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Resource Documents: Americas (4 items)


Unless indicated otherwise, documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are shared here 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. • The copyrights reside with the sources indicated. As part of its noncommercial effort to present the environmental, social, scientific, and economic issues of large-scale wind power development to a global audience seeking such information, National Wind Watch endeavors to observe “fair use” as provided for in section 107 of U.S. Copyright Law and similar “fair dealing” provisions of the copyright laws of other nations.

Date added:  March 5, 2020
Noise, Ontario, RegulationsPrint storyE-mail story

Industrial Wind Turbine Seismic Source

Author:  West, Michael


Despite their generally positive reputation as sources of clean, safe energy, Industrial Wind Turbines (IWTs) do have their critics. For years, residents living in the vicinity of IWT clusters have reported a variety of physical ailments which they attribute to the sounds and vibrations emanating from wind turbines (Kelley, 1985; CBC.ca, 2011). Noise bylaws, setback distances and other regulations applied to IWTs appear to be based on analysis methods used historically with industrial applications, where noise tends to be constant or semi-constant and in the audible range. The noise generated by IWTs is quite different – spiky and high amplitude – like an exploration seismic source pulse, and mainly found in low frequencies not detectable by human hearing (i.e. infrasound or “below hearing”). This article looks at the signals generated by IWTs from a geophysicist’s perspective. …

The pulse travels down the support column and through the near-surface as shown, while the air-pulse travels directly through the air. Seismic and air waves spread spherically outward in all directions while the amplitude envelope for the air wave may be higher downwind. Multiple copies of the pulse arrive at different times through different paths to create the time-series at the geophone receiver by summation.


The analysis of the operating IWTs on the ground and the seismic and air-pulse recordings confirms that large horizontal axis Industrial Wind Turbines act like airgun seismic sources that create low frequency pulses approximately once per second. The audible part of the air pulse makes a sound like “whump” so, as per geophysical industry tradition, we should name the IWT a “whumper” seismic source (as opposed to a thumper or puffer which would require a faster rise-time on the pulse). Most of the amplitude of the pulse exists at frequencies below the audible range, so a person stopping by the roadside to listen to an IWT may not hear anything and is likely to think that they make no significant “noise” at all.

Two aspects of IWT-generated noise do not appear to have been adequately accounted for in the creation of regulations for the IWT industry: that the noise contains many spurious, high amplitude spikes, and that it is mainly found in the low, infrasonic frequencies. An impulsive noise source such as an IWT requires amplitude measurements over short time windows like 1 second and little or no averaging of data during analysis. Long analysis time windows and averaging amplitude over 1/3 octave band frequency ranges is an acoustics industry testing method appropriate only for higher frequency “whirring” machines like diesel generators or milling machines. Current Ontario Government regulations do not include testing frequencies lower than 31.5 Hz. “Noise” testing procedures for regulation of IWTs should be revised to include all low frequencies created by the IWTs because the low frequency events contain the most power and highest amplitudes.

Conversion of non-weighted peak pulse amplitudes from the microphone recording in Figure 9, at 550 meters offset in 20 kph winds including the full frequency range to 1 Hz, revealed peak Sound Pressure Levels of 65 dB or more. Additionally, the SPL noise limit specification should not be increased with increased wind speed as this makes no sense. Governments and agencies tasked with the regulation of IWT installations should review and revise their testing protocols, so that regulations that reliably protect the health of people and animals living in the vicinity of IWTs can be implemented.

Michael West, P. Geoph., B.Sc., GDM

Canadian Society of Exploration Geophysicists | Recorder, Jun 2019, Vol. 44, No. 04

Download original document: “The Industrial Wind Turbine Seismic Source

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Date added:  March 4, 2020
Contracts, South DakotaPrint storyE-mail story

Wind Lease and Easement Agreement

Author:  Invenergy Wind Development

Deuel County, State of South Dakota

Download original document: “Invenergy Wind Lease and Easement Agreement

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Date added:  February 14, 2020
Minnesota, Noise, Regulations, TechnologyPrint storyE-mail story

Why “Ground Factor” Matters

Author:  Overland, Carol

Minn. R. 7030.0400 is the MPCA’s noise rule, setting standards for industrial noise. It was developed to limit industrial noise, from a noise source on the ground to a “receptor” on the ground. ISO 9613-2 was also developed to measure ground based noise reaching a ground based receptor.

A primary input is the “ground factor” set to address conditions on the ground, the ground effect, between the noise source and the receptor:

7.3  Ground effect (Agr)

7.3.1  General method of calculation

Ground attenuation, Agr, is mainly the result of sound reflected by the ground surface interfering with the sound propagating directly from source to receiver.

While there may be some reflected sound reaching the “receptor” (that is such an obnoxious term for people!), the sound from a wind turbine with a hub height of 300 feet or more! That’s a direct path to the “receptor.” The ground, grasses, corn, trees, buildings, do not get in the way.

The ground factor to be used for wind turbines is ZERO.

Dr. Schomer stated this clearly and thoroughly in the Highland Wind docket in Wisconsin (PSC Docket 2535-CE-100).

Download  Schomer Pages from Transcript Vol 4 (see page 572)

The use of a 0.0 ground factor for wind is standard practice, and that a 0.5 ground factor is NOT appropriate for wind because it’s elevated. This was inadvertently confirmed by Applicant’s Mike Hankard in the Badger Hollow solar docket, also in Wisconsin (PSC Docket 9697-CE-100):

The model that we use has been shown to predict conservatively with 0.5. I mean, 0.5 ground factor is used in probably – well, with the exceptiion perhaps of wind turbine projects which are different because the source is elevated. But for projects like a typical power plant, a solar plant where the sources are relatively close the ground, I would say 90 to 99 percent of the studies use 0.5. And when consultants like myself go out ad measure these plants after they’re cpmnstricted tp verify our modeling assumptions, that assumption checks out as being, if anything, overpredicting the levels. So there’s no need to – there would be no justification to use something like a .2 or .3 which would predict yet higher levels because we’re already demonstrating that the model is probably overpredicting. So that would not be justified for those reasons.

Who cares? Well, it’s bad enough that in that WI PSC Highland Wind docket, when the applicants couldn’t comply with the state’s wind noise limit, they redid their noise “study” using the inappropriate ground factor of 0.5 to give them more compliant numbers – they moved the goal posts, garbage in, garbage out. They think they can do that in Minnesota too, and are trying oh so hard in the Freeborn Wind docket (PUC Docket 17-410).

Last September, 2018 that is, Freeborn Wind did a deal with Commerce, admitted to in its “Request for Clarification/Reconsideration” pleading:

Freeborn Wind requests the Commission clarify its Site Permit to adopt Section 7.4, as proposed by Freeborn Wind and agreed to by the Department and MPCA, in place of the current Sections 7.4.1 and 7.4.2, to both ensure consistency with the Order and avoid ambiguity in permit compliance.

Freeborn Wind’s September 19, 2018, Late-Filed proposal for Special Conditions Related to Noise outlines the agreement reached between Freeborn Wind, the Department and the MPCA on this issue.

(fn. citing Late Filed—Proposed Special Conditions Related to Noise (Sept. 19, 2018), eDocket No. 20189-146486-01).

In this deal, they put language in the permit that was a fundamental shift in noise monitoring, one for which there is no justification under the noise modeling standards, whether state or ISO 9613-2 – that of using a 0.5 ground factor.

The language in the proposed special conditions requires Freeborn Wind to submit updated modeling and/or proposed mitigation demonstrating that modeled wind turbine–only noise will not exceed 47 db(A) L50-one hour at receptors. Specific guidance is included regarding the modeling assumptioins to be used. Specifically, proposed Section 6.1 directs Freeborn Wind to follow the NARUC ISO 9613-2 standard with a 0.5 assumed ground factor. As reflected in the special condition language, setting a turbine-only noise limit at 47 dB(A), using the specified model assumptioins, ensures that the Project will not cause or significantly contribute to an exceedance of the MPCA Noise Standards. This limit is supported in this record by expert testimony from Mr. Mike Hankard and the MPCA’s 2015 Noise Guide, both stating the 3 dB(A) is the generally recognized minimum detectable change in environmental noise levels. To illustrate, when nighttime background sound levels are at 50 db(A) L50-one hour, a maximum turbine-only contribution of 47 db(A) L50-one hour would result in a non-significant increase in total sound of less the 3 dB(A).

The day before the Commission’s meeting, they filed for a “Special Condition,” and oh, was it special:

Download  20189-146486-01_LateFiling

At the meeting, they presented a chart with made up numbers on it, not supported by any noise study:

This chart was shown for a few seconds at most, it was not provided in the “Late Filing” above, and there were no copies for parties or the public. Did Commissioners get a copy? Who knows …

The Commission then granted the site permit! There were a few rounds before we got to where we are today, with Xcel Energy acquiring the project, and with a new site plan, bigger turbines, and some specific site permit amendments. In its permit amendment application, Xcel Energy is now the owner of Freeborn Wind, and Xcel wants to use larger Vestas V120 turbines rather than the V116.

From testimony in the original Freeborn Wind hearing, and in an Affidavit submitted by Commerce-EERA’s Davis:

7.  It is generally understood that turbine noise output increases with higher blade tip speeds …
(Aff. of Davis, EERA Motion, 20181-139379-01)

In its permit amendment application, Xcel Energy is now the owner of Freeborn Wind, and Xcel wants to use larger turbines. In so doing, they have filed a noise study, Attachment E, utilizing that 0.5 ground factor. Xcel’s claim is that they’re using a 0.5 ground factor because the permit specifies that:

This Xcel filing is the first noise study in the Freeborn Wind record to utilize a 0.5 ground factor.

This Xcel filing is the first noise study in the Freeborn Wind record following the ALJ’s recommendation of denial:

The Administrative Law Judge concludes that Freebron Wind has failed to demonstrate that the proposed Project will meet the requirements of Minn. R. 7030.0040, the applicable Minnesota Noise Standards. Therefore, the Administrative Law Judge respectfully recommends that the Commission either deny Freeborn Wind’s Application for a Site Permit, or in the alternative, provide Freeborn Wind with a period of time to submit a plan demonstrating how it will comply with Minnesotat’s Noise Standards at all times throughout the footprint of the Freeborn Wind Project.

There’s a 3 dB(A) margin of error – even using Hankard’s numbers, look at the yellow lines right up against the homes, and look at the blue 50 dB(A) lines and how many homes are inside of those lines:

Turbine noise at the hub for the V120s can be maximum of 110.5 dB(A), and serrated edges provide an option to reduce noise (which Xcel says it plans on using for some turbines), per the Vestas spec sheet.

Compliance? Modeling with the improper 0.5 ground factor doesn’t come close to demonstrating compliance, instead it demonstrates a high probability of non-compliance. It demonstrates that using the proper ground factor for wind, it won’t do the modeling, likely (assuredly) because the project cannot comply. Freeborn Wind could not demonstrate that it could comply with state noise standards as originally designed with the smaller wind turbines and the proper modeling ground factor, and now Xcel Energy wants to use larger turbines. Larger turbines are noisier … once more with feeling:

7.  It is generally understood that turbine noise output increases with higher blade tip speeds …

And now we see, hot off the press, the Plum Creek wind project (PUC Docket WS-18-700), proposed by Geronimo …

Vestas 150 and 162 turbines, 5.6 MW each! The noise for the V150 is a maximum of 104.9 dB(A), and for the V162 is a maximum of 104.9 dB(A), with “sound optimized modes available.” That’s in the brochure.

They have provided a noise study, BUT, much is NOT PUBLIC:

201911-157475-05_Noise_Appendix B

And I wonder why … well, it says that they’re not using a ground factor of 0.0. Look at p. 48 of the sound study above, deep breathe and take a peek:

They’re using a ground factor of 0.7 !

Really …

For this analysis, we utilized a ground factor of G=0.7, which is appropriate for comparing modeled results to the L50 levels.18 A 2-dB uncertainty factor was added to the turbine sound power per typical manufacturer warranty confidence interval specifications.

18 Generally accepted wind turbine modeling procedure calls for a ground absorption factor of G=0.5, with a 2-dB uncertainty factor added to the manufacturer’s guaranteed levels, to predict a maximum LEQ(1-hr). In this case the state limit utilizes and L50 metric instead of maximum LEQ(1-hr), which means a ground factor of G=0.7 can be used.


They say it again on p. 62, elsewhere too:

How stupid do they think we are?

How stupid do they think Commerce-EERA is? … oh … never mind …

Anyway, here are the sound study maps based on that bogus 0.7 ground factor – look how many homes are affected:

Geronimo gets the gong:

The applicants know exactly what they’re doing.

At least twice in the Freeborn record I have asked whether the Commissioners understand “0.5 ground factor” and “0.0 ground factor” and have been vigorously assured that yes, they do understand. And Commerce-EERA staff? You’re responsible for doing the footwork on these siting applications. Do you understand?

If they do not understand, or misunderstand, they’ve got some learnin’ and edumacation to do. If they DO understand, and are approving site permits knowing that the modeling is off, that ground factor is misused, they’re complicit. They’re knowingly afflicting those who have to live with the noise sound levels that exceed Minnesota state standards.

As we saw in Bent Tree, where the noise standard compliance is in question, it is Commerce’s job to do the noise monitoring and deal with the problem. Once a turbine is up, there aren’t many options other than “shut down the turbines” or “buy out the landowners.” How many landowner buy-outs do you think we need before it’s admitted there’s a problem? Why is it so hard to develop responsible, precautionary, and respectful siting? Why is there resistance? The costs of their failure to do so are … well … we may see exactly what those costs are.

Commissioners and Commerce staff, make sure you know how the state noise standard and ISO 9613-2 was designed, how it is to be used, and what ground factor means.

If you know what it means, and are siting turbines using 0.5 and 0.7, you are responsible.

Legalectric, November 17th, 2019

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Date added:  February 13, 2020
Contracts, South DakotaPrint storyE-mail story

Wind farm lease and easement agreement – Crowned Ridge Wind Energy Center, S. Dak.

Author:  Crowned Ridge Wind Energy Center

1. Parties. This Wind Farm Lease and Easement Agreement (“Agreement”) is -made and entered as of the ____ day of ____________, 2013 (“Effective Date”), by and between ____________________, ____________________ (collectively, the “Owner”) and Crowned Ridge Wind Energy Center, LLC, a Delaware limited liability company, (“Operator”) an affiliate of NextEra Energy Resources, LLC, a Delaware limited liability company. …

2. Project. This Agreement relates to the wind-powered electrical power generation and transmission project known as the “Crowned Ridge Wind Energy Center” to be located in Codington County and Deuel County, South Dakota (“Wind Farm”), which may be wholly or partially located on the Owner’s property legally described on the attached Exhibit A-1 to this Agreement (“Owner’s Property”). Upon Operator’s exercise of the Option (as defined below), the Wind Farm shall include (i) the Leases referenced in Section 4 that are located on the Owner’s Property; (ii) the Easements granted in Section 5, and (iii) the Improvements to be constructed on Owner’s Property referenced in Section 8. The Leases, Easements and Improvements are sometimes collectively referred to as the “Operator Property.” …

3.3 Use of Owner’s Property. During the Option Term, Operator and its employees, agents and contractors shall have a non-exclusive right to enter upon the Owner’s Property and the right of ingress and egress over and across the Owner’s Property for the purposes of (i) surveying the Owner’s Property; (ii) performing such other tests and studies as Operator may desire in connection with the Option, including, without limitation, environmental, avian and cultural resource assessments, threatened or endangered species assessments, and geotechnical, foundation and soil tests; provided that such activities do not unreasonably interfere with Owner’s use of the Owner’s Property as set out in Section 11.3; and (iii) installing, maintaining, operating, inspecting and removing one or more wind monitoring devices and all associated activities (including the Met Towers referenced in Section 8.3), and including the performance of all tests and studies associated therewith. Owner shall not permit any other individual or entity except Operator or its affiliates to install a Met Tower on Owner’s Property. …

4.1 Construction Right. (a) Owner grants Operator rights for purposes of constructing, operating, maintaining, repairing, replacing, and removing all or any part or component of the Improvements whether located on or off Owner’s Property. This construction right is referred to as the “Construction Right” and the property subject to the burden of this Construction Right is referred to as the “Construction Property.” Operator may exercise its right to use all or any part of the Construction Property as and when Operator deems it necessary or advisable to do so to perform the activities for which this Construction Right is granted, including, without limitation, constructing, operating, maintaining, repairing, replacing, and removing laydown areas, staging areas, crane pads and parking for Operator’s employees. After each use of the Construction Right, Operator to the extent reasonably possible shall restore the Construction Property to the condition it was in before Operator’s use.

(b) When installing, maintaining or removing the nacelle and rotor from any Turbine, whether located on or off of Owner’s Property, this Construction Right also shall permit Operator to: (1) (for the purpose of securing tag lines) travel on foot or in a pickup truck, SUV, small forklift or other similar vehicles onto Owner’s Property up to seven hundred (700) feet in any direction from the center of the Construction Property; and (2) drive an erection crane on Owner’s Property and make use of earthmoving equipment for purposes of building suitable access routes for such crane. Operator shall be permitted to maintain a 120 foot by 40 foot crane pad at each Turbine Site Property (hereinafter defined) on Owner’s Property for purposes of constructing and maintaining the Wind Farm.

4.2 Access Right. (a) Owner grants Operator the right of access over the Owner’s Property for unobstructed vehicular, equipment and pedestrian ingress to and egress from the Improvements, the Construction Property, the Turbine Site Property, the Collection Property, the Overhang Property, and the Met Tower Property, whether located on or off Owner’s Property. This right of access is referred to as the “Access Right” and the property subject to the burden of this access right is referred to as the “Access Property.” Operator shall have the right to travel over, across and along the Access Property by means of existing roads and lanes, and by roads Operator or Owner may construct or improve from time to time on, over, and across the Owner’s Property.
(b) Owner reserves the right to use all roads on the Access Property provided, however, that Owner shall not and shall not permit others to obstruct or damage the roads or in any other way interfere with Operator’s rights under this Access Right.

4.3 Turbine Site Lease. Owner grants Operator a lease to construct, operate, replace, relocate, remove, and maintain a Turbine, Collection Facilities, together with associated roads and parking areas on Owner’s Property. This grant is referred to as the “Turbine Site Lease” and each Turbine site so leased is referred to as a “Turbine Site Property.”

4.4 Collection Lease. Owner grants Operator a lease for the construction, operation, maintenance, replacement, relocation or removal of Collection Facilities on and under the Owner’s Property. This grant is referred to as the “Collection Lease” and the property so leased is referred to as the “Collection Property.”

4.5 Telecommunication Facilities Lease. Operator leases Owner’s Property for Operator to construct, operate, maintain, replace, relocate or remove Telecommunication Facilities (hereinafter defined) on, over, across, along and under the Owner’s Property.

4.6 Overhang Right. Owner grants Operator the right and privilege to permit the rotors of Turbines located on adjacent properties to overhang a portion of the Owner’s Property. This right is referred to as the “Overhang Right” and the property subject to the Overhang Right is referred to as the “Overhang Property”. Owner shall not interfere with the operation of Turbine rotors that overhang the Overhang Property.

4.7 Met Tower Lease. Owner grants Operator a lease to construct, operate, replace, relocate, remove, and maintain a Met Tower and Collection Facilities on Owner’s Property. This grant is referred to as the “Met Tower Lease” and each Met Tower site so leased is referred to as a “Met Tower Property.”

5. Easements. Upon the exercise of the Option by Operator, Owner grants to Operator, and Operator accepts from Owner, for the Lease and Easement Term referenced in Section 6.1, the following easements over and across the Owner’s Property in accordance with the terms and conditions of this Agreement. The following easements are for the benefit of Operator and Operator’s agents, contractors and employees, are located on the Owner’s Property and are collectively referred to as the “Easements.”

5.1 Wind Non-Obstruction Easement. (a) Owner grants Operator an irrevocable, exclusive easement for the right and privilege to use, maintain and capture the free and unobstructed flow of wind currents over and across the Owner’s Property (“Wind Non- Obstruction Easement”). Along with the Option Notice, Operator shall deliver to Owner the following legal descriptions which shall become Exhibit A-2 of this Agreement: (a) a description of the Wind Non-Obstruction Easement property subject to this Agreement; (b) a description Of the Wind Non-Obstruction Easement in vertical and horizontal angles; and (c) a description of real property benefiting from the Wind Non-Obstruction Easement. Owner shall not engage in any activity on Owner’s Property that might interfere with wind speed or wind direction over any portion of any Turbine or Met Tower Easement Properties, whether located on or off the Owner’s Property; cause a decrease in the output or efficiency of any Turbine or accuracy of any meteorological equipment; or otherwise interfere with Operator’s operation of the Wind Farm or exercise of any rights or the Leases granted in this Agreement (“Interference”). Owner reserves the right to erect structures on Owner’s Property in compliance with all applicable laws and ordinances except as specifically limited in this Agreement. Owner must consult with and obtain Operator’s prior written approval as to the location of all structures greater than forty (40) feet in height located one thousand (1000) feet or less from any Turbine or Met Tower. Approval shall be based on whether, in Operator’s sole judgment, informed by appropriate professional engineering and meteorological opinions; the proposed structures at the proposed location are likely to cause Interference.

(b) This grant of easement of the Wind Non-Obstruction Easement expressly includes the right of Operator to enter on any part of Owner’s Property to enforce Operator’s rights, including the physical removal of trees or structures (except existing trees and structures) causing Interference to the project contemplated by Operator. Operator shall consult with Owner before making any such removals.

5.2 Effects Easement. Owner grants to Operator a non-exclusive easement for audio, visual, view, light, flicker, noise, shadow, vibration, air turbulence, wake, electromagnetic, electrical and radio frequency interference, and any other effects attributable to the Wind Farm or activity located on the Owner’s Property or on adjacent properties over and across the Owner’s Property (“Effects Easement”). …

Download original document: “Wind farm lease and easement agreement – Crowned Ridge Wind Energy Center, S. Dak.

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