Wind Turbine Noise RegulationPerspectives in New England

Kenneth Kaliski, P.E., INCE Bd. Cert.New England Wind Energy Education ProjectWebinar #2

July 2010

Typical noise impact study process

Identify preliminary turbine locations and sound power of turbine

M it b k d d l l i Monitor background sound levels in representative areas (protocol-depending)

Conduct sound propagation modeling

Compare results to standards or g id liguidelines

Refine turbine locations and remodel

Prepare report

Present testimony

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Determine sound power level of the turbine

S d f 106

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l (dB

A)

Sound power of various turbines

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und

Pow

er L

evel

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0 500 1000 1500 2000 2500 3000 3500

So

Turbine Output (kW)

90100110120

ower

Lev

el (d

BA)

Sound power by

4050607080

weig

hted

Sou

nd P

o

Weighted sound pow er

Unw eighted sound pow er

Sound power by frequency

3

40

20 31.5 50 80 125 200 315 500 800 1250

2000

3150

5000

8000

1/3 Octave Band Center Frequency

A-w

Background sound monitoring

Identify sensitive receivers –Identify sensitive receivers –homes, places of worship, schools, wilderness areas, campgrounds, etc.

Set up sound level monitoringShorter time frame if background levels are not critical to the standardLonger time frame for relative standardsSeasonal, if important

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Propagation modeling

ISO 9613

Sound power

Spreading Loss

Atmospheric attenuation

Barriers

Ground attenuation

Has significant impact on model results

Meteorology

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Different modeling parameters yield different results

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A)

30

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22:00 23:00 0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00

Soun

d Pre

ssur

e Lev

el (d

BA 50dB

A)

Time of Day

dBA to 1kHz ISO Not Spectral ISO SpectralISO No Ground ISO Spectral G=0 Concawe Not SpectralConcawe Spectral Concawe No Ground

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re Level (d

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nd Pressur

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Soun

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4:00 5:00 6:00 7:00 8:00 9:00 10:00

Time of Day

Monitored Level Model Parameters 1 Model Parmeters 2 Model Parameters 3

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What is being modeled

Modeling is typically done to •Modeling is typically done to estimate the maximum level, but we can also 1000

120014001600

Spec

ifie

d

1000120014001600

Spec

ifie

d

estimate sound levels under other conditions

•The percentile sound levels 0200400600800

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er Y

ear

at S

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rs P

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ear

at S

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•The percentile sound levels at a receiver is dependent on

0

15 20 25 30 35 40 45 50 55Hou

r

Sound Level (dBA)

0

15 20 25 30 35 40 45 50 55Hou

r

Sound Level (dBA)Turbines on one side Turbines on two sides

• The distribution of wind speed and direction over the year 70%

80%90%

100%Ye

ar

to

vel Within 5 dB of

12% f ththe year• The placement of the turbines with respect to 0%

10%20%30%40%50%60%70%

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pthe receiver

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15 20 25 30 35 40 45 50 55

Sound Level (dBA)

Wind direction and speed effects

Sound generally propagates worse (i.e. lower levels at receivers)

UpwindUnder an unstable atmosphere, like sunny daysWith lower wind speeds and flatter vertical wind speed

di tgradients

What has been regulated

Total level Total level

Usually expressed in units of A-weighted decibelsL l b fLevel by frequency

Full or 1/3 octave bandsT litTonality

Pure tone penalties and limitationslImpulsiveness

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Components of good regulations

Detail noise limits and parametersDetail noise limits and parameters

Include application requirements

l f Detail components of pre-construction noise studies, including

D t il f b k d d it i—Details of background sound monitoring—Acceptable models and parameters

Spatial limits of monitoring and modeling—Spatial limits of monitoring and modeling—Modeled receivers

Address post constructions issuesAddress post-constructions issues

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Components of good regulations

Sound level limitsSound level limits

AbsoluteR l tiRelativeHybrid

Low frequency soundLow frequency sound

Limit noise-induced vibration (ANSI S12.2)

T lit Tonality (ANSI S12.9 Part 4)

Time-averaging

1-second, 10-minute, 1-hour, nighttime, daytimeTime above

Percent of any hour, day, or month

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Additional components of regulations

Exemptions and exceptionsExemptions and exceptions

Construction noiseM i tMaintenanceEmergenciesWaiversWaivers

Complaint response procedure

P t t ti it i gPost-construction monitoring

Participation guidelines

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Examples of regulatory approaches

New ZealandNew Zealand

Specific to wind turbine soundM it i g d d li g t lMonitoring and modeling protocolsHybrid standard (greater of an absolute and relative level) with no maximumrelative level) with no maximumUses regression to determine wind speed/SPL correlationPenalties for tonality and impulsivenessDetails compliance protocolp p

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Examples of regulatory approaches

Oregon 340 035 0035 statewide noise rulesOregon 340-035-0035 statewide noise rules

Existing regulation modified to address wind turbinesturbinesExisting regulations consisted of hybrid standard–greater of a relative and absolute level, with a g ,maximumExisting regulations included tonal penalties and provided optional standard for octave bands

Wind turbine portion of standard established rules on participation and identified options for evaluating existing levelsevaluating existing levels.

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New England States’ Wind Turbine Noise Regs

MaineMaine

Statewide “Site Law” not specific to wind turbinesAb l t li it ith l “ i t ” li it—Absolute limits with lower “quiet area” limits

—Measurement proceduresPenalties for—Penalties for

TonalityShort duration repetitive soundsShort duration repetitive sounds

—Includes submission requirementsExemptions—Exemptions

—Variances—WaiversWaivers

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New England States’ Wind Turbine Noise Regs

ConnecticutConnecticut

Statewide noise regulations not specific to wind turbinesturbines—Absolute standard (except in high noise areas)—Penalties for—Penalties for

Impulse noiseTonesTonesInfrasound and ultrasound

—Measurement proceduresMeasurement procedures—Exclusions and exemptions—Variances—Violations and Enforcement provisions

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New England States’ Wind Turbine Noise Regs

MassachusettsMassachusetts

Wind farm precedentsV i d h t tti g t d d—Varied approaches to setting standards

Massachusetts Dept. of Air Quality Control PolicyRelative standard at property line and home—Relative standard at property line and home

—No pure tones allowedNo consistent approach on whether an how it —No consistent approach on whether an how it applies to wind turbines

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New England States’ Wind Turbine Noise Regs

New HampshireNew Hampshire

No statewide noise regulationsSit E l ti C itt P d tSite Evaluation Committee Precedent—Absolute limit

Post construction monitoring required—Post-construction monitoring requiredVermont

N t t id i g l tiNo statewide noise regulationsPublic Service Board Section 248 precedents

Absolute limit measured inside and outside home—Absolute limit measured inside and outside home—No pure tones allowed

Post construction monitoring required—Post-construction monitoring required

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Mitigation

Re siting project turbines•Re-siting project turbines• Increase setbacksReduce turbulence• Reduce turbulence

• Identify quieter turbines or components

•Automatic controls to slow tip •Automatic controls to slow tip speeds/reduce noise under specific conditions

•Improve noise insulation on target homeshomes

•Increase the number of project participantsparticipants

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Kenneth Kaliski, P.E., INCE Bd. Cert.

Resource Systems Group, Inc.

55 Railroad Row55 a l oad ow

White River Junction, VT 05001

kkaliski@rsginc.com

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