RWE's Sofia Offshore Wind Farm will be the first UK offshore wind farm to integrate both light detection and ranging (LiDAR) and traditional digital aerial surveys in a single aircraft for its pre-construction ornithology surveys. Two UK consultancies – aerial survey company APEM and ornithological consultants NIRAS – have been engaged by Sofia to develop the project’s Ornithology Monitoring Plan and carry out the work.Twelve surveys, gathering data on potentially thousands of individual birds, will be carried out over two years before the 1.4GW wind farm’s offshore construction begins on Dogger Bank in late 2023. The surveys will look primarily at kittiwakes during their breeding season although data on other bird species and marine mammals will also be collected.
Two aircraft provided by UK aviation firm Ravenair will be equipped with APEM’s combined LiDAR and digital hi-resolution camera equipment to capture data and images of birds and marine mammals. By collecting the height data and images at the same time, individual flying birds can be matched with LiDAR points.Through a remote sensing technique that uses light pulses to measure ranges, when installed on a survey aircraft, LiDAR can identify the height of birds in flight to an estimated accuracy of within one metre over the sea surface. The two aircraft carrying out Sofia’s pre-construction surveys will fly at 450 metres altitude to minimise any risk of disturbance to the birds being measured. They will traverse survey lines spaced two kilometres apart across the whole array area, with each aircraft will survey half of the transects to ensure the full 593 km2 wind farm site is covered.
The surveys will be completed by the end of summer 2022. All data will be made publicly available for further strategic research projects, which will help ornithologists, developers and regulators better understand how birds interact with wind farms, particularly with wind turbines.
