioration of the soil quality over the typical 25-year lifetime. In contrast, vertical PV or an agri-PV designed fairly high above the ground leads to more and homogeneous ground irradiance; these designs are favored for pastures and croplands. In general, the amount and distribution of ground irradiance and precipitation will strongly affect which crops can grow below and between the PV tables and whether this supports the associated food chain. As agrivoltaics is the direct competition between photosynthesis and photovoltaics. Understanding when, where and how much light reaches the ground is key to relate the agri-PV solar park design to the expected agricultural and electricity yields. We have shown that by increasing the minimum height of the system, decreasing the size of the PV tables and decreasing the coverage ratio, the ground irradiance increases, in particular around the gaps between the tables. The most direct way of increasing the lowest irradiance in a solar park design is to use semi-transparent PV panels, such as the commercially available bifacial glass-glass modules. In conclusion: we have shown that we can achieve similar ground irradiance levels in an east- and west-facing design with 77% ground coverage ratio as is achieved by a south-facing design at 53% coverage.