This paper, presented at the Windpower ’87 Conference & Exposition in San Francisco by N.D. Kelley, a physicist at the Solar Energy Research Institute in Golden, Colorado validates the fact that turbines (both upwind and downwind) produce low-frequency sound emissions that can negatively impact humans within their homes. Although modern wind turbines are different from those studied in 1987, the research is significant in that it demonstrates the need to test for low-frequency sound emissions and to do so inside buildings.
Library filed under Noise
This report summarizes extensive research by staff of the Solar Energy Research Institute and its subcontractors conducted to establish the or1g1n and possible amelioration of acoustic disturbances associated with the operation of the DOE/NASA MOD-1 wind turbine installed near Boone, North Carolina. Results have shown that the most probable source of this acoustic annoyance was the transient, 'unsteady aerodynamic lift imparted to the turbine blades as they passed through the lee wakes of the large, cylindrical tower supports. Nearby residents were annoyed by the low-frequency, acoustic impulses propagated into the structures in which the complainants lived. The situation was aggravated further by a complex sound propagation process controlled by terrain and atmospheric focusing. Several techniques for reducing the abrupt, unsteady blade load transients were researched and are discussed.
This document has been prepared by Terry Matilsky, Professor of Physics at Rutgers University. For almost 40 years, he has been funded by NASA and other federal agencies to do data analysis from various scientific satellites; to examine what information tells us about a phenomena, and draw rational and solid, scientific conclusions from them.