Under the title “Joint analysis of resident complaints, meteorological, acoustic, and ground motion data to establish a robust annoyance evaluation of wind turbine emissions”, an article on the measurement campaign at the Tegelberg wind farm has been published in the journal “Renewable Energy”.

The publication is freely accessible here

A citizens' meeting was held online for the residents of the Lauterstein wind farm, at which the project team presented the initial results of the survey and the on-site measurements.

As a survey of residents living near the wind farm had already been carried out in 2018, it was possible to look at the change in acceptance characteristics over time. It became clear that attitudes towards the wind farm were more positive in the 2020 survey than in 2018. The emissions from the wind turbines (noise, shadow flicker, obstacle marking) were perceived by fewer people in 2020 than in 2018, but the level of annoyance caused by the noise was not rated as significantly lower. The proportion of people severely annoyed by the wind farm was lower in 2020 than in 2018. The greatest source of annoyance is traffic noise, which led to 25% of residents being severely annoyed in 2020.

Noise immissions and ground motion waves were measured at a household in Degenfeld and in the vicinity of the wind turbines. Indications of audible wind turbine noise were found, but not of exposure to non-audible noise (infrasound). In detail:

A) The amplitudes of the ground movements propagating from the WTGs are well below the perceptibility threshold. During the measurement period, the measuring devices were able to measure ground motion waves caused by a minor earthquake in Austria. The movements caused by this earthquake were also below the perception threshold for humans on site, but nevertheless more than 10 times stronger than the ground motion waves that can be attributed to the wind turbines.

B) The low-frequency sound measured outside and inside the house (including low-frequency infrasound) is also below the perception threshold (according to draft DIN 45680-2013). The strength of the low-frequency and low-frequency sound caused by WTGs indoors is comparable to the sound levels emitted by everyday appliances, such as a refrigerator (LUBW 2014 measurements).

C) Sound immissions can be detected in the audible frequency range. In closed indoor areas, however, no differences in sound immissions can be detected between running and stationary WTGs. In outdoor areas, these differences are somewhat clearer and the immissions are higher overall than indoors. However, the ambient noise makes up the majority of the measurable immissions in the outdoor area, and noise from traffic in particular can be clearly detected.

The image shows the ground movement as ground vibration velocity from 6 measuring points near Degenfeld. In the first approx. 70 seconds you can see the usual ground movement including the emissions from the Lauterstein wind farm. This is followed by the waves of a weak earthquake in Austria. All movements are at least a factor of 10 smaller than the perceptibility limit (approx. 0.1 mm/s), the emissions from the wind farm are even a factor of 100 smaller (© KIT-GPI).

A citizens' meeting was held online for the residents of the Tegelberg wind farm, at which the project team presented the initial results of the survey and on-site measurements.

The on-site survey revealed a higher proportion of people severely disturbed by wind turbine noise than at comparable wind farms. Annoying noise occurred mainly in the evening and at night.

The majority of complaints occurred during two operating states of the wind turbines: When the rotor speeds were constantly high and when the speeds changed significantly. These two conditions differ in other characteristics: The constant high speed was experienced as a nuisance primarily during westerly winds, whereas strong changes in speed were experienced during winds from the southeast. While the noise is annoying at night and in the mornings when the speed is constantly high, complaints with variable speed occur mainly in the evening and at night and mainly affect the residents' sleep.

Ground motion (seismic) and noise immissions were measured at four highly annoying households in Kuchen. Indications of exposure to audible wind turbine noise were found, but not to non-audible noise (infrasound). In detail:

A) The level of ground movements propagating from the WTGs are well below the perceptibility threshold. The ground movements caused by train traffic are more noticeable to local residents than those associated with the WTGs.

B) The low-frequency noise measured outside and inside the houses (including low-frequency infrasound) is also below the perceptibility threshold (according to draft DIN 45680-2013). The strength of the low-frequency and low-frequency sound caused by WTGs indoors is comparable to the sound levels emitted by everyday appliances, such as a refrigerator (LUBW 2014 measurements).

C) Sound immissions can be detected in the audible frequency range. In closed indoor areas, however, hardly any differences in sound immissions can be detected between running and stationary WTGs. In outdoor areas, these differences are somewhat more noticeable and the immissions are higher overall than indoors. However, the ambient noise makes up a large part of the measurable immissions in the outdoor area, and train signals in particular can be detected very clearly.

Together with the wind farm operator, it will now be examined to what extent measures can be tested in order to achieve a reduction in nuisance during operation.

Now that the survey in the vicinity of Stöttener Berg has been completed, the on-site measurements have begun. Acoustic, seismic and meteorological measurements are being carried out at the WINSENT test site and in the surrounding area.

Now that the survey on the Lauterstein wind farm has been completed, the on-site measurements have begun. Acoustic, seismic and meteorological measurements are being carried out at the wind turbines, in the vicinity of the wind farm and in the village of Degenfeld.

In the immediate vicinity of Stöttener Berg, 1000 randomly selected residents were contacted and invited to take part in the survey. The survey is intended to shed light on the perspective on the WINSENT wind energy test field and the expectations associated with it, as well as the experiences with the existing wind farms in the immediate vicinity. We look forward to a lively participation. All interested parties who have not received a letter are also cordially invited to contact us and take part in the survey.

The measurements for the Tegelberg wind farm are underway. Now that two lidar measuring devices, which collect weather data, have already been set up in Kuchen with some lead time, the noise measurements are also starting. We have installed measuring devices at the wind turbines on the Tegelberg as well as at a first household in Kuchen, where the noise pollution is perceived as very disturbing. Over the next few weeks, the measuring devices in Kuchen will be moved to other households where a high level of noise pollution has been reported.

The survey on the Tegelberg wind farm has been completed. Around 130 residents from Kuchen and Geislingen gave an interview about their experience of the wind farm and almost 170 others provided information in a short interview. Interview participants who perceive disturbing noises have the option of using a complaint app to report disturbing noises when they occur.