Resource Documents — latest additions
Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are 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.
Author: Tidgren, Kristine
We’ve recently received a number of inquiries regarding wind energy agreements. This article, while not offering legal advice, is intended to inform landowners as to some of the key legal issues they should consider when evaluating a wind energy agreement proposed by a developer.
According to the American Wind Energy Association, more than 31 percent of Iowa’s in-state electricity generation came from wind in 2015. The Iowa Utilities Board has reported that this is the first time that wind has ever supplied a state with more than 30 percent of its yearly electricity. Sustaining this increase in wind energy output is an increase in wind farm development. When wind farm developers approach landowners about constructing wind turbines on their property, many are left with many questions. Landowners are encouraged to consult with legal counsel and their tax advisors regarding the implications of the agreement they are evaluating. Following are some important considerations.
It’s All in the Contract
The backbone of any wind farm is the wind energy agreement. Every landowner who sells an easement or leases property to a developer does so pursuant to a detailed contract drafted by the developer. It is important that landowners fully understand the rights and obligations detailed in these contracts before signing them. With many of these agreements dictating land usage for the next 50 years or so, it is well worth the expense of hiring an attorney experienced in these matters to review the paperwork before signing. Given the voluntary nature of these projects to date, there may not be a lot of room for negotiation. Even so, landowners should not be afraid to ask for terms that better meet their needs. And landowners should not hesitate to walk away from negotiations if they are not comfortable with the terms offered. Because these contracts often contain a confidentiality clause, landowners usually don’t know the terms of their neighbors’ agreements. As such, it is sometimes difficult to evaluate the fairness of a financial offer.
Lease v. Easement
One sometimes confusing element of wind energy agreements is the nature of the interest being conveyed. Sometimes the agreement will use the term “lease,” and sometimes it will use the term “easement.” Sometimes the agreement will use the terms interchangeably. Many times, the agreement actually conveys a combination of both. While the two interests are similar, they are legally distinct. An “easement” is a right to use a landowner’s property for a specific purpose. Title to the property remains with the landowner, but the purchaser obtains a limited property interest. Because this is an ongoing interest, an easement is recorded in the county land records. It remains binding upon future owners or occupiers for the term of the easement.
Although an easement can be perpetual, wind energy easements are generally for a term, often between 30 and 50 years. Developers often purchase easements to secure a number of rights, including those for ingress and egress, installing transmission lines and facilities, and accessing unobstructed wind. Called “unobstruction” easements, the latter easement restricts landowners from building or conducting activities on their property that would impact the amount of wind reaching the turbine. An easement is usually nonexclusive, meaning that the landowner may continue to farm or otherwise use the land, subject to the rights conveyed by the easement. Some easements may be temporary. Construction easements, for example, usually allow the developer to travel over a larger portion of the property to build the turbine, but end when the construction phase of the property is complete.
A lease, on the other hand, is a conveyance of an interest in land for a term of years in exchange for a rental payment. Without special language in the lease agreement, a lease typically conveys an exclusive right of possession to the tenant. Developers often seek long-term leases for the small parcel of land on which the turbine is located.
Tax Treatment of Payments
The nature of the interests conveyed and the way the payments are structured impact the tax treatment of the payments. Landowners are strongly encouraged to consult with the tax advisors before signing a wind energy agreement. This will prevent surprises at tax time. Generally, if a landowner receives a payment in exchange for an easement in place for 30 or more years, that transaction—for tax purposes—is treated like a sale of the impacted property. If the price does not exceed the basis (generally, the cost) of the impacted property, the basis is reduced by the amount of the easement payment, and the landowner recognizes no income from the sale. If the amount of the payment exceeds the basis, the amount of the payment in excess of the basis is taxed at capital gains rates if the landowner has owned the property for more than one year.
Payments for short-term easements are taxed like lease payments. Both are taxed at ordinary income rates, not subject to self-employment tax. Payments to compensate farmers for crop damages are taxed as ordinary income, subject to self-employment tax. Because these transactions can be complicated, landowners should always consult with their tax advisors for information on the specific tax implications of any agreement before signing.
Another key issue for landowners to consider is liability stemming from the construction and operation of wind towers on their property. Landowners should ensure that developers agree in the contract to indemnify them for damages. This should include defending landowners in future lawsuits and compensating them for legal damages incurred because of the wind farm. The agreement should also require the developer to maintain a sufficient amount of liability insurance to protect the landowner. Landowners should review potential tort liability arising because of a wind farm—including nuisance, negligence, and trespass—with their legal advisors and their own insurers.
Wind farm improvements on a landowners’ property will cause property tax assessments to increase. The agreement should provide that the developer, not the landowner, is responsible for the taxes attributable to the wind farm. Iowa Code § 427B.26 allows counties, by ordinance, to provide for the special valuation of wind energy conversion property, which includes all wind farm facilities, including the wind charger, windmill, wind turbine, tower and electrical equipment, pad mount transformers, power lines and substation. If such an ordinance is passed, the wind conversion property is assessed as follows:
0% of acquisition value for the first year
5% of acquisition value through the sixth year
30% of acquisition value for the seventh and succeeding years
Acquisition value is the acquired cost of the property including all foundations and installation cost less any excess cost adjustment.
Impacted Third Parties
Landowners must not enter into a wind energy agreement without first consulting with and receiving approval from any lenders with a security interest in the property or any tenants farming the land.
A landowner risks accelerating the mortgage if he or she signs an agreement that inadvertently impacts the rights of the lender. Landowners should also ensure that the wind energy agreement will not restrict their ability to encumber the property in the future.
Farm tenants are largely impacted by wind energy agreements. Landowners risk breaching their lease agreements if they enter into a wind energy agreement without the permission of the tenant. While landowners with one-year leases can terminate those leases and renegotiate terms that accommodate the installation of a wind turbine on the property, landlords with multi-year farm leases must engage the tenant in any discussions with a developer. The tenant is in possession of the property for the term of the lease and cannot be displaced. Landowners should consider the impact of the wind farm on future farm tenants as well.
Farm Program Payments
Wind energy agreements can also impact farm program payments. If the land is enrolled in the Conservation Reserve Program, for example, the landowner should consult with the Farm Service Agency to determine the impact of the proposed development on the contract. Sometimes developers are interested in buying back contracts or repaying all benefits paid under the contract to release the land from future CRP obligations. Landowners should consult with their advisors to assess any legal obligations stemming from such an approach.
Land Restrictions and Damages
Landowners must also carefully consider the impact of a wind farm on their farming or other activities. Wind turbines can, for example, interfere with GPS technology. Although that is becoming less of a concern as technology advances. Turbines can also prevent aerial spraying. Some agreements allow farmers to schedule times for spraying when the turbines are shut down. Landowners must also ensure that they understand the full scope of the rights and obligations created by the contract. How many turbines can be built? Who controls the exact location of the turbine? What building and use restrictions accompany the agreement? These are just some of the many questions for which landowners should seek answers.
Landowners should also make sure that the agreement fairly compensates them for ongoing damage incurred because of these restrictions or provides that the developer will timely repair damage to the landowner’s property. For example, the agreement should specify that the developer must repair (within a reasonable period of time) any drain tile damaged because of the developer’s activities. The agreement should also provide for repair and/or compensation for soil compaction and similar types of damage.
What about the Neighbors?
In an effort to reduce future problems, developers often enter into agreements with landowners owning property adjacent to the wind turbine sites. Although not legally required, these agreements provide for a smaller stream of payments to these neighbors in exchange for refraining from activities that may interfere with the operation of the wind park. These agreements also lessen the possibility of tort litigation down the road.
Removal of the Tower
Wind energy agreements typically provide that the developer is responsible to remove the tower (up to a certain depth below ground) when the project ends. Landowners should read these provisions carefully and understand at what point this removal obligation is triggered.
This is merely a brief overview of some of the many issues landowners should consider before signing a wind energy agreement. These agreements can provide a stable source of income over a period of many years. They can also increase tax revenue for schools and bring new jobs to an area. However, landowners must understand the long-term consequences of any agreements they sign. Those consequences will impact the landowners, successive owners, and tenants far into the future. Investing in some trusted legal and tax advice before signing such an agreement will likely yield a positive return.
Kristine A. Tidgren
Center for Agricultural Law and Taxation, Iowa State University, Ames
May 19, 2016
Author: Freiberg, Alice; et al.
Objectives. The wind industry is a growing economic sector, yet there is no overview summarizing all exposures emanating from wind turbines throughout their life cycle that may pose a risk for workers` health. The aim of this scoping review was to survey and outline the body of evidence around the health effects of wind turbines in working environments in order to identify research gaps and to highlight the need for further research.
Methods. A scoping review with a transparent and systematic procedure was conducted using a comprehensive search strategy. Two independent reviewers conducted most of the review steps.
Results. Twenty articles of varying methodical quality were included. Our findings of the included studies indicate that substances used in rotor blade manufacture (“>epoxy resin and styrene) cause skin disorders, and respectively, respiratory ailments and eye complaints; exposure to onshore wind turbine noise leads to annoyance, sleep disorders, and lowered general health; finally working in the wind industry is associated with a considerable accident rate, resulting in injuries or fatalities.
Conclusions. Due to the different work activities during the life cycle of a wind turbine and the distinction between on- and offshore work, there are no specific overall health effects of working in the wind sector. Previous research has primarily focused on evaluating the effects of working in the wind industry on skin disorders, accidents, and noise consequences. There is a need for further research, particularly in studying the effect of wind turbine work on psychological and musculoskeletal disorders, work-related injury and accident rates, and health outcomes in later life cycle phases.
Freiberg Alice, C. Schefter, M. Girbig, V.C. Murta, and A. Seidler
Boysen TU Dresden Graduate School, Technische Universität Dresden, Germany
Scandinavian Journal of Work, Environment, and Health. Published on line Jan 23, 2018. doi: 10.5271/sjweh.3711
Download original document: “Health effects of wind turbines in working environments – a scoping review”
Author: Pohl, Johannes; Gabriel, Joachim; and Hübner, Gundula
To better understand causes and effects of wind turbine (WT) noise, this study combined the methodology of stress psychology with noise measurement to an integrated approach. In this longitudinal study, residents of a wind farm in Lower Saxony were interviewed on two occasions (2012, 2014) and given the opportunity to use audio equipment to record annoying noise. On average, both the wind farm and road traffic were somewhat annoying. More residents complained about physical and psychological symptoms due to traffic noise (16%) than to WT noise (10%, two years later 7%). Noise annoyance was minimally correlated with distance to the closest WT and sound pressure level, but moderately correlated with fair planning. The acoustic analysis identified amplitude-modulated noise as a major cause of the complaints. The planning and construction process has proven to be central − it is recommended to make this process as positive as possible. It is promising to develop the research approach in order to study the psychological and acoustic causes of WT noise annoyance even more closely. To further analysis of amplitude modulation we recommend longitudinal measurements in several wind farms to increase the data base ─ in the sense of “Homo sapiens monitoring”.
Johannes Pohl, Joachim Gabriel, and Gundula Hübner
Institute of Psychology (J.P.), Martin-Luther-University Halle-Wittenberg, Halle (Saale); MSH Medical School Hamburg (J.P., G.H.), Hamburg; and UL DEWI (UL International GmbH) (J.G.), Wilhelmshaven, Germany
Energy Policy 112 (2018) 119–128
Download original document: “Understanding stress effects of wind turbine noise – the integrated approach”
[NWW note: The researchers note that their findings suggest that German emission protection laws are generally effective in establishing adequate setbacks. For “general” residential areas, the noise limit is 40dBA outside at night. For “purely” residential areas, spas, nursing homes, and hospitals it is 35dBA.]
Author: Alves-Pereira, Marian; 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.
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.
Table 1: Dates and times of recordings
|Home No.||Date||Time||Blue Channel||Red Channel|
|1||04 Jul||04:05–06:48||In child’s bedroom, 1||In child’s bedroom, 2|
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).
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.
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.
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 , which is impossible to identify using the classical dBA, 1/3-octave, 10-minute averaging methodology.
Health concerns associated with excessive exposure to ILFN in the workplace have been around since the industrial boom in the 1960s . 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.
School of Economic Sciences and Organizations (ECEO), Lusófona University, Lisbon, Portugal
School of Engineering and Advanced Technology, Massey University, Palmerston North, New Zealand
Atkinson & Rapley Consulting, Palmerston North, New Zealand
School of People, Environment and Planning, Massey University, Palmerston North, New Zealand
 Wikicommons (2017). Fletcher-Munson Curves. https://commons.wikimedia.org/wiki/File:Lindos4.svg
 Dirac (2017). Dirac Delta Science & Engineering Encyclopedia, A-Weighting. http://diracdelta.co.uk/wp/noise-and-vibration/a-weighting/
 Atkinson & Rapley Consulting Ltd (2017). Specification sheet for the SAM Scribe FS Mk 1. www.smart-technologies.co.nz
 Primo Co, Ltd. (Tokyo, Japan) (2017). Specification sheet for the electret condenser microphone, custom-made, model EM246ASS’Y. http://www.primo.com.sg/japan-low-freq-micro
 Bakker HHC, Rapley BI, Summers SR, Alves-Pereira M, Dickinson PJ (2017). An affordable recording instrument for the acoustical characterisation of human environments. ICBEN 2017, Zurich, Switzerland, No. 3654, 12 pages.
 Cooper S (2014). The Results of an Acoustic Testing Program Cape Bridgewater Wind Farm. Prepared for Energy Pacific (Vic) Pty Ltd, Melbourne, Australia.
 Alves-Pereira M (1999). Noise-induced extra aural pathology. A review and commentary. Aviation, Space and Environmental Medicine, 70 (3, Suppl.): A7-A21.
 Torres R, Tirado G, Roman A, Ramirez R, Colon H, Araujo A, Pais F, Lopo Tuna JMC, Castelo Branco MSNAA, Alves-Pereira M, Castelo Branco NAA (2001). Vibroacoustic disease induced by long-term exposure to sonic booms. Internoise2001, The Hague, Holland, 2001: 1095-98. (ISBN: 9080655422)
 Araujo A, Alves-Pereira M, Joanaz de Melo J, Castelo Branco NAA (2004). Vibroacoustic disease in a ten-year-old male. Internoise2004. Prague, Czech Republic, 2004; No. 634, 7 pages. (ISBN: 80-01-03055-5)
 Alves-Pereira M, Castelo Branco, NAA (2007). In-home wind turbine noise is conducive to vibroacoustic disease. Second International Meeting on Wind Turbine Noise, Lyon, France, Sep 20-21, Paper No. 3, 11 pages.
 Castelo Branco NAA, Costa e Curto T, Mendes Jorge L, Cavaco Faísca J, Amaral Dias L, Oliveira P, Martins dos Santos J, Alves-Pereira M (2010). Family with wind turbines in close proximity to home: follow-up of the case presented in 2007. 14th International Meeting on Low Frequency Noise, Vibration and Its Control. Aalborg, Denmark, 9-11 June, 2010, 31-40.
 Lian J, Wang X, Zhang W, Ma B, Liu D (2017). Multi-source generation mechanisms for low frequency noise induced by flood discharge and energy dissipation from a high dam with a ski-jump type spillway. International Journal of Environmental Research and Public Health, 14 (12): 1482.
 Rapley BI, Bakker HHC, Alves-Pereira M, Summers SR (2017). Case Report: Cross-sensitisation to infrasound and low frequency noise. ICBEN 2017, Zurich, Switzerland (Paper No. 3872).