This study looked at whether the visual, shadow flicker and noise impacts predicted by wind farm developers in documentation submitted with their planning applications are consistent with the impacts experienced once the wind farm is operational.

The research extends our understanding of how local residents experience wind farms in terms of these three impacts. The report makes a number of recommendations for better guidance on how they can be predicted and mitigated. It also identifies several improvements in planning guidance and best practice that have been implemented in the time between the case study wind farms were planned and built, and the present.

The report is particularly valuable as it points to a constructive path towards consistent and valid assessments of visual, shadow flicker and noise impacts, and to how consultation with residents when assessing developments can be improved. It aims to inform any future decisions on changes to Scottish Government online planning guidelines and good practice on managing the impacts of wind farms on local residents.

Ten case studies were selected to include a spread of wind farm sizes, wind turbine heights, environmental assessment process, landscape character, wind farm age, geographical location across Scotland, and consents process, as well as on the basis of having known complaints about visual, shadow flicker or noise impacts. The sites selected represented 4% of the total number of built onshore wind energy developments in Scotland in 2013.

Data was collected through:

  • evidence of how local residents experience and react to visual, shadow-flicker and noise impacts, gathered in a Residents’ Survey, and 
  • a review of planning documentation, monitoring and as-built data, supported by site survey, predictions and mapping which was assessed by professional consultants.

The project was overseen by a Project Steering Group (PSG) with representatives from various local and national interest groups representing both those living near wind farms and wind farm developers and operators, including Scotland Against Spin and Scottish Renewables, and representatives from local and national government planning interests. The PSG was put in place to ensure a balanced approach throughout the research and analysis.

Main findings

  • The majority of assessments presented at planning stage for the ten case study wind farms identified and mainly followed extant guidelines.
  • However, for some of the case study wind farms, extant guidelines were not consistently followed and/or the impacts predicted in the documentation submitted with developers’ planning applications were not consistent with the actual impacts as assessed in this study or as reported by some local residents.
  • Assessments and public engagement activities had not always adequately prepared residents for the impacts of the operational wind farm in terms of visual, shadow flicker or noise impacts.

Main recommendations

  • The prediction, measurement, assessment and documentation of impacts across all sizes of developments need to be more consistent. For certain aspects of the impact assessment this has not always been the case, for example assessing residential visual amenity impacts.
  • The processes and procedures relating to retaining and accessing documentation need to be consistent across planning authorities, and throughout the consenting process, including post consent agreements, for example in respect of micro-siting.
  • Those making recommendations (planning officers, councillors, planning reporters) should consistently make clear in their reports whether they consider the relevant assessment to have been carried out in accordance with recognised guidance and whether they concur with the findings.
  • The implications of micro-siting need to be identified in assessments, in particular for visual and shadow flicker and, to a lesser degree, noise impacts, noting that there are also likely to be impacts for other environmental aspects not covered by the scope of this study, such as protected species, sensitive habitats or peat.