A Practitioner’s Guide to Pollinator-Friendly Solar Development

In Brief

This toolkit provides background on pollinator-friendly solar and its advantages, and tips, resources, and important considerations to kick-start the integration of pollinator habitat into a solar development portfolio.

In addition to the diverse environmental benefits that pollinator-friendly solar projects can produce, there are an array of private benefits for solar developers to reap from planting perennial vegetation under their solar panels.

The guide offers a set of best practices for understanding local context, building support for a project, designing a site, financing, and development.

Flowers grow between solar panels

Watchfield, England / RTPeatCC BY-NC-ND 2.0

This article is the last in a three-part Clean Energy Finance Forum series on the potential of pollinator-friendly solar development in Minnesota and beyond. For more, see the Yale Center for Business and the Environment white papers on the land use benefits of the practice, and strategies for financing it.

Pollinator-friendly solar projects offer an attractive option for more than just birds and bees. In addition to providing critical habitat for declining pollinators, solar sites planted with a pollinator-friendly seed mix can generate an array of environmental benefits, while also saving developers time and money.

Interested? This guide draws on insights from the Yale Center for Business and the Environment’s recently released white papers on pollinator-friendly solar. Pollinator-friendly solar is taking off across the country, and with the help of this toolkit, it won’t take long to learn what the buzz is all about. This toolkit is intended for solar developers interested in learning what it takes to turn your next solar project into a pollinators’ paradise.

The toolkit begins with a quick background on pollinator-friendly solar and its advantages for developers, and then provides tips, resources, and important considerations to kick-start the integration of pollinator habitat into a solar development portfolio.

Benefits of Pollinator-Friendly Solar

Pollinator-friendly solar development refers to the co-location of solar with deep-rooted perennial wildflowers and grasses planted throughout a project site. Pollinator-friendly solar projects can provide a host of ecosystem services, including habitat for wild insect pollinators, improved groundwater recharge, reduced erosion, soil carbon sequestration, and higher crop yields from the increase in pollination services.

In addition to the diverse environmental benefits that pollinator-friendly solar projects can produce, there are an array of private benefits for solar developers to reap from planting perennial vegetation under their solar panels.

Reduced operations and maintenance (O&M) costs: Pollinator-friendly solar sites often require less maintenance over a project lifetime than sites with conventional turf grass. This is because perennial vegetation, once established, thrives without frequent mowings and pesticide sprayings. Additionally, the deep root system characteristic of most perennial plants improves soil health, reduces soil compaction, and better insulates the ground. In cold climates, this increase in soil organic matter may reduce the risk of frost heave damage during the winter.

Panel efficiency gains: Early and ongoing research suggests that planting deep-rooted vegetation beneath solar panels creates a cooler micro-climate around the panels. That helps improve the efficiency and energy output of a solar project, driving increased project revenues. Developers who implement pollinator-friendly solar practices at their site also stand to benefit from reduced need to suppress efficiency-reducing dust.

Smoother permitting process: In almost all cases, developing a solar project requires taking land out of some other use, whether it be forest, farmland, open space, etc. Because pollinator-friendly solar development provides auxiliary benefit for a range of stakeholders, including farmers, opting for these practices may help mitigate the potential land use conflicts of conventional development. Marketing solar projects as aesthetically attractive sites with the potential to improve local soils, water, and food can help garner more widespread support for your solar project, lower permitting costs, and reduce litigation vulnerability.

Stronger environmental credentials: The solar industry has the opportunity to play an important role in reversing the decline of native insect pollinators, which has been driven primarily by habitat loss. Many developers see merit to boosting the environmental sustainability of their projects above and beyond energy, and are committing to these practices across their portfolios. Pollinator-friendly solar development is a low-risk, highly visible action that can deliver cost savings while generating positive press and reputational benefits. Taking action soon could also help developers get ahead of future regulations and industry competition, which is mounting.

Early and ongoing research suggests that planting deep-rooted vegetation beneath solar panels creates a cooler micro-climate that helps improve efficiency and energy output.

New sources of project finance support: Implementing pollinator-friendly solar practices can help developers access to new sources of capital to finance their projects. For instance, some states already offer policy subsidies, such as Massachusetts' Solar Massachusetts Renewable Target (SMART) Program, which offers a cost-adder for low-impact land use decisions for new solar developments. In addition, developers could capitalize on the environmental benefits their projects deliver by participating in carbon offset markets or water quality trading schemes. The CBEY white paper “Mobilizing Finance for Land Conservation at the Energy-Land-Agriculture Nexus” details more innovative ideas for investment arrangements and market structures that can help monetize the ecosystem services that pollinator-friendly solar projects can realize.

Best Practices

1. Understanding the Local Context

Understanding the specifics of the local context and land characteristics is an important first step in pollinator-friendly solar development. Developers should identify local concerns and sentiments that might support or impede a pollinator-friendly solar project. For instance, have other developers tried to implement pollinator-friendly or conventional solar projects in this area? How were those efforts met? What factors could determine project success or failure, and how can pollinator-friendly solar practices help your project come to fruition?

Environmental context: Becoming familiar with the most pressing environmental and land use issues can clarify the unique benefit that pollinator-friendly solar can drive in a certain place. For instance, if erosion is a particularly prevalent issue, local water utilities might support pollinator-friendly solar development to reduce erosion conditions upstream and lower treatment costs. Engaging relevant stakeholders could help increase public support and facilitate the permitting process.

A growing number of states have implemented voluntary pollinator-friendly solar standards; Xcel Energy is now requiring vegetation management plans for all future solar RFPs.

Local stakeholders: In order to best highlight the mutual benefits that pollinator-friendly solar projects can provide, developers should consider who the project might impact. For instance, land that is suitable for solar development often overlaps with highly productive agricultural lands. Developers engaging in land lease negotiations with farmers would do well to mention that farmers with nearby pollinator-dependent crops stand to benefit from the increased pollination services that their project will likely enable. Other local stakeholders might be happy to learn about improvements to drinking water quality thanks to the nutrient filtration that deep-rooted plants provide; the increased groundwater stocks from improved groundwater recharge; or just the prospect of having a beautiful field of wildflowers as a new neighbor.

Policy landscape: Federal, state, and local policies influence the feasibility and direction of new solar development. For instance, many states have a natural resource district and/or board of soil & water conservation, and are further broken up into a number of watershed districts and utility jurisdictions. It’s useful to understand the capacity and concerns of these organizations, and the ways in which existing permitting, leasing, and land use regulations apply to your goals. What’s more, a growing number of states have implemented voluntary pollinator-friendly solar standards; Xcel Energy, for example, is now requiring vegetation management plans for all future solar RFPs.

2. Identifying and Engaging Support

Across the U.S., a growing number of resources and experts are lining up to support pollinator-friendly solar planning, implementation and maintenance. The Minnesota-based non-profit Fresh Energy, for example, has established the Center for Pollinators in Energy to serve as a clearinghouse for information and resources on pollinator-friendly solar projects. Consulting these resources early can alleviate learning costs of adopting a new development approach. Some categories of entities or individuals to considering seeking out are listed below.

Ecologists, entomologists and conservationists: Ecologists, entomologists and conservationists can help assess existing habitat and site prospects to maximize the environmental benefit your pollinator-friendly solar project can deliver. Regional universities and research institutions might have capacity and existing tools to help map and understand the potential benefit of land conversion from a solar project.

Ecological restoration experts and native landscaping companies: Ecological restoration experts can help select and procure the appropriate seed mix and clarify the trade-offs between different seed costs and benefits for maximum returns over a project’s lifetime. Identifying a trusted restoration expert is crucial for site preparation and seed establishment as well as site maintenance over time.

Co-financiers or funding partners: Depending on the composition of local stakeholders, concerns and policies identified above, there may be opportunities to secure additional funding for pollinator-friendly projects. For instance, imagine that a local watershed district is already paying for projects to increase local streamflow. While it might cost slightly more to implement pollinator-friendly solar in an area that would significantly contribute to improved streamflow conditions, costs might be marginally less than the district would otherwise pay to improve streamflow on its own. Collaborating with local interests can reveal additional funding sources to optimize the potential benefit of pollinator-friendly projects at the best price for all parties.

Publications and online tools: Experts in the field are developing an extensive knowledge base of tools and resources to support pollinator-friendly solar practices. One valuable resource is the Natural Capital Project’s InVEST Model. InVEST is a package of free, open-source “models for mapping and valuing ecosystem services provided by land- and seascapes.” InVEST can help you understand the location-specific benefits that pollinator-friendly solar development can generate. Additionally, the collaborative Innovative Site Preparation and Impact Reductions on the Environment (InSPIRE) project is collecting data from field sites across the U.S. to better understand how pollinator-friendly solar projects are performing in practice.

3. Designing a Site

After identifying a knowledgeable local contractor or native landscaping company, site and vegetation management plans should be designed together. As Gavin Meinschein, ENGIE’s lead civil engineer, has noted, “given the variations in soil conditions, the slope of the site, and what time of year the vegetation is planted, every site will be different.” The ecosystem services that a project is capable of enabling will also vary depending on existing habitat, geography and climate, and the project timeline.

“Given the variations in soil conditions, the slope of the site, and what time of year the vegetation is planted, every site will be different.”

Early attention to site-specific development and management plans can help set up a project for success. An experienced local contractor can shed light on trade-offs and timelines for various site decisions –– for instance, the appropriate seed mix and erosion control plan. Other considerations include factors like panel height adjustments to control for shading. Planning ahead to raise panels or proactively considering costs of strategically mowing around panels can help mitigate surprises down the line.

4. Financing a Project

When beginning to understand the costs and benefits associated with new land management practices, Meinschein emphasizes that it is important to maintain a portfolio-level analysis. Some sites may be more difficult than others to maintain. Some sites may come in over budget, while others will come in under budget, but developers have found that pollinator-friendly practices reduce overall portfolio costs. Synergies between projects (such as shared operations and maintenance providers and contractors) can also offer cost reductions.

On the investment side, it may prove wise to engage investors upfront to understand any hesitation or concerns they may have; in all likelihood, if developers can make a sound case that the vegetation won’t shade panels, investors’ primary concerns should be assuaged. Pursuing pollinator-friendly solar practices may also unlock new sources of investment to offset any increased risk premiums, especially when starting out. The “Mobilizing Finance for Land Conservation” white paper contains more in-depth ideas on opportunities to realize additional financing and overcome any cost barriers for pollinator-friendly solar projects.

5. Developing a Site

Here again, establishing a trusted relationship with a native landscaping contractor will expedite site development. We offer some high-level expectations and tips for site establishment during this project phase below.

Deep in the weeds: Depending on initial site conditions, a project might need to initially remove invasive species and weeds through spraying or other means. If invasive species persist or re-sprout, a second spraying may be necessary before playing, after weeds grow to a certain height. Be patient and give site preparation the time it needs to ensure the long-term success of the project.

The grass won’t always be greener: Even after site prep and initial seeding, pollinator-friendly solar projects won’t immediately flourish into a vegetative oasis. Educational signage indicating that the site is a work-in-progress, for example, can help manage expectations in the interim.

Avoid seeds of doubt: Average timelines for perennial vegetation establishment after initial seeding is roughly three years, assuming all goes well. Projects sometimes require reseeding of vegetation, as well. Patience and a portfolio-level perspective are key in the interim.

References

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