Shoney Renewables Consulting South Africa (SRC- SA) recently delivered the first ornithological collision risk modelling (CRM) in South Africa using the Band (2007)  model for G7 Renewable Energies, a leading developer of wind farms in South Africa.
The study brought together UK and South African ornithological experts together to examine and predict the likely collision risk associated with a consented wind farm in the Karoo focussing on Verreaux’s Eagle, Martial Eagle and Booted Eagle. The terms of reference for the CRM were drafted between G7 and Birdlife South Africa and utilised the Band (2007)1 CRM model, as extensively used in the UK.
The study began with an examination of field data and earlier previous environmental impact assessment reports carried out by Anchor Environmental, in the context of international literature and relevant raptor modelling approaches from other countries with substantial onshore wind capacity installed and similar raptor concerns as encountered on site (such as Golden Eagles in Scotland and the USA, White-tailed Sea Eagles in Norway and raptors in Spain).
SRC-SA brought in their UK CRM expert, Dr Steve Percival to carry out the modelling. A renowned expert in CRM, Dr Percival has carried out more than 500 CRM’s for wind farms including Golden Eagle to assess Scottish wind farms. SRC- SA worked with local experts including Dr Rob Simmons, (from the Percy FitzPatrick Institute of African Ornithology) who brought invaluable experience of local raptor habitat preferences and knowledge of the behaviour of the selected bird species of concern. Dr Simmons has detailed knowledge of the Karoo, and experience of the proposed wind farm site gained from his field work on behalf of Anchor Environmental.
SRC-SA conducted collision risk modelling based on international best practice to determine and classify collision risk across the entire wind energy facility site, and to model different layouts and input parameters to ‘stress- test’ the model. SRC-SA drew up recommended mitigation measures based on the results of the collision risk modelling and after considering the key issues in order to reduce the predicted impacts of the wind farm on birds to an environmentally acceptable level.
The layouts which were modelled were as follows:
- The initial 70 WTG layout using Turbine Type B.
- The 40 WTG layout using Turbine Type C that was authorized by the Department of Environmental Affairs.
- The 27 WTG Layout current at the start of the CRM study using Turbine Type A.
- The 27 WTG layout but with two turbines (located within an area of higher eagle use) removed, using the same Type A turbine.
- An updated ‘reduced eagle collision risk’ 27 WTG layout with 5 turbines moved from an area of higher eagle activity to a lower activity area, using the same Type A turbine.
As the Band 2007 CRM model has very specific data input requirements, there were understandably a number of issues identified with the baseline data which were not collected with CRM in mind. These issues included a) lack of recording of flight times b) the viewing distances from the vantage points were in some cases rather long in comparison with the maximum usually used c) flight heights were recorded to wide zone bands that did not perfectly match up to the proposed turbine/rotor heights d) 360-degree viewing which may have reduced detectability overall and e) low numbers of juvenile flights for the Verreaux’s Eagle which necessitated using a precautionary theoretical approach to estimate the number of juvenile flights compared with adults. These challenges were resolved using theoretical mathematical approaches, and were agreed between the local and international experts.
The study resulted in multiple wind farm layout design iterations, additional site visits to assess the potential for relocating turbines, a rapid coarse GIS terrain modelling exercise, and an assessment of bird flight behaviour and avoidance rate to be allocated to species and life stages. Once the model input parameters and differing layouts options were agreed, collision modelling was repeated until a preferred layout was identified.
The final preferred layout took account of appropriate species-specific buffer zone (which in themselves took account of differing juvenile v adult risks) as well as turbine types, terrain, and wind speeds. The final modelled results were considered in terms of conservation importance at the regional, and national level and necessitated reaching agreement on population estimates particularly at the local Karoo level.
Nicolas Rolland Director of G7 said: “It’s been a real pleasure and relief to work with Shoney Renewables Consulting. They demonstrated a clear understanding of our challenges and were able to provide objective, constructive and practical recommendations to balance both conservation and project development needs. Shoney’s wealth of experience in the renewable energy industry joined with a genuine interest in finding viable compromises is a breath of fresh air in the local nascent, inexperienced industry. We will most definitely re-appoint Shoney going forward.”
Nathalie Stevenson the Director for SRC – SA said “SRC-SA worked very hard to deliver a highly transparent collision risk model based on best available knowledge, and deliver a workable and environmentally acceptable layout for the client, particularly as it was the first CRM carried out for a South African wind farm. More importantly, all the parties made a concerted effort to contribute and share information to create as complete a picture of raptors at the site as possible, and ultimately this paid off, as the contributors reached agreement on methods, preferred wind farm layout and the final modelled results. It was extremely satisfying to realise that all parties learned something from the collaboration and that this knowledge and experience will benefit future South African wind projects.”
More information on G7 Renewable Energies can be found here http://www.g7energies.com/
 Band, W, Madders, M, and Whitfield, D.P. 2007. Developing field and analytical methods to assess avian collision risk at wind farms. In: Janss, G, de Lucas, M and Ferrer, M (eds.) Birds and Wind Farms. Quercus, Madrid