EVIDENCE REVIEW OF THE IMPACT OF SOLAR FARMS ON BIRDS, BATS AND GENERAL ECOLOGY (NEER012)

 
EXECUTIVE SUMMARY

i. The UK energy landscape is partially orienting towards renewable electricity generation. Recently, this has begun to include solar PV (photovoltaic) technologies.

ii. Solar PV technologies exist at a distributed scale (e.g. roof mounted solar panels) and at utility scale (i.e. solar farms) in the UK.

iii. Utility scale solar PV developments are likely to have a greater ecological impact than distributed scale developments due to their larger size and the requirement for new infrastructure. As such, this review will focus on utility scale solar PV developments.

iv. Natural England has identified birds and bats as the taxa most urgently requiring an evidence base for potential impacts relating to solar PV developments. The focus of this review will be on these taxa, however general ecological impacts will also be considered.

v. Around 420 scientific documents with potential relevance to this review were identified using tailored search strings and subsequently screened for evidence relating to the ecological impacts of solar farms. The majority of these documents were of no relevance, and were returned by the literature search due to irresolvable linguistic and conceptual ambiguities. These documents were not considered further.

vi. Grey literature from 37 non-governmental and governmental organizations was examined for evidence of the potential ecological impacts of solar farms.

vii. Twelve rejected planning applications for solar PV developments with generating capacity of > 1 MW in the north west of England were examined to determine whether these rejections were made on an ecological basis.

viii. No peer reviewed experimental scientific evidence exists relating solely to the ecological impacts of solar PV developments.

ix. Some scientific and grey literature data, based upon carcass searches around solar PV developments suggests that bird collision risk from solar panels is very low. There is likely to be more of a collision risk to birds presented by infrastructure associated with solar PV developments, such as overhead power lines.

x. Evidence from both the grey literature and the peer-reviewed scientific literature suggests that protected areas should be avoided when considering site selection of solar PV developments, with some sources suggesting that locations close to protected areas should be avoided also. This recommendation is not quantified in any of the reviewed literature.

xi. Indirect evidence of bird presence is often presented in the engineering literature, where designs for solar panel cleaning devices often cite bird droppings as a contaminant.

xii. Solar panels have the capacity to reflect polarised light, which can attract polarotactic insects, which has the potential to impact their reproductive biology. The polarizing effect of solar panels may also induce drinking behaviour in some bird taxa, where the birds mistake the panels for water.

xiii. Birds and bats should be assessed by taxon or guild, with different behavioural traits and habitat requirements taken into consideration. The potential for solar developments to attract or repel birds or bats should be considered, alongside the potential for negative interactions to occur between these taxa and solar farms.

xiv. Future research should focus on examining the potential of solar PV developments to support biodiversity. The grey literature often refers to mitigation/enhancement practices such as wildflower meadow planting, hedgerow laying and tree planting with some grey literature studies attempting to quantify diversity on solar PV sites. These studies should be formalised and replicated within a scientific framework.

xv. Governmental and non-governmental organisations that provide advice and guidance that may have ecological implications have a duty to contribute to evidence towards their guidance, especially where evidence is lacking. In the case of solar farms, there is almost no evidence and research into their ecological impacts is urgently needed.

• Harrison et al. 2016. Evidence review of the impact of solar farms on birds, bats and general ecology. Manchester Metropolitan University. 125 pp. [PDF]