Entries in Dan Ebert WPPI (2)
9/11/10 Wisconsin Eye hosts panel on wind issues: WeEnergies, WPPI, Vice Chair of Wind-siting council and Wisconsin author weigh in on wind rules.
09.10.10 | Newsmakers: Future of Wind Energy
Wisconsin has more than 300 electricity-generating wind turbines, which can cost up to $4 million each, and developers have plans for hundreds more to meet a requirement that 10% of the state’s energy come from renewable sources by 2015.
Although the Public Service Commission has proposed permanent rules on the siting of those turbines, members of the Wind Siting Council, which studied the issue for six months, have warned that they can pose shadow “flicker,” health and property values problems.
Wind energy was discussed in a Sept. 10 Newsmakers with Dan Ebert, a vice president of WPPI Energy and former Public Service Commission chairman; Andy Hesselbach, Wind Energy Project Manager for We Energies; Doug Zweizig, Town of Union planning official and Wind Siting Council vice chairman, and Lynda Barry, author now researching a book on homes near turbines.
WIND TURBINES IN THE NEWS:
WIND TURBINE NOISE, AN INDEPENDENT ASSESSMENT
SOURCE Herald Gazette, knox.villagesoup.com
September 10 2010
By Stephen Ambrose and Robert Rand,
Stephen Ambrose and Robert Rand are members of the Institute of Noise Control Engineering. In 2009, they became concerned about the negative comments from residents living near wind turbine sites and, the apparent lack of regulatory action to address the potential for adverse health impacts from wind turbine generator noise in Mars Hill. They launched their own evaluation, and came to the following conclusions in a series of guest columns.
Wind turbines larger than one megawatt of rated power have become an unexpected surprise for many nearby residents by being much louder than expected.
The sounds produced by blades, gearing, and generator are significantly louder and more noticeable as wind turbine size increases. Long blades create a distinctive aerodynamic sound as air shears off the trailing edge and tip.
The sound character varies from a “whoosh” at low wind speeds to “a jet plane that never lands” at moderate and higher wind speeds. Blade-induced air vortices spinning off the tip may produce an audible “thump” as each blade sweeps past the mast.
Thumping can become more pronounced at distance, described as “sneakers in a dryer,” when sounds from multiple turbines arrive at a listener’s position simultaneously.
Wind turbines are not synchronized and so thumps may arrive together or separately, creating an unpredictable or chaotic acoustic pattern.
The sounds of large industrial wind turbines have been documented as clearly audible for miles. They are intrusive sounds that are uncharacteristic of a natural soundscape.
Studies have shown that people respond to changes in sound level and sound character in a predictable manner. A noticeable change in sound level of 5 decibels (dB) may result in “no response” to “sporadic complaints.” An increase of 10 dB may yield “widespread complaints,”; a 15 dB increase “threats of legal action.”
The strongest negative community response occurs with an increase of 20 dB or more, resulting in “vigorous objections.”
Audible tones, variability in sound level, and an unnatural sound character can amplify the public response. For a distinctive or unpleasant sound, a small change in sound level, or the sound simply being audible, may provoke a strong community response.
Community response can intensify further if sleep is disturbed and quality of life or property is degraded.
Weather conditions influence the sound level generated and how it travels to nearby homes. Sound waves expand outward from the wind turbine with the higher frequencies attenuating at a faster rate than low frequencies.
Locations beyond a few thousand feet may be dominated by low frequency sounds generated by the wind turbines.
Wind turbulence and icing, both common in New England due to topography and latitude, increase aerodynamic noise from intensified or chaotic dynamic stall conditions along the blade surfaces.
Atmospheric conditions at night and downwind enhance sound propagation toward the ground by increasing levels over longer distances.
Wind turbines are elevated hundreds of feet to receive stronger winds yet winds down on the ground or in nearby valleys may be non-existent with correspondingly low background sound levels, accentuating the impact of the intrusive sounds.
Other professionals have developed thresholds, or criteria, for sound level to protect public health that may be applied to planning for wind turbine permitting.
Recommendations from Hayes McKenzie Partnership in 2006 limited maximum wind turbine sound levels at residences to 38 dBA and no more than 33 dBA when “beating noises” are audible when the turbines spin.
Dan Driscoll presented his analysis in 2009 (Environmental Stakeholder Roundtable on Wind Power, June 16, 2009) with a Composite Noise Rating analysis of 33 dBA to reduce rural community response to the level of “sporadic complaints.”
Michael Nissenbaum issued his findings in 2010 from his medical study at Mars Hill, recommending a 7000-foot setback for public health.
The World Health Organization published sound level thresholds of sleep disturbance and adverse health effects from peer-reviewed medical studies (Night Noise Guidelines for Europe, October 2009).
Our next column will compare our sound level versus distance data with these medical, health, and community response criteria and show what distances are necessary to protect public health.
Currently there is no effective, reliable noise mitigation for wind turbines of this size other than shutdown.
Therefore, at this time it appears appropriate that proposed wind turbine sites should position wind turbines at least one mile away from residential properties and further for sites with more than one wind turbine. Smaller wind turbines (under one megawatt power rating) produce less noise than those currently being marketed and installed for grid power in Maine; these may be an option when distance is an issue.
NOTE FROM THE BPWI RESEARCH NERD:
The wind farm mentioned in the following story was cited an example of a successful community wind project by Wind Siting Council member Michael VickermanState of Maine finds Fox Island Wind Turbines in violation of noise standard
7/28/10 DOUBLE FEATURE: Wind foxes finalize rules for hen house, and they look just like the old ones that have caused so much trouble for residents of rural Wisconsin AND Yet another wind turbine blade failure in an Invenergy wind project
What happens when rules are written by those who stand to gain financially from the outcome?
Wind siting council member Larry Wunsch has been living with a 400 foot tall wind turbine sited just 1100 feet from his door for over two years.
Council Member Dwight Sattler lives about half a mile from the closest turbine to his house. He says he can sometimes hear them, but at half a mile it doesn't bother him.
At half a mile, no problem. At 1100 feet, the noise is bad enough to cause the Wunsch family to put their home up for sale.
Longer setbacks and lower noise limits mean greater protection for rural Wisconsin residents, but less money for those with financial interests.
Should the wind siting council consider what Larry Wunsch has to say when creating siting recommendations for our state?
Or should they follow Wind Sitng Council chairman Dan Ebert's lead and gloss over the issues to speed up the process in order to create guidelines which protect business interests instead of residents of rural Wisconsin?
ANOTHER 'CAUSE UNKNOWN' TURBINE BLADE FAILURE IN ILLINOIS
SOURCE: The Times, mywebtimes.com
July 27, 2010 Dan Churney,
Barbara Ellsworth was troubled, but not surprised Saturday morning when she spotted a broken blade on a wind tower near her home.
“We thought, ‘Hah! We knew that would happen.’”
Ellsworth and her husband Mike live three miles south of Marseilles on East 2450th Road, about 1,200 feet from a wind turbine and about 2,500 feet from one of the two towers damaged during the weekend, possibly by high winds. Chicago-based Invenergy Wind operates the string of towers that run through southeastern La Salle County.