The substantial body of empirical research now available on wind farm visual impact (VI), from
very credible and impartial teams, shows a consistent and essentially linear relationship between
turbine height, distance and wind farm VI. For any degree of VI (such as the zone of visual
influence, or threshold for visual dominance), if turbine height is doubled, the distance threshold
for that degree of impact also typically doubles.
The research based distances for thresholds for key levels of VI are many times larger than
thresholds proposed by the NSW Department of Planning and Environment in its draft VI
Assessment Bulletin. The Department’s proposed thresholds are repudiated by the consistent
The research also identifies a number of other ways in which wind farm VI assessment practices
accepted by NSW planning agencies are defective, in particular relating to the neglected
importance of blade movement for VI, the fact that photomontages tend systematically to
underestimate VI, and the assessment frameworks commonly used are too simplistic to describe
real world experience.
The NSW Government has a responsibility to reassess its draft VI Assessment Bulletin explicitly in
the context of the published research and produce proposals which it can intellectually justify in the
context of that research – which at present it cannot do.
[ABSTRACT; 6th November 2016]
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