Ground-mounted solar photovoltaic (PV) systems
In the UK, large solar PV systems are almost always ground-mounted. These present a negligible collision risk and do not electrocute, dazzle or burn Barn Owls. In fact, solar PV ‘farms’ have the potential to be of great benefit to Barn Owls as the array frameworks are typically at a height from which Barn Owls can perch-hunt. In order to benefit Barn Owls, the grass below and around the arrays should be allowed to develop into good Barn Owl foraging habitat – rough tussocky grassland with a litter-layer not less than 70mm deep.
The fact that most solar PV arrays in the UK have bare ground or short grass beneath them is a huge waste of space. Rough grassland, and the biodiversity it supports, is completely harmless to the arrays, no more costly to manage, and of huge benefit to wildlife.
Our recommendations for new solar PV systems
For industrial-scale solar farms we recommend that a full Environmental Assessment be carried out, including desktop surveys and an assessment of the likely impact of the proposal on both Barn Owl roost/nest sites and foraging habitat before planning permission is considered. This is especially important where roost and nest sites and/or suitable foraging habitat is to be removed or lost. Where this is the case, it should be mitigated or compensated for in line with guidance contained in Barn Owls and Rural Planning Applications – a guide 2015.
Irrespective of the size of the proposed array, and at existing solar PV sites, opportunities to enhance habitat for the benefit of Barn Owls should be taken unless the proposed solar farm is within 1 km of an unscreened major road (dual-carriageway or motorway).
Other solar systems and their hazards
Some solar systems represent a risk to birds. Solar power towers, such as those in use in Southern California, are responsible for the deaths of many different species of birds. Hundreds of mirrors capture the sun’s rays and reflect the energy towards a water tower. The water in the tower is heated to steam, which then runs a generator that produces electricity. Injuries are caused by either impact trauma against the tower or solar flux injuries. Solar flux results in the scorching or incineration of some species due to the high temperatures generated around the tower. However, given our climate, it is unlikely any such systems will be developed in the UK.