Soil, water, and vegetation—three critical ecological components of a successful utility-scale solar or distributed generation solar site. Although these elements may be an afterthought from an asset management perspective, an effective vegetation management plan plays a critical role in the long-term efficiency, safety, and sustainability of a solar energy site. It helps maximize energy production, protect infrastructure, and comply with regulatory requirements, while also contributing to community and environmental stewardship.
In its simplest form, vegetation management focuses on establishing and maintaining desired vegetation growth to avoid or mitigate undesired outcomes. Solar energy site developers, operators, and owners often view vegetation management from the asset down, with a focus on making sure vegetation does not shade the solar panels, become entangled in drivelines, or create fire hazards or other safety issues. As ecologists, my colleagues and I view vegetation management from the soil up, striving to understand the soil composition and the vegetation that would benefit the project in many ways—contributing to soil health, stabilizing the site to reduce erosion, promoting beneficial wildlife habitat, and making the visual landscape more appealing for the community.
Yet, vegetation management is anything but simple. Inadequate vegetation planning and management can lead to timeline and cost increases that threaten a solar energy project’s profitability during operation and maintenance (O&M). At SWCA, we see various vegetation challenges across utility-scale facilities that relate to these premises: soil and vegetation are not appropriately considered during project planning, and soil and vegetation management plans are not implemented throughout the construction and operation of a solar energy site. Failure to properly address soil and vegetation resources within solar sites can lead to considerable increases in maintenance challenges and repairs; the cost of addressing these is often 5 to 10 times the cost of implementing proper vegetation management strategies from the beginning.
Green grass with yellow flowers blooming under a Minnesota Solar farm. INTEGRATING ECOLOGICAL VEGETATION MANAGEMENT INTO SOLAR ENERGY SITE DEVELOPMENT PHASES
Each phase of solar energy site development has its own goals and objectives. From a vegetation management perspective, here is what you need to consider for each phase of the project life cycle.
Planning: Siting and Permitting / Design and Engineering
Considerations and decisions made for soil and vegetation management during the planning phase always have substantial impacts during the construction and O&M phases of solar development. First, it is necessary to understand the requirements for vegetation the development may be subject to (local permitting revegetation standards; pollinator scorecards) and create a vegetation management strategy to achieve those requirements. Second, it is just as important to recognize what elements of those requirements are practical in the successive phases. There is often a disconnect between what is agreed to during the planning and permitting phase and what is possible to implement during construction and maintain while operating. At the very least, we recommend having discussions with regulatory authorities on the practicality of such requirements. Planning is not a one-size-fits-all approach.
During the planning phase, vegetation management specialists will want to assess the water availability and the current vegetative and soil conditions across the proposed solar energy site to create the best plan for vegetation establishment based on actual site conditions and desired conditions for operations.
Construction
Consider how the site will need to be developed, and how construction activities and certain applications will guide the direction of vegetation establishment across a site. Generally, the engineering, procurement, and construction (EPC) contractors take on the responsibility to achieve the approved commitments and required actions that became permit conditions in the planning and permitting phase of the project. Yet, the goal of this phase—to build in the most cost-effective and efficient manner—conflicts with the time needed for successful vegetation establishment, which typically extends beyond the construction timeline (more than two years, and potentially greater than five years in arid environments).
During the construction phase, vegetation management specialists will want to carefully handle (or minimize disturbance to) the topsoil, stabilize the soil, establish cover crops and/or nurse crops, plant pioneer species in project seed mixtures, and control noxious and invasive weed species. The benefits and cost savings of this proactive approach will become evident years later during operations; therefore, it is critical to incentivize the EPC to ensure site preparation and revegetation activities are all done right the first time.
Operations and Maintenance (O&M)
The owner/operator inherits the commitments, standards, and challenges that come with vegetation management, for better or worse. Vegetation management decisions, or failure of proper implementation, that carry through the construction of solar energy sites can bear great weight on asset management, future financing, and implications for insurance. Proper vegetation maintenance ensures regulatory compliance while reducing O&M costs in the long-term. Well established native and desired vegetation will successively reduce long-term maintenance costs over the life of the project, increasing efficiency and profitability.
During the O&M phase, vegetation management specialists will want to monitor and evaluate revegetation and soil health recovery, maintain desired long-term vegetation, and incorporate additional ecological solutions to support the entire ecosystem and provide beneficial habitat. My ecological restoration colleagues and I recommend developing an aggressive adaptive management strategy before the operations phase, so that systems are in place to respond to emerging issues (e.g., weed outbreaks, soil erosion, vegetation losses) before they become expensive management problems.
Various flowers thriving beneath solar panels FREQUENTLY ASKED QUESTIONS REGARDING VEGETATION MANAGEMENT
Our team of experts at SWCA consistently hear the following questions when discussing these topics with solar industry professionals (developers, builders, contractors, owners, operators, and asset managers).
What will improve long-term budgeting for vegetation management and maintenance?
Vegetation management is expensive and rarely appropriately budgeted. Poor vegetation management design or inadequate implementation in any of the project phases can escalate costs by an order of magnitude. Therefore, budgeting adequately for effective implementation and ongoing maintenance will save money and headaches. But how can this be done?
We, the solar industry, need to start blending the phases of the development life cycle of a utility-scale or distributed generation solar site to improve long-term budgeting for vegetation management and maintenance during operation. It starts with better communication across the teams leading the various project phases. Those who will manage the site need to have conversations with the developers to understand the vegetation management consensus and permit conditions. In an even more proactive approach, site managers would have a voice in the permitting agreements during the planning phase. Once a plan is ready, further conversations need to happen with the EPC contractor before construction begins.
How is soil affected during construction and O&M? And what can be done to maintain or improve soil health?
Soil is certainly affected during construction when clearing and moving soil, primarily through the improper handling of topsoil and the potential mixing with subsoil that can result.
Topsoil and subsoil have very different biological, chemical, and physical attributes, and topsoil is like an ecologist’s gold with a nutrient- and mineral-rich composition. If developers take care of the topsoil and preserve the properties that impact soil health and plant growth, desired vegetation is much easier to reestablish. This also fosters a positive feedback loop, where maintaining desired, native vegetation feeds into promoting and maintaining long-term soil health. If subsoils are left at the surface or mixed with topsoil, it risks exposing salts and other soil-limiting properties that will restrict revegetation potential.
Questions to address in the vegetation management plan before construction include: What soils are the team working with? Are there any notable limitations (chemical, physical, other)? What is the team doing with the topsoil? Is the team going to salvage soil, or is leaving the topsoil in place an option? (Note, leaving topsoil intact and protected [where possible] is generally a more effective restoration strategy than salvaging and redistributing soils.) How is the team addressing the compaction of soil when heavy equipment moves across the site? And finally, how is the team redistributing the most important resource to support vegetation—the topsoil? What actions are the team taking to further promote the establishment of vegetation? In other words, how is the team preparing the site to grow the desired native vegetation?
Why is seed mixture design critical to the success of vegetation management on utility-scale solar sites?
A well-designed seed mixture accounts for the vegetation that will grow well within a site, which doesn’t always align with what someone wants to grow there. A solid seed mixture should also consider the number of seeds per square foot, how different species will interact with each other, and how desired species can compete with weeds in the short and long term.
Taking time to design targeted seed mixtures across a site for different objectives will go a long way in facilitating the establishment of vegetation. Generally, my colleagues and I recommend having a buffer seed mix (for areas within the site that do not have operational infrastructure; these may include elements like access roads, retention ponds, sediment basins, or undisturbed areas), an array seed mix (for areas under operational infrastructure), and other seed mixtures that consider the hydrology and other resources within the site.
What is the benefit of a well-designed vegetation management strategy?
Consider the long-term value of well-designed vegetation management strategies and the ecological benefits that healthy native vegetation can bring to your site. Implementing these strategies can provide tangible benefits such as carbon sequestration from deep-rooted perennial plants, healthy soils, and clean water.
By incorporating high pollinator-friendly scores into vegetation management plans, you can foster positive public opinion and create opportunities for community engagement and stewardship. This approach includes educational initiatives, community involvement, and environmental awareness programs that strengthen the bond between your project and the local community. Dive deeper into this topic with our The Perks of Pollinators: How Natural Habitat is Heating Up in the Solar Industry article.
Tailoring strategies to meet the specific goals of individual projects, with a focus on sustainability and stewardship, helps comply with environmental permitting requirements and adheres to regulations and policies that protect and enhance the natural landscape. Aesthetically pleasing designs that integrate into the surrounding environment promote long-term ecosystem health and foster positive public perception.
As a restoration ecologist, I am passionate about how vegetation management can improve ecological ecosystems in three significant ways:
1. Climate: Promoting renewable energy sources and enhancing carbon sequestration directly contribute to climate change mitigation.
2. Water: Strategies that help retain water and protect water bodies from sedimentation ensure the health and sustainability of local water resources.
3. Biodiversity: Promoting biodiversity supports wildlife and attracts beneficial species, contributing to a thriving and balanced ecosystem.
SWCA stabilized large-scale erosion at Davidson County Solar Farm, NC, by armoring flow areas, redirecting runoff, and implementing a native plant and pollinator re-vegetation strategy.TAILORED VEGETATION MANAGEMENT STRATEGIES WITH SWCA
At SWCA, we specialize in providing vegetation management strategies and detailed, actionable plans designed for long-term success and sustainability. Our expert team is dedicated to delivering innovative and practical services tailored to meet your specific needs throughout the entire life cycle of your project. Additionally, we enhance the aesthetic appeal and community acceptance of your projects with landscape screening plans and design sets. Our stormwater integration services ensure compliance with environmental regulations while minimizing impact on local waterways.
We offer comprehensive weed management solutions through integrated vegetation management, incorporating mechanical, chemical, and biological methods to maintain optimal site conditions. Our team can define the scope of work for EPC contractors, ensuring clarity and efficiency in project execution, and help streamline your EPC contractor contracts by identifying and removing unnecessary elements, thereby reducing costs and complexities. We provide thorough performance inspections and environmental compliance monitoring to help your project meet all regulatory requirements and operate at peak efficiency.
Our adaptive management approach allows for continuous improvement and adjustment of strategies based on real-time data and changing conditions. Additionally, we offer forecasting services to predict and plan for future vegetation management and maintenance needs, ensuring your project remains sustainable and cost-effective.
We encourage the solar development community to continue discussing vegetation management across the development life cycle of utility-scale and distributed generated solar. Partner with SWCA to support the success of your solar energy projects from planning and permitting through construction and operation. Together, we can achieve beneficial ecological outcomes, strengthen community connections, and promote environmental stewardship.
MEET THE EXPERT
Nate Wojcik, Principal Restoration Ecologist
With more than 20 years of experience, Dr. Nate Wojcik provides a wide range of ecological and environmental research services to clients in the renewable energy, oil and gas, transmission, mining, and land development industries. View bio.