Resource Library Category: Regulations (142 items)
Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. This resource library is provided 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.
Pragmatic view of a wind turbine noise standard
Source: Dickinson, Philip
Abstract
New Zealand Standard 6808:2010 Acoustics – Wind farm noise is unique in that it acknowledges, up front under committee representation, that a representative of a university involved in its development does not support the Standard. Since that time a number of papers and presentations have decried this opposition to the Standard without giving the committee member the privilege of comment or reply. This paper is to put the record straight and explain why the Standard is not supported. Wind farms may well be a viable alternative energy source, but the effects of noise immissions on the health of people living within several kilometres of the wind farms is becoming a concern. The noise level from a wind farm may be quite low, but its characteristics compared to that of the normal background sound make it stand out as something quite different. Often the sound is heard more clearly indoors than outside due to its ability to excite room resonances, making it an irritant causing severe loss of sleep and extreme annoyance. New Zealand Standard 6808:2010 closely follows that used in Britain and parts of Europe, even though there are clear indications that the criteria to be met do not fully conform with World Health Organization recommendations, and the method used is likely mathematically, scientifically and ethically wrong. This Standard and similar standards across the world are clearly biased towards cost effective wind farm development, and it appears public health concerns are not being given enough attention.
Philip J Dickinson
College of Sciences, Massey University Wellington, New Zealand
Updated from paper presented at Acoustics 2009, 23-25 November 2009, Adelaide, Australia
Download “A pragmatic view of a wind turbine noise standard”
Response to HGC Literature Review
Source: Harrison, John
Response to “Low Frequency Noise and Infrasound Associated with Wind Turbine Generator Systems – A Literature Review”
Also see: “Compliance Protocol for Wind Turbine Noise – Guideline for Acoustic Assessment and Measurement”
Introduction
The low frequency report, prepared by Howe Gastmeier Chapnik Ltd. was commissioned by the Ministry of the Environment (MOE), released in draft form in August 2010, released in final form to MOE in December 2010 and to the public in August 2011. Why MOE is issuing it now as a press release is a mystery. This response will address the report itself and the news release from the Ministry of the Environment.
A glaring omission from the report and the news release is the motivation for the commission to HGC. The motivation of course is that a large number of residents living in proximity to wind turbines are suffering from annoyance, sleep deprivation and resulting adverse health effects. The root cause of the annoyance is the noise generated by wind turbines.
Not only does the report and news release avoid mention of the motivation for the commission, neither MOE, the Ontario Chief Medical Officer of Health nor HGC made any attempt to interview those suffering from adverse health effects
The commission focused on low frequency audible sound and infrasound because at a distance of several hundred metres from a turbine much of the high frequency sound has been absorbed by the atmosphere.
The annoyance associated with turbine noise is considerably larger than noise of a similar sound pressure level generated by traffic or industrial noise. For instance field studies by Pedersen, van den Berg, Bakker and Bouma (referenced in the report) show 15% and 27% of a population are annoyed by sound pressure levels in the ranges 35 to 40 dBA and 40 to 45 dBA respectively. [Pedersen et al. consider five reactions to turbine noise: do not notice; notice but not annoyed; slightly annoyed; rather annoyed; and very annoyed. They group rather and very annoyed together under the heading “annoyed”.] These numbers are to be compared to 3% of a population annoyed by traffic noise in the same sound pressure level range. The present Ontario noise limit is 40 dBA; the noise limit before the Green Energy Act was 51 dBA in a sufficiently high wind. As noted below the Ontario noise limit is based upon prediction with significant noise contributions to the prediction not considered.
Possible reasons for the difference in response to turbine noise and road or industrial noise is the predominance of low frequencies in the turbine noise and the characteristic amplitude modulation of turbine noise at the blade passage frequency; this amplitude modulation draws continual attention to the turbine noise in the way that a dripping tap does. The wind industry and its lobbyists make much of the contribution of attitude to wind turbines to the annoyance. However, it is difficult to think that the attitude to industrial plants or road noise would be any less benign. In addition, while Pedersen et al. show a linear dependence of annoyance on the turbine sound pressure level there is no similar study showing a linear dependence of annoyance on attitude!
Not for nothing do the following health and other experts propose setbacks well beyond those allowed by the Ontario Ministry of the Environment:
The HGC report gives considerable prominence to the Colby et al. health study and to the Chief Medical Officer of Health, Dr. Arlene King, health study. The one was commissioned by the Canadian/American Wind Energy Authorities and the other by the Ontario Government which is far from unbiased with respect to wind energy. Both are seriously flawed, notably in having no interest in the numerous people suffering from adverse health effect and in emphasizing the absence of direct health effects. Generally the adverse health effects are indirect: sleeplessness and annoyance leading to stress-related illnesses. This is recognized by the World Health Authority which considers annoyance and stress as adverse health effects. A recent paper by Dr. Carl Phillips, a noted epidemiologist, offers a detailed critique. The King report is marred by an erroneous quotation from the 2009 Pederson et al. paper of the number of people annoyed by turbine noise. Dr. King has yet to acknowledge this error/deception.
Technical Review
As must be, much of the HGC report concerns technical aspects of noise generation and sound propagation. Here there is a fairly complete literature review. However, this section fails to emphasize that the turbine manufacturers are aware that the future of widespread acceptance of wind energy will depend upon reducing noise and low-frequency noise. To quote:
“The acoustic noise radiating from wind turbines continues to be the dominant design driver that must be incorporated into the design process. The tip speed of many turbine designs is limited by the amount of noise created by the blades passing through the atmosphere.” Moriarty (NREL, USA) et al., AIAA Conference Proceedings (2005).
“… noise emission … has become one of the most important environmental impacts of wind energy.” (Romero-Sanz and Matesanz (Gamesa Spain), Wind Engineering, 32, 27-44 (2008))
As stated in the report a major cause of turbine noise is aerodynamic trailing-edge vortex creation. There has been theoretical and wind-tunnel research to investigate the effect of different blade cross-sections on TE noise.
Perhaps of far more importance for low frequency and infrasound noise is the work on inflow turbulence. HGC, the Ministry of the Environment and CanWEA continue to bury their heads in the sand concerning this issue. This important noise source has been brought to the attention of MOE and the Canadian acoustics community by bringing to light the early work at the National Renewable Energy Laboratory (NREL) in the USA. This work demonstrated through theoretical work based upon the mathematical modelling by Amiet and through experimental work with the NREL CART up-wind test turbine that turbulent inflow considerably enhances the low frequency noise emitted by turbines. More recently, Dr. Moriarty has brought to my attention their continuing work, in collaboration with Dr. Guidati, well-known as a co-author of the Wagner et al. treatise on wind turbine noise.
On July 8th, 2011, The National Laboratory for Sustainable Energy, Risø, Denmark placed the following description in an advertisement for a scholarship: “Noise is an interesting concern for wind turbine manufacturers and communities living near wind turbines. These concerns are exacerbated by the constant increase of wind turbine sizes and the cost advantages of placing turbines close to the consumers. The design of low-noise turbines requires the use of validated and accurate engineering models. The main sources of noise generated by a wind turbine have been identified as turbulent inflow noise and trailing edge noise”
If still not convinced then Figure 32 of a recent report by K.D. Madsen and T.H. Pedersen should be enough (“Low Frequency Noise from Large Wind Turbines” DELTA report AV-1272/10 (2010)).
Other work not referenced concerns measurement of turbulence intensity. This work is being done because turbulence increases dramatically low frequency noise, because it puts stress on the turbine blades and because, with associated wake loss, it decreases the capacity factor of downwind turbines. A list of references that needed to be addressed is as follows:
Lange et al., “Modeling of Offshore Wind Turbine Wakes”, Wind Energy, 6, 87 (2003).
Barthelmie et al., “Modeling and measured Power Losses and Turbulence Intensity …”, Wind Energy, 10, 517 (2007).
Wagner et al., “Influence of Wind Speed Profile on Wind Turbine Performance Measurements”, Wind Energy, 12, 348, (2009).
Barthelmie et al., “Off-Shore Wind Turbine Wakes Measured by Sodar”, J. Atmos. Oceanic Tech., 20, 466 (2003).
Bertaglio, “NACA0015 Measurements in LM Wind Tunnel and Turbulence Generated Noise”, Risø National Laboratory for Sustainable Energy (2008) (report # Risø-R-1657(EN))
In Europe, the European Commission is supporting turbine research through the SIROCCA Project: http://www.ecn.nl/nl/units/wind/projecten/sirocco/
Propagation of Low Frequency Noise (Section 3.2)
The report makes important points concerning the propagation of turbine noise: The cylindrical decrease in sound energy, the acoustically hard character of ground for low frequency sound, the low absorption by the atmosphere for low frequency sound and the ready penetration through residence walls. These points needed to be emphasized in the executive summary, the conclusions and the recommendations. At present they are not acknowledged by the Ministry of the Environment. This is especially important as guidelines are drawn up for off-shore wind energy.
Noise Annoyance (Sections 3.5, 3.6 and 3.8)
Laboratory studies have their place. Nevertheless, for reasons that Dr. Leventhall gives, as referenced in section 3.6, far more weight needs to be given to field studies in comparison to laboratory studies. Missing from Section 3.6 is consideration of the amplitude modulation. This is typically 5 dBA but higher values have been reported. Dr. Leventhall himself has written: “A time-varying sound is more annoying than a steady sound of the same average level and this is accounted for by reducing the permitted level of wind turbine noise”. As we are well aware, the Ministry of the Environment refuses to do this.
Section 3.8 quotes the work of Pawlaczyk and Luszczynska. It was only fair to have quoted also the work of Persson Waye et al. (“Low Frequency Noise “Pollution” Interferes with Performance”, Noise Health, 4, 33, (2001)). This paper comes to the opposite conclusion for low frequency noise at the 40 dBA level.
Health Effects (Section 3.11)
The Colby et al. and King reports were dealt with above. Turning to the discussion of Dr. Pierpont’s work, the report is bizarre. There is no mention of the bulk of the work on the medical study of a large number of people suffering adverse health effects resulting from wind turbine noise. This work analyses the range of symptoms and finds reason to treat them collectively as a syndrome. Separately, there are hypotheses for the cause of the syndrome. Hypotheses are not proofs; scientifically, the presentation of a hypothesis is reason to study the problem and to demonstrate proof or otherwise. Whether the hypotheses are correct or not is irrelevant to the fact that there are adverse health effects. The energy devoted by Colby et al., King, CanWEA to denigrate the medical and diagnostic work of Dr. Pierpont is reminiscent of the methods we saw some decades ago used by the tobacco industry! Again, I recommend a reading of the Phillip’s report on the power of crossover analysis in understanding the reality of adverse health effects from wind turbine noise. There is a reference to Leventhall (2010) missing from the bibliography; nevertheless, I know that Drs. Leventhall, Colby and King are not epidemiologists!
Conclusions (section 5.0)
1) Although turbine noise is broadband, at a distance of 500 metres, much of the high frequency sound has been absorbed. Distance enhances the low frequency component as does turbulent inflow.
3) Reference needs to be made to the Salt study demonstrating other pathways for the perception of very low frequency sound.
4) This conclusion is wrong and is a red herring. Turbine noise in the range 35 to 45 dBA causes annoyance and sleep disturbance. These are adverse health effects and in turn lead on to other adverse health effects. 100 people reporting adverse health effects and more than a dozen families abandoning their homes in Ontario alone gives the lie to this conclusion.
5) Non-trivial (a derogatory and unworthy expression) has no place in a professional report. It should be replaced by about 20% being annoyed.
Recommendations (Section 6)
Given that the review of current technical literature in the HGC report has missed completely research dating back to Amiet and forward to detailed comparisons between theory and experiment on turbulent inflow noise, the first recommendation needs to be revised. MOE does need to revisit its guidelines to include turbulent inflow noise, to treat the ground parameter as hard for low frequency sound, to reconsider spherical spreading, particularly for off-shore sound propagation, to address the uncertainty in the prediction of sound at a residence and, given the accepted enhancement of annoyance due to amplitude modulated noise, to apply a penalty for amplitude modulation.
Response to Backgrounder: Low Frequency Sound and Infrasound Report
What kind of noise do wind turbines produce? Turbines do indeed produce a wide range of frequencies. However, the noise 550 metres or more from the turbine is skewed towards low frequency noise because of selective absorption of the high frequencies by the atmosphere.
Is wind turbine sound harmful? The Minister of the Environment writes that there is no direct health risk. However, field studies have demonstrated that 15 to 27% of people exposed to turbine noise at the Ontario regulated limit will suffer annoyance. This is an adverse health effect and in time leads on to other adverse health effects such as stress, tinnitus, headaches and sleep disturbance.
Are Ontario’s rules to control wind turbine sound stringent enough?
The minister writes that at the Ontario regulated setback much of the sound that turbines produce lays outside the range that people can hear. This is untrue. Field studies show that at the regulated setback, 80% of people can hear the turbine noise. Also, the minister fails to note that Germany, with its more extensive experience with wind energy, has a lower night-time noise limit than Ontario.
John Harrison, harrisjp/physics.queensu.ca
Peer review of acoustic assessment, Flyers Creek wind farm
Source: Acoustic Group
EXECUTIVE SUMMARY
The Acoustic Group has performed a desk-top review of the acoustic documents comprising the acoustic assessment for the Flyers Creek Wind Farm. Further, The Acoustic Group has conducted preliminary sound monitoring at an existing operational wind farm (the Capital Wind Farm) which was approved in New South Wales on the basis of similar analyses, guidelines and reports to that provided for the Flyers Creek Wind Farm. The conclusions of the Acoustic Group are set out below.
The Background Noise Monitoring Survey Report has been found to be flawed:
- Noise data that has been supplied does not truly reflect ambient background level;
- Logger positions with respect to residences and trees have not been adequately identified to enable assessment;
- One “residence” had two different logger positions;
- There are unexplained discrepancies in wind speed data;
- There is no evidence re essential wind speed correlations;
- There is no evidence that wind direction has been analysed for correlation to background levels nominated for residential receivers.
The Noise Impact Assessment (Chapter 12, Environmental Assessment and Appendix G2 Noise Impact Assessment) has been found to be inadequate and likely to be inaccurate. They fail to properly examine:
- The lack of data for the type of turbine assumed;
- An appropriate sound power level for modelling purposes that reflects actual operating turbines;
- Modulation, interference patterns, low frequency noise and infrasound;
- The impact of meteorological conditions on sound propagation;
- Identify the actual noise impact of the wind farm;
- Substation noise, construction noise and transmission line noise.
There has been found to be a fundamental inadequacy in the acoustic assessments in that they do not attempt to discuss or examine the actual noise impact for the community. Such an analysis is required by the Director-General’s Requirements and by the principles contained in the South Australian legislative framework.
The adequacy of the South Australian Guidelines in protecting the amenity of the community surrounding the wind farm has been examined. Fundamental inconsistencies and omissions in the South Australian legislative framework relating to wind farm noise have been identified. There are fundamental inconsistencies and omissions in relation to Indicative Noise Levels and in relation to low frequency noise and infrasound. It has been found that the Guidelines establish criteria which conflict with their own objectives.
It has been found that application of the South Australian Guidelines cannot be reconciled with the New South Wales Protection of the Environment Operation Act (POEA) nor with the New South Wales Industrial Noise Policy. The proposed wind farm will result in the generation of offensive noise breaching the New South Wales legislative framework.
Initial results from preliminary testing at the Capital Wind Farm have been found to confirm concerns that the Flyers Creek Wind Farm will result in the generation of intrusive and offensive noise. Testing has demonstrated that the Capital Wind Farm is generating audible noise significantly above predicted levels and above levels prescribed by its consent at the residential site tested. These noise levels validate complaints of significant adverse impacts.
Preliminary testing at the Capital Wind Farm demonstrates low frequency noise and infrasound at levels and fluctuations likely to impact on residents.
On the basis of the above, The Acoustic Group has found that approval of the Flyers Creek Wind Farm proposal would expose the surrounding community to intrusive and offensive noise and would leave the approval authority, land owners and the proponent open to litigation and complaint accordingly.
Prepared for: Flyers Creek Wind Turbine Awareness Group Inc, PO Box 135, MILLTHORPE NSW 2798
Date: 15th December, 2011
THE ACOUSTIC GROUP PTY LTD, CONSULTING ACOUSTICAL & VIBRATION ENGINEERS, 20-22 FRED STREET, LILYFIELD, 2040, NSW, AUSTRALIA
Download original document: “Peer review of acoustic assessment, Flyers Creek wind farm”
Wisconsin Citizens Safe Wind Siting Guidelines
Source: Wisconsin Citizens Coalition
Created by the following organizations:
BCCRWE, Brown County Citizens for Responsible Wind Energy – Brown County
CCCRE, Calumet County Citizens for Responsible Energy – Calumet County
Concerned Citizens of Smelser & Paris Township, Grant County residents – Grant County
Concerned Citizens of Trempealeau County – Trempealeau, Monroe, Rock, LaCrosse, and Dane counties
Forest Voice – St Croix County
Forward Wind Factory Victims Coalition – Fond du Lac County
Glenmore Constitutional Coalition – Brown County
Western Wisconsin Landowners Alliance – Monroe County
WINDCOWS, Wisconsin Independent Citizens Opposing Wind Turbine Sites – Manitowoc & Kewaunee Counties
Contents:
Noise Guidelines
Shadow Flicker
Wind Turbine Setback
Real Property Value Protection Plan
Citizen and Consumer Protection
Site Reclamation / Decommissioning
Electrical Pollution
Physical Protection
Communications Protection
Groundwater Protection
Wildlife / Environmental / Domestic Animal Studies and Protection
Surveillance
Wind Turbine Lighting
Change of Developer / Owner / Operator
Shared Revenue Protection
Construction Inspection
General
Audible Sound Limit
- No Wind Turbine or group of Wind Turbines shall be located so as to cause an exceedance of the pre- construction/operation background sound levels by more than 5 dBA anywhere on receiving Non-Participating property(s). The background sound levels shall be the dBA L90A sound descriptor measured during a pre-construction noise study during the quietest time of the evening or night. All data recordings shall be a series of contiguous ten (10) minute measurements. L90A results are valid when L10A results are no more than 10 dBA above L90A for the same time period. Noise-sensitive sites are to be selected based on the wind development’s predicted worst-case sound emissions (in dBA and dBC), which are to be provided by the Developer/Owner/Operator. This includes the compounding effect that multiple Wind Turbines have on noise-sensitive sites.
- Certain types of noise are more detrimental to some people than to others. As such, the following adjustments are to be made for compliance:
- A 5 dB penalty is applied for tones as defined in IEC 61400-11
- A 5 dB penalty is applied if a sound has an audible cyclic variation in sound level such as beating or other amplitude modulation.
Low Frequency Sound Limit
- The dBC sound levels from the Wind Turbines, anywhere on the receiving Non-Participating property(s), shall not exceed the lower of either:
- dBC less dBA L90A greater than 20, or
- A maximum not-to-exceed sound level of 50 dBC from the Wind Turbines without other ambient sounds for properties located at one mile or more from State Highways or other major roads or 55 dBC for properties closer than one mile. These limits shall be assessed using the same nighttime and wind/weather conditions required in section I.A.1. Wind Turbine operating sound emissions (dBA and dBC) shall represent worst-case sound emissions for stable nighttime conditions with low winds at ground level and winds sufficient for full operating capacity at the Wind Turbine hub.
- If computer modeling or sound testing at any time shows a difference between dBC and dBA sound level measurements that is more that 10 dB, a frequency analysis shall be performed to determine the source and nature of the low frequency sound. If the Wind Turbines are the source, the degree of impact on residents and animals shall be determined and action taken to eliminate the impact.
Download original document: “Wisconsin Citizens Safe Wind Siting Guidelines”
