Resource Documents: Ireland (22 items)

RSSIreland

Date added:  October 23, 2018
Ireland, Wildlife •

Effects of development of wind energy and associated changes in land use on bird densities in upland areas

Author:  Fernández‐Bellon, Darío; et al.

Abstract—
Wind energy development is the most recent of many pressures on upland bird communities and their habitats. Studies of birds in relation to wind energy development have focused on effects of direct mortality, but the importance of indirect effects (e.g., displacement, habitat loss) on avian community diversity and stability is increasingly being recognized. We used a control‐impact study in combination with a gradient design to assess the effects of wind farms on upland bird densities and on bird species grouped by habitat association (forest and open‐habitat species). We conducted 506 point count surveys at 12 wind‐farm and 12 control sites in Ireland during 2 breeding seasons (2012 and 2013). Total bird densities were lower at wind farms than at control sites, and the greatest differences occurred close to turbines. Densities of forest species were significantly lower within 100 m of turbines than at greater distances, and this difference was mediated by habitat modifications associated with wind‐farm development. In particular, reductions in forest cover adjacent to turbines was linked to the observed decrease in densities of forest species. Open‐habitat species’ densities were lower at wind farms but were not related to distance from turbines and were negatively related to size of the wind farm. This suggests that, for these species, wind‐farm effects may occur at a landscape scale. Our findings indicate that the scale and intensity of the displacement effects of wind farms on upland birds depends on bird species’ habitat associations and that the observed effects are mediated by changes in land use associated with wind‐farm construction. This highlights the importance of construction effects and siting of turbines, tracks, and other infrastructure in understanding the impacts of wind farms on biodiversity.

Darío Fernández‐Bellon, Mark W. Wilson, Sandra Irwin, John O’Halloran
School of Biological, Earth and Environmental Sciences, University College Cork, Ireland

First published: 22 October 2018; https://doi.org/10.1111/cobi.13239

Download original document: “Effects of development of wind energy and associated changes in land use on bird densities in upland areas”

Download supplemental information: Details on site locations (Appendix S1), survey methods and density calculations (Appendix S2), and bird species recorded and their conservation status and densities (Appendix S3)

Date added:  January 25, 2018
Health, Ireland, Noise •

Infrasound and low-frequency noise – does it affect human health?

Author:  Alves-Pereira, Mariana; Bakker, Huub; Rapley, Bruce; and Summers, Rachel

On the Engineers Ireland website, a search for ‘infrasound’ or ‘low-frequency noise’ yields zero results. A search on ‘noise’, however, yields 44 results. Why is it that infrasound and low frequency noise (ILFN) is still such a taboo subject? While it is improbable that this particular question will be answered here, an exposé of ILFN will be provided with a brief historical account of how and why ILFN was ultimately deemed irrelevant for human health concerns.

Infrasound and low-frequency noise (ILFN) are airborne pressure waves that occur at frequencies ≤ 200 Hz. These may, or may not, be felt or heard by human beings. In order to clarify concepts, in this report the following definitions are used:

• Acoustic phenomena: airborne pressure waves that may or may not be perceived by humans;
• Sound: acoustic phenomena that can be captured and perceived by the human ear;
• Noise: sound that is deemed undesirable;
• Vibration: implies a solid-to-solid transmission of energy.

In the early part of the 20th century, Harvey Fletcher of the Western Electrics Laboratories of AT&T, was tasked with improving the quality of reception in the telephone. To generate the sounds in a telephone earpiece, he used an AC voltage and had some of his colleagues rate the loudness of the sound received compared to the quietest tone heard.

The company was already using a logarithmic scale to describe the power in an electrical cable and it made sense to rate the loudness of the sounds also on a logarithmic scale related to the quietest voltage that could just be heard.

Initially he called this metric a ‘sensation unit’ but later, to commemorate their founder Alexander Graham Bell, they renamed it the ‘Bel’. A tenth of a Bel became known as the deciBel, corrupted to decibel, which has stuck with the scientific community to this day.

Fletcher-Munson curves and the dBA metric

To address the problem of industrial noise in the early 20th century, measurement was essential, as was a metric. At that time, researchers were critically aware that the readings on a sound level meter did not represent how loud or intense the sound was with respect to the subject’s perception of hearing.

From a biomedical perspective, this concept of perception is subjective, and changes between individuals and over timescales from minutes to decades. These serious constraints notwithstanding, it was acknowledged that some average measure of loudness would have some value for medicine and public health.

Harvey continued his research with Wilden Munsen, one of his team, by varying the frequency of the electricity to give pure tones, to which it is understood 23 of his colleagues listened to different levels of loudness, again through a simple telephone earpiece. (It is assumed they all had good hearing). They were then asked to score the sounds for equal loudness to that generated by an alternating current at 1000 cycles per second.

The level of the sound of course depended on the voltage applied, which could be measured. It is important to note two significant constraints here: The sounds were ‘pure’ sine waves, which are not common in nature, and the headphones enclosed the ear of the subject. This is a very unnatural way to listen to a very unnatural sound.

The numerical results of this study are known as the Fletcher-Munsen Curves (Fig 1). The (logarithmic) units of these curves are known as ‘phons’ and the inverse of the 40 phon curve forms the basis of the A-frequency weighting scale used everywhere today (Fig 2).

A-Frequency weighting scale

The minimum pressure required for humans to perceive sound at 1000 Hz is considered to be 20 micropascal, or an intensity of 10⁻¹² watts per square meter. This corresponds to 0 phon on Figure 1, and 0 dBA in Figure 2. For all its shortcomings, the A-weighting has endured for decades and has become the de facto standard for environmental noise measurement. But is the A-weighting sufficient for all circumstances?

The answer is an emphatic ‘No’. It relates to the perception of loudness, which heavily discounts all frequencies below 1000 Hz and ends at 20 Hz. This 20-Hz limit was a consequence of equipment limitations of the 1920s and 30s, but has remained as the lower limit of human hearing to this day. The assumption that harm from excessive noise exposure is directly related to the perception of loudness has also remained to this day.

Observe in Fig 2 that, at 10 Hz, there is a 70-dB difference between what is measured and what is, de facto, present in the environment. In other words, three-and-a-half orders of magnitude of energy are discounted at this frequency.

The implications for public health are considerable, and within this line of reasoning, any event below 20 Hz becomes of no consequence whatsoever – and more so because it is not implicated in the classical effects of excessive noise exposure: hearing loss.

There are also issues of time and frequency resolution. Acoustic phenomena are time-varying events. A 10-minute average of acoustic events can hide more than it reveals. Similarly, segmenting frequencies into octave or 1/3-octave bands for analysis can also hide much that needs to be seen.

Today, affordable and highly portable equipment can record acoustical environments, and allow for post-analysis in sub-second time increments and 1/36-octave resolution. Waveform analysis from the sound file directly can achieve an even better resolution.

Field studies in Ireland

The following results, recently obtained in field-studies conducted in Ireland (July-November 2017), show why such resolution is needed to understand ILFN-rich environments. The classical metric (in dBA, 10-min averages and 1/3-octave bands) will be contrasted with what is needed for human health-related concerns (in dB with no frequency weighting, and resolutions of 0.2s and 1/36-octave bands), and not merely compliance with regulations.

Equipment and methods
Acoustical environments were recorded with a SAM Scribe FS recording system, a 2-channel recorder with sampling rates up to 44.1 kHz at 16-bit resolution and linear response down to almost 0.1 Hz [4-6]. Recordings were saved as uncompressed WAV files including the 1000 Hz/94 dB reference calibration tone prior to and after measurements. Windshields were placed on both microphones during the entire measurement sessions. Microphones were attached to tripods at approximately 1.5 m above the ground.

Location
Five homes located around the same industrial wind turbine (IWT) development have been the object of study. The data presented here refers to Home 1 (Fig 3). Table 1 shows the dates and times of all recordings that have been made to date in this home. The recordings selected for analysis and presentation herein were chosen on their educational value.

Fig 3: Reconstruction using a Google Earth image and showing the relative position of Home 1 and each of the six industrial wind turbines

The information classically obtained with the dBA metric, 1/3-octave bands and 10-min averaging (on 10 October, 2017, at 18:30) is given in Figs 4 and 5. Weather conditions obtained from Met Éireann for the closest weather tower at this time were as follows: air temperature: 14°C, precipitation: 0.1 mm, mean sea-level pressure: 1006.0 hPa, wind speed: 5.1 m/s (10 kt), wind direction: southwest (200° az).

Results

The values obtained for the sound pressure level and 1/3-octave bands are seen in Figs 4 and 5. The overall dBA metric (red bars labelled ‘Tot’) reflects the sound that humans would hear if they were present in this environment.

The sound pressure level in dBLin metric (grey bars labelled ‘Tot’) reflect the amount of acoustic energy to which humans are concomitantly exposed. The growing discrepancy between the two can be seen as the frequency falls below 1000 Hz.

Fig 4: Data covers a 10-minute interval analysed between 0.5-4000 Hz, in 1/3-octave bands, as recorded in Home 1, on 10 October 2017, at 18:30 (red microphone, i.e. inside child’s bedroom-2). The red bars are A-weighted values, while the gray bars indicate the acoustic energy that is, de facto present, in dBLin. In this environment, the human being would perceive through the ear an overall A-weighted pressure-level of approximately 34 dBA (Tot – red bar), while being concomitantly exposed to an overall acoustic pressure-level of approximately 74 dBLin (Tot – grey bar).

Fig 5: Data covers a 10-minute interval analysed between 0.5-1000 Hz, in 1/3-octave bands, as recorded in Home 1, on 10 October 2017, at 18:30 (red microphone, i.e. inside child’s bedroom-2). The red bars are A-weighted values, while the gray bars indicate the acoustic energy that is, de facto present, in dBLin. In this environment, the human being would perceive through the ear an overall A-weighted pressure-level of approximately 26 dBA (Tot – red bar), while being simultaneously exposed to an overall acoustic pressure-level of approximately 74 dBLin (Tot – grey bar).

Figure 6 shows the sonogram corresponding to the same 10-min period. This visual representation of time- and frequency-varying acoustic events provides much more information than the classical approach (Figs 4 and 5).

Here, short-term events can be seen in the region of 20-50 Hz (Fig 6). Tonal components can be seen at 10 Hz and 20 Hz that are not steady in amplitude and may be amplitude modulated, i.e., where the amplitude of the pressure is not continuous and varies periodically with time. The 10-minute averages, used in almost all legislation, hide these variations and are representative only of tonal components that are essentially unvarying over the 10-minute period in question.

Fig 6: Sonogram that covers the same 10-minute interval (600 s) as in Figs 4 and 5 showing time-varying features. The colour-coded bar on the right indicates sound pressure level values in dB Linear (no weighting). The horizontal line seen at 20 Hz is not a continuous tone because over the 600 s, its pressure level (colour-coded data) varies. A strong (yellow) acoustic phenomenon can be seen to exist at 1.6 Hz and also at 0.8 Hz. Home 1: No weighting, 1/36 octave bands (0.5-1000 Hz), 0.2 s average – Red Channel

The periodogram (Fig 7) over the same 10 minutes shows that there are distinct tonal components that form a harmonic series. When IWTs are the source of ILFN, the rotating blades generate repeated pressure waves as each blade replaces the previous one at any position.

A harmonic series is formed with the ‘blade pass frequency’ as the fundamental frequency (0.8 Hz here). These harmonics constitute what is called the wind turbine signature [7], which is impossible to identify using the classical dBA, 1/3-octave, 10-minute averaging methodology.

Fig 7: Periodogram covering the same 10-minute interval (600 s) as in Figs 4-6, and analyzed between 0.5-1250 Hz. The blade pass frequency of the IWT is 0.8 Hz. Harmonics of this fundamental frequency are shown in the figure. Each frequency band composing the harmonic series has a well-defined peak, e.g., the horizontal line seen in Fig 7 at 20 Hz is represented here as a peak at 20 Hz.

Final thoughts

Health concerns associated with excessive exposure to ILFN in the workplace have been around since the industrial boom in the 1960s [8]. In recent years, however, residential neighbourhoods have also begun to be flooded with ILFN [9-14]. The family living in Home 1, for example, has abandoned their residence due to severe health deterioration in all family members.

Accredited acousticians cannot ascertain compliance levels for ILFN because there are none – the vast majority of regulations worldwide do not cover this part of the acoustic spectrum. Nevertheless, public health officials and agencies should fulfil their job descriptions by becoming aware of the limitations of current noise guidelines and regulations.

Alternatives exist to gather the acoustic information relevant to the protection of human populations, in both occupational and residential settings. Noise regulations and guidelines need urgent updating in order to appropriately reflect ILFN levels that are dangerous to human health.

Mariana Alves-Pereira
School of Economic Sciences and Organizations (ECEO), Lusófona University, Lisbon, Portugal

Huub Bakker
School of Engineering and Advanced Technology, Massey University, Palmerston North, New Zealand

Bruce Rapley
Atkinson & Rapley Consulting, Palmerston North, New Zealand

Rachel Summers
School of People, Environment and Planning, Massey University, Palmerston North, New Zealand

Engineers Journal, 25 January 2018

References:

Date added:  February 6, 2016
Aesthetics, Economics, Environment, Ireland, Property values •

Refusal/Diúltú: North Meath Wind Farm

Author:  An Bord Pleanála

IARRATAS ar chead faoi alt 37E den Acht um Pleanáil agus Forbairt, 2000, leasaithe, de réir na bpleananna agus na sonraí, lena n-áirítear ráiteas tionchair timpeallachta agus ráiteas tionchair Natura, a thaisc North Meath Wind Farm Limited faoi chúram Fehily Timoney and Company Limited as Core House, Bóthar Pholl an Duibh, Corcaigh leis an mBord Pleanála an 6ú lá de Dheireadh Fómhair, 2014. …

Meastar go mbeadh feirm ghaoithe den scála, den mhéad agus den airde atá beartaithe ina gné thiarnasach sa cheantar tuaithe faoi líon daoine seo, go ndéanfadh sé dochar mór do thaitneamhachtaí na réadmhaoine sa chomharsanacht, go gcuirfeadh sé isteach ar charachtar an tírdhreacha agus nach mbeadh sé de réir chuspóirí forbartha iomlána Phlean Forbartha Chontae na Mí 2013-2019. Ina theannta sin, meastar nach mbeadh an fhorbairt bheartaithe ag teacht leis na Treoirlínte um Fhorbairt Fuinneamh Gaoithe de bhrí nár samhlaíodh sa doiciméad treorach seo go dtógfaí tuirbíní gaoithe a bheadh ar scála chomh mór sin i gceantar atá tréithrithe go príomha mar thírdhreach thalamh feirme cnocach agus réidh agus atá chomh cóngarach sin do líon mór áiteanna cónaithe. Mar sin bheadh an fhorbairt bheartaithe contrártha le pleanáil chuí agus forbairt inbhuanaithe an cheantair.

APPLICATION for permission under section 37E of the Planning and Development Act, 2000, as amended, in accordance with plans and particulars, including an environmental impact statement and a Natura impact statement, lodged with An Bord Pleanála on the 6th day of October, 2014 by North Meath Wind Farm Limited care of Fehily Timoney and Company Limited of Core House, Pouladuff Road, Cork. …

It is considered that a wind farm of the scale, extent and height proposed would visually dominate this populated rural area, would seriously injure the amenities of property in the vicinity, would interfere with the character of the landscape and would not be in accordance with the overall development objectives of the Meath County Development Plan 2013-2019. Furthermore, it is considered that the proposed development would not align with the Wind Energy Development Guidelines as this guidance document did not envisage the construction of such extensive large scale turbines in an area primarily characterised as a hilly and flat farmland landscape and in such proximity to high concentrations of dwellings. The proposed development would, therefore, be contrary to the proper planning and sustainable development of the area.

Download original document: “Refusal/Diúltú: North Meath Wind Farm”

Date added:  March 14, 2015
Human rights, Ireland, Law •

In sowing the wind, how Ireland could reap the whirlwind

Author:  Barrett, Eva

On 1 July 2010, Ireland gave an ambitious pledge to convert a significant share of electricity generation from conventional to onshore wind generation. This pledge was designed to support a legal obligation to reach a 16 per cent share in renewable energy consumption by 2020. More recently, buoyed by the apparent success of the initial policy, the Irish Government indicated its intention to explore the potential for a wind generated electricity export market. However, problems are evident that threaten these ambitions as Ireland’s wind policy and most of its commercial wind developments (namely those constructed before 2011) are open to legal challenge for having breached EU law. Although the case law that supports this proposition will be considered solely in relation to the threat it poses to Ireland’s wind policy and developments, the jurisprudence has broad-ranging implications for renewable energy across the EU, and for environmental lawyers and policy-makers in all 28 of the EU’s Member States.

Journal of Energy & Natural Resources Law, 2015
Vol 33, No 1, 59–81, doi: 10.1080/02646811.2015.1008847

Download original document: “‘In sowing the wind, how Ireland could reap the whirlwind’ – a case against Irish wind development(s)”

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