Tag Archive for: Agrivoltaics

Timing field management in and around solar fields to optimize conservation opportunities for declining grassland birds

Dr. Amy Johnson, Conservation Biologist and Program Director, Virginia Working Landscapes, Smithsonian’s National Zoo and Conservation Biology Institute

Biodiversity is declining globally at an alarming rate. While multiple ecosystems are at risk, our planet’s terrestrial grasslands are suffering precipitous losses. In North America, less than 1% of native grasslands remain.

As a result, species that rely on grassland habitat are in trouble. A recent study published in Science revealed that grassland birds are declining more than any other group of birds (Rosenberg et al, 2019; Figure 1). These are species that rely on contiguous open spaces, mostly free from trees, for nesting, foraging, and survival.

Figure 1. Grassland birds have declined more than any group of birds in North America. Infographic: Cornell Lab of Ornithology

In the eastern United States, the majority of grassland habitat is under private ownership. Much of these grasslands are working lands, with hay production and grazing being the most common land uses. A growing number of these working lands are also contributing to an expanding network of solar fields, often integrating solar infrastructure into actively farmed or post-agricultural fields. Simultaneously, these eastern grasslands are host to some of North America’s most vulnerable grassland birds, including Eastern meadowlarks, Grasshopper sparrows, and Bobolinks, which have experienced population declines of 75%, 68%, and 65%, respectively, since the 1970s. As such, it is critical that we prioritize research to better understand how these populations are impacted by grassland management. More importantly, in order to be successful in developing effective conservation strategies for these species on working lands, it’s necessary to facilitate a model that considers the needs of both wildlife and people.

In Virginia, a team of conservation scientists is collaborating with community partners and a network of private landowners and producers to conduct research on grassland birds on working lands. Virginia Working Landscapes (VWL) is a program of Smithsonian’s National Zoo and Conservation Biology Institute, and its mission is to promote the conservation of native biodiversity and sustainable land management through scientific research, education, and community engagement. Since 2010, VWL has recruited over 180 properties (totaling over 80,000 acres) that have provided researchers access for the purpose of conducting ecological research on how land management impacts biodiversity. Grasslands included in this research include fallow post-agricultural fields, solar fields, active hayfields, and livestock pastures, restored native grasslands and wildflower meadows. From this, VWL researchers have been able to assess how bird communities respond to different land management practices, including the timing of management, and have been able to apply these findings to best management practices that support grassland bird populations.

Solar is quickly emerging as one of the Virginia’s leading sources of renewable energy, with more arrays being constructed every year. With the majority of these installations occurring in and around agricultural fields, we often think about the impacts that solar may have on grassland bird communities. While there’s been minimal research on this topic (Horváth et al., 2009; DeVault et al., 2014), there are several organizations actively looking into it (see SUNY New Paltz, Virginia Pollinator Smart, Grassland Bird Trust).

One aspect of solar management that hasn’t been discussed in great detail in scientific literature is vegetation management in solar fields specific to grass and shrubland birds. With much of VWL’s research focusing on field management (not to mention the fact that it’s currently peak mowing season here in Virginia!), I wanted to use this as an opportunity to share some insights on how landowners and managers can optimize grassland management for bird communities within solar fields and beyond.

In eastern grasslands specifically, we have identified two distinct communities of birds nesting in grasslands. One we identify as grassland obligates, which include those birds that nest directly on the ground in open grasslands, including species like Eastern meadowlarks, Bobolinks, and Grasshopper sparrows. Others we refer to more commonly as shrubland birds, which often build their nests off the ground in low-lying vegetation amongst the branches of woody shrubs or weaved through the stems of sturdy wildflowers. Examples of these species include Indigo buntings, Field sparrows, and Prairie warblers. Depending on the composition and structure of the vegetation growing in and around your solar fields, it’s possible that both groups of these birds are nesting amongst solar arrays and surrounding habitat. For example, if a solar array is installed in conjunction with a pollinator wildflower mix, it may be likely that shrubland species are nesting nearby. VWL research is demonstrating that wildflower meadows support significantly higher densities of shrubland birds than fallow or agricultural fields. In contrast, arrays surrounded by fescue pasture and/or hay grasses it may be more likely to have higher densities of grassland obligates present, potentially nesting directly on the ground. Therefore, the composition of the vegetation surrounding your solar array could help determine the optimal time for field management based on the nesting phenology of the species most associated with that habitat.

In Virginia, Eastern meadowlarks start nesting as early as April 15, with peak nesting activity occurring in mid- to late May (Figure 2). Bobolinks follow shortly behind with peak nesting activity occurring in early June. Unfortunately, this is also the most popular time for field management, especially if fields are managed for hay and/or grazing, and this can have drastic negative impacts on grassland bird survival. For example, a New York study showed that hay harvests during peak nesting season resulted in 94% mortality of eggs and nestlings of grassland birds (Bollinger et al.,1990). Other species more commonly associated with wildflower meadows, like Blue grosbeaks and Field sparrows will nest into late June/early July. As such, it is important to consider the species using your fields when scheduling field management activities. For this reason, we created a “Field Management Risk Calendar” (Figure 3) to help guide managers on the optimal times to manage fields for the benefit of birds.

Figure 2. An Eastern meadowlark nest hidden amongst hay grasses at the edge of a solar field in Fauquier County, VA. Photos: Amy Johnson
Figure 3. Field management risk calendar for eastern grassland birds in the mid-Atlantic. Infographic: Amy Johnson, Smithsonian’s Virginia Working Landscapes, using data collected in Virginia grasslands.

As the calendar illustrates, delaying field management from mid-June to July 1 can make a significant difference for the survival of nestling grassland birds. Delaying to July 15 or even August 1 is even more impactful, especially for those late-nesting shrubland species. We also recognize, however, that delaying management isn’t always feasible. As such, we are currently collaborating with farmers in Virginia to identify optimal windows for early field management that will still offer opportunities for birds to fledge their young. For example, is it possible to mow early in the season, prior to peak grassland bird nesting, and still provide the necessary vegetation structure for nesting birds in late May and into June? Stay tuned to www.VAWorkingLandscapes.org to hear more as we continue collecting data on this front. In the meantime, I encourage you to refer to our Field Management Guidelines for Grassland Birds to learn more about the species that use our eastern grasslands and how we can adapt our management regimes to optimize their conservation.


Bollinger, E.K., P.B. Bollinger, and T.A. Gavin, . 1990. Effects of Hay-Cropping on Eastern Populations of the Bobolink. Wildlife Society Bulletin, 18(2): 142-150.

DeVault, T.L., T.W. Seamans,, J.A. Schmidt., J.L. Belant,, B.F. Blackwell, N. Mooers, L.A. Tyson, and L. Van Pelt. 2014. Bird use of solar photovoltaic installations at US airports: Implications for aviation safety. Landscape and Urban Planning,122: 122-128.

Horvath, G., G. Kriska, P. MalikB. . and Robertson. 2009. Polarized Light Pollution: A New Kind of Ecological Photopollution. Frontiers in Ecology and the Environment, 7: 317-325.

Rosenberg, K.V., A.M. Dokter, P.J. Blancher, J.R. Sauer,, A.C. Smith, P.A. Smith, J.C. Stanton, A. Panjabi, L. Helft, M. Parr, and P. Marra. 2019. Decline of the North American avifauna. Science, 366: 120-124.

Australian Guide to Agrisolar for Large-scale Solar Published by Clean Energy Council 

“As interest grows in agrisolar – using land for both agriculture and solar power – the Clean Energy Council has produced the Australian Guide to Agrisolar for Large-scale Solar to assist proponents of utility-scale solar and the landholders and farmers who work with them to integrate agricultural activities into solar farm projects.” – Renewable Energy Magazine 

Agrisolar: Solar Industry Hopes Farmers Will Help Solve Grid Access Problems  

“The Clean Energy Council says working with Australian farmers could help solve the growing problem of grid access for new large-scale solar farms, in a new paper promoting ‘agrisolar’” If done right, the paper argues solar farms can improve both grazing and crop land, while allowing solar farms to be built in areas where the electricity network is strong, providing a win-win for both solar developers and farmers.” – Renew Economy 

Dairies Powered By the Sun and Batteries: Trans-Tasman AgriSolar Start-up Gathers Pace 

“A New Zealand-based start-up offering dairy farmers cheap and reliable solar and battery-backed power purchase contracts has raised $4 million from an Australian-led investment round. Based in Christchurch, Solagri installs solar and batteries on dairy farms in the Canterbury region of New Zealand at no up-front cost, instead signing the farmers up to long-term PPAs guaranteed to supply 100% of their dairy sheds’ electricity needs.” – One Step off the Grid 

By: Andrew Valainis

Director, Montana Renewable Energy Association (MREA)

According to the Solar Energy Industries Association, the cost to install solar has dropped more than 60% over the last decade alone, with the average residential system costing half of what it did in 2010.[1] Still, solar photovoltaic systems are a large investment, and the up-front cost can be challenging for many Americans. In this blog post, I will explore some of the financing and financial incentive options available to help pay for these systems. I use Montana’s available options as examples, though financing and incentive programs will vary state to state.

One of the most popular and most important incentives in the U.S. is the Solar Investment Tax Credit (ITC). The ITC is a federal income tax credit that you can claim against the cost of the installation. This credit applies to the total cost of the installation, including labor. If you decide to install a storage system at the same time as the solar system, then you can include that cost as well. There is no upper dollar limit on how much the credit is worth. The ITC was originally set at 30% but stepped down to 26% in 2020 and will continue to step down over the next few years. In 2020, the phase-out schedule was extended for two years as part of the spending bill that Congress negotiated. The ITC will remain at 26% until 2023, when it will step down to 22% for all customers. In 2024, it will expire for individuals, while stepping down permanently to 10% for businesses.

Federal ITC Step Down 2020 Extension.

Another great option is the U.S. Department of Agriculture’s “Rural Energy for American Program” (REAP). The REAP program provides grants – not loans – to qualifying agricultural and small businesses for up to 25% of the cost of a renewable energy project, up to $500,000. Energy efficiency grants and loan guarantees are also available through the program. This is an excellent option for agricultural producers. USDA has local offices all around the country, and I highly recommend calling them to ask about the program and how you can benefit.

In 2022, Congress passed the Infrastructure Investment and Jobs Act (IIJA), which provides a large amount of funding for the installation of renewable energy technologies. Details are still coming out about several of the different funding opportunities, which may apply to businesses or individuals. These are worth monitoring for further information. You can learn more here.

Some states offer state-level programs specifically supporting the development of solar and other renewable energy technologies. In Montana, we have the Alternative Energy Revolving Loan Program (AERLP). This program was established by the Montana Legislature in 2001 and provides zero-down, low-interest loans of up to $40,000 to individuals, small businesses, nonprofit organizations, and government entities in order to increase investments in alternative energy systems and energy conservation measures in Montana. The program, managed by the Montana Department of Environmental Quality’s Energy Office, has financed more than 500 renewable energy installations across the state since its first loan in 2003. States also often offer tax incentives or rebates for renewable energy installations, which are great options to help lower the up-front cost of the installation. Reach out to your state energy office or solar advocacy group to ask what options your state offers.

Property Assessed Clean Energy (PACE) programs are becoming more popular across the country. PACE programs offer the opportunity to finance the up-front cost of an installation and then pay back that cost as an assessment on the property taxes of the building or location where the system was installed. One of the greatest benefits is that the cost of the system is tied to the location, making for a simpler process if there is a change in ownership. The nuances of these programs are important and will vary from state to state. For example, the recently adopted PACE program in Montana is only available to commercial entities.

Your utility may offer discounts, rebates, or other incentives that can help with the cost of renewable energy and/or energy efficiency technologies. In Montana, we have the Universal Systems Benefits (USB) program. Our largest investor-owned utility, NorthWestern Energy, administers this state-authorized incentive program through its “E+ Renewable Energy Program” to qualifying non-profit organizations, government agencies, and schools in NorthWestern Energy’s Montana service territory. Projects receiving these funds often provide civic value, including education and visible representation of renewable energy technologies to a broad audience. The Montana USB program provides grants, but other utility territories may offer programs with discounts or rebates on certain energy efficiency products. Reach out to your energy provider to ask what incentives it offers. 

Private financial institutions are beginning to offer their own renewable-energy focused products. For example, Clearwater Credit Union (based in Missoula, MT) offers two home energy loans: an unsecured, easy-access Home Solar Loan; and a Home Energy Efficiency Loan. Because it is a private institution (and not a state agency), the credit union can usually offer a decision in minutes. These options can be particularly attractive for businesses or households that already have an account with that institution.

Third-party financing is another option to consider. In this scenario, a private, third-party financer will develop a solar project on leased or purchased land or roof space. The financer provides the capital and, in doing so, is often able to take advantage of tax breaks that can lower the overall project cost. They enter into a contract with the system host (i.e., the building or land owner) who then benefits from the project by receiving the energy produced on-site. The host may pay the financer a regular payment (fixed or otherwise) related to the value of the energy delivered. At the end of the contract term, the host may also have an option to purchase the system from the financer. The crux is finding a third-party financer you are comfortable working with. These types of contracts can be technical, and the nuances are very important. If you are interested in this model, I recommend working with a legal expert to make sure you understand the terms and conditions of any agreement that you sign. Missoula County recently worked on the first third-party financed system in Montana. MREA hosted a webinar about the experience, and about third-party financing in general. A link to the recording is provided below.

A closing note on tax incentives (generally): Be sure to consult with a tax professional to ensure that these options are available to you. Unless the tax credit is specifically noted as refundable, you must have a sufficient tax liability to claim the value of the credit. For example, the Federal ITC is not currently refundable (though SEIA and other solar advocates have lobbied Congress to make it so).

As you can see, there are varied options available to help with the cost of a solar installation. However, the nuances are important and can drive the cost and savings that you will eventually realize. As you explore these different options, be sure to reach out to local solar advocates and legal and tax experts in your area with any clarifying questions.


Federal ITC (for businesses)

Federal ITC (for residences)


IIJA funding opportunities

MREA webinar on Third-Party Financing

Montana-specific Programs and Examples:

MREA website on financing and incentives

Alternative Energy Revolving Loan Program

Clearwater Credit Union energy loans

Northwestern Energy E+ Renewable Incentives

[1] Solar Energy Industries Association. (2022). “Solar Industry Research Data.” https://www.seia.org/solar-industry-research-data

2 Connecticut Solar Farms Will Also Grow Crops 

“Connecticut-based Greenskies Clean Focus is bringing farming to solar fields across Connecticut. Following the recent green light from the Connecticut Siting Council, two new Greenskies solar power and agricultural co-use projects will break ground later this year in Orange and East Windsor. The solar array in Orange will act as a distributed energy resource facility benefiting the Connecticut State Colleges and Universities (CSCU) through a virtual net metering agreement.” – Solar Power World 

Australian Solar Farm Set to Co-exist with Existing Lamb Production 

“A potential 300MW solar farm with a 600MWh battery energy storage system founded by a group of local farmers in Bungendore, New South Wales, has gained backing from the federal government’s Clean Energy Finance Corporation and investment company Octopus Australia. As the project website details, the solar farm will co-exist with existing lamb production, which will be accommodated by placing the rows of panels around six meters apart, allowing for grazing as well as for the optimal performance of the planned single-axis tracking system.” – Renew Economy 

Solar Farm in Dunfermline Could Power Roughly 7,000 Homes 

“A new solar farm in Dunfermline will have the capacity to power 7,000 homes per year if it gets the green light. Plans for the energy park with 75,000 solar panels have been lodged with Fife Council at the former Lochhead open cast mine in Wellend. The company behind the application, Dunfermline Solar Ltd, part of AMPYR Solar Europe, says the plans will be a source of new low carbon power and supports the Scottish Government’s commitment to renewable energy.” – The Courier

Cannon Valley Graziers is a vegetation-management company based in Southeastern Minnesota. Since 2018, Arlo Hark and Josephine Trople have been using their flock of sheep to manage vegetation in a variety of environments, working closely with customers to meet their management goals. Cannon Valley Graziers provides vegetation-management services for solar developers throughout southern Minnesota. The vegetation on community and utility solar sites is traditionally mowed multiple times per year, incurring high operations/maintenance costs. By applying adaptive-grazing strategies on these solar sites, Cannon Valley Graziers can reduce the annual maintenance costs for developers, while also having a positive impact on the soil health and water quality of southern Minnesota. 

Photo Courtesy of Cannon Valley Graziers

The principles of adaptive grazing are well-suited for vegetation management. By mob grazing—introducing a large number of sheep into a small area for a short amount of time—Hark is able to deploy his flock with surgical precision to meet the needs of each site. After the desired objectives are met, he moves the flock to the next site. Meanwhile, the vegetation is allowed to recover, strengthen its root systems, and grow more resilient. Hark says these root systems are key for soil regeneration and water quality. Deeper roots build organic matter and allow for the transfer of minerals deeper into the soil. Strong root systems also improve the soil’s ability to store and maintain water, which reduces soil erosion and chemical runoff into nearby waterways. 

Photo Courtesy of Cannon Valley Graziers

Growing a sheep-powered vegetation-management company is not without challenges. Large flocks require large trucks and trailers to move from site to site. In addition, most sites do not have water, so water must be supplied by the grazier. But to Hark, the effort is worth it. “It makes sense to stack benefits on these sites,” he explains. “We are providing a top-notch service to our customers, improving soil and water quality, and providing meat and fiber to our community. It just makes sense.”

The U.S. Department of Energy, Solar Energy Technologies Office has announced it award up to $8 million for agrivoltaic research through its Foundational Agrivoltaic Research for Megawatt Scale (FARMS) program. The research dollars are intended to examine how agrivoltaics can scale up to maximize land and increase farm revenue.

According to it’s funding announcement:

DOE expects to make between 4 and 6 awards under FARMS, each ranging from $1-2 million. SETO is interested in projects that partner with farmers who are pursuing climate-smart and sustainable agriculture and are considering agrivoltaics to enhance the economic efficiency and sustainability of these farms. Additionally, SETO is interested in projects that offer economic benefits to underserved communities in these farming areas.

This funding opportunity announcement (FOA) has three areas of interest:

  • Integrated agriculture-energy impact studies that investigate how agrivoltaic designs impact both agriculture production and energy production;
  • Socioeconomics of agrivoltaics research that studies how agrivoltaics can fit into existing agricultural communities and economies or enable new ones; and
  • Resources for replicable and scalable agrivoltaics that lower the barrier of entry to agrivoltaics, making it easier for interested agricultural producers and solar developers to benefit from the opportunities that agrivoltaics provides.

Letters of interest are due June 1 at 5 p.m. See the full funding announcement here.

By Lee Walston and Heidi Hartmann, Argonne National Laboratory

Pollinator habitat at a solar facility in Minnesota. Photo: Lee Walston, Argonne National Laboratory.

Many of us have witnessed regional land-use transformations towards renewable energy in the last decade. As the fastest growing electricity generating sector in the U.S., solar energy development has grown more than 20x in the past decade and is projected to be the dominant renewable source of electricity by 2040. The recent DOE Solar Futures Study predicts that over 1 terawatt (TW) of utility-scale solar electricity developments will be required to meet net-zero clean-energy objectives in the U.S. by 2050 (Figure 1). This represents a solar land-use footprint of over 10 million acres across the U.S. – roughly the combined area  of Connecticut, Massachusetts, and Rhode Island.

Figure 1. Source: Solar Futures Study

A fundamental question we all face is how to balance solar energy development with other land uses such as agriculture. Given the current and projected land-use requirements, sustained development of solar energy will depend on finding renewable energy solutions that optimize the combined outputs of energy production, ecosystem services, and other land uses. Dual land-use approaches that co-locate solar energy with other forms of land uses, such as agriculture or habitat restoration, have emerged as promising strategies to improving the landscape compatibility of solar energy. The establishment of native pollinator-friendly vegetation at solar facilities (“solar-pollinator habitat”) is one strategy to improve the multifunctionality of these lands that not only provide renewable energy but also offer several ecosystem service benefits such as: (1) biodiversity conservation; (2) stormwater and erosion control; (3) carbon sequestration; and (4) benefits to nearby agricultural fields.

Understanding the true ecosystem service benefits of solar-pollinator habitat will require field studies in different geographic regions to examine the methods of solar-pollinator habitat establishment and link these processes with measured ecosystem service outputs. Given the time required to conduct these direct field studies, most discussions of solar-pollinator habitat thus far have centered on qualitative ecosystem outcomes. Fortunately, there are ways to quantitatively understand some of these potential outcomes. Native habitat restoration has been a focus of scientific research for many years, and we can use these studies to understand the regional methods for solar pollinator habitat establishment (e.g., types of seed mixes, vegetation management) and relate these habitat restoration activities with quantifiable ecosystem responses. For example, there are decades of research on the restoration of the prairie grassland systems in the Midwest and Great Plains – regions that have seen losses of over 90% of their native grasslands due to agricultural expansion.

Because many solar facilities in the Midwest are sited on former agricultural fields, research on ecological restoration of former agricultural fields could be very useful in understanding the establishment and performance of solar-pollinator habitat in the same region. We can look to these studies as surrogate study systems for solar-pollinator habitat and utilize the data from these studies to make inferences on the ecosystem outcomes of solar-pollinator habitat. Along with a team of research partners, we recently took this approach to quantify the potential ecosystem services of solar-pollinator habitat in the Midwest. Our goal was to understand how solar energy developments co-located with pollinator-friendly native vegetation may improve ecosystem services compared to other traditional land uses. We began by reviewing the literature to collect a range of data on vegetation associated with three different land uses: agriculture, solar-turfgrass, and solar-pollinator habitat. The data for each land use included information on vegetation types, root depths, carbon storage potential, and evapotranspiration, to name a few.  

We then developed ecosystem service models for each land use scenario. The land uses corresponded to the following scenarios (Figure 2):

1. Agriculture scenario (baseline “pre-solar” land use);

2. Solar-turfgrass (“business as usual” solar-turfgrass land use) and

3. Solar-pollinator habitat (grassland restoration at solar sites).

We mapped and delineated 30 solar sites in the Midwest and used the InVEST modeling tool to model the following four ecosystem services across all sites and land-use scenarios:

Figure 2. Illustration of land use scenarios at each solar site. Source: Walston et al., 2021.

Our results, published in the journal Ecosystem Services, found that, compared to traditional agricultural land uses, solar facilities with sitewide co‑located, pollinator‑friendly vegetation produced a three-fold increase in pollinator habitat quality and a 65% increase in carbon storage potential. The models also showed that solar-pollinator habitat increased the site’s potential to control sedimentation and runoff by more than 95% and 19%, respectively (Figure 3). This study suggests that in regions where native grasslands have been lost to farming and other activities native grassland restoration at solar energy facilities could represent a win‑win for energy and the environment.

What do these results mean? We hope these results can help industry, communities, regulators, and policymakers better understand the potential ecosystem benefits of solar-pollinator habitat. These findings may be used to build cooperative relationships between the solar industry and surrounding communities to better integrate solar energy into agricultural landscapes. While our study provides a quantitative basis for understanding these potential ecosystem benefits, additional work is needed to validate model results and collect the primary data that would support economic evaluations to inform solar-native grassland business decisions for the solar industry and quantify the economic benefits of services provided to nearby farmers, landowners, and other stakeholders.

Figure 3. Average ecosystem service values for the thirty Midwest solar facilities modeled with InVEST: (A) pollinator supply; (B) carbon storage; (C) sediment export; and (D) water retention. Source: Walston et al. 2021.

It should come as no surprise that farmers are busy people. Success in farming requires hard work and long days, not to mention staying up to speed on farming practices and technologies. As renewable energy deployment on farmland becomes more common, farmers can face challenges understanding how to site and maintain these systems.

Drew Shiavone of the University of Maryland is meeting farmers where they are by providing digestible information on farm-based solar photovoltaics (PV) via 10- to 15-minute YouTube clips. The “Solar Clips” video series shows practical, step-by-step tutorials on various phases of the solar installation and maintenance process, from site assessment and shading analysis to wiring panels and replacing diodes. The series was created by Shiavone under a Sustainable Agriculture Research and Education (SARE) grant that will expand solar installations on farms in Maryland.

The grant project, led by Shiavone, is focusing on “train-the-trainer” workshops that will allow Extension agents and other agriculture service providers in the region to deliver education and training to farmers on topics such as solar PV technology basics, on-farm applications, and solar contracts and leasing options.

Along with the common “not in my backyard” mentality or concerns for the local economy, aversion to renewable energy installations is also often rooted in a lack of knowledge about the technology. Educational tools such as the Solar Clips series can help close the knowledge gap for farmers and increase support for on-farm renewable energy development. By empowering the farmer through practical solutions, agricultural production and decarbonization efforts are strengthened.

Italian University Signs Four-Year Agrivoltaics Research Agreement

“Statkraft Italy has signed a four-year research agreement with the Department of Agro-Environmental and Territorial Sciences (DiSAAT) at the University of Bari Aldo Moro in Southern Italy. The title of the project is “Agri-photovoltaics for a sustainable future. The aim of the research activities is to deepen new approaches, methodologies, and innovative technologies in the field of electricity generation and agriculture, and to achieve the correct integration between photovoltaic systems and primary production, optimizing the yield in both fields. The solutions will be aimed at public administrations, entrepreneurs, farmers, and local communities,” – Statkraft

Rooftop Agrivoltaics Research Continues in Colorado

“While rooftop agrivoltaics is in its infancy, this vertically integrated approach to urban land use can increase resilience in urban food systems, expand renewable energy production, and decrease water consumption. The benefits associated with rooftop agrivoltaics warrant further investigation as we re-envision underutilized spaces in urban environments. Colorado State University is continuing research on rooftop agrivoltaics to analyze the growing conditions, yield, and power generation potential of these systems,” – Live Architecture Montioring

Arizona’s First Solar Closes Agreement with Silicon Ranch

“Arizona’s First Solar announced that it has come to terms on a multi-year master supply agreement with southern utility-scale solar developer, Silicon Ranch, under which First Solar will supply 4GWof advanced thin film photovoltaic modules to Silicon Ranch’s projects in the United States from 2023 to 2025. While this is not the first supply partnership to be reached between the two companies, the level of commitment dramatically expands on their prior partnership, under which First Solar has supplied modules to over 30 projects totaling more than 1GW since 2015.” – PV Magazine

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.