There is no doubt about the significance of renewable energy as a means to help curb the effects of climate change.
Solar energy has proven to be one of the cleanest, cheapest and most abundant energy sources available today, and is highly effective at eliminating leading factors that contribute to our warming planet.
Conversely, with the U.S. solar market growing rapidly, concerns arise about the environmental impact both during and after construction.
RP Construction Services (RPCS) is in the business of solar site construction and solar tracker installation on sites ranging from 2 MW to 100 MW. In each of my visits to one of our sites, I never fail to spot some incredible wildlife. From horned lizards to pronghorn antelope, I’ve seen an array (pun intended) of both plant and animal life in and around our solar sites — and both seem to be thriving. I decided to do some thorough research on the topic, and this article presents my findings.
The construction of a solar site can cause short-term disturbance to the local environment — including factors such as noise, site grading, greenhouse gas emissions, soil erosion and compaction from heavy equipment used to construct the arrays. However, these are only temporary impacts and can be minimized through careful planning and execution.
Comparatively, solar site construction is not nearly as destructive as other types of large-scale energy construction or extraction projects — coal extraction, surface mining and oil drilling are a few examples.
Once the site is constructed, solar energy is completely free, produces no pollution, no emissions and no noise, which means generating solar power produces no carbon footprint. Solar also uses zero water per megawatt hour to operate, compared to a coal plant’s 1,100 gallons per megawatt hour, nuclear’s 800 gallons and natural gas’s 300 gallons.
One particular study conducted at one of the world’s largest solar sites, the 550-MW Topaz Solar Farms project in California describes specifically how “responsibly developed large-scale PV facilities can provide sanctuaries for flora/fauna to thrive,” proving that such developments can support biodiversity in the long term.
When responsibly and sustainably developed, large-scale PV projects can provide shelter for sensitive species, promote land stability, preserve habitat and support biodiversity. These sites have the potential to become sanctuaries for plant and animal life.
Siting and assessments
Proper siting of a parcel of land for potential solar use is important; the incorporation of thorough surveying in the planning process can ensure each site is properly investigated prior to construction. Any utility-scale solar project requires investigation into and evaluation of potential environmental impacts, including those imposed upon wildlife and their habitat.
Professional, licensed and experienced biological and geological surveyors are hired on every site to ensure ground disturbance is kept to a minimum and site boundaries are obeyed. Proper biological surveying can help identify sensitive species and highlight any potential wildlife-facility conflicts, both before and during construction. In some cases, archeologists will be brought on site to assess the presence of historical artifacts. Native American tribal representatives will work closely with contractors to make sure sensitive items are collected and dealt with appropriately prior to construction.
Avoidance measures, such as creating buffer areas on the site or relocating sensitive species, help confirm that construction activities are environmentally conscientious. Biologists work closely with construction crews to make sure buffer zones are respected. In the case of a sighting of a sensitive species, measures can be taken to temporarily halt construction or reexamine the need for additional buffer zones. Biologists often accompany crew members during operations, especially while operating machinery, to ensure responsible development. Oftentimes, biologists onsite can outnumber construction crew members.
One particular RPCS-installed site in Lost Hills, California, required navigating a changing construction plan due to several sensitive species on site: the coachwhip snake, kangaroo rat, antelope squirrel, blunt-nosed leopard lizard (a federal- and state-protected species) and kit fox (a state-protected species). The site was built with proper compliance to permits that regulate the level of disturbance or harm, and now provides protection from predators and from the elements (in the form of shade) for these species.
While working around sensitive flora and fauna species can pose a number of challenges to the construction process that may slow progress, proper survey and proactive measures to protect sensitive species is paramount to practicing responsible development of large-scale solar sites.
More often than not, solar sites are fenced for security purposes — to protect the landowner and the site owner’s clean energy investment. Cordoning off a sizable land area ensures that it is largely undisturbed for the life of the site. This is beneficial for more reasons than keeping any intruders away from the solar array.
Flat land is preferred for most solar sites. However, the sites compete with other land uses that require minimal terrain fluctuation. Sites are often surrounded by agricultural, grazing, recreational or residential land that can pose ongoing threats to flora and fauna. Effective fencing alone can preserve the acreage inside the fence from substantial disturbances and degradations that occur outside the fence. Consequently, the land isolated within a solar site’s boundary can create a perfect haven in an otherwise volatile location.
What’s more, fencing can be designed to exclude top predators for small mammals as well as aid plant regrowth and natural habitat creation for the local animal life, enabling challenged species to thrive.
Greenfields, brownfields and brightfields
Brownfields, or brownfield land, is a term used to describe any previously developed land that has been abandoned, lays idle or is underutilized, whether contaminated or not, that still has potential for redevelopment or economic opportunity.
Brownfields can be an ideal location for solar sites. Building on previously disturbed land, like a former landfill or land no longer suitable for agriculture, eliminates the necessity to develop undisturbed land. The potential for habitat loss is greatly reduced and serves as a better utilization of space.
Brownfields converted to solar fields, defined appropriately by the U.S. Department of Energy as “brightfields,” are becoming increasingly popular to developers moving away from “greenfields,” or undeveloped lands. Greenfields are becoming scarcer and can often be expensive.
There are a number of value propositions posed by brownfields, including close proximity to grid interconnection points, reduced land costs and high potential for profit, as most brownfields have associated maintenance costs that can now be offset by profits by converting to a solar brightfield.
In some cases, state and local governments offer tax incentives or streamlined permitting to encourage turning brownfields into once-again productive parcels, lessening the pressure to find and develop greenfields.
Brownfields present an opportunity to invest in solar energy. By concentrating utility-scale solar developments on otherwise unusable land, some of the potential downsides, such as ecological impact, are greatly reduced.
The Topaz Solar Farm’s study previously mentioned showed that vegetation productivity was not affected by the development of the solar site. The vegetation had the ability to return to its native state, along with associated fauna, free from predators. Thick vegetation must be cleared in the short term in order to install the solar system, but can regrow or be replanted, as studies have shown.
In some cases, land previously used for agriculture necessitated regular removal of problematic vegetation like weeds or invasive plant species. The use of fertilizers and pesticides on solar sites can be eliminated, leading to overall better health of the surrounding environment.
Tests showed that solar sites generally have higher percentages of ground cover compared to surrounding areas, providing both a food source and protection for natural fauna, with the added benefit of dust control for modules — another factor that limits disturbance caused by site maintenance by way of module washing.
Several studies have proven that vegetation can grow well even in the shaded areas beneath the panels, receiving adequate sunlight and shade as well as moisture from condensation or rain runoff from the panels — which is more evenly distributed with solar tracker systems versus fixed-tilt systems.
Symbiotic relationships can occur between solar sites and native plants — or even crops, as seen in agrophotovoltaic practices — and can create pollinator-friendly environments.
One study conducted by the National Renewable Energy Laboratory proved that revegetation of solar sites after construction was not only possible but could provide sufficient ground cover to control erosion and restore wildlife habitat. Moreover, successful establishment of low-growing plants and grasses would not interfere with solar panels’ energy production and would minimize fuel load for potential wildfires.
The return of vegetation, whether naturally or introduced, can support wildlife cover, nutrient cycling, soil retention and carbon sequestration.
Building on slope to avoid grading
RPCS specializes in installing Array Technologies’ DuraTrack HZ v3 single axis solar trackers for developers and EPCs nationwide. Array trackers can be installed on existing topography, without the need to grade the designated land parcel.
Array’s terrain flexibility addresses both elevation change as well as parcel boundary constraints on slope angles as high as 37°. This combination of unique technical design and robust architecture make it the most adaptable system for following natural land contours, ensuring both ease of installation — and ultimately less time spent onsite during the construction process — and a significant reduction in ground disturbance traditionally caused by site grading.
By avoiding site grading, the duration and severity of ground disturbance is greatly reduced. Additionally, following existing ground surface contours preserves the land’s natural drainage patterns of ground water, which means less pressure is put on surrounding ecosystems.
RPCS’s Plug-N-Play tracker solution, customized to the Array system, utilizes above-ground wire management solutions to eliminate the need for trenching — and further degradation of ground surfaces.
Developing methods to install solar sites without grading or trenching can significantly mitigate environmental impacts on the landscape and minimize invasiveness.
From an environmental perspective, any type of energy production has its associated drawbacks. The impacts of a solar site on wildlife — both during construction and long term — is complex. Additional research is desirable before any definitive claims can be made, both for and against solar sites and their ability to provide sanctuary.
To date in this emerging industry, it’s been shown that not all is lost once a solar site is constructed. In fact, the vegetation returns, and associated fauna can return, too, to its natural state — and perhaps even flourish. Learning how best to reduce disturbance on future projects will play a key role in preserving biodiversity and land conditions.
Understanding the effects of construction projects on local environments will dictate the future of environmentally conscious construction. Devising ways to minimize habitat destruction is paramount in aiding vulnerable species to persist.
Many agencies have imposed guidelines for solar sites when it comes to protecting biodiversity and habitats, and new research informs amendments to these guidelines.
The cooperation of lawmakers, community leaders and developers to conduct research with qualified ecologists and geologists, devise responsible methods and impose tighter regulations and enforcement on construction firms is fundamental to elevating stewardship of the environment.
Low-impact solar development and more environmentally responsible construction practices will lead to reducing the negative effects on local habitats and potentially sensitive species, creating a place where flora and fauna can thrive.
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