Tag Archive for: Pollinator-Friendly

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.

By Rob Davis, Connexus Energy

Seven years after designing our first solar array, more than 20 million deep-rooted and pollinator-friendly plants across more than 150 acres are helping us control costs while maximizing local benefits for our community, resulting in national recognition and hometown goodwill — but it almost didn’t happen. Now, our standard practice is to require pollinator-friendly ground cover across all of the large-scale solar arrays that feed into our grid.

Connexus Energy is Minnesota’s largest electric cooperative and one of the 15 largest retail electric cooperatives nationwide, serving more than 320,000 people (141,000 meters) in parts of eight Minnesota counties. By embracing innovations including grid-scale battery storage, more than $25 million of local solar generation, customer-centric demand response programs, and automated metering infrastructure, Connexus has kept retail rates to our members flat for five consecutive years, while progressing with greening the grid.

Our first solar array—built in 2014 immediately adjacent to our headquarters—was initially designed with gravel, but a change set us on a different course. Working with one of our co-op members, Prairie Restorations of Princeton, Minnesota, a low-growing meadow seed mix was designed and implemented. Making productive use of the land under and around a ground-mounted solar array fits with one of the seven cooperative principles — Concern for Community. After a year or two of growing in, the site’s beneficial plants were crowding out weed species, reducing mowing costs, and making a positive impression with the community.

Connexus Energy’s HQ Solar Array Built in 2014. Photo: Rob Davis

Having now partnered in the development of four additional grid-scale solar projects—two of which include 15 MW of battery storage—Connexus’ decision to proactively ask for productive use of the land under and around the panels is continuing to pay dividends:

  • Last fall one of Minnesota’s award-winning filmmakers teamed up with Prairie Restorations on a short documentary, Pollinators, Prairie, and Power, which included Connexus Energy CEO Greg Ridderbusch. Click HERE to watch it.
  • The Associated Press recognized Connexus Energy’s leadership in solar land-use practices in a major news story that generated more than 150 million media impressions nationwide. Connexus was the only electric utility included in the expansive story that also included interviews with scientists from the National Renewable Energy Laboratory. The story, “Bees, Sheep, Crops: Solar Developers Tout Multiple Benefits,” appeared in more than 240 media outlets in 41 states and territories.

Earlier this year, the U.S. Department of Energy Secretary Granholm highlighted Connexus Energy, sharing an extraordinary Minnesota Public Radio story about co-op innovation and use of local solar to keep rates flat. 

  • Research on one of Connexus’ solar projects by NREL, the University of Minnesota, and nonprofit partners is quantifying substantial stormwater benefits of deep-rooted ground cover. The PV-SMaRT project is monitoring and collecting water-quality data from five U.S. solar sites with different land and climate conditions. “The end goal is to develop research-driven tools and best practices that can be used by permitting authorities and PV developers to make more informed decisions on stormwater management measures that are tailored to the true impacts of a PV array on the environment,” says Jennifer Daw, principal investigator for the PV-SMaRT project and Group Manager for Strategy, Policy & Implementation at NREL.

This white paper provides an overview of these state efforts and offers suggestions for what other states can do to promote solar while also creating or preserving healthy habitats for pollinators.

The avenues by which Michigan and the United States provide the electricity essential for the economy and quality of life are in urgent need of change to ensure reliability and affordability while reducing the environmental impacts of this generation and improving social equity. These energy transitions are among the greatest challenges facing countries worldwide today. Another salient global challenge is reversing the decline in pollinators, including numerous species of native bees, honey bees, butterflies and birds. Pollinators provide critical ecosystem services but are facing numerous threats. These two grand challenges intersect as stakeholders work to identify the appropriate landscapes and places to develop solar power in Michigan. Agricultural land is desirable for solar installations for reasons that will be explained in this report. The state of Michigan is allowing solar developers to locate, or “site,” solar panels on preserved farmland but only if they develop habitat on this land to support pollinators. Other states are developing or have already developed standards developers must meet before they can advertise solar power plants as pollinator friendly. This intertwines these two urgent challenges in ways that are laudable; however, numerous questions of feasibility and best practices for achieving quality habitat remain unanswered. Multiple types of expertise and experiences from stakeholders from both energy and agricultural domains are required to successfully address these two challenges. In order to effect change, these stakeholders should collaborate more closely to overcome challenges of interpretation, problem definition and costs. This report identifies and characterizes those issues to facilitate stakeholders’ development of more optimal solutions. Overall, we identified several different paradigms through which stakeholders in Michigan viewed the appropriateness of solar power development on farmland. Some stakeholders viewed solar siting as a decision that should be left to an individual landowner because they have private property rights. Moreover, solar leasing would help to diversify farmers’ incomes, reducing the risks from seasonal and price volatility. Some stakeholders even saw solar leasing as part of farmland preservation, as it could enable a struggling farming operation to stay in business and a farmer to continue to own the land leased for solar rather than selling it for housing development. Other stakeholders saw farmland as a public good and opposed using prime farmland for solar power generation. These stakeholders often assumed that solar power could be targeted specifically toward low-quality agricultural land, or urban rooftops and brownfields rather than agricultural lands. For these stakeholders, inclusion of pollinator habitat and other multi-land uses tended to improve their opinion of solar power.

This American Solar Grazing Association Beekeeping Agreement Template is a template for a contract between a solar site operator and a beekeeper for the establishment and maintenance of a “solar site apiary,” i.e., an arrangement in which beehives are maintained at a solar site.

This document includes entomologist-approved standards for the managed landscape of a solar PV facility to be considered “beneficial to pollinators.” The scorecard includes the following options for entering data: site planning and management, seed mixes, insecticide risk and outreach education, among others.

This report provides a summary of Fresh Energy’s key considerations related to pollinator-friendly solar. The report includes considerations for the development of agrisolar operations, including: design, construction, maintenance, pollinator basics and a business case for pollinator-friendly solar. Included within these topics are discussions and considerations for ground-mounted utility solar, hosting honey bees on solar farms, adding solar to dairy land and required vegetation for solar RPFs at Xcel Energy.

With a focus on north-west Europe, this paper systematically reviews the available evidence on how land management practices relevant to solar parks can enhance pollinator biodiversity. The methods in this research systematically review all of the available evidence on land-management practices in northwest Europe and their impacts on pollinator biodiversity.

The assessment provides information relating to improving solar park management for pollinators by providing foraging and reproductive resources, undergoing considered management practices, increasing landscape heterogeneity and connectivity, and providing microclimatic variation.

This technical guide serves as a starting point for the establishment and management of pollinator-friendly ground cover at ground-mounted solar photovoltaic arrays. This guide is intended to serve as a resource in understanding pollinator-friendly solar components and identify organizations,vendors, and experts who can provide more site-specific guidance. Also provided here are general guides for seed-mix development, planting layout and maintenance of pollinator-friendly vegetation to be used in agrivoltaic systems.