| Title | Growth and attenuation of seismic noise generated from a 12.0MW wind farm |
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| Author | Edwards, W N |
| Source | CTBT: Science and Technology 2015 Conference (SnT2015), oral presentations and scientific posters; T2.3-P9, 2015 p. 1  Open Access |
| Links | Online - En ligne (PDF, 1.75 MB)
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| Image |  |
| Year | 2015 |
| Alt Series | Earth Sciences Sector, Contribution Series 20160073 |
| Publisher | Comprehensive Nuclear-Test-Ban Treaty Organization |
| Meeting | CTBT: Science and Technology 2015 Conference (SnT2015); Vienna; AT; June 22-26, 2015 |
| Document | Web site |
| Lang. | English |
| Media | on-line; digital |
| File format | pdf (Adobe® Reader®) |
| Program | Canadian Hazard Information Service |
| Released | 2015 06 01 |
| Abstract | (unpublished)
Development of renewable wind-generated energy as an alternative to traditional energy resources is occurring in numerous countries. As wind power generation facilities increase
in power, size and number, encroachment upon seismic instrumentation is occurring, wherein vibrations induced by the turbines can become an undesirable source of noise within the regional and teleseismic earthquake monitoring band. To better
understand, identify and characterise the noise of modern megawatt wind turbines, a multifaceted study to monitor the seismic and infrasonic noise of a megawatt-class wind facility was conducted between May 2013 and 2014. Four temporary
seismo-acoustic monitoring stations were deployed to passively record the noise generated by four Vestas 3.0MW V90 wind turbines at the Summerside Wind Farm on Prince Edward Island, Canada. Analysis of the seismic component of the data identifies
several vibrational modes and harmonics within the 1 ¿ 10Hz monitoring band visible up to a 10 km distance associated with the turbine blade-pass frequency and structural bending modes of the tower superstructure. Observations of spectral growth and
attenuation identify the turbine vibrations as propagating surface waves that grow in amplitude with wind speed in a manner consistent with the manufacturers electrical power generation curves. Modeling of the turbine noise are compared with ambient
background noise as a function of wind speed to provide estimates of the separation required to safeguard a hypothetical monitoring station from observing the facility. Finally, spectral observations of the turbine noise are compared to human
whole-body vibration perception levels to establish that the recorded turbine vibrations lay 2 ¿ 3 orders of magnitude below the threshold of perception. At such low levels of shaking it is highly unlikely that these vibrations would be perceptible,
a finding supported anecdotally by observations of the passage of larger amplitude seismic waves from a regional earthquake that passed unnoticed in the area during the monitoring period. |
| Summary | (Plain Language Summary, not published)
The manuscript discusses results of a cooperative project between Health Canada and NRCan to monitor the seismic and infrasonic noise generated by the
Summerside, PEI wind turbine facility in 2013-2014. Analysis of the seismic data is discussed, showing that the turbine noise is composed of low frequency vibrations between 1 - 10 Hz associated with the rotation rate of the turbine blades and
vibrations of the tower superstructure. Modelling indicates the noise grows with increasing wind speed at a rate consistent with the manufacturer's electrical power generating specifications and decreases with increasing distance at a rate of
1/sqrt(distance), consistent with surface waves. A minimum distance of >15 km from the facility is predicted to be adequate for a sensitive seismometer to no longer observe the facility's noise. While ¿felt¿ by sensitive instruments, comparison to
whole-body-vibration data, indicates that these vibrations are 100 - 1000 times below human perception. |
| GEOSCAN ID | 298814 |
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