Wind energy is one of the safest ways to generate electricity.
Unlike other generation types, wind energy doesn’t require potentially hazardous activities to mine or extract its fuel, and that fuel doesn’t have to be transported – sometimes over great distances – to the point where it will be used. Our fuel is literally blowing in the wind. That helps increase the overall safety of wind generation.
Additionally, wind power does NOT emit harmful pollution like heavy metals, particulates, and sulfur and nitrogen oxides, which can contribute to pulmonary disease and increased healthcare costs. similarly, wind power DOESN’T need water for cooling purposes like conventional thermal generation power plants do and is thus a smart way to keep our fresh water resources pollution-free.
Wind Turbines in the U.S.
Dr. Mark Roberts discussing the health & safety impacts of wind turbines being located near people.
Iowa Environmental Council: Wind Turbines and Health (2019)
- High-Level Findings: “To date, no peer reviewed scientific journal articles demonstrate a causal link between people living in proximity to modern wind turbines, the noise (audible, low frequency noise, or infrasound) they emit and resulting physiological health effects.”
- Executive Summary: https://www.iaenvironment.org/webres/File/IEC_Wind_Health_Exec_Summary_2019_FINAL.pdf.
- Full Study: https://www.iowapolicyproject.org/2019docs/190131-Wind-Health.pdf.
Wind Turbines and human health (Knopper et. al., 2014)
- High-Level Findings: “The available scientific evidence suggests that EMF, shadow flicker, low-frequency noise, and infrasound from wind turbines are not likely to affect human health…”
- Full Study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4063257/.
Like any mechanical equipment, wind turbines do make some sound. However, that sound is minimal and often quieter than other ambient noises like wind blowing through crops or trees (since the turbines only spin when the wind is blowing strongly enough), and they are significantly quieter than common noise in agricultural communities like combines, farm equipment, or light traffic. In fact, you can carry on a conversation at normal speaking volumes right under a wind turbine with no problem. The State of Wisconsin also requires the wind farm not to exceed 50 dBA during the daytime and 45 dBA during nighttime. RWE will conduct a comprehensive sound analysis to ensure compliance with this mandate, along with selection of a state-of-the-art turbine model with modern design enhancements and responsible siting of turbine locations to minimize any sound produced.
Health Canada: Wind Turbine Noise and Health Study (2014)
- High-Level Findings: A major study in Canada of over a thousand homes confirmed this again, stating: “No evidence was found to support a link between exposure to wind turbine noise and any of the self-reported illnesses.”
- Summary: https://www.canada.ca/content/dam/hc-sc/migration/hc-sc/ewh-semt/alt_formats/pdf/noise-bruit/turbine-eoliennes/pamphlet-brochure-eng.pdf
World Health Organization: Environmental Noise Guidelines (2018)
- High-Level Findings: For average sound exposure, the GDG conditionally recommends reducing sound levels produced by wind turbines below 45 dB. However, they do so out of a self-identified abundance of caution and note repeatedly that there is no clear and conclusive evidence establishing a link between sound produced by wind turbines and adverse human health effects.
- Full Study: http://www.euro.who.int/__data/assets/pdf_file/0009/383922/noise-guidelines-exec-sum-eng.pdf?ua=1
From the American Wind Energy Association:
How loud is a wind turbine?
Independent studies conducted around the world, including the U.S. have consistently found no evidence that wind farms cause any negative physical health effects.
- Typically, two people can carry on a conversation at normal voice levels even while standing directly below a turbine.
- Many thousands of people worldwide live near wind farms with no ill effects.
- Emitting virtually no air or water pollution, wind energy is essential to reducing energy-sector public health impacts.
- Studies and government health organizations around the world have given wind a clean bill of health. For example, a Massachusetts study found no evidence for a set of health effects from exposure to wind turbines or for the existence of what some have tried to characterize as “Wind Turbine Syndrome.”
- A major study in Canada of over a thousand homes confirmed this again, stating, “No evidence was found to support a link between exposure to wind turbine noise and any of the self-reported illnesses.”
- Studies have found that a “nocebo” effect can take place, the opposite of the well-known “placebo” effect. The nocebo effect describes a situation in which individuals who are led to expect physical symptoms may actually experience these symptoms, whether or not the supposed cause of the symptoms is actually present. In this case, increased exposure to misinformation about wind actually seems to increase the likelihood that certain individuals will report negative health effects such as headaches or nausea, although no scientific evidence shows wind turbines cause any such health effects.
Shadow flicker refers to the moving shadows that a turning turbine blade can cast on houses when the sun is in just the right position at certain times of the day and at certain times of the year. RWE carefully designs its projects to minimize the incidence of shadow flicker impacting surrounding houses. We make sure that flicker only happens – at most – for a few minutes a day when it’s sunny and bright with clear skies, and when the sun is just at the right angle.
From the American Wind Energy Association:
Shadow flicker is predictable, harmless, and passes quickly. It is based on the sun’s angle, cloud cover, wind conditions, turbine location, foliage and terrain, and distance to the observer. Shadow flicker can be avoided and minimized by several methods
- With proven mitigation techniques such as responsible siting and screening plantings, turbines can be sited to minimize flicker to a few hours a year.
- Shadow flicker typically lasts just a few minutes near sunrise and sunset and can be addressed through use of proven mitigation techniques such as screening plantings.
- The rate at which wind turbine shadows flicker is far below the frequency that, according to the Epilepsy Foundation, normally is associated with seizures.
- An expert panel for the National Academy of Sciences found shadow flicker “harmless to humans.” A study commissioned by the Massachusetts Departments of Environmental Protection and Public Health found that according to scientific evidence shadow flicker does not pose a risk for causing seizures.
- State regulations restrict shadow flicker to 30 hours per year, at most.
Analysis of the Research on the Health Effects from Wind Turbines, including Effects from Noise (2012)
- High-Level Findings: Scientific evidence suggests that shadow flicker does not pose a risk for eliciting seizures as a result of photic stimulation.
- Full Study: https://www.maine.gov/dhhs/reports/health-effects-from-wind-turbines-2-12.pdf
As with any structure, ice can accumulate on a wind turbine. This ice can potentially come loose with temperature increases, wind, turbine motion or gravity. RWE takes the risk of ice throw very seriously and design our projects with the safety of the community in mind. We always do the following:
- Monitor the turbines and multitude of sensors within them to enable us to detect the accumulation of ice and ensure that they are deactivated until the ice dissipates or no longer poses a risk.
- Create appropriate setbacks based on turbine height and blade diameter.
- Utilize feedback from on-site staff and others regarding physical and visual concerns to provide an additional layer of safety.
Stray voltage refers to small voltage differences that can exist between two surfaces that are accessible to animals (e.g. stanchion, waterer, floor, etc.). When an animal touches both surfaces simultaneously, a small electric current will flow through its body. If the current is high enough, it can be felt by the animal and may cause behavioral changes. Most often, this stray voltage is the result of improper premises wiring that has deteriorated over time without proper maintenance.
Wind farms do not contribute to stray voltage for several important reasons, including:
- A wind farm is connected to the bulk power transmission grid via balanced three-phase 60 Hz AC circuits; it does not connect directly to the local distribution systems that deliver power to homes and businesses and there are important regulating safety mechanisms between transmission systems and local distribution systems.
- Due to the balanced three-phase power design, neutral and ground current is near zero during normal operations and far, far smaller than typical residential or commercial facilities that have single phase power circuits.
- Similar to all grid-connected power plants, a wind farm is designed to respond to grid demands and only supplies electricity when there is demand. A wind farm stores no electrical power nor does it shunt energy to ground or elsewhere.
- Substations are designed per NEC and NESC requirements to detect and clear faults in under a tenth of a second.
- Underground cables are designed per NEC and NESC requirements. The fully insulated and shielded three-phase circuits with additional supplementary ground wire are typically buried at least 48 inches (four feet) below the surface.
- Wind turbine generators have grounding systems designed and regularly tested according to IEC and IEEE standards to ensure no risk of stray voltages during operations.
- Extensive regulations and design requirements via the National Electrical Code, National Electric Safety Code, International Electrotechnical Commission, Institute of Electrical and Electronics Engineers, and the Public Service Commission of Wisconsin ensure that design and construction of a wind farm results in a safe and high-quality project.
Lastly, PSC regulations require RWE to test before and after construction of the wind farm to verify that the project does not contribute to stray voltage. To read more about stray voltage and how it can be mitigated, please visit the Public Service Commission and the Midwest Rural Electric at the links below.