Earlier this month, I arranged to visit the wind research teams at Sandia National Lab and the National Renewable Energy Lab’s National Wind Technology Center, both of which are relatively nearby here in the southern Rockies.  I’ve been following the work of many of these researchers for the past year or so—it was central to my 2012 Renewable Energy World conference paper and presentation on efforts to quiet turbines—and was very interested in learning more about their past, current, and future studies.  

In particular, the Sandia team has recently built a Scaled Wind Farm Testing (SWiFT) facility, at which they’ll be studying wake interactions between turbines, and they’ve long been on the forefront of developing new materials and experimental active systems to reduce load strains caused by inflow turbulence.  They’re also leading the development longer blades, which may have important noise implications. Their most exciting forward-looking project is a 5-year effort to re-activate development of vertical axis turbines, with the goal of moving toward 5-10MW scale vertical axis turbines for use offshore (this will be a 10-20 year project, if the first phase shows promise).  Meanwhile, at NREL’s NWTC, lots of research has looked at the pinpointing the sources of sound on turbine blades, as well as advanced modeling of sound propagation in various atmospheric conditions.  Researchers there have quantified the power-production trade-offs caused by wake interactions within wind farms, and are on the leading edge of new technology that might allow individual turbines to monitor incoming air flows and adapt their operations to minimize loads and noise.  All of this research has intrigued me, because of the likely role of wakes and atmospheric turbulence in wind turbine noise levels, and in creating some of the more intrusive sound qualities that neighbors find hard to live with.  My hope was to sit down with these researchers and learn more about their work, as well as draw on their experience to see whether they thought the turbulence factors they study to reduce stress on turbines may indeed also have an effect on the sounds.  

As it turns out, they were also intrigued by such a dialogue, and both labs asked me to present their teams with a seminar on what I’ve been learning about community responses to turbine sound.  Much of what I shared was new to them, and we had some great discussions.  One of the central take-aways from both teams was that very little research has really looked at the acoustic effects of inflow turbulence, and there was universal agreement that this is an important area for future study (as a start, the SWiFT facility will incorporate some acoustic measurements).  Many of them were especially interested in the varying sound quality of turbines, and the ways that this may trigger negative responses among neighbors; there was much speculation about the potential to identify the conditions that create the troublesome knocking, banging, thumping sounds, and perhaps adapt turbine operations to minimize or eliminate them.  As I’ve long found in my interactions with academic and agency researchers, there was an easy openness and curiosity in both rooms, with many questions tossed around, and an excitement about studies they hadn’t seen before. 

Read or download my presentation: The possible role of turbine, wake and shear effects on community response to wind farm noise  (This is the “director’s cut,” including a few slides deleted for length from the final version, along with some additional slides from the REW conference presentation that cover related topics) 

Community Response to Wind Farm Noise: The possible role of turbulence, shear, and wake effects by jimcummings

Planners have long recognized what they call a “demographic shift” in areas near new or expanded airports and highways: in the years after construction of the new noise source, some proportion of nearby residents move away, seeking a return of the quiet they desire.  Since about half the population is very noise tolerant, buyers who don’t mind the moderate noise are usually found. Sometimes homes must sell at a discount, and in other cases, the price isn’t significantly affected; rarely, homes with especially severe noise exposures cannot find a buyer at all.

An article in South Coast Today gives a sense of how this is playing out in Falmouth and Fairhaven, where dozens of families within a half mile or so of turbines have been struggling with noise.  As is often the case, the takeaways are ambiguous.  Two residents near the Fairhaven turbines are quoted, both of whom are reluctantly moving from their homes.  One, who’s been sleeping in his living room because the noise in the bedroom keeps him awake, has found a buyer who’s paying just 7% below his asking price.  The other, whose kids and their mom have already moved away because their 8-year old was having trouble sleeping, had his house on the market at a low-end price, and after “watching buyers come by, look at the turbines and drive away” for several months, he’s now hoping to find renters.  Likewise, a local realtor speaks of a house around a half mile from the turbines that’s been on the market for two years: “They ask about the noise, they ask about the flicker, and then they don’t put in an offer,” she says, noting that the asking price has dropped from $389,000 to $244,900.

In Falmouth, realtors speak about similar troubles finding buyers, with some homes being passed from realtor to realtor as they attempt to sell.  However, the director of Falmouth’s Assessor’s Office says that homes near the turbines have sold at “close to or more than” the assessed value.  At the end of last year, a couple that was one of the closest neighbors to the one privately-owned turbine in Falmouth abandoned the home they designed and built, and started over with a cheap fixer-upper; I have not heard whether it has been sold or not.

In the first town-wide vote on the question of what to do about noise issues around two town-owned turbines, Falmouth voters overwhelmingly defeated a measure that would have authorized the Selectmen to continue on their preferred path of dismantling the turbines.  The proposal carried a likely pricetag of about $800 per household, spread over ten years, largely to pay back loans and renewable energy credits that the town received in advance in order to buy and install the turbines.  The measure fell by a 2-1 margin, with about 40% of the town’s registered voters turning out.

Board of Selectmen Chairman Kevin Murphy said that the board will now begin looking at other ways to try to address the long-simmering dispute.  About 40 households have formally filed complaints, representing 15-20% of the homes within about a half mile. Since noise monitoring showed some violations of state noise limits, the two turbines do not run at night, so operate at a loss to the town, though they still produce carbon-free electricity for use at the town’s wastewater treatment plant.

For more on the Falmouth vote, see coverage in the Cape Cod Times and from the AP.
UPDATE, 5/25/13: Three neighbors respond to the vote in this local article.
UPDATE, 6/5/13: Neighbors emphasize that the vote was about funding the previous decision of the Selectmen to take the turbines down (not about whether the turbines should operate), and that the problems will need to be addressed by the incoming Board of Selectmen and/or the Board of Health.  They also say the state should step up with some financial help or forgiveness to lessen the burden on town taxpayers.

Across the bay in Fairhaven, the first results of noise testing were announced at a Board of Health meeting, marking a turning point not unlike one Falmouth encountered about a year ago.  Monitoring by the state Department of Environmental Protection has found that the two turbines in Fairhaven exceeded state noise limits in 5 of the 24 testing periods analyzed so far (more testing in varying wind conditions is ongoing).  All of the violations ranged from 0.7-1.5dB over the limit of 10dB above background ambient conditions.  Two to three decibels is considered the threshold of the human ear being able to hear an audible difference, so these noise levels are not perceptibly louder than sound just below the 10dB threshold; however, we once again see evidence that the 10dB-over-ambient standard is pushing the tolerance of neighbors.  As Fairhaven board of Selectman Chairman Charlie Murphy said, “Before, people didn’t believe the turbines were that loud at night, but now the study shows it,” adding that the results leave him more determined to “give our residents a good night’s sleep.”

As in Falmouth, where violations were also found in only some conditions and just over the limits, dozens of neighbors are complaining of lost sleep and other related health issues.  EPA standards developed in the 1970′s suggested that noise sources are fairly well tolerated when they remain within 5dB of existing ambient levels, and that at 10dB above ambient, “widespread complaints” are likely.  The detailed results from Fairhaven were not released, but the Falmouth report showed all locations exceeding 5dB, and most exceeding 7dB.  Some states still use 5-6dB thresholds, though many have moved to the 10dB used in Massachusetts, or refrain from the difficult task of regulating noise based on ambient conditions.  The Massachusetts measurement protocol has elements that may in part compensate for the larger 10dB threshold, and other elements that could counter that compensation: the standard compares the L90 sound level (quietest times) of ambient conditions with the absolute peak sound levels of noise from the turbines, rather than the average of each, which may somewhat increase the dB difference; however, the use of “slow” five-second time averaging, rather than “fast” one-second samples (closer to how the human ear perceives sound) likely results in lower peak measurements. Again, though, quibbling over exactly how the measurements take place can obscure the larger issue, which is that current standards appear to be insufficient to keep complaints to a minimum.

The three large wind farms currently operating in Vermont have spurred enough noise complaints to trigger an investigation by the state Department of Public Service.  DPS Commissioner Chris Recchia said “I want to get to the bottom of this….It’s not what was expected.”  Recchia suggested that he’s considering asking the Public Service Board to reconsider their existing noise standards.

Since last fall, 105 formal complaints have been filed, by 23 different individuals living near the Sheffield, Lowell, or Georgia Mountain wind projects.  Annette Smith of Vermonters for a Clean Environment is also collecting confidential complaints, some from people who have filed formal complaints, and some from neighbors who have felt it to be futile to complain to the turbine operators and/or state.  

The DPS is hiring a noise expert to analyze the complaints, and comparing them to quarterly noise measurements made near each wind project.  After this analysis, the DPS has three options, and could recommend one or more: enforce standards if they find violations, create a more effective system for operators to respond to complaints, or ask the PSB to change the noise standards if necessary.

See this recent local news article for more, including details of a recent bad night for neighbor Kevin McGrath, whose house is pictured above.

On June 9, 2008, 26 common dolphins, 21 of them infants, stranded and died in river estuaries around Falmouth Bay, as several days of Naval exercises involving over 30 ships wound down (see AIEnews coverage at the time).  A four-year study (read it online) has  concluded that unspecified Naval activities are “the most probable (but not definitive) cause” of the strandings, which involved at least 60 animals in all, with most of the adults re-floated and guided back to sea.  

The study ruled out other common causes of cetacean strandings, including foraging for fish in shallows, attack by orcas, illness, algal toxins, recreational boats, and earthquakes.  However, the researchers also could not identify a likely trigger among the Naval activities taking place on the morning of the strandings or the day preceding the discovery of the struggling animals.  Press reports at the time suggested that locals heard some large explosions on the day before and day of the strandings, though the researchers did not find records to indicate such activity. Mid-frequency sonar transmissions ended four days earlier; that or other ongoing activity is thought to have driven the dolphins into the bay, with unknown further disruptions triggering the fatal strandings early on the 9th.  According to lead author Paul Jepson, “Eyewitnesses described their behaviour as swimming continuously in tight circles, being vocal, fluke-slapping, leaning sideways, and often with one or more individuals attempting to strand.” 

The lack of a clear cause for the final stranding event during a relative pause in Naval activity on the day before the early-morning discovery of the floundering dolphins adds a familiar ambiguity to the situation.  A Naval spokesman noted that they disagreed with the report’s conclusion and stressed their decades of similar exercises in the area without mass strandings, while conservation groups including the NRDC and the UK-based Whale and Dolphin Conservation called for exercises to be redesigned. While cetaceans can often move away from unwanted noise, it’s long been known that strandings can occur when animals become trapped in areas with no escape route, such as apparently happened here.

Despite Naval denials of responsibility, this event did spur some changes that have led to later exercises being temporarily suspended when dolphins appeared on the verge of being trapped in a similar situation.  As detailed in the new study:

Following this MSE (Mass Stranding Event) and recommendations from the organisations involved in the rescue of dolphins in the MSE, the UK Ministry of Defence initiated the Marine Underwater Sound Stakeholders Forum in the UK to regularly meet with all interested stakeholders (scientists, other Government Departments like Defra and a range of non-Governmental organisations) to discuss these issues in some detail. A direct line of communication was also established after the Falmouth MSE to facilitate rapid exchange of information between cetacean strandings/sightings organisations and Royal Navy Naval Command Headquarters to report groups of pelagic cetaceans seen unusually close to shore and potentially at increased risk of stranding. This was used to report a near-MSE of over 20 common dolphins in the Fal estuary in April 2009 that was seen 15 minutes after RN sonar trials were initiated in the region. The RN immediately modified the naval exercise (including use of active sonars) until the group of dolphins had returned to open sea several hours later. The need to alter training excercises due to the presence of dolphins has not subsequently occurred in this region.

According to the authors, “Such continual improvement of mitigation strategies by the military themselves is probably the best way to limit future environmental impacts of naval activities, including cetacean MSEs.”

Southern right whales have begun giving birth in the waters around New Zealand.  Beginning in the 1920′s, none frequented waters around the New Zealand mainland, after an intensive decade of hunting in the 1800′s decimated populations.  In the 1990′s,  a few scattered sightings began, and in recent years, females and calves are started utilizing sheltered bays. According to Emma Carroll of Auckland University, the whales appear to have lost the knowledge that New Zealand was a valuable winter and calving habitat, but the early exploratory trips by individual whales seems to have led to it being “rediscovered.”

Ironically, considering the growing concern over the impacts of human noise on whales worldwide, early settlers in Wellington complained that whales in the harbor there kept them awake at night!  How the times have changed….

A month after Falmouth’s Board of Selectmen voted to recommend dismantling of the two town-owned wind turbines, a Town Meeting vote fell seven votes short of the two-thirds majority necessary to authorize borrowing money to do so.  A follow-up measure authorizing $100,000 to develop proposals for decommissioning will be discussed as the Town Meeting continues tonight; since that measure won’t require borrowing money, it will need a simple majority.  The Selectmen plan to put the question of decommissioning before the entire town during a May 21 town election. (In Falmouth the Town Meeting is a representative body of about 300 residents.)

UPDATE, 4/11/13: On the final night of Town Meeting, a 90 minute discussion resulted in a measure that will put the $100,000 question before the full town in the May 21 election, rather than authorizing that money to begin to be spent immediately; in addition, this money may only be spent if the town as a whole votes to dismantle the turbines. At its April 11 meeting, the Board of Selectmen agreed to put a binding referendum on the May 21 ballot, approving additional tax levies to cover deconstruction of the turbines.  Coverage of this discussion and vote is here.  Also, the town meeting in nearby Scituate voted down a non-binding citizens proposal to urge revocation of the local permits for a single turbine that has also spurred complaints from its nearby neighbors; coverage here and here.

Last week, the Massachusetts Clean Energy Center said that it would consider forgiving the town $2 million in Renewable Energy Credits already paid and due to be delivered in the future, but only if the turbines were not dismantled, and the town did not impose any noise restrictions more stringent than state regulations.  This represents a small part of the estimated $12-15 million total necessary for decommissioning; over $10 million of this is outstanding loans, which the town hopes will be reduced via debt forgiveness by the state for one turbine, and possible state financial assistance for the other.  In the recent vote, though, the Town Meeting was considering a measures that would authorize the town to spend up to $14 million, since state support is uncertain.  The proposed borrowing would raise average property taxes by $48 per year, or a total per household of about $800.

The two town-owned turbines had been projected to create a net revenue of several hundred thousand dollars a year, in electricity saved at the town Wastewater Treatment Plant, electricity sold on the open market, and Renewable Energy Credits.  However, for the past year, since state DEP noise monitoring found noise levels exceeding state limits in the nearby neighborhood at night, the turbines have been shut down at night, and so operating at a deficit of about $100,000 a year due to the significantly diminished output. This recent article in Cape Cod Times provides a history of the turbine project in Falmouth, the emergence of impacts among neighbors, and the town’s efforts to decide how to respond.

At the town meeting, local green energy advocates urged a “no” vote, saying that it would be more  cost-effective to buy houses from those most upset with the turbine noise, while two Selectmen spoke in favor of the measure, because of the current annual losses, the need to heal the split in the town, and the fact that a town Wind Turbine Options Process group that met for several months came to the conclusion that, among several final options, decommissioning was the best choice.  

If the May 21 town-wide vote agrees to dismantle the turbines, the matter of borrowing funds to complete that process will return to the Town Meeting at another of its biannual sessions.  Meanwhile, town officials will continue to develop plans to navigate the “considerable complexity” of arranging all the necessary financing, contract revisions, and special legislation that will be needed to complete the process.

A environmental planning Tribunal in Victoria, Australia recently completed 28 days of hearings about a proposed new wind farm above the Trawool Valley.  In a recent statement and preliminary report, the Tribunal noted that health effects were the central issue, and that the testimony presented left them still unable to make a clear determination about whether the wind farm will pose an undue impact on human well-being: “In summary the Tribunal has been made acutely conscious of the questions but finds itself in a less than satisfactory evidentiary vacuum regarding the answers.”

The Tribunal notes that it found the evidence of health effects to be both consistent and convincing, though both the extent of the problem and the cause were far less clear. It also notes that many (though not all) of the health effects referred to in the literature occurred at distances of less than 2km, which is the statutory setback in effect in Victoria.  Getting more clarity on how common effects are beyond that distance appears to be at the heart of the Tribunal’s decision to postpone a decision for six months:

The Tribunal considers that the issue of health and wellbeing raises two distinct questions. The first question is whether there is a causal link between sound pressure emissions from wind turbines and adverse health effects on nearby residents. The link may be physiological or psychological. However, given that the respondents expressly disavow that the impact is psychological and that the so-called “nocebo effect” lacks any empirical basis, the inquiry in this case must be as to whether there is a physiological cause. In this regard Mr Cooper hypothesised that wind turbines may emit a particular low frequency “signature” that gives rise to the problem.

One difficulty facing the satisfactory resolution of this question is that there appears to be no overlap of expertise between the acousticians and the health experts. The acousticians can measure the noise but are unable to say what effect it has on human health. The health experts can identify the health issues but are unable to connect those issues with particular levels of noise or sound pressure. It is this that creates the need for interdisciplinary studies.

If the first question produces an affirmative answer, the second and equally important question is what is the incidence of health problems amongst the nearby residential population, and how does that incidence vary or attenuate with distance from the wind turbines. Obviously the problem must be given greater weight by decision makers if 50 per cent of the population surrounding a wind farm is affected rather than 5 per cent.

The full statement linked above (which also has a long section on noise annoyance and sound limits), and an excerpt containing the section on health and well-being, paint a pretty solid and concise picture of the Tribunal’s quandary.  The South Australian EPA is conducting a study around the Waterloo wind farm in the next couple of months that may help answer at least some of the questions, and the Tribunal is eagerly awaiting these results.  It has also invited both sides in the dispute to submit further information that contribute some of that interdisciplinary insight mentioned above.  

A surge of widely-publicized papers purporting to show that those complaining about wind farm noise are being unduly influenced by expectations of harm, or have personalities that are easily upset, may be fostering distrust among residents of Ontario who are randomly selected to participate in an upcoming large-scale survey funded by the provincial government and an ongoing 5-year study by University of Waterloo researchers.

This post, for example, notes that “mischaracterizations are coming out from all around,” and encourages residents to beware of any new surveys that appear to be asking questions about one’s overall quality of life or any annoyances other than wind farms.  The concern seems to be that general quality of life or attitudinal/psychological questions can contribute to the sorts of extreme claims that have filled the press recently, suggesting that “nocebo” type effects are the primary cause of health symptoms and annoyance complaints.  A detailed comment in the post includes a letter sent by one resident who returned a recent University of Waterloo survey without completing it, noting that “questions appear to be constructed in a manner that can be manipulated to achieve any desired result.” Here’s another site that similarly characterizes the UW survey as a political and wind industry sham.

All of these surveys, in order to be representative, need to have responses from a representative sample of both people being bothered and those who are not bothered.  Here, as in some previous research local efforts, distrust has grown to the point that those most affected may not participate.  While for many of those being kept awake or otherwise affected by nearby turbines, the question at hand appears very simple—the turbines are the issue, and they affect me—a useful survey will need to do more than simply ask about turbine health effects.  There are a lot of contributing factors, and it can be useful to consider many of them.  

While such surveys may be subject to misleading interpretations at times, the fact is that surveys and studies are always interpreted differently by those on opposite sides of the issue—where one side sees proof of their supposition, the other sees vague results, poorly designed data collection, or exaggerated significance.  It’s clear that both the idea that turbine noise has nothing to do with the problems being reported, and the idea that turbine noise is inevitably harmful for those living nearby, are overstating what studies and surveys have found. Still, such disputed studies provide raw data that can help quantify the extent of issues and become valuable sources of clear information for those on both sides of the issue, and especially for local decision-makers. 

In particular, if those most affected decline to participate in the Ontario studies, these surveys will come to conclusions that far fewer people are bothered by noise than are, in fact, affected.  This can’t be good for anyone.  Rather than fear the possible misinterpretations, it would be better to help assure that these surveys obtain results that reflect the actual extent of the noise problem.

UPDATE, 4/15/13: Some area residents are telling the University of Waterloo researchers that it’s already too late to measure pre-construction stress and other health markers.  This study is meant to provide a “before and after” picture of local sleep and overall well-being.  But, according to  an article in Niagara This Week, residents question whether it will do so:

“You’re not starting in the right place,” resident Debbie Hughes told Bigelow, during the public comment portion of Monday’s meeting. “We are already affected by the turbines. Our stress is already high.”

A dozen residents, all opposing wind turbines, shared similar messages. “It’s too late, two years too late,” said Helen Kzan, wearing an NRWC receptor 2418 bib. “I’ve been to the doctor. They told me to move.  My stress level has skyrocketed. My physician told me my stress will kill me before the wind turbines.”

While what the locals are calling “the pre-stress level” is likely already be elevated, it would still seem likely that the study could identify any trends in sleep disruption and more widespread stress that may be caused by the noise of the turbines once they’re built (at least, if those affected choose to respond to surveys). The whole situation highlights the ambiguities that exist in trying to determine the cause of any health effects that do occur.

When the US Forest Service initiated far-reaching Travel Management planning in 2005, mandating that all National Forests analyze off-road vehicle use on their lands, and specify roads and trails where off-road vehicles would be allowed, wilderness and quiet-use advocates were thrilled.  Before that, many forests allowed free-ranging use of ATVs, dirt bikes, and other vehicles on any trail not specifically designated as off-limits with posted signs.  Thanks to the all-too-common practice of removing such signs, along with the more-than-occasional off-trail use that created “new” trails over time, the new rules, which turned the tables by allowing vehicles only in areas clearly designated for their use was a big step forward.  Those traveling by foot could look forward to having a bit more separation between themselves and lovers of motorized recreation; often, ridgelines separated basins where visitors could expect to find substantial natural quiet.

Except in winter.  The groundbreaking Travel Management Rule specifically exempted snowmobiles from being subject to the limits contained in each forest’s local Travel Management Plan.  The reasoning was that many of the damaging aspects of unfettered ORV use were less relevant in winter; in particular, damage to vegetation and streambeds, and all the related risks of increased erosion.  These impacts are indeed significantly less in winter, though some soil compaction can occur beneath snowmobile trails over meadows.

But one key impact from motorized use can actually be worse in winter: the noise footprint of the vehicles.  Thanks to better sound transmission in cool air and across frozen, leafless landscapes, the sounds of snowmobiles often travel much further than the sounds of ATVs and dirt bikes in summer. This can clearly impact other forms of recreation, as well as disturbing animals who are sensitive to noise intrusions. In Idaho, lovers of “quiet recreation” worked hard to get snowmobiles included in national and regional travel planning, and when they failed, the national Winter Wildlands Alliance took the question to the courts.

This week, a Federal Judge in Boise agreed that the exclusion of snowmobiles from an otherwise comprehensive approach to travel management planning was “arbitrary and capricious” and “contrary to law,” ordering the Forest Service to revise the 2005 Travel Management Rule within 180 days to include snowmobile management.  According to the AP:

Mark Menlove, executive director with the Winter Wildlands Alliance, said the decision was a monumental victory for backcountry skiers and other winter recreationists seeking a peaceful experience in the woods.  The group’s goal is to not shut down snowmobiles in national forests, but force the agency to designate specific boundaries that carve out distinct areas for those who want to explore on powered sleds and those preferring skis, snowshoes and hiking boots.

“Many of our members use snowmobiles more and more to get to certain places, so we’re not in any way asking the forest service to ban them,” Menlove told The Associated Press on Monday. “But we are asking for some balance there, where our constituents can go and find peace and powder snow in the backcountry.”

While this ruling applies only to National Forests in Idaho, it may lead to similar reviews and expansion of travel management planning nationwide.  

AEI lay summary of:

• Simon Chapman, Alexis St. George, Karen Waller.  2013. Spatio-temporal differences in the history of health and noise complaints about Australian wind farms: evidence for the psychogenic, “communicated disease” hypothesis. Download this paper (pdf)
• Crichton, F., Dodd, G., Schmid, G., Gamble, G., & Petrie, K. J. (2013, March 11). Can Expectations Produce Symptoms From Infrasound Associated With Wind Turbines? Health Psychology. Advance online publication. doi: 10.1037/a0031760 Read/download this paper (Scribd)

Click here to download a 12p PDF version of this extended post 

If the detail in this post is more than you can tackle, I encourage you to take a look at the first several paragraphs through the brief assessments, then click through and scroll all the way down to the final few paragraphs, which look beyond these two particular studies and reflect on the health effects issue and its role in the larger debate over wind farm siting 

In Australia, the debate about wind farm siting standards has ramped up beyond what we’ve seen in the US and Canada.  Several states have adopted more precautionary setbacks (2km, with some options for closer siting), and this has spurred some pushback from wind energy advocates.  Meanwhile, the Waubra Foundation has become a central repository for information on negative impacts, and has released a series of reports and statements highlighting health effects and home abandonments, while calling for an even more precautionary 10km setback standard.

Recently, two reports were released in Australia that have garnered worldwide attention for their claim that health effects around wind farms are caused primarily by negative expectations promulgated via the web and local chapters of groups such as Waubra.  One of these is a formal study published in the journal Health Psychology by a team from the University of Aukland, and the other is the latest (and most comprehensive) paper from Simon Chapman, a University of Sydney Professor of Public Health and outspoken skeptic about wind farm health claims.  

I’ve long been concerned that the adamantly contradictory statements of both wind advocates and concerned citizens groups are likely to be inadvertently contributing to anxiety and stress among wind farm neighbors, which could well be a major contributor to many of the most widespread health effects (especially headaches and sleep troubles).  These new papers are investigating plausible psychological factors, and both studies add some useful new insights; however, similar to my assessment of a recent peer-reviewed article touted as proof of health effects, digging into these two papers reveals data that is far less clear-cut and absolute than the conclusions drawn by the researchers, and especially as reflected in the simplified popular press accounts of the studies. 

The short version of my assessment of these papers:
The Chapman paper gathers a wealth of information about complaint rates around all the wind farms in Australia, and taken at face value, makes an apparently convincing case for Chapman’s preferred hypothesis about the differences he finds: that the presence of local and national groups harping on possible health effects is the proximate cause of health complaints, and indeed, for the actual appearance of the symptoms themselves among wind farm neighbors.  But Chapman’s insistence that the negative influence of “anti wind farm groups” can totally explain away all the noise problems is ludicrous. His paper frames all his data through this one lens, and makes no effort to consider other possible contributors to the differences he finds in complaint levels. At the same time, his inclusion of existing public health research on the nocebo effect and studies of psychologically-mediated responses to perceived environmental threats is a welcome addition to our consideration of wind farm noise issues; still, as I begin to dig into the actual academic studies that he cites, they seem to be at best suggestive of modest contributing factors, rather than offering data that’s strong enough to be posited as the sole or primary explanations for most noise complaints.

For example, the Crichton paper finds that expectations of negative health effects can create a statistically significant increase in the number and severity of symptoms reported by study subjects exposed to infrasound (and to sham infrasound).  However, the actual data shows only moderate changes in reported health responses, especially in symptom severity, rather than a dramatic difference between the subjects primed with negative expectations and those who were given reassuring information prior to exposure to the sounds.  The average severity of symptoms, rated on a scale of 0-6, averaged 1.67 for the group primed to expect no health effects, and an only slightly higher 1.94-2.13 among those primed to expect negative impacts—a far cry from the intolerable responses being reported by some wind farm neighbors.

Despite the fact that these papers don’t contain a “smoking gun” that explains away negative health effects, as wind advocates may be claiming, their findings can be seen as a likely part of the story.  The small differences found in the Crichton study may be due to averaging over all participants; perhaps some individuals responded more dramatically than her data shows; a stronger effect on some individuals could be embedded in the similarly subtle yet statistically significant trends in the Nissenbaum study that found worse sleep and psychological health among those closer to wind farms.  And the Chapman paper reminds us that those reporting health effects remain a small minority, even in areas with substantial community outcry.  As AEI has often mentioned, even empathetic researchers tend to suggest that significant health effects occur in only 5-10% of the nearby population; as discussed below, a divide is emerging between those who feel that such small numbers reflect insignificant impacts, and those who feel that we can and should avoid or better minimize such effects by increasing setbacks.

A local example of health effects: While statistical or laboratory studies can provide valuable insights, they can also distance us from the actual experiences under consideration. In Falmouth, MA, dozens of turbine neighbors have had enough sleep and health issues that the town is considering removing two turbines.  A bit over 10% of those living within a half mile have filed formal complaints; in some directions, 25% or more have had problems.  This recent article features quotes from a couple of these neighbors (including one, Neil Anderson, who is a longtime renewable energy supporter), and from state and local wind advocates.

Click on through for a more complete summary of these papers, and AEI’s current reflections on the health effects controversies

Read the rest of this entry »

Researchers at Woods Hole Oceanographic Institution (WHOI) have completed a proof of concept study that appears to be able to identify individual whale calls in the data collected by seismic surveys.  In the initial data, the researchers were able to cull fin whale calls from the recordings made as airguns blasted their pulses of sound into the ocean floor.  Blue whales are also likely candidates for being heard on the recordings, since their calls also overlap with the frequencies of interest to seismic mapping efforts.

“We have a huge amount of data that can say, ‘Did they change their behavior? Did they stop feeding? Did they stop talking? Did they talk louder?’, and that’s what we want to know,” said WHOI seismologist Dan Lizarralde.

Lizarralde and collaborators are currently seeking funding to develop a computer algorithm that can help with the daunting task of extracting the whale calls from massive amounts of seismic survey data.

For the full story, including spectrograms and comments from other researchers, see this story on LiveScience.com

Ocean-based renewables are destined to be a huge piece of a future carbon-free energy system—tidal, wave, and offshore wind are all likely to become more technologically and economically viable over the coming decade or two. As these offshore renewables mature, they will reduce the current pressure to site wind farms in more populated areas closer to urban electricity load centers.

Watching the decade-long struggle in Massachusetts to build Cape Wind, the nation’s first offshore wind farm, researchers and state officials in Maine have chosen a different path: they decided to tackle the engineering challenges of building turbines that can float in deep water far offshore, rather than the social challenges of building wind farms in shallow water close to shore (which use fundamentally the same foundation designs as onshore turbines).  Floating deepwater turbines can take advantage of even stronger, more consistent winds than their nearshore counterparts; along most of the east coast, offshore wind is far more reliable than onshore locations.

After several years of planning, 2013 will see two floating turbine projects in the water off the Maine coast.  A one-eighth scale (57-foot tall) prototype will be tested in a relatively sheltered bay near Castine; the small model must be sited in waves that are proportionately smaller as well, to simulate how a larger unit will do with bigger offshore waves.  Meanwhile, Statoil will be installing 4 3-MW turbines two miles off the coast of Boothbay Harbor; this close-to-shore site will allow for closer monitoring and testing of the units’ durability.  Both projects are aiming toward the eventual construction of large-scale wind farms, likely using 6-8MW turbines, in waters far offshore, though likely not for another decade or so.  The Bangor Daily News puts the big dream in perspective: “to harness the Gulf of Maine’s winds by 2030, placing a full-scale wind farm of about 170 turbines, each taller than the Washington Monument, in the Gulf of Maine. That farm would bring 5 gigawatts, or the equivalent of about five nuclear power plants, of wind energy to Maine’s shore.”

UPDATE, 5/9/13: University of Maine researchers unveiled their 1/8 scale floating turbine foundation.  See article and video here.

The challenges for floating offshore wind are well-summarized in a recent article from SustainableBusiness.com:

Floating turbines cost less to install than conventional tower-based designs. They can be assembled onshore and then towed out to the installation site, eliminating the expensive and arduous process of building them out in the open ocean. On the flip side, the huge amount of steel needed to make turbines sturdy and heavy enough to withstand rough waves is too expensive. Engineers are working on solutions to get around that, such as intelligent systems that pump ballast water from one tank to the next as a way to stabilize turbines.

One thing that’s clear is the need for specialized turbine blades that can produce energy even as they rock and tilt on ocean waves. All that motion means more wear and tear and can also interfere with power generation. For now, all these designs are performing well, the question is more about which can be produced reliably at the lowest cost.

There has been some local resistance in Maine, especially about the power purchase agreements between Statoil and Central Maine Power for the energy from the pilot project near Boothbay Harbor, for which Maine’s electricity customers will be paying a premium.  State officials maintain that the small extra cost is a worthwhile investment in an offshore wind industry that could pay huge dividends in manufacturing and construction jobs in the years to come.  This is also a long-term investment in an electricity-generating future that can wean us from fossil fuels.  

While Maine’s electricity is already relatively climate-friendly, thanks to significant hydroelectric resources, the development of floating offshore wind in the Gulf of Maine could send lots of clean electricity to Boston and other New England cities.  Onshore wind in the Maine hills faces significant resistance as well, with locals feeling that the price paid by industrializing ridgetops and building new transmission corridors is not worth the modest benefit in green energy for neighboring states; the much smaller impacts of offshore wind may change that cost-benefit equation.   First, though, floating turbines will have to prove themselves durable, and the materials cost must be trimmed.  While that research is underway, offshore wind planners will need to insure that wind farm locations don’t interfere with key fishing habitat.

The California Coastal Commission has rejected the Navy’s 5-year plan for training and testing activities that recently received provisional approvals from the National Marine Fisheries Service.  In a unanimous vote, CCC members said the Navy’s environmental studies failed to back up its claim that impacts on marine life would be negligible during the years 2014-2019.

The Navy’s studies and permit requests suggest that its activities off Southern California could cause 9 million behavioral impacts, 2000 injuries, and up to 130 deaths, though the Navy and NMFS expect impacts to be far lower, and whatever effects do actually occur to have negligible biological impact on populations.  The CCC wants to see more solid science to back up the Navy’s claim that the large numbers will not reflect actual impacts.  Contrary to the Navy’s claim that their projected impact numbers are much higher than what will actually occur, Michael Jasny of the National Resources Defense Council told Commissioners, “We think these are underestimates.”  (See previous AEInews coverage of the Navy and NMFS assessments: New NMFS Navy “take” permits: outrageous or reasonable?)

During the previous 5-year planning round, the CCC took a similar stand, and a Federal Court agreed to some additional precautionary requirements that somewhat limited Navy operations; that ruling led first to a Marine Mammal Protection Act exemption issued by President Bush, and finally to a Supreme Court ruling granting the Navy broad discretion to make operational decisions, and limiting court oversight.

Mark Delaplaine, a coastal manager for the CCC, noted the difficulty of assessing actual impacts: ”I’m just torn between the fact that we haven’t seen strandings in this area, and these very large numbers (in Navy estimates) that are really a cause for alarm,” he said.  Still, he stressed that “you have to have additional precautions….It doesn’t make sense to train where there are large amounts of sea mammals.”

The CCC asked the Navy to voluntarily adopt a set of additional precautions in California waters, including larger safety zones in which they would shut down sonar and explosive operations when animals are nearby, avoiding several designated marine sanctuaries and areas known to host seasonal concentrations of blue, fin, and gray whales, and remaining at least 1km (a bit over a half mile) offshore.  The NRDC concurs with these requirements, and encourages a couple more, including avoiding sonar and explosive activity at night, when nearby animals are much harder to detect, and using the Navy’s instrumented ranges to help detect animals.

The Navy declined these requests. ”We understand that the Navy is obligated to be consistent with the state’s coastal zone requirements, to the maximum extent practicable,” said Navy spokesman Mark Matsunaga. “And we believe we are.”

For more details on the hearing, see these articles from the Orange County Register and AP.  For a deeper look at the Navy and NMFS studies, see the AEInews lay summary of the Atlantic and Pacific 5-year plans.

It’s been a couple of years since we’ve checked in on the eternal Snowmobiles in Yellowstone debate, and in what’s sure to be a shock for those who’ve been following the issue since the Clinton administration, not much has changed!  During Team Obama’s first summer, Ken Salazar announced that the ongoing string of temporary winter use plans would be extended for a couple of years while the NPS accepted comments on yet another round of EIS preparation.  The Clinton adminstration completed an full EIS process, and announced its final ruling (which banned snowmobiles) just in time for the winter during which W was sworn in; the Bush NPS team suspended that plan and launched a brand new round of comments under a new set of temporary rules.  While the Bush plan didn’t ban snowmobiles, it did require, for the first time, that all groups of snowmobilers go with a local professional guide.  This requirement led to a dramatic decrease in snowmobiles entering Yellowstone; most snowmobilers prefer being able to be footloose, and the huge expanses of National Forest land in the region became their preferred playground.  Complicating implementation of that plan, however, were dueling Federal court rulings that appeared to contradict each other; some of these uncertainties lingered on into 2009, as the Obama administration began overseeing the process.

In the years since, the two-year extension of the Bush-era temporary plan stretched to four, and finally the new proposed plan has been released.  In truth, it isn’t all that different than the Bush plan in terms of total numbers of snowmobiles and snowcoaches, though it tweaks a few elements in ways that may reduce some impacts, especially air quality, over time.   It seems likely that the noise impacts will be roughly similar to those documented in a series of studies we covered here in 2009, in which NPS researchers found that snowmobiles or snowcoaches were audible over half the day in many popular areas, including at Old Faithful 68% of the time, and 59% of the time at Madison Junction.  Still, the new plan does include some absolute dB limits for snowmobiles (67dB) and snowcoaches (75dB), and requires best-available technology on all vehicles by five years from now. The plan opens the door a crack to unguided groups (allowing one per day from each Park entrance), and continues the expensive practice of using explosives to keep a rarely-used pass open to snowmobiles (at the behest of the businesses in nearby Cody, Wyoming).  While the plan slightly increases the average number of snowmobiles to be allowed (from 318 to 342), the actual daily average over the past several winters has been under 200 per day.

Given that previous plans have triggered lawsuits from both environmental groups seeking stricter rules and local business interests wanting fewer restrictions, it’s probably a good sign that both the Greater Yellowstone Coalition and the snowmobile group Blue Ribbon Coalition responded with generally positive comments, while unlike 2009, no instant legal challenge came from the State of Wyoming, either. Fatigue has finally settled in, it appears, as the BRC’s spokesman suggested: “I think for my organization it would be important to resolve this and come up with a long-range plan that doesn’t get challenged in the courts.”

For detailed coverage of the new plan, see this article from National Parks Traveller.  The local Billings Gazette is always a good source for those wanting to track how this all unfolds.

A new documentary from the CBC’s Doczone series, titled Windrush, takes a look at the widespread resistance to wind power in Ontario, which is largely based on noise and health impacts.  While the CBC video is only viewable in Canada, a regional organization opposing industrial wind has posted a version on YouTube (it’s 42 minutes long and ends a bit abruptly; it’s unclear whether it’s abbreviated, or simply missing the end credits).

This is a fairly balanced program, especially in highlighting the differences between building wind farms in the wide-open spaces of Alberta and the more densely populated rural areas of Ontario.  While it gives a lot of screen time to researchers and public officials who are studying the negative responses of many neighbors to nearby turbines, it’s useful and important to hear these sober and measured voices of concern.  The conventional wisdom, as reflected in the MOE health effects report, is also presented, though more as a context within which the program attempts to explore the persistent claims that living near turbines can be more difficult than these reassuring assessments suggest.

At times, the time constraints of the program lead to unfortunately abbreviated presentation of some key issues.  Grid integration issues are greatly simplified and distorted, leaving the impression that wind farms are inherently incapable of “playing nicely” with the rest of our energy generation system; the minute or two spent on this issue would have been better left on the cutting room floor, as it presents little more than a cartoon version of an important and over-hyped element of the story.  The treatment of low-frequency noise and infrasound is fleshed out a bit more, though some of the material would have benefitted from a bit more context, especially in areas where the science is still emerging and isn’t yet totally settled.  Finally, as local health official Hazel Lynn discusses the health effects being reported, she makes a comment that flits by so quickly that viewers may miss this crucial bit of context: while noting consistent symptoms being reported by people in many areas, Lynn stresses that these impacts are important even if they are only affecting 5-10% of the population that is more susceptible.  The rest of the program may leave the impression that severe impacts are being felt by most or all of the residents in these towns. (The question of what proportion of residents are negatively affected by turbine noise remains woefully under-studied.  Clearly there are many places where 20-50% of nearby residents dislike the turbines, most commonly due to some degree of sleep disruption, but this number is itself reflective of just a handful of actual surveys; we have no concrete sense of what proportion of people around most wind farms are either annoyed or experiencing chronic health effects.  Still, as Lynn suggests, for many, the question of “how many” is secondary to the need to address the fact that the noise does affect some.) 

Perhaps the most powerful element of the program is the aerial photography of wind farm areas, which give a compelling sense of the scale of the turbines as compared to the homes, as well as the vast landscape impacts, leaving many homes surrounded by turbines.  The segments filmed in Denmark are valuable as well; these reflect the growth of turbines from the 660kW machines common there, to the newer 3MW giants that are causing far more pushback, in both Canada and Denmark.  It also feels very valuable to hear and see some of the people who’ve been so widely cited about their concerns, including Lynn, Michael Nissenbaum, otologist Alec Salt, and acoustician Henrik Moller.  Too often, the basic human empathy and spirit of inquiry that fuels their work is obscured by the crassly dismissive near-vilification of these researchers by supporters of the industry (and also, to a lesser degree, by the hyperbole of some industrial wind opponents).  And, throughout the program, retired nurse Norma Schmidt, who eventually moved out of her house, is a calm and compelling voice for the experiences of neighbors who have been affected.  I heartily encourage anyone involved with wind farm issues to watch the film.  

For more, see the CBC Doczone’s Windrush web page, which includes a Director’s Statement, graphics, and several related stories.  And, here’s an article from The Observer about the film.

The Wisconsin Public Service Commission rejected the only large wind project currently in development in the state, citing noise concerns for homeowners in the vicinity.  The Highland Wind project sound models suggested that turbine sound would not meet the 45dB night time noise standard at about 20 homes. Some of the acousticians who submitted testimony in the Highland hearings suggested that limits of 40dB or less would be more appropriate; doubtless many more homes would be living with sound between that level and the current 45dB standard.  The recent collaborative sound study in Brown County was funded by the PSC in order to help understand the experience there before deciding on Highland’s application.  The developer of Highland, Emerging Energies, is likely to resubmit the application with adjustments to the turbine layout to keep all homes under 45dB.

UPDATE, 5/3/13:  The PSC has agreed to consider a revised plan from Emerging Energies, which may include night-time curtailments of turbines near the closest homes—apparently not routinely, but just when atmospheric conditions especially enhance sound propagation. 

Meanwhile, in the town of Heath, Massachusetts, the Planning Board and Renewable Energy Committee (REAC) has recommended that citizens approve a ban on industrial wind at the Town Meeting later this month.  Again, noise was a primary factor, thanks to the very quiet level of ambient sound in the deeply rural area; the REAC recommended a 2-mile buffer to maintain current ambient sound levels and preclude against any possible property value losses.  

The decision in Heath came on the same week that residents of nearby Monroe and Florida began speaking publicly about their experiences with the new noise from the Hoosac Wind project, which began operations in December.  Michael Fairneny says that at his house 3000 feet away, “My quiet, peaceful, serene world and home has been turned into a reeling of unending noise, annoyance and constant dealing with those in charge to help us.”  Six residents met the press to discuss their experiences, and say that at least 20 are struggling with noise issues. (A rough scan of a Google Earth image of the area, and referring to a map in the the 2003 permit application, suggest that around 150 homes are within about a mile of the turbines, with perhaps 80 within 3000 feet.)

The release of Proposed Rules to govern US Navy training and testing operations in the waters of the Atlantic, Gulf of Mexico, Southern California, and Hawaii from 2014-2019 has put the National Marine Fisheries Service (NMFS) in the crosshairs of an outraged response from environmental groups.  NRDC, the Center for Biological Diversity, and others point to the staggering numbers of “Level B” harassment that will be allowed: over 31 million incidents, along with “Level A” injury predictions including permanent hearing loss numbering in the thousands, capped by several hundred deaths.  These numbers reflect far more than sonar training; also included in these permits are impacts from ongoing training and testing of systems used in live gunnery and torpedo exercises, explosive mine-neutralization, air, surface, and submarine battle exercises, and ship-shock trials (in which large explosives are set off near ships to test their resilience).

“We’re talking about a staggering and unprecedented amount of harm to more than 40 species of marine mammals that should give any federal agency involved, be it the Navy or the National Marine Fisheries Service, pause,” NRDC attorney Zak Smith said in a statement.  The take numbers are generally about twice as high as those in the last round of permitting, which covered a five year period from 2009-2013.

“We absolutely share the concern about protecting marine mammals,” said Alex Stone, an environmental program manager with the Navy’s Pacific Fleet. “We think that the mitigation measures are effective, but it’s true, you’re never going to see every marine mammal that’s there. But in terms of impacts on species, we really haven’t seen any of those after years and years of doing these same types of training and testing activities in these same areas.”

“That’s always been a dubious argument but in light of new information it’s wearing especially thin,” said Michael Jasny of the Natural Resources Defense Council, in a KQED segment. “We now know that beaked whales off California are declining precipitously. We know that blue whales aren’t recovering.” Jasny says the Navy should avoid key areas, like gray whale migration routes and the summer feeding grounds of endangered blue and fin whales. “Southern California is a globally important feeding habitat for them,” said Jasny. “It should be elementary common sense to avoid the core feeding habitat of blue whales. “

How could NMFS sign off on such a seemingly devastating number of permitting takes?  Well, as is often the case, the picture isn’t quite as clear as the headlines may make it seem.  Indeed, we are once again thrust into a funhouse-mirror world of wildly divergent ways of framing the proposed plans.  Press releases and resultant popular press headlines trumpet the NMFS rule as “allowing the Navy to harm whales, dolphins more than 31 million times,” with the permitted incidental takes being described as including “a wide range of harms, including destruction of habitat, physical injury and death.”  The Navy’s statement offers a much more sanguine perspective on the tens of millions of behavioral takes, describing these effects as “e.g., turning head, changing swim direction.”  Huh? What to make of all this?

I dug into the Draft EISs and Letter of Authorization requests developed by the Navy, and the two Proposed Rules announced in January, in order to try to understand how Navy and NMFS biologists could have approved the scary numbers.  I came away far less freaked out, though still disappointed that the Navy and NMFS don’t appear ready or willing to keep noisy Navy activities out of some biologically rich areas.  This has been one of the central points of contention pushed by environmental groups for the past few years, and it remains valid to ask why this practical protective step has not been taken, at least regarding explosive activities with a higher risk of injury. (The vast distances over which some of these sounds travel likely means that exclusion zones to avoid behavioral “takes” may need to extend up to 50-100 miles from the regions of concern in order to provide full protection from noise disruptions; the practicality of such large exclusion zones may be harder to establish, though worthy of discussion.)

After a few hours of reading and digesting several hundred pages of environmental analysis and permitting documents, I was able to distill a few of the key take-aways that may help readers to understand NMFS’s reasoning, as well as the shortcomings of the plans.  Click through for my ten-minute version of what’s in these permits.

Read the rest of this entry »

Deepwater Wind, developers of a proposed 5-turbine wind farm off Block Island, Rhode Island, has agreed to refrain from pile driving for one month a year in order to minimize impacts on critically endangered North Atlantic right whales.  Pile driving, a key part of building the foundations for shallow-water offshore wind turbines, is the loudest aspect of offshore wind construction and operation.  Deepwater Wind, in consultation with the Conservation Law Foundation (which is deeply involved in right whale protection), agreed to suspend pile driving in April, the time of year when right whales are most commonly present in nearby waters.

You may have seen some press coverage recently of the latest iteration of Cornell’s Macauley Library of Natural Sounds online.  Today, Wired put together a fun little game in a slide show on their site, in which you can listen to clips of odd animals sounds, and try to guess whose voice you’re hearing.  The accompanying article is a good introduction to the new Macauley archive, too.  After reading the article, you can start playing the game by clicking “next” on the upper right corner of the animal picture grid on that page…

Even before meetings began, facilitators of the multi-stakeholder group convened in Falmouth  to address widespread neighborhood complaints about noise from two town-owned turbines realized that the original goal of having group develop a consensus recommendation was too high a bar to aim for.  So, the process was dubbed the “Wind Turbines Options Analysis Process,” with a hope of being able to present two or three options to the Selectmen for consideration before this spring’s Town Meeting.

As it turns out, even that goal was elusive; in the end, the WTOP report summarizes four options, which generally reflect the initial stances of various stakeholder groups: take them down (the unwavering stance of the affected neighbors), run them at full power (the preference of the climate action groups in town and of those representing the town’s budgetary interests), or settle for one of two options involving shutting them down for all or part of the night (which satisfies neither the neighbors nor the climate or fiscal constituents).  In all three of the options that will cost the town money (removing turbines and replacing a third to half of their capacity with solar panels, running them full-time and compensating neighbors, and shutting them down for 12 hours each night), the WTOP recommended that the town seek funding from the state to support the initiatives.

UPDATE, 1/30/13: The Falmouth Board of Selectmen voted tonight to recommend that the two town-owned turbines be dismantled, and for the town to ask the state for funding to help cover the town’s debt for the turbines, and for the MassCEC to forgive the town for Renewable Energy Credits  previously purchased as part of the project financing.  The Selectmen will prepare a warrant article for the April Town Meeting, likely to be followed by a town-wide vote in May.

A few things stood out for me as I read through the 55-page report and some of the supporting materials (available at this link).

First and most striking, even among those advocating operating the turbines at full capacity it appears that the reality of the impacts on neighbors is generally acknowledged.  The report stresses that:

Although most of the discussion of acoustic measurement centered around whether, where, and how often the turbines exceeded DEP guidelines, most members of the WTOP acknowledged that operation within these guidelines would still not result in acceptance of the turbines by affected neighbors, since neighbors stated that compliance with the guidelines did not alleviate the health concerns they experienced.

In keeping with this understanding, the section of the report fleshing out the option of running the turbines at full capacity includes several measures meant to provide compensation for nearby neighbors; while brief, these options include purchasing (and reselling) homes, providing financial compensation that neighbors could use as they see fit (sound insulation or masking equipment, pay utility bills, etc.), and the possibility of the town offering a Property Value Guarantee.

A unique feature of the WTOP group was that it included two members whose charge, unlike all the other stakeholders, was to hold “multiple perspectives;” in essence, their task as individuals was to synthesize all the information, much as the group as a whole would ideally do.  With the group unable to find a synthesis of its own, the conclusions of these members are especially valuable.  

Read the rest of this entry »

In December, four acoustic consulting firms collaborated to study wind turbine noise at three Brown County, Wisconsin homes that had been abandoned by their owners after the nearby Shirley Wind Project began operations.  The study, organized by regional environmental group Clean Wisconsin and paid for by the state Public Regulatory Commission, will help inform the PRC’s consideration of a proposed new wind farm in the area.  

Two things stand out about this new study.  The first is the choice to bring together several acousticians who have previously been widely cited by opposite sides of the turbine siting debate. The study team included one firm  (Hessler and Associates) commonly hired to do sound assessments for wind developers, another (Rand Acoustics) that has become widely championed by concerned citizens groups because of its much more cautionary assessment of turbine noise, and a third (Schomer and Associates) whose work has often been in the middle ground, with particular papers being seized on by each side in the siting debate; the fourth firm (Channel Islands Acoustics) has worked much less on wind farm issues than the other three.  This diverse group of acousticians produced a 13-page consensus report (edited to 12 pages in the final version submitted to the PSC), along with an appendix report from each team, all of which focus on different aspects of the study that they found most compelling. 

The second virtue of this study is that it clearly documented, for the first time, specific sources of infrasound (sound at frequencies below 20Hz) and low-frequency noise (audible sound above about 20Hz) from turbines that are consistently measurable inside homes. The data they collected clearly showed peaks in the sound spectrum that correspond to the “blade passing frequency” (BPF) of just under 1Hz, or one pulse per second, and several harmonics of the BPF up to about 5Hz.  These pulses showed up both inside and outside the closest home, 1280 ft from the nearest turbine.  In addition, they measured a more modest infrasound and low-frequency peak at 15-30Hz, which reflects the natural resonance and flexibility of typical home construction; this peak may have been triggered by turbine sound or by wind or other outdoor sound sources. One of the acousticians, Rand, notes in his appendix a possibly corresponding pulse of outdoor sound in the 9-14Hz range that can be associated with inflow turbulence hitting turbines.  Still, the infrasound that was measured in this study, as in most other similar measurements of wind turbine noise, is at lower dB levels than what is typically considered perceptible by humans. (Ed. note: two emerging yet still limited bodies of work suggest that turbine infrasound may have rapid peaks that approach standard perceptual thresholds, and that our ears may respond physiologically to sounds at lower levels than are perceived; nothing in this Wisconsin study address these questions, though later analysis of the data may contribute to the study of short-term peaks.)

Since the study took place in homes that were abandoned by homeowners who all complained of debilitating health effects, including sleeplessness, nausea, and depression, part of the goal of the study was to see whether they could identify any possible acoustic triggers for these negative responses.  The authors collectively noted that “the issue is complex and relatively new” and concluded that this work “was extremely helpful and a good start to uncover the cause of such severe adverse impact reported at this site.”  

The consensus report, signed by all members of the team, introduces a new hypothesis, based on a US Navy study that found that vibrations can trigger nausea in pilots when in the frequency range of up to 0.5-0.9 Hz, with the peak “nauseogenicity” occurring at 0.2 Hz.  Of particular concern is that as turbine blades get longer, the BPF is being reduced; only the recent generation of turbines has dropped below 1Hz (thus perhaps helping to explain the recent surge of health complaints among a subset of turbine neighbors), and planned larger blades will drop close to that 0.2Hz range of maximum inducement of nausea.  While stressing that this is, as yet, a very preliminary supposition, especially since it involves a study based on physically vibrating the body, while turbine infrasound is a vibration of the air around a body, the authors still agreed that:

The four investigating firms are of the opinion that enough evidence and hypotheses have been given herein to classify LFN and infrasound as a serious issue, possibly affecting the future of the industry. It should be addressed beyond the present practice of showing that wind turbine levels are magnitudes below the threshold of hearing at low frequencies.

In particular, the research team agreed that a further literature search for studies related to vibration-induced nausea should take place (Paul Schomer is working on this), and that a “threshold of perception” test should be conducted, to see what proportion of residents are able to perceive the faint signals in either audible or infrasonic ranges.  Only one of the five acousticians, Rand, could detect sound at all residences; he also reported headache and/or nausea (it is also noted that he is the only one among the five researchers who suffers from motion sickness).

As often happens, the reaction to this study ranged from “this changes everything” to “this is nothing new,” with some saying it proves negative effects and others that it proves wind energy is safe.  For a run-down of the reactions, a brief look at each of the four appendices, and links to download the study, click on through… 

Read the rest of this entry »

In the wake of NOAA’s large-scale ocean noise mapping project, two much more detailed studies from the Pacific Northwest have highlighted the likelihood that current shipping noise is already pushing the limits of what biologists think many ocean creatures can cope with.

The first study recorded the sound from several types of boats and ships traversing Admiralty Inlet, between Whidbey Island and Port Townsend, WA, and used these recordings, correlated with ship traffic records, to model sound levels throughout the area.  The Seattle Times summarizes this work, which found that at least one large vessel (container ship, ferry, or large tug) was in the area at least 90% of the time, and that the average noise level was about 120 decibels, which is the threshold above which federal agencies begin being concerned about behavioral impacts on some ocean species.  

“Continuous noise at that level is considered harassment of marine mammals,” said University of Washington’s Christopher Bassett, one of the authors of the paper. “About 50 percent of the time, we even exceed that threshold.”

“It is concerning that the noise levels are so high,” said Marla Holt, a research biologist at Seattle’s Northwest Fisheries Science Center. “When you see how often this happens and how chronic the noise exposure is, that’s when you start to say, ‘Wow.’”

Interlude: Brief OrcaLab recording of threatened Northern Resident killer whales in Caamano Sound, BC, chatting with each other and then being drowned out by a cruise ship:
 

To the north, another study mapped shipping noise in the Salish Sea (south and east of Vancouver Island), and on up the British Columbia coast to the port of Prince Rupert.  This work, funded by World Wildlife Fund-Canada, introduces a comprehensive approach to modeling sound transmission from ships, incorporating differences between vessel types, transmission loss in a variety of bathymetric and seabed conditions, and temperature-driven variations in sound speed during different seasons. (Download a PDF presentation summarizing the full WWF-Canada report here; a shorter version appeared in JASA in November). Here, too, large areas are subject to excessive shipping noise; the maps below show total sound levels, and the areas where the annual average of two specific low frequencies are above the 100dB threshold that the European Union considers the target for biologically sensitive areas:

But now, check out that lighter colored patch about halfway between BC’s two big offshore islands.  

That’s an inland waterway that heads up to Kitimat, the proposed site of a major new port, the Northern Gateway, which would serve as the primary port for shipping tar sands oil to Asia.  An annual total 220 super-tankers would head though that currently mostly-yellow zone, all the way up that long, narrow channel that points to the upper right hand corner of this close-up (and leave again—so more than one passage a day on average).  As you might imagine, there is widespread concern about the risks of accidents and spills in these often treacherous passages, but the increase in shipping noise is also being raised as a question.

A second study by the same research team, led by Christine Erbe, took a close look at current and likely increases in shipping noise, should Northern Gateway go forward, and what they found is not reassuring.  Noise levels will increase by up to 6dB in the approach lanes in Caamano Sound, and by 10-12dB in the narrow fjord into Kitimat (see map on right).  In the western channel (the wider approach), where sound would likely increase 3-6dB (representing a doubling to quadrupling of sound energy), Humpbacks would hear tankers and their accompanying two tugboats for 43% of daylight hours, and orcas (due to thier higher-frequency hearing, less intruded upon by low-frequency ship noise) would hear the tankers 25% of the time.  Fewer whales venture all the way up the fjords, but some would likely be present in the bend in the route, where noise levels would increase by 10dB, representing a 10-fold increase in sound energy.

“There is a worry they will go away and not come back to these fiords,” says Erbe. “This is critical habitat, important to them. Are they going to be able to feed elsewhere? We can only answer that with long-term monitoring.”

These studies, one of which utilized four seasons of recordings, and the other presenting a comprehensive and verifiable sound modeling approach, both offer exciting steps forward in the study of coastal and oceanic acoustic habitats.  Let’s hope that coming years produce many more studies from other regions around the world that continue to develop these innovative techniques.

Detailed Northern Gateway study: Erbe, C., Duncan, A., and Koessler, M. 2012. Modelling noise exposure statistics from current and projected shipping activity in northern British Columbia. Report submitted to WWF Canada by Curtin University, Australia.

BC sound modeling study: Erbe, C., MacGillivray, A., and Williams, R. 2012. Mapping Ocean Noise: Modelling Cumulative Acoustic Energy from Shipping in British Columbia to Inform Marine Spatial Planning. Report submitted to WWF Canada by Curtin University, Australia.
Shorter version:   Erbe, C., MacGillivray, A., and Williams, R. 2012. Mapping cumulative noise from shipping to inform marine spatial planning.  J. Acoust. Soc. Am. 132 (5), November 2012. 423-428.

Puget Sound study: Bassett, C., Polagye, B., Holt, M., Thomson, J. 2012. A vessel noise budget for Admiralty Inlet, Puget Sound, Washington (USA). J.Acoust.Soc.Am. 132(6), December 2012

Related:
Kathy Heise and Hussein Alidina.  Ocean Noise in Canada’s Pacific Workshop, January 31-February 1, 2012.  Summary Report.  WWF-Canada.  54pp.  Read or download PDF

WWF-Canada Submission to Enbridge Northern Gateway Joint Review Panel, 9/19/12. (mostly terrestrial impacts; some ocean noise sections) Read or download PDF

Perhaps we’re too distraught about the ways shipping noise affects whales, airplanes intrude on hikers’ solitude, or wind turbines disturb sleep of nearby neighbors.  Wouldn’t it be nice to settle into the peacefully silent world of the International Space Station?  Well, maybe not.  Canadian astronaut Chris Hadfield has been following in the grand Canadian tradition of exploring the acoustic ecology of his home place, and the results are not at all like the stillness of the 2001 spaceship, nor the calm-broken-only-by-sudden-alien-encounters of the Starship Enterprise.  Though he does highly recommend the Japanese Experiment Module as a place to get away from the cacophony that a CNET article calls “more like a noisy tin can.”

Here’s a taste of his recordings; see the CNET link above, or this Soundcloud page, for many more.

Boston’s WBUR recently interviewed Jesse Ausubel, of Rockefeller University and Woods Hole Oceanographic Institution, about an ambitious project dubbed the Quiet Ocean Experiment.  The idea is to dedicate a year to making detailed observations of wildlife responses to temporary reductions in normally noisy ocean activities, and ideally, to spur a period of several hours to a day during which nearly all human activity in the oceans might cease, in order to see what effect that may have.  Rather than studying the impacts of new noise sources, Ausubel and his colleagues hope to see what removing sound might do.

Here’s a link to a transcript of the five-minute interview.  Or listen below: