Draft National Wind Farm Development Guidelines - July 2010

Establish background noise monitoring requirements
• Select relevant receivers
Preliminary noise emission predictions should be used to identify ‘relevant receivers’;
that is, those noise-sensitive receivers where the preliminary noise predictions indicate
that the minimum noise level limit (including any adjustments for noise characteristics)
may be exceeded. In order to establish noise criteria based on a ‘minimum noise level
limit + background’ basis, background noise monitoring will be required at any
receivers (or a receiver judged to be representative of a group of such receivers)
identified as relevant receivers.
If the preliminary predicted levels of wind farm noise emission are less than the
minimum noise level limit (including any adjustments for noise characteristics) for the
wind speed of maximum noise emission at each receiver, background noise
monitoring will generally not be required as there is minimal risk that receivers will be
adversely affected by wind farm noise emission. AS4959–2010 notes the following
exception:
However, if a location is particularly sheltered and wind-related background noise
may be low even when wind speeds on the wind farm itself are high, measurements
should still be taken.
AS4959–2010 also notes that the assessment of background noise levels at the
locations of future development may be of little benefit, as the noise environment is
likely to change significantly should the development take place.
AS4959–2010 further notes that:
When considering a group of receivers it is acceptable to select as relevant the
receiver that is likely to be representative of the worst case situation, e.g. a house
that has very few likely sources of wind induced background noise that is located
amongst a group of nearby houses.
Further discussion of representative dwellings is provided in Section B.5.3.
• Review historical wind data
Section 6.3.1 of AS4959–2010 notes:
The wind direction or wind directions which will result in the maximum noise impact
from the WTG or wind farm at relevant receivers, seasonal variation in the
occurrence of these wind directions and the likelihood of obtaining data with the
wind from these directions should also be considered prior to the commencement
of monitoring.
Annual wind historical data should be reviewed to establish the range of wind speeds
that are likely to occur at the wind farm site and that should therefore be represented
in the monitored data. Wind direction data may also be similarly reviewed.
In addition, a review of air stability conditions should be carried out. Where a
significant trend for stable air is found to occur at the site (particularly during nighttime
hours), this should be accounted for both in the data covered by the monitoring
and also in the setting of noise level limits and the assessment of noise impact from the
wind farm.
Review requirements for wind monitoring data
Subsequent phases of the assessment process require monitoring both of background
noise levels and, potentially, post-construction noise levels of the operational wind farm.
Although these future phases can be 12 months or more away, it is recommended that the
proponent review these future requirements with regard to wind monitoring and ensure
they can be achieved with the proposed wind monitoring strategy.
Draft National Wind Farm Development Guidelines – 2 July 2010 Page 49