Draft National Wind Farm Development Guidelines - July 2010

Other noise-sensitive uses such as hospitals, prisons, caravan parks and camps, and
educational institutions;
Potential future noise-sensitive developments with development approval, or areas
promoted as such by the planning system for that jurisdiction;
Areas where there is a potential risk that a permitted noise-sensitive development – such as
a second farmhouse on a rural property – may occur within the life of the project.
An initial assessment of receivers surrounding a site should be undertaken. This may be
done either as a desktop study or by visiting the site and noting the location of receivers in
the surrounding area.
The approach taken in AS4959–2010, and reflected in these Guidelines, is to carry out
preliminary noise predictions at the identified receiver locations under an initial ‘worst
case’ scenario, in order to identify which receivers may be ‘relevant receivers’ where more
detailed assessment is required.
Undertake noise emission predictions (preliminary)
Once receivers have been identified, preliminary wind farm noise emission predictions at
each receiver should be carried out in accordance with the guidance in Section 5 of
AS4959–2010. The Standard proposes two approaches to noise predictions: a simple
prediction algorithm (section 5.2 of the Standard) or the use of more complex noise
models. The limitations of the simple algorithm are as follows:
• It provides a slightly conservative estimate of noise emission, ignoring the effects of
wind direction, topography, ground absorption etc, not providing for optimal siting of
turbines by the proponent;
• It may provide single-point predicted noise levels only, and instead of the graphic
noise contours that are needed for community consultation and for assessing
potential impacts over future development areas; and
• The simple method may not be accepted in the local jurisdiction.
Given that the developer should already have engaged a suitably qualified acoustic
professional by this stage, these Guidelines recommend that the preliminary predictions
should be carried out using the more complex method according to Section B.4.2 Carry
out noise emission predictions (detailed). The recommended output would be a noise
model that shows predicted noise contours over the area covering all identified noisesensitive
receivers. These contours should represent an initial ‘worst case’ model based on
the turbines operating at the wind speed that would result in the highest noise output.
In order that the noise predictions may take into account noise characteristics that may
be difficult to eliminate post-construction, the relevant authority may require that the
predicted noise levels should include an adjustment, for example +5dB, in anticipation.
Establish noise criteria
The principles of the noise impact assessment criteria should be established at this stage.
The relevant authority will be responsible for establishing criteria and they should be
consulted to confirm what noise criteria will apply to a particular project.
The following discussion is provided for information and to assist the relevant authority with
determining suitable noise criteria.
• Approach to noise criteria
It is recommended that noise level limits be set according to the framework outlined
in AS4959–2010 and comprise a minimum noise level limit (that is, a lower bound) and
variation of the minimum noise level limit during periods of elevated background
noise. The important considerations in relation to establishing noise criteria at this
stage include issues such as:
Draft National Wind Farm Development Guidelines – 2 July 2010 Page 45