Simultaneous measurement of wind turbine noise at 1.5 and 4.0 meters

This study examines the influence of measurement height on the accurate assessment of noise emissions from utility-scale wind turbines. While some standards and regulations specify a prediction height of 4 meters above ground to account for upper-level receptors, noise measurements are overwhelmingly conducted at a height of 1.5 meters, which is representative of typical human exposure at ground level. Some jurisdictions require adjusting 1.5-meter measurements to better represent noise levels experienced at elevated receptor heights. This paper presents the results of noise levels measured at one location at an operational wind farm in the U.S. Midwest, taken at a distance of approximately 1,700 feet from the nearest turbine at heights of 1.5 and 4.0 meters above the ground simultaneously. The measurement results are compared to the ISO 9613-2 model predicted results of the site for each height.