Wind turbine AM review: Phase 2 report

Perkins, Richard; Lotinga, Michael

Abstract

BACKGROUND
Current planning policy for the assessment and rating of wind turbine noise in England, Scotland,
Wales and Northern Ireland refers to the ETSU-R-971 document. Wind turbines are known for
their distinctive acoustic character often described as a ‘swish’, which is also referred to as
amplitude modulation (AM). Recent evidence suggests that at times this ‘swish’ can become more
of a pronounced ‘thump’, leading to complaints from wind farm neighbours.
In response to growing concerns about the impact of excessive AM on residents, WSP | Parsons
Brinckerhoff was commissioned by the Department of Energy and Climate Change to undertake a
review of research into the effects of and response to AM and, if considered necessary, to
recommend a control method suitable for use as part of the planning regime.

AIMS
The aims of the study are to review the evidence on the effects of AM in relation to wind turbines,
the robustness of relevant research into AM, and to recommend how excessive AM might be
controlled through the use of a planning condition, taking into account the current policy context of
wind turbine noise. The work included working closely with the Institute of Acoustics’ AM Working
Group, who have proposed a robust metric and methodology for quantifying and assessing the
level of AM in a sample of wind turbine noise data.

METHOD
The study has involved the collation and critical review of relevant literature on the subject of AM,
which included published papers on dose response studies, case studies, existing planning
conditions, and current planning guidance. Key points from the reviewed evidence have been
extracted and summarised upon which to draw the reports’ conclusions.

CONCLUSIONS
The review has concluded that there is sufficient robust evidence that excessive AM leads to
increased annoyance from wind turbine noise, and that it should be controlled using suitable
planning conditions. Key elements required to formulate such a condition have been
recommended.

RECOMMENDATION
It is recommended that excessive AM is controlled through a suitably worded planning condition
which will control it during periods of complaint. Those periods should be identified by
measurement using the metric proposed by work undertaken by the Institute of Acoustics, and
enforcement action judged by Local Authority Environmental Health Officers based on the
duration and frequency of occurrence.

Citation

Perkins, R., & Lotinga, M. (2016). Wind turbine AM review: Phase 2 report. London: Department of Energy & Climate Change

• Report Type: Research Report
• Publication Date: Oct 25, 2016
• Deposit Date: Dec 4, 2024
• DOI: https://doi.org/10.13140/RG.2.2.26722.20168
• Publisher URL: https://www.gov.uk/government/publications/review-of-the-evidence-on-the-response-to-amplitude-modulation-from-wind-turbines