Hares and skylarks emerge as the prominent wildlife inhabitants of UK solar farms, as revealed by the largest survey conducted in the sector to date.
Both species are deemed vulnerable, with skylarks, renowned for their melodic springtime songs, now red-listed due to significant population declines in recent years. The survey, encompassing 87 sites, documented a total of 279 skylarks last year. Additionally, sightings of other red-listed bird species such as yellowhammers, linnets, and starlings were recorded, along with occasional glimpses of spotted flycatchers, corn buntings, and nightingales.
Among mammal observations, the brown hare, a species of conservation concern, comprised 40% of recorded sightings. Other mammals documented included badgers, foxes, rabbits, weasels, common shrews, field voles, and three species of deer. However, it is likely that these figures underestimate the true population, as field surveys were conducted during times when these animals are less active.
The survey also identified the presence of the small heath butterfly, a species crucial for biodiversity conservation that has experienced declines across the UK, at ten sites. Scarce species such as the amber-listed Dartford warbler and the red-listed tree pipit were also observed, alongside the legally-protected common rosefinch—a rare visitor to the UK, making an unexpected appearance.
The report underscores the potential of solar farms to serve as biodiversity havens, playing a pivotal role in nature restoration efforts nationwide.
Furthermore, the study indicates a positive correlation between plant species diversity and the presence of invertebrate species, which, in turn, contributes to the diversity of bird species.
Solar farm meadow rich in wildflowers. Credit: Hollie Blaydes
The ecological survey was conducted by Clarkson & Woods and Wychwood Biodiversity last year, utilising a standardised methodology developed collaboratively with Solar Energy UK and Lancaster University in 2022. The expanded survey analysed 50 additional sites compared to the initial assessment, reflecting a broad geographical distribution mirroring that of the industry.
However, it’s important to note that the new dataset may not be directly comparable to the initial report due to variations in the frequency of biodiversity monitoring, as well as the influence of seasonal factors and weather conditions on the results. Over time, the aim is to accumulate data from consistent locations across multiple years, enabling the identification of trends and changes in management practices. It is anticipated that this methodology will be adopted by more ecological consultancies and applied to a greater number of solar farms in the coming years, driven by growing demand for monitoring within the expanding solar sector. The increased data collection from numerous sites enhances the reliability of the findings.
Also Read: The leading Solar Hotspots in England Are Revealed
Nevertheless, the latest results underscore the success of biodiversity promotion efforts. Sites managed with a specific focus on biodiversity, incorporating measures such as conservation mowing or grazing, removal of vegetation, and diverse habitat creation, exhibited significantly higher levels of plant species diversity. A similar relationship was observed for invertebrates, with positive correlations between plant and bird species diversity, as well as between bird abundance and invertebrate presence.
Beyond environmental benefits, such findings hold potential economic advantages for the sector, offering incentives for improved habitat management. A complementary study of ten solar farms, also detailed in the report, revealed that habitat enhancement measures such as pond creation, tree planting, and hedge improvement could elevate biodiversity by 8-110%, as assessed by the Government’s biodiversity net gain (BNG) framework. Natural England is leveraging this research to implement BNG standards for solar farms, with a forthcoming case study slated for later this year.
The regulatory framework, which came into effect last month, mandates major developments to achieve a minimum 10% increase in biodiversity, either onsite, off-site, or through biodiversity credit acquisition.
However, solar farms have the potential to exceed the statutory biodiversity targets by a considerable margin. While some habitat loss may occur due to the construction of access tracks, mounting frames, and substations, land occupancy typically amounts to only 2% of the total development area, with panels covering approximately 40%.
Net gain
“Our understanding of biodiversity at solar farms is growing as more ecological monitoring data are collected across an increasing number of UK solar farms. Groups such as birds and invertebrates appear to respond positively to biodiversity-focused management at solar farms and we hope to continue working with the data to further unpick the patterns identified,” said report analyst Hollie Blaydes, PhD Researcher at Lancaster Environment Centre, Lancaster University.
Butterflies at a solar farm. Credit: Hollie Blaydes
We are thrilled to witness further evidence showcasing the indispensable role of solar farms in nature restoration. Solar Energy UK is dedicated to collaborating with the industry to continuously enhance this knowledge base,” remarked Chris Hewett, Chief Executive of Solar Energy UK.
The significance of these findings is underscored by the publication of the first peer-reviewed scientific paper on insect pollinators on UK solar farms, which appeared last month in the journal Ecological Solutions and Evidence. Authored by Blaydes and colleagues, the study, led by Lancaster University in partnership with the University of Reading, surveyed 15 sites throughout 2021.
The research revealed that enhancing the diversity of flowering plant species is pivotal in augmenting the abundance and variety of bumblebees, butterflies, and hoverflies. Interestingly, the study found that the variety of flowering plants is more influential than the sheer number of plants present. Moreover, the paper noted that solar farms serve as crucial biodiversity hotspots within landscapes that may otherwise lack wildlife habitats.
The Solar Energy UK report comprises a collection of case studies.
Utilizing eDNA: Environmental DNA, which consists of genetic material left behind by wildlife, has been employed for the first time to assess the presence of vertebrates on solar farms. While this technique may not always pinpoint wildlife to the species level, it offers a means to confirm the existence of elusive species such as polecats, harvest mice, and otters.
Cultivating shade-tolerant wildflowers: Planting plugs and pot-grown plants beneath the panels has proven significantly more successful than seed sowing, with survival rates of up to 80% observed after two years. Wild garlic and bluebells demonstrated optimal growth, while lesser celandine and wood anemone performed less robustly. These species collectively create a vibrant array of spring blossoms, providing crucial nectar sources for insects.
Championing chamomile cultivation: A trial revealed the feasibility of achieving commercial yields of annual chamomile between rows of solar panels, showcasing the application of the ‘agri-PV’ concept.
Solar Energy extends its gratitude to Bluefield Solar Income Fund, Eden Renewables, RES, NextEnergy Capital, Gridserve Sustainable Energy, Foresight, and JLEN for their contributions to the report.
