Draft National Wind Farm Development Guidelines - July 2010

• An example boundary is shown that represents an area that may be affected by
shadow flicker, while not being significantly affected by noise.
Table 4-3
Typical areas of shadow flicker from a single turbine showing number of hours of shadow flicker per
year
There are a range of impacts that have been suggested as being a consequence of
shadow flicker. Each of these have been examined and it has been determined that the
risk of some of the suggested impacts is, in fact, negligible and does not need to be
addressed in the guidelines (see Section E.2.2).
The key risk associated with shadow flicker is annoyance of residents, and this risk is
addressed in the Guidelines.
Shadow flicker can theoretically extend many kilometres from a wind turbine. However,
the intensity of the shadows decreases with distance. While acknowledging that different
individuals have different levels of sensitivity and may be annoyed by different levels of
shadow intensity, these guidelines limit assessment to moderate levels of intensity (i.e. well
above the minimum theoretically detectable threshold) commensurate with the nature of
the impact and the environment in which it is experienced. Details of the intensity of
shadow to be considered are provided in Section E.4.2.
Annoyance of residents can occur over a long term basis if they are repeatedly subject to
shadow flicker, or on a short term basis as a consequence of an extended period of
continuous exposure. Both are considered important impacts. However for any location
within Australia, the recommended limits for continuous exposure are inherently satisfied if
the limits for long term exposure on an intermittent basis are satisfied. The methodology
reflects this, requiring only assessment of the long term exposure.
E.2.2
Issues not addressed in the Guidelines
Annoyance of land users other than residents
There is a negligible risk associated with impact on amenity of land users other than
residents, such as where a recreation facility such as a park or gardens experiences
shadow flicker. These risks are not covered in the Guidelines for the following reasons:
Page 148 Draft National Wind Farm Development Guidelines – 2 July 2010