The WINDFARMperception project, carried out in 2007/08 in the Netherlands, aimed to explore the impact of wind turbines on people living close to wind farms. The study group was selected in three types of area (countryside, countryside with major road, built up area) by means of a Geographic Information System (GIS). Each selected address was sithin 2.5 km of a wind turbine of at least 500 kW electric power and a similar turbine within 500 m of the first. Aural impact was calculated according to three different sound propagation models: the international ISO-9613 standard, the model legally required in the Netherlands, and a simplified model as in the New Zealand Standard NZS-6808. Visual impact was quantified in two ways: the vertical angle determined by the height of the apparently tallest turbine, and the solid angle determined by all turbines where each turbine was replaced by a vertical rectangle just enclosing the turbine. Immission sound levels from the wind farms at 1948 receiver locations varied from 21 to 54 dB(A), relative size from 0.01% to 30% of the total field of view. Results show that all impact measures are highly correlated with distance to the nearest wind turbine.
