Is Graveney the right location for such a large solar development?

Despite the rapid increase in solar farms, little research has been conducted on their impact on biodiversity or ecological implications.  The majority of research found was commissioned by renewable companies, and no research was found on solar panels positioned with dual orientation.  This clearly demonstrates that more focussed research is required.

In principle, the RSPB [1] support all forms of solar energy technology provided they are developed in suitable locations.  If the site is already valuable for wildlife, particularly if it is in or near a protected area, the scheme will require greater scrutiny as there is potential for significant impact.

The RSPB identified a number of impacts on wildlife including:

  • Insects that lay eggs in water (e.g. mayflies, stoneflies) mistake solar panels for water bodies (due to reflection of polarised light). Laying their eggs on the panels reduces their reproductive success.  This ‘ecological trap’ could have wider impacts on rare or endangered aquatic invertebrates or birds, who rely on these insects for food.
  • Security fencing is a barrier, restricting the movement of wild mammals and amphibians, and presenting a collision risk for some bird species. RSPB suggest little scientific evidence exists for fatality risks to birds associated with solar PV arrays. As birds can strike any fixed object, this lack of evidence might reflect an absence of monitoring effort rather than an absence of collision risk.
  • Loss of habitat for rare arable weeds, invertebrates etc.
  • Land use change impacts could result in direct habitat loss, habitat fragmentation and/or modification, and disturbance/displacement of species during construction and maintenance activities.

Research on single orientation panels, with wide swathes of open ground either seeded with wildflowers or grazed on by sheep, conclude that solar farms are beneficial to biodiversity.  Studies funded by a number of renewable companies [2] concluded that solar farms increased biodiversity in botany, invertebrates, birds and bats.  A study commissioned by Orta Solar [3] state that, where solar farms implement management focused on wildlife, an increase in biodiversity can be detected across a number of different species groups.

The Solar Power Portal [4] suggest there is no problem with building solar farms next to nature reserves as they buffer them and keep them from development.  For important local EU protected nature reserves, consideration must be given to whether they have an adverse impact.  They assert it has been proved that swans do not see solar arrays as bodies of water for landing on, and that studies in Kent showed lizards and slow worms moving onto a reptile free field within six months of panels being installed.  No evidence was provided to support these findings.

Research by the National Photovoltaic Environmental Research Centre (US) [5] showed the majority of impact to habitat and wildlife is due to:

  • Land occupied by power plant
  • Fences limiting animal movement
  • Dramatic land habitat changes
  • Impacts on hiding spots, preying strategy, and food availability
  • Soil sometimes scraped to bare ground, kept free of vegetation with herbicide, or vegetation allowed to grow but mowed regularly
  • PV panels casting shadows and changing the microclimate, causing an unstudied effect on vegetation

The European Commission Science for Environmental Policy [6] also highlighted microclimate impacts.  Soil under panels is up to 5.2⁰C cooler in spring and autumn, affecting many important plant–soil processes including productivity and decomposition.  They also found that areas under panels were likely to be a source of carbon dioxide (CO2) whereas control and gap areas tended to be a CO2 sink.

[1] RSPB Policy on Solar Energy

[2] The Effects of Solar Farms on Local Biodiversity: A Comparative Study (Hannah Montag, Dr Guy Parker and Tom Clarkson)

[3] Effects Of Solar Farms On Local Biodiversity (Cynthia Shahan)

[4] Solar farms and biodiversity

[5] Environmental impacts from the installation and operation of large-scale solar power plants

[6] Solar park impacts on microclimate, plants and greenhouse gas emissions