Risk of seabirds colliding with offshore wind turbines less than half than expected

THE risk of seabirds colliding with offshore wind turbines is less than half of what would be expected, new analysis has suggested.

A major collaborative study found that seabirds avoided wind turbines more than previously thought and changed their flight path to do so.

Experts said the conclusions from the research on collision risk will allow better-informed wind farm design and decisions on planning consent.

The Offshore Renewables Joint Industry Programme (ORJIP) bird collision avoidance study combined human observer-based tracking with a system that automatically recorded seabird movements at a working offshore wind farm. Radars were also used to record data 24 hours a day for two years.

During the two years of fieldwork, a significant number of videos were recorded at a representative area of Vattenfall’s Thanet offshore wind farm off the Kent coast.

This resulted in the analysis of more than 600,000 videos, of which only 12,131 contained evidence of bird activity and only six collisions with turbines were observed.

The collaborative study was commissioned by eleven leading offshore wind developers, The Crown Estate, The Crown Estate Scotland and Marine Scotland.

It was supported with funding from the UK Government and was managed by the Carbon Trust.

Jan Matthiesen, director offshore wind at the Carbon Trust, said: “Today marks the result of four years of collaborative work from a range of stakeholders, all focused on bridging the gap between the theoretical and real understanding of how birds behave around an operational offshore wind farm.

“In March 2018, offshore wind generated 12% of the UK’s total energy, its highest contribution to date.

“ORJIP offshore wind has been designed to help contribute to the environmental evidence base to pave the way for a sustainable roll-out of UK offshore wind.

“This study marks a significant step forward on this journey.”

To obtain planning consent for an offshore wind development, the developer needs to provide evidence of how seabirds will behave within and around the farm.

In order to quantify bird collision risk with turbines, collision risk models (CRM) are used to estimate the impact.

The research was designed to generate robust, empirical evidence on the levels of avoidance behaviour and collisions to improve CRMs, as researchers say that until now there was only limited evidence to substantiate the birds’ actual behaviour.

Piers Guy, UK country manager for Vattenfall, said: “This pioneering study, hosted at Vattenfall’s Thanet offshore wind farm, is a significant step forward in our understanding of the way in which seabirds avoid offshore wind turbines and comes at a crucial time as the next generation of wind turbines are designed and developed.

“This research will support UK Government plans to rapidly and sustainably grow the offshore wind sector by 2030.”

Scottish Government energy minister Paul Wheelhouse said the study provides “invaluable data” for understanding the potential impact of offshore wind developments on seabirds.

He said: “The data yielded will, therefore, be of great help to inform our offshore wind consent and planning process, and help achieve our objective of growing a sustainable offshore wind sector whilst preserving Scotland’s much-loved wildlife.”