Wind Energy: Noise Aspect Overview

According to Global Wind Energy Council estimates the world wind power development will contribute to a reduction of annual CO2 emissions by 1.5 billion tons by the year of 2050.

Wind power plants produce two kinds of noise:

  • mechanical noise – noise of mechanical and electrical components (for modern wind turbines this aspect is virtually negligible, though it is significant as for older models of wind turbines)
  • aerodynamic noise – the noise from the interaction of wind flow with the unit (amplified by the wind pressure on the blades)

Currently, in determining the level of noise from wind turbines use only the calculation method. The method of direct measurements of the noise level does not provide information about wind turbine noise, since the effective separation of wind turbine noise from wind noise at the moment is not possible.

Noise sources comparison

  • The pain threshold of human hearing – 120db
  • The noise of a jet engine turbine at a distance of 250 m – 105db
  • The noise from a jackhammer to 7m – 95db
  • The noise from the truck at a speed of 48 km/h at a distance of 100 m – 65db
  • Background noise in the office – 60db
  • The noise from the passenger car at a speed of 64 km/h – 55db
  • Noise from a wind turbine at a 350 meters distance – 35-45db
  • Background noise during the night in the village – 20-40db

In the vicinity of the wind turbine at the axis of the propeller the noise is sufficiently increasing and wind turbines may exceed 100 dB. An example of such a wind turbine design miscalculations was Grovian Turbine. Due to the high noise level setting it worked for about 100 hours and was dismantled.

The laws passed in the UK, Germany, the Netherlands and Denmark, limit the noise level of operating wind power plant up to 45 dB in the daytime and 35 dB at night. The minimum distance from the installation to residential buildings is 300m. In addition, the business owners are forced to initiate regular check-ups to ensure proper functioning. Typically, the 3rd party companies are involved in the activity; in the UK, perhaps, the largest provider is Granada Material Handling, the company offering wind turbine services as well as wind turbine inspections at moderate pricing to keep operational expenses at an acceptable level.

Low-frequency vibrations transmitted through the soil, causing significant trembling in windows in the houses at a distance of 60 m from the megawatt-class wind turbines.

Typically, homes are located at a distance of not less than 300 m from the wind. At that distance, the contribution of wind turbines in the infrasonic vibrations can not be separated from the background fluctuations.

During operation of wind turbines in the winter when humidity is high, the formation of ice build-ups on the blades takes place. At start-up wind turbines may throw ice for a considerable distance. As a rule, the territory in which the cases are possible icing of blades, the warning signs are installed at a distance of 150 m from the wind turbines.

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