Challenges in post-construction sound monitoring for rural wind projects

Abstract

Postconstruction sound monitoring for rural wind projects has unique challenges. While background sound levels tend to be lower than more urban areas, the sound levels from the wind turbines also tend to be lower, making signal to noise ratios rather low. Thus, differentiating wind turbine sound with wind-induced sound can be difficult, especially when wind speeds are variable. Other issues include safety, wildlife, harsh weather conditions, access to remote sites, difficult protocols, and noise contamination. These issues will be discussed in the context of several recent postconstruction sound monitoring campaigns. Each campaign uses wind turbine shutdowns to measure adjacent background sound levels so that turbine-only sound levels can be calculated. Advantages and disadvantages of the wind turbine shutdown method will be discussed and compared with other methods that don’t require wind turbine shutdowns, such measuring under high wind shear conditions (low ground wind speeds and high hub-height wind speeds), proxy locations, and wind speed binning.