German wind energy protest site windwahn.de (windmadness.de) tells us of a new study: “Numerical modelling of micro-seismic and infrasound noise radiated by a wind turbine” and the possible the effects on human health.
It turns out that not only infrasound have negative impacts on humans, but perhaps so do the micro-seismic waves that turbine vibrations generate in the ground. In the new study, the Karlsruhe Institute for Technology (KIT), in partnership with University Patras of Greece, examined the micro-seismic and infrasound noise radiated by a wind turbine.
Higher levels of noise inside a house
According to the study’s highlights, modeling of the operation of a wind turbine under strong winds generated micro-seismic waves that would cause annoyance for neighbors. 2D simulations were performed for a specific geometry and a structure located 500 m far from a wind turbine. The most important conclusions:
(i) the micro-seismicity creates higher levels of noise inside a house than that of the airborne noise radiated by a wind turbine and
(ii) bedrock being in low depths underneath the soil has an additional contribution to the generated acoustic noise by the induced micro-seismicity.”
The study also found that micro-seismic waves impact the measurements of seismological centers that were even 15 km away from a wind turbine farm and that the “larger disturbances occurred at a frequency range of 5-10 Hz“.
The abstract of the study:
Infrasound, low frequency noise and soil vibrations produced by large wind turbines might disturb the comfort of nearby structures and residents. In addition repowering close to urban areas produces some fears to the nearby residents that the level of disturbance may increase. Due to wind loading, the foundation of a wind turbine interacts with the soil and creates micro-seismic surface waves that propagate for long distances and they are able to influence adversely sensitive measurements conducted by laboratories located far from the excitation point. A numerical study on the creation and propagation of those waves to the surrounding area is the subject of the present work. Besides, the contribution of those waves to airborne sound generated by the soil-air interaction is also investigated. All numerical simulations are performed with the aid of the Boundary Element Method (BEM), which is ideal for solving such problems since it takes automatically into account the radiation conditions of the waves and thus only the soil-foundation interface and the free surface of the surrounding soil are needed to be discretized. Foundation and soil are considered as linearly elastic materials with interfacial bonding. The frequency domain Helmholtz equation is employed for the simulation of acoustic waves. Numerical results dealing with the airborne and soil borne noise propagation and attenuation are presented and disturbances that might be caused to nearby and far-field structures are discussed.”
Potential health risks
Windwahn.de advises of the potential health risks at their site:
The determined frequency range of the largest disturbances found in the the study of 5 – 10 Hz, according to KIT University Patras are within the natural frequencies of, for example, the following organs:
Abdomen (4-10 Hz), general poor feeling (4-9 Hz), chest (5-7 Hz), impact on breathing (4-8 Hz), shoulder area (4-5 Hz), bent knee (2 Hz), arm (5-10 Hz),
Spine: (10-12 Hz)
Many of the described illness symptoms influenced by acoustic noise are found in the above mentioned organs.”
So not only is infrasound a problem for human health, but also the ground vibrations produced by vibrating wind turbines are likely to impact humans as well.
So far not a single German media outlet has reported on the findings. Not exactly the thing the public should know about in these times of wind energy profiteering.