Field Validation of Octave Band Sound Modeling for Wind Turbines

The Sugar Creek Wind Project is a 57-turbine wind farm in Logan County, Illinois, with a capacity of up to 202 megawatts. Preconstruction sound modeling of the final Project layout was conducted in July 2019. Following construction of the Project, postconstruction attended sound measurements were made at 38 sites in the vicinity of Project turbines in September, October, and November 2021. Measured postconstruction sound levels were compared to the octave band sound level limits applicable under the Project's Conditional Use Permit. A comparison of the modeled and background-adjusted measured octave band sound levels for the Project indicate that with the proper modeling parameters, octave band sound levels can be conservatively predicted.