Collision-risk modelling

Presence of Marine Renewable Energy Devices (MREDs), such as wind or tidal turbines, poses potential risks of collision between turbine blades/rotors and wildlife, including birds, bats, fish, and marine mammals.

Assessing the risk of collision between these structures and wildlife is crucial to address the strategic, operational, mitigation, and compliance aspects of a project.

Several models have been developed for assessment of collision risk. Commonly used are the Encounter Rate Model, ERM (Wilson et al., 2006), Collision Risk Model, CRM (Band, 2000; Band et al., 2007), and Exposure Time Population Model, ETPM (Grant et al., 2014). 

Each model has several pieces of information that are required as inputs, these can include:

  • Time period;
  • Turbine data (e.g. rotor/blade specifications, rotational speed, non-operational time, etc.);
  • Animal data (e.g. observed animal density, number of observed animals, species’ body measurements and flying/swimming behaviour, etc.);
  • Behavioural data (e.g. foraging duration, dive frequency, surface time, number of foraging trips in period, etc.); and, 
  • For tidal turbines, current data (speed, channel depth, etc.).

Selection of which model to use is dictated heavily by the specific circumstances that surround the scenario/s for which investigation is sought, including turbine design; therefore, a free initial consultation with OSC’s experts is required to identify the most suitable model. In some instances, one of these standard models may not be appropriate, and development of an alternative approach is required. Outcomes of collision-risk models can also be inputted into a Population Consequences of Disturbance (PCoD) modelling framework to increase utility of results, a service in which is also provided by OSC (e.g. OSC, 2019). 

Contact (+44 (0)1368 865 722) to find out how OSC can estimate collision risk of your wind or tidal turbines.



Band, W. (2000): Windfarms and birds: calculating a theoretical collision risk assuming no avoiding action. In S. N. Heritage (Ed.): Guidance Notes Series. Scotland.

Band, W., Madders, M., and Whitfield, D.P. (2007): Developing field and analytical methods to assess avian collision risk at wind farms. In M. De Lucas, G. Janss, and M. Ferrer (Eds): Birds and wind farms: risk assessment and mitigation. Quercus, pp. 259-275.

Grant, M., Trinder, M., and Harding, N. (2014): A diving bird collision risk assessment framework for tidal turbines. 773. Scottish Natural Heritage. 1-38 pp.

OSC (2019): Interim population consequences of disturbance (iPCoD) for harbour porpoise, bottlenose dolphin, minke whale, and grey seal from Aberdeen Harbour Expansion Project (AHEP) Technical Report No. 7 for Dragados. Ocean Science Consulting Limited, Spott Road, Dunbar, Scotland. 40 pp. PAGES 352-391 here

Wilson, B., Batty, R., Daunt, F., and Carter, C. (2006): Collision risks between marine renewable energy devices and mammals, fish and diving birds: report to the Scottish executive. Scottish Association of Marine Science, Oban, Scotland. 90 pp.

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