Tag Archive for: Agrivoltaics

Case Study: A Pollinator-Friendly Solar Site in Minnesota that Manages Stormwater.

By Briana Kerber, Fresh Energy

As we continue to deploy clean energy across the United States, more attention is being paid to how best to develop clean energy projects at the pace and scale that the climate crisis requires, while also ensuring that we are taking care of the sites and communities that host those projects. That’s where a national project from the National Renewable Energy Laboratory (NREL), Great Plains Institute (GPI), Fresh Energy, and the University of Minnesota comes in. Funded by the U.S. Department of Energy’s (DOE) Solar Energy Technology office, the Photovoltaic Stormwater Management Research and Testing (PV-SMaRT) project is using five existing ground-mounted photovoltaic (PV) solar sites across the United States to study stormwater infiltration and runoff at solar farms.

Jake Galzki, researcher at the University of Minnesota, measures water infiltration and runoff at Connexus Energy’s Ramsey Renewable Station site. Photo: Aaron Hanson

Together, the five sites represent a range of slopes, soil types, geographical locations, and PV configurations that will help solar developers and owners, utility companies, communities, and clean energy and climate advocates better understand how best to support solar projects and the host communities in which they are built, in particular lowering the costs of clean energy development while ensuring protection of the host community’s surface and ground waters.

On the banks of the Mississippi

With black-eyed Susan flowers dotting its expanse, the Minnesota site stands out among the five sites in the project. Situated on 18 acres of county-owned land near the Mississippi River in Ramsey, Minnesota, 30 miles northwest of the Minneapolis-St. Paul metro area, Connexus Energy’s Ramsey Renewable Station is flanked by an RV service center to its east, a highway to the north, and a specialty vegetable farm that grows pumpkins and peppers on the project’s west and south sides. Thanks to a partnership with the team at Bare Honey, a Minnesota-based honey producer, the site hosts beehives, too. The 3.4 megawatts of solar panels face south, in a two-in-portrait configuration on a fixed-mount racking system. Throughout the array, the panels are 24-36″ above the ground at the lowest edge.

Blanketed with sandy soil, the Connexus site was seeded with a pollinator-friendly vegetation mix throughout the array and open areas. And the pollinator-friendly aspect was the lynch pin in garnering community support. Pollinator experts and ecologists testified this wouldn’t be just any solar development—it would be a seasonally blooming, low-growing meadow, giving work opportunities to local seeders and apiaries as well as providing ecological benefits to the nearby crops surrounding watershed. Between the sandy soil and the ground cover, when it rains—or even pours—any excess water is channeled into the ground. And that has significant meaning for researchers, solar developers, utilities, and clean energy advocates alike.  

The Minnesota PV-SMaRT site, developed by Engie Distributed Solar for Minnesota’s Connexus Energy. Photo:Aaron Hanson


Designing solar sites for extreme weather

Part of the process of planning out or conducting analyses on clean energy developments like solar farms is to test how well the site will hold up against an extreme weather event, like a flood. Engineers and researchers utilized three different design storms, essentially model storms of various magnitudes, to test Ramsey Renewable Station’s response and evaluate rainfall and soil moisture as well as determine how fast excess water would soak into the ground.

Through these models, the PV-SMaRT research team discovered that, against three design storms—two-year frequency storm, 10-year frequency storm, and 100-year frequency storm, the most intense of the three—all stormwater was channeled into the soil by the deep-rooted vegetation. Using both an InVEST modeling framework and a 2D Hydrus water model, University of Minnesota (UMN) researchers involved in the PV-SMaRT project, including Aaron Hanson and Jake Galzki, led by UMN professor Dr. David Mulla, have been able to keep tabs on the site, monitoring data from moisture sensors and comparing numbers from the site to those of other PV-SMaRT locations.

In fact, the team found that if they wanted to observe a runoff response, they had to actually reverse engineer the site to provoke one. For example, if the team conducted a model of the site in which vegetation suffered due to heavily compacted soil, then they could observe a runoff response. But, in virtually every other scenario, the combination of the diverse, deep-rooted pollinator-friendly vegetation and sandy soil ensures that all excess water soaks directly into the ground. In the research team’s eyes, that made the Connexus Energy Ramsey site a prototype for the rest of the PV-SMaRT project.

Benefits for the site and the study

And Brian believes that those involved in stormwater permitting at solar sites can learn something from the Ramsey example. “As a result of this study, stormwater permitting at sites such as this can be predictable and transparent to both the city or county and the developer,” he says, “reducing soft costs for solar developers while ensuring good water quality outcomes for regulators and habitat co-benefits for local communities.”

Vice President of Renewable Energy at GPI, Brian Ross notes that the site is important because it serves as a sort of bookend for the project: “It is a site that requires only ground cover green infrastructure in almost any circumstances. Comparing this site to our other project sites is incredibly useful. The characteristics at play at Connexus Energy’s Ramsey solar site point toward the potential capacity of a solar farm to mitigate not only the site but also contribute to broader watershed management.”

At Connexus Energy, Rob Davis, communications lead, points out that there was an overwhelmingly positive community response to the pollinator-friendly aspects of the project. “That’s why Connexus requires pollinator-friendly ground cover for all our solar sites, and it was especially important for this project due to the location near the Mississippi River and a specialty crop grower. The site’s soil and ground cover combine to easily handle heavy rainfall events,” he says.

Jake Galzki, researcher at the University of Minnesota, inspects soil and water monitoring equipment at Connexus Energy’s Ramsey Renewable Station site. Photo:Aaron Hanson

Rob notes that when the project was built, it did not have the advantage of accurate hydrological models for PV solar projects, which resulted in a requirement for grading that included carving a two-foot bump diagonally through the project. Thanks to insights from the PV-SMaRT study, Rob is confident that policy changes can be made to avoid grading in the future, as it unnecessarily disturbs the soil and creates an uneven surface for vehicles managing a site. In its place, Rob points to the high-performance vegetation, as it requires less grading and fewer stormwater containment basins and is therefore a much better use of limited maintenance funds.

Insights yet to come

Data and observations from the Connexus Ramsey site serve as a benchmark as the PV-SMaRT research team continues to gather insight about the four other project sites across the country. Overall, the findings from the Ramsey site further validate the project’s recommended best practices in exemplifying how we can lower the soft costs of clean energy development and of ongoing maintenance while protecting the host community’s surface and ground waters, create needed habitat, sequester carbon in the soil, and help craft a truly sustainable clean energy future that will benefit everyone for generations to come. Read more about ongoing validation of this foundational research via Great Plains Institute.

A version of this article was originally published via Fresh Energy. Read it here.

Fostering Social Acceptance of Solar Through Agrivoltaic Solutions

By Alexis Pascaris

What if we shifted our perspective to view Not in My Backyard (NIMBY) syndrome as an occasion for innovation? What if we strategically integrated local community interests into a solar project, rather than grappling to override them? Luckily, embodying these ideals may not be as lofty as it seems.

Combining agriculture and solar energy production in an agrivoltaic system shows promise as a sensible method to reduce siting conflict, generate rural economic opportunity, and ultimately increase social acceptance of solar. The majority of the solar professionals interviewed in a recent study on industry perspectives about agrivoltaics discussed the great potential to leverage these systems strategically to retain local agricultural interests in project development and consequently gain receptivity in a community. Minimizing threat to existing community interests by pursuing a dual-use project provides a distinct advantage over traditional ground-mounted solar projects, which are often challenged on the basis of land conservation and farm preservation values.

But do solar energy deployment and farmland preservation have to be mutually exclusive pursuits? Can the agrivoltaic solution properly reconcile these competing interests in a way that benefits all stakeholders?

Jack’s Solar Garden. Longmont, CO. Photo: Thomas Hickey
Jack’s Solar Garden. Longmont, CO. Photo: Thomas Hickey

Let’s consider for a moment that we are at a delicate yet opportune inflection point in large-scale solar deployment. Previous case studies exemplify how the community relation component of project development has rippling consequences (both positive and negative) on our ability to sustain the build-out rate of solar. Poorly developed projects perpetuate lack of trust in developers, resistance from rural communities and ag-interest groups, as well as restrictive land use policy. Research concerned with New England’s energy transition evaluated the factors that contribute to energy project outcomes, finding that stakeholder relations is instrumental, and that social conflict is a key contributor to project failure. Collaboratively designed projects that generate co-benefits leave a legacy of community pride and positive perception about solar. The Long Island Solar Roadmap Project demonstrates how the solar development process can be enhanced through stakeholder engagement, which includes incorporating community preferences in project siting and design.

Based on precedence, the path of least resistance is clear – to meet our ambitious renewable energy targets, we must develop innovative, inclusive practices to minimize siting conflict and harmonize solar deployment goals with existing community interests. By upholding community values and agricultural interests in a solar project, agrivoltaics provide a means to enhance development practice remarkably well.

You may say I’m a dreamer, but I’m not the only one. Last spring, we surveyed two U.S. counties to investigate whether public support for solar increases when a project incorporates agricultural production. Survey respondents indicated that they would be more likely to support solar development in their community if it combined energy and agriculture. The study further investigated the importance of a range of planning and development factors – land type, distribution of project benefits, and impacts on local interests were determined to be of highest priority to community members when considering their support for a solar project. These findings imply the importance of community engagement in the planning process and suggest that a solar project designed to maintain the agricultural function of land is likely to experience receptivity rather than resistance – a valuable co-benefit of the agrivoltaic approach.

Thinking long-term about our commitments to sustain the deployment rate of solar not only includes optimizing economic and technical efficiency but fostering social acceptance as well. “Social acceptance” can either be our mighty ally, or a formidable opponent to our solar development pursuits. The agrivoltaic solution illuminates a pathway to alleviate siting conflict, generate localized benefits, and contribute to a legacy of solar projects everyone is proud of.

What if all future solar systems served a greater purpose than electricity generation? Would you be more likely to support them in your backyard?

Examining Existing Policy to Inform a Comprehensive Legal Framework for Agrivoltaics in the U.S.

This study applies Legal Framework Analysis to identify barriers and opportunities for a comprehensive legal infrastructure to enable agrivoltaics in the U.S. e State of Massachusetts is used as a case study to understand what elements of their regulatory regime contribute to their novel agrivoltaic policy program, while also considering the surrounding federal and local government dynamics in which this state program is embedded.

The case study shows that a comprehensive legal framework for agrivoltaics should arguably include a combination of federal and state energy financing mechanisms coupled with favorable state and local land use policies. Specifically, a state-level feed-in tariff and local government allowances for mixed land use between solar and agriculture will be the key features of an enabling legal framework.

Legal-Framework-Manuscript_PascarisDownload
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The Agricultural, Economic and Environmental Potential of Co-Locating Utility Scale Solar with Grazing Sheep

The study revealed that grazing sheep on solar sites is a cost-effective method to control on-site vegetation and prevent panel shading. At no time in the growing season did vegetation shade the panels. Maintenance was less labor-intensive than traditional landscaping services and, thus, less expensive. The grazing trial at the Musgrave solar site was a full success for the site owners and operators, as well as the sheep farmer.

The aim of this study was to compare economic and agricultural benefits and challenges of traditional land management strategies (mowing, string trimming) with rotationally grazed sheep on solar sites. Sheep were grazed between May and November 2018 to obtain agronomic and economic data, as well as to gather knowledge of the feasibility of grazing sheep on solar sites.

The-Agricultural-Economic-and-Environmental-PotentialDownload
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Planning and Zoning for Solar Energy Systems

The purpose of this guide is to help Michigan communities meet the challenge of becoming solar- ready by addressing SES within their planning policies and zoning regulations. This document illustrates how various scales and configurations of photovoltaic SES fit into landscape patterns ranging between rural, suburban, and urban. This guide will aid in community development and guidance related to public policy decisions related to solar energy development, which often includes agrivoltaic operations and development as well.

Follow the Sun Tour: Learning from Arizona’s Biosphere 2 and Manzo Elementary Agrivoltaics  

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. Greg Barron-Gafford
Sewing seeds for 2022 research
On-site agrivoltaic research at Biosphere 2
Biosphere Agrivoltaic Research
Follow the Sun Tour’s first stop: Biosphere 2
Manzo Elementary’s agrivoltaic site
Manzo Elementary’s Mariah Rogers explaining agrivoltaic food science

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 Develops New Solar Cells 

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. 

Planning and Zoning for Solar Energy Systems

The purpose of this guide is to help Michigan communities meet the challenge of becoming solar ready by addressing SES within their planning policies and zoning regulations. This document illustrates how various scales and configurations of photovoltaic SES fit into landscape patterns ranging between rural, suburban, and urban.

Planning-and-Zoning-for-Solar-Energy-SystemsDownload

AgriSolar News Roundup: Biosphere 2 Visit, Rooftop Agrivoltaics, New French Solar Canopy 

AgriSolar Clearinghouse Visits Biosphere 2 

“The AgriSolar Clearinghouse is taking a national tour of operational agrivoltaic operations, sharing knowledge, and bringing attention to a practice with numerous (and perhaps unexpected) benefits. The first stop on the tour is the agrivoltaic array at Biosphere 2, a research center run by the University of Arizona. Biosphere 2 is nothing short of incredible, it is a 3.14-acre laboratory in the middle of the hot, dry Sonoran Desert that is referred to as the world’s largest earth science experiment. Contained inside the massive facility is a climate-controlled environment, complete with ocean, rainforest, mangrove, desert, and savanna-simulating conditions.” – PV Magazine 

Rooftop Agrivoltaics Shows Potential to Revolutionize Urban Farming 

“Rooftop agrivoltaics have the potential to revolutionize urban farming. Just like the multifunctionality of agroforestry, which arguably revolutionized rural farming in the 1980s and 1990s, the multifunctionality of rooftop agrivoltaics can provide parallel co-benefits in urban spaces. Agroforestry has the co-benefits of growing food, sequestering carbon, and providing other ecosystem services in the same space – rooftop agrivoltaics is an urban analog. Although, rather than storing energy in the form of slow-growing biomass (wood), it harnesses the power of a rapidly renewable source – the sun.” – Live Architecture Monitor 

New Agrivoltaic Solar Canopy Designed in France 

French solar company TSE has released a new photovoltaic canopy for applications in agrivoltaic projects. The system features a rotating canopy that can host bifacial solar modules at a height of more than 5.5 meters. The canopy is placed on a four-post structure measuring 27 m x 12 m. “Our canopy is compatible with all agricultural machinery, including very large ones like combines, sprayers and spreaders,” the company’s president, Mathieu Debonnet, told pv magazine. The company said the canopy technology is particularly suitable for cereal farms that grow rapeseed, maize, barley, and vegetable protein, as well as sheep and cattle farms.” – PV Magazine 

Renewable Energy Meets Pollinator Habitat in Minnesota Solar Fields

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.”