Peer reviewed research article by William K.G. Palmer*
* Independent Researcher
Wind turbines are often perceived as benign. This can be attributed to the population majority dwelling in urban locations distant from most wind turbines. Society may understate the risk to individuals living near turbines due to an overstatement of the perceived benefits of turbines, and an understatement of the risk of injury from falling turbine parts, or shed ice. Flaws in risk calculation may be attributed to a less than fully developed safety culture. Indications of this are the lack of a comprehensive industry failure database, and safety limits enabling the industry growth, but not protective of the public. A comprehensive study of wind turbine failures and risks in the Canadian province of Ontario gives data to enable validation of existing failure models. Failure probabilities are calculated, to show risk on personal property, or in public spaces. Repeated failures, and inadequate safety separation show public safety is not currently assured. A method of calculating setbacks from wind turbines to mitigate public risk is shown. Wind turbines with inadequate setbacks can adversely impact public health both directly from physical risk and indirectly by irritation from loss of safe use of property. Physical public safety setbacks are separate from larger setbacks required to prevent irritation from noise and other stressors, particularly when applied to areas of learning, rest and recuperation. The insights provided by this paper can assist the industry to enhance its image and improve its operation, as well as helping regulators set safety guidelines assuring protection of the public.
The public safety risk posed by wind turbines requires a study of the frequency of accidents or incidents that may cause consequential harm to the public. It is different than looking at harm to employees injured at work. Usually public safety refers to direct health impacts, of injury or death, but this study also looks at how the health impacts may be indirect, caused by the irritation that itself results in stress and harm. The overall goal of the study was to determine if existing regulations, protective barriers, and mitigation strategies assured public safety. A corollary goal was to identify changes that might be required, to assist the industry, and regulators assure public protection.
The study began with a literature search conducted using Google Scholar, with the criteria “wind turbine” AND “public safety” OR “risk”. Relevant files suggested are identified in this paper.
Consideration of factors that might bias public acceptance of wind turbine failures either in a positive or negative manner were sought to avoid prejudice.
The existing safety culture of the wind turbine industry was studied by comparing it to the safety culture existing in mature industries, using the nuclear industry as an example.
Contribution to public safety risk from turbine failures was studied through a detailed examination of seven verified failures that have occurred in the lifetime operation of 2546 industrial wind turbines in the Canadian province of Ontario to show how each resulted in wind turbine blade parts on the ground. This examination was undertaken to ensure that all known failure modes that might harm the public were considered. Failures of smaller wind turbines and failures that did not result in significant blade pieces hitting the ground so they might adversely impact the public were eliminated.
From the seven failures identified the wind turbine failure rate was calculated in a manner consistent with that done in a mature industry. The failure rates identified were compared to the typical “bathtub curve” of failure rates to determine if the failures were indicative of a normal operating service period, and can thus be used to predict future failure rates with confidence.
The public safety harm from wind turbine failures were compared to harm from other public safety issues to identify anomalies.
The examination of the seven verified failures was expanded by considering the contribution for ice shed from wind turbines which is a public safety risk common to all wind turbines operating in an environment where icing can occur.
The methods used to calculate public safety risk from wind turbine accidents and icing was examined to identify logical shortcomings.
Finally, conclusions of the study were identified.Please read on