Energy Matters has a post on designing quieter, more efficient wind turbines - Quieter Wind Turbines = More Power.
GE has been conducting research into new low-noise wind turbine blade design. It's not about addressing infrasound - which has already been shown not to be an issue in areas surrounding wind farms - it’s all about producing more power.
“There’s no question, aerodynamic noise is a key constraint in wind turbine blade design today”, says Mark Jonkhof, Wind Technology Platform Leader at GE Global Research. “By using high-performance computing (HPC) to advance current engineering models that are used to predict blade noise, we can build quieter rotors with greater blade tip velocity that produce more power. This not only means lower energy costs for consumers, but also a significant reduction in greenhouse gas emissions.”
Aerodynamic noise refers to the “swooshing” sound created as the leading edge of a turbine blade moves through the air. GE predicts that a mere one decibel drop in this sound would lead to an annual two percent increase in power per turbine. With an estimated 240 gigawatts of wind power to come online globally over the next five years, GE says this would be the equivalent of 5 gigawatts of added wind energy capacity.