Resource Documents — latest additions
Unless indicated otherwise, documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are shared here to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate. • The copyrights reside with the sources indicated. As part of its noncommercial effort to present the environmental, social, scientific, and economic issues of large-scale wind power development to a global audience seeking such information, National Wind Watch endeavors to observe “fair use” as provided for in section 107 of U.S. Copyright Law and similar “fair dealing” provisions of the copyright laws of other nations.
Evidence of region-wide bat population decline from long-term monitoring and bayesian occupancy models with empirically informed priors
Author: Rodhouse, Thomas; et al.
Strategic conservation efforts for cryptic species, especially bats, are hindered by limited understanding of distribution and population trends. Integrating long‐term encounter surveys with multi‐season occupancy models provides a solution whereby inferences about changing occupancy probabilities and latent changes in abundance can be supported. When harnessed to a bayesian inferential paradigm, this modeling framework offers flexibility for conservation programs that need to update prior model‐based understanding about at‐risk species with new data. This scenario is exemplified by a bat monitoring program in the Pacific Northwestern United States in which results from 8 years of surveys from 2003 to 2010 require updating with new data from 2016 to 2018. The new data were collected after the arrival of bat white‐nose syndrome and expansion of wind power generation, stressors expected to cause population declines in at least two vulnerable species, little brown bat (Myotis lucifugus) and the hoary bat (Lasiurus cinereus). We used multi‐season occupancy models with empirically informed prior distributions drawn from previous occupancy results (2003–2010) to assess evidence of contemporary decline in these two species. Empirically informed priors provided the bridge across the two monitoring periods and increased precision of parameter posterior distributions, but did not alter inferences relative to use of vague priors. We found evidence of region‐wide summertime decline for the hoary bat (λ trend = 0.86 ± 0.10) since 2010, but no evidence of decline for the little brown bat (λ trend = 1.1 ± 0.10). White‐nose syndrome was documented in the region in 2016 and may not yet have caused regional impact to the little brown bat. However, our discovery of hoary bat decline is consistent with the hypothesis that the longer duration and greater geographic extent of the wind energy stressor (collision and barotrauma) have impacted the species. These hypotheses can be evaluated and updated over time within our framework of pre–post impact monitoring and modeling. Our approach provides the foundation for a strategic evidence‐based conservation system and contributes to a growing preponderance of evidence from multiple lines of inquiry that bat species are declining.
Thomas J. Rodhouse, National Park Service and Human and Ecosystem Resiliency and Sustainability Lab, Oregon State University—Cascades, Bend
Rogelio M. Rodriguez, Human and Ecosystem Resiliency and Sustainability Lab, Oregon State University—Cascades, Bend
Katharine M. Banner, Department of Mathematical Sciences, Montana State University, Bozeman
Patricia C. Ormsbee, Willamette National Forest, Springfield, Oregon
Jenny Barnett, Mid‐Columbia River National Wildlife Refuge Complex, U.S. Fish and Wildlife Service, Burbank, Washington
Kathryn M. Irvine, Northern Rocky Mountain Science Center, U.S. Geological Survey, Bozeman, Montana
Ecology and Evolution. 2019;00:1–11.
First published: 11 September 2019
Author: Sedaghatizadeh, Nima
«The results of this study show that underlying mechanism associated with the perceived noise in the far-field of the turbine blades is amplitude modulation due to partial stall on the blades or interaction of the blades with incoming turbulent structures. This is in contrast with the common belief of trailing edge noise to be the dominant source for the perceived noise and its amplitude modulation due to rotation of the blades. Moreover, it is observed that the majority of the locations in which the noise from whole turbines is perceived by the community, are in close proximity of the wake region. … Results revealed that, the highest noise level in the vicinity of a wind turbine corresponds to blade pass frequency and is due to amplitude modulation of the trailing edge noise caused by the rotation of the blade, as well as blade tower interaction. Results also showed that the emitted noise is refracted due to the wind shear in atmospheric boundary layer, as well as the wake and associated turbulent structures. The [computational fluid dynamics] outcomes showed that the wake breakdown occurs at a distance of 12 diameters downstream of the turbine with a strong downwash due to longitudinal vortices. Contours of sound pressure level at the breakdown location of the wake of the wind turbine showed refraction and modulation of the sound at this location. Results also revealed refraction of the noise towards the ground and wider areas due to existence of the longitudinal vortices.»
School of Mechanical Engineering, University of Adelaide, Australia
Thesis submitted in fulfilment of the requirements for the degree of Ph.D. in Mechanical Engineering
Download original document: “The effect of unsteady flow on wind turbine wake development and noise generation”
Author: Asten, Heidi; Tarasenko, Ellen; and Ellicott, Thomas
Wind energy facility proponents should take note of recent developments in the regulation of noise impacts from wind energy facilities in Victoria, which signal increased scrutiny of noise impacts from operations. This includes:
- South Gippsland Shire Council’s finding of statutory nuisance under the Public Health and Wellbeing Act 2008 (Vic) (PHW Act) in relation to the Bald Hills Wind Farm;
- The impending introduction of the general environmental duty in relation to noise under the Environment Protection Act 2017 (Vic); and
- The Victorian Civil and Administrative Tribunal’s (VCAT) consideration of the application of the high amenity noise limit under the New Zealand Standard Acoustics – Wind farm noise NZS 6808:2010 (2010 NZS) to the Farming Zone in Naroghid Wind Farm Pty Ltd v Minister for Planning  VCAT 800 (3 June 2019) (Naroghid).
These developments highlight the significance of proactive and robust management of noise impacts for both existing and proposed wind energy facilities.
South Gippsland Shire Council’s investigation of Bald Hills Wind Farm under the PHW Act
In March 2019, the South Gippsland Shire Council (Council) determined that the Bald Hills Wind Farm had caused nuisance under the PHW Act as a result of noise from the operation of its wind turbines. The decision followed a Supreme Court of Victoria ruling requiring the Council to engage an independent health assessor to consider the complainants’ concerns.
In reaching its finding that a nuisance had been caused, the Council attributed weight to noise logs, and evidence of health impacts provided by the complainants. Significantly, the decision was made notwithstanding reported compliance with the noise conditions of the planning permit for Bald Hills Wind Farm. The lack of directly comparable data correlating timing, location and nature of noise emissions between the formal noise compliance monitoring and the noise complaints presented some challenges to all parties.
The decision is the first finding of nuisance under the PHW Act in relation to noise from the operation of wind turbines. The decision has not been appealed, and may set a precedent for other local government authorities in PHW Investigations. Our key observations in relation to the decision are:
- Compliance with planning permit conditions does not necessarily preclude a finding of nuisance under the PHW Act in relation to noise from wind energy facilities;
- Evidence of impacts on sleep, and corroboration by an independent expert of high levels of audible noise from wind turbines within dwellings was central to the finding of nuisance;
- Wind energy facility proponents may wish to consider whether their post-construction monitoring addresses consideration of any noise complaints they receive; and
- Wind energy facility operators will need to engage with complainants and councils if nuisance complaints are made under the PHW Act.
The new general environmental duty
The Environment Protection Act 2017 (Vic) will require wind energy facilities to comply with a new ‘general environmental duty’ (GED) when it comes into effect (along with a whole suite of other reforms), currently expected to be in mid-2020. The GED will operate separately from planning permit requirements, and from noise nuisance considerations, including under the PHW Act.
The GED will require that ‘a person who is engaging in an activity that may give rise to risks of harm to human health or the environment from pollution or waste must minimise those risks, so far as reasonably practicable’. Significantly, ‘human health’ is defined to include ‘psychological health’. The GED will require management of noise impacts from operations, given that the definition of ‘pollution’ includes noise pollution. A person commits an offence if they contravene the GED in the course of conducting a business undertaking.
The Environment Protection Authority (EPA) will have primary responsibility for regulating the GED. However, third parties may also bring actions for breach of the GED in some circumstances, and seek civil and compensation orders in respect of injury, loss or damage resulting from a contravention.
Wind energy facility operators should consider:
- What are the risks of harm to human health or the environment from operation of the wind farm, including in respect of noise?
- To what extent can the risk of harm be avoided, and has this been done so far as reasonably practicable?
- To what extent can the risk of harm be mitigated, and has this been done so far as reasonably practicable?
- To what extent are their procedures to engage with the local community effective in resolving issues or complaints that may arise during operation?
The EPA is yet to release detailed guidance as to how it intends to regulate the GED, including in the context of wind energy facilities. Once released, such guidance will be an important means of understanding the EPA’s likely approach. The EPA will also be releasing subordinate legislation under the new regime, including environmental reference standards which will regulate noise emissions and replace existing State environment protection policies.
The Naroghid decision
In Naroghid, VCAT considered a planning permit application for a 12 turbine wind energy facility in Corangamite, in the vicinity of Cobden.
VCAT refused to grant a permit for the wind energy facility on a number of grounds. However, of broader relevance to the industry, the decision provides a discussion of the application of the high amenity noise limit under the 2010 NZS to the Farming Zone. The high amenity noise limit under the 2010 NZS applies a limit of 35dB or background +5 dB, as opposed to 40dB or background +5 dB in other areas under the 2010 NZS.
While the Tribunal did not make a final ruling on the issue, it expressed the view that the high amenity noise limit should apply to non-stakeholder dwellings in the Farming Zone. The discussion on this point is contrary to the finding in another VCAT decision in Cherry Tree Wind Farm Pty Ltd v Mitchell SC & Ors (Includes Summary) (Red Dot)  VCAT 521 that the high amenity noise limit does not apply in the Farming Zone. While the Tribunal in Naroghid agreed that the planning scheme is the relevant ‘plan’ relevant to application of the NTS 2010 in this context, the Tribunal’s discussion went on to attach particular weight to EPA Publication 1411 Noise from Industry in Regional Victoria (October 2011). Based on the approach to noise amenity in NIRV (a reference document in the Planning Scheme which is currently being updated), the Tribunal suggested that a high amenity noise limit should be applied to the Farming Zone.
While the discussion in Naroghid is not authority for the application of the high amenity noise limit to the Farming Zone, wind energy facility proponents may wish to consider noise compliance risks at dwellings within the 35dB noise contour.
Herbert Smith Freehills LLP – Heidi Asten, Ellen Tarasenko and Thomas Ellicott
August 30 2019 lexology.com
Long-term wind turbine noise exposure and the risk of incident atrial fibrillation in the Danish Nurse cohort
Author: Bräuner, Elvira; et al.
- Long-term exposure to wind turbine noise was linked to incidence of atrial fibrillation in the Danish Nurse Cohort of 28,731 nurses.
- Nurses exposed to wind turbine noise levels ≥20 dB, compared to <20 dB at night had a 30% higher risk of AF.
- Relatively few nurses were exposed to wind turbine noise: 13% lived within a 6,000 m radius of a wind turbine and 5% of all nurses were exposed to levels >25 dB.
BACKGROUND: The potential health effects related to wind turbine noise (WTN) have received increased focus during the past decades, but evidence is sparse. We examined the association between long-term exposure to wind turbine noise and incidence of atrial fibrillation (AF).
METHODS: First ever hospital admission of AF amongst 28,731 female nurses in the Danish Nurse Cohort were identified in the Danish National Patient register until ultimo 2013. WTN levels at residential addresses between 1982 and 2013 were estimated using the Nord2000 noise propagation model, as the annual means of Lden, Lday, Levening and Lnight at the most exposed façade. Time-varying Cox proportional hazard regression models were used to examine the association between the 11-, 5- and 1-year rolling means of WTN levels and AF incidence.
RESULTS: 1430 nurses developed AF by end of follow-up in 2013. Mean (standard deviation) baseline residential noise levels amongst exposed nurses were 26.3 (6.7) dB and slightly higher in those who developed AF (27.3 (7.31) dB), than those who didn’t (26.2 (6.6)). We observed a 30% statistically significant increased risk (95% CI: 1.05-1.61) of AF amongst nurses exposed to long-term (11-year running mean) WTN levels ≥20 dB(A) at night compared to nurses exposed to levels <20 dB(A). Similar effects were observed with day (HR 1.25; 95% CI: 1.01-1.54), and evening (HR 1.25; 95% CI: 1.01-1.54) noise levels. CONCLUSIONS: We found suggestive evidence of an association between long-term exposure to WTN and AF amongst female nurses. However, interpretation should be cautious as exposure levels were low.
Elvira V. Bräuner, Jeanette T. Jørgensen, Anne Katrine Duun-Henriksen, Zorana J. Andersen
Section of Environmental Health, Department of Public Health, University of Copenhagen, Denmark
Claus Backalarz, Jens E. Laursen, Torben H. Pedersen
DELTA Acoustics, Hørsholm, Denmark
Mette K. Simonsen
Diakonissestiftelsen; and The Parker Institute, Copenhagen University Hospital, Bispebjerg, Frederiksberg, Denmark
Environ Int. 2019 Sep;130:104915. doi: 10.1016/j.envint.2019.104915. Epub 2019 Jul 22.
Download original document: “Long-term wind turbine noise exposure and the risk of incident atrial fibrillation in the Danish Nurse cohort”