X-shaped Radical Offshore Wind Turbine for Overall Cost of Energy Reduction (X-ROTOR)

We conducted a comprehensive review of flight behaviour, sensitivity to disturbance and conservation status for the 81 seabird species present in European water and calculated the corresponding Collision and Displacement Vulnerability Indices (see deliverable D7.9 and D7.10). We combined those indices with distributions of 12 commonly occurring seabird species in the North-East Atlantic to generate vulnerability maps for breeding, wintering and migration periods when risk is likely to vary (see deliverable D7.10).

We identified 60 species for which further data collection is necessary to reduce uncertainty about vulnerability to wind turbine collisions. We also identified areas of higher vulnerability at the European scale, highlighting where further surveys, monitoring, tracking studies, or mitigation might be needed. During the fieldwork seasons (summer 2021 and 2022), we have been working to fill these gaps by deploying a wide variety of loggers on species identified as relevant in our previous analyses (Atlantic puffin, Manx shearwater, Northern gannet, Storm petrel, Lesser Black-backed gull). Methods and preliminary results have been described in the deliverable D7.11, providing a methodological framework and data to discuss and refine the results described in previous deliverables.

Using GPS data, we will be able to verify the accuracy of the vulnerability maps as well as collect more critical flight height information. We also deployed acoustic recorders within the colonies and on-board to better understand the acoustic cues typically experienced by seabirds. In total, more than 120 individuals have been equipped and the excellent recapture rates allowed to update the Collision and Disturbance Vulnerability Index calculated in D7.9.

We reviewed seabird auditory sensitivity and compared it with the turbine sound spectra and concluded on the detectability of the turbine: depending on the location of the bird (upwind/downwind), noises emitted at frequencies between 0.5kHz and 1kHz by the turbine might be detectable at 200m by some species, potentially decreasing their collision risk. The next step is to use noise propagation model to assess this detectability from further.

Finally we built a “cradle-to-grave” model to assess the overall carbon emission of the XROTOR project and are currently waiting material inventory to implement it.