The anti-wind and pro-fossil fuels lobbies frequently make a lot of fuss about the (allegedly) deleterious effects of being in close proximity to operational wind turbines. There is a lot of heat generated and not much light in these debates. But one University is going to grasp the bull by the turbine blades/horns and shed some facts rather than fiction on this landscape.
The South Karelian Institute of Lappeenranta University of Technology (LUT) is currently examining the possible levels of disruptiveness of the noise generated by wind power plants in Finland. The study is combining the measurement of the noise produced by wind power with the noise experienced by humans in relation to both sound pressure levels and the time and frequency behaviour of sound.
Most wind power farms generate some degree of sound, despite the more modern turbines being generally quieter than early models. Depending on the volume and characteristics of the noise, people exposed to it may claim to suffer from physical and psychological symptoms, while others experience no issues. Not much is known about the link between the noise and the way in which it is experienced and this area of wind energy has been crying out for some detailed independent research. Consequently, the aim of the study conducted at LUT is to combine empirical knowledge and physical measurement data.
The study is not only measuring decibel levels but also trying to analyse what kind of sound the power plants generate. The way in which the noise is generated and how it travels through the air depends on a number of factors, such as the prevailing weather, temperature, wind conditions and the terrain over which or through which the sound moves.
Sari Janhunen is a researcher at the South Karelian Institute. She says
“Simultaneously with the noise, we also measure wind, which means that we can combine the wind data with the volumes and characteristics of the perceived noise. In the future, it might be possible to use this data in the planning of wind power plants.”
Of course, the study needs wind power locations to conduct the research. The study is being carried out in two areas of Finland, which both have wind farms. In both locations, the nearest domestic houses are located between 500 and 800 metres from the wind turbines.
The study was launched with a questionnaire to 1,600 residents asking them about their noise experiences and factors concerning their health and well-being. The study will move forward to measure and record sound pressure levels of the wind power plants. Residents and people living close to the wind power parks will also keep a noise observation diary to log their day-to-day experiences over a set period. At the end of the study, the residents will also be interviewed.
In Finland there is legislation proposed that the daytime level of outdoor noise produced by wind power turbines should not exceed 45 decibels. At night the level should not be more than 40 decibels. It is anticipated that the information about the noise experiences collected in this study can be applied to the development of new technology. In other words, making wind turbines even quieter as well as more efficient.
Lappeenranta University of Technology (LUT) is a pioneering science university in Finland, bringing together the fields of science and business since 1969. It has an international community of approximately 6,500 students and experts engaged in scientific research and academic education.