© Southwest Windpower 1801 W. Route 66 Flagstaff, AZ 86001 USA www.windenergy.com

wind turbine SitinGConsumer Guide

2 Siting Guide © Southwest Windpower, Inc. All rights reserved. May be reprinted with permission.

IntroductIon

Is wind power right for you? Wind generators are an effective source of renewable energy in many areas across the world. the American Wind Energy Association estimates there are as many as 13 million homes in the united States with a viable wind resource.

A small wind system may be right for you, if:

• You have at least 10 MPH (4.5 m/s) average wind speed. Best results at 12 MPH (5.4 m/s) or more.

• Yourpropertyisunobstructedfromtallbuildingsandtrees.Ide-ally,youshouldhave1/2acreormore

• Thelocalzoningallowsastructurethatisatleast42feet(12.8m)tall(see“GettingConnectedConsumerGuide”)

• Yourlocalutilityhasanexistinginterconnectionagreement(see“GettingConnectedConsumerGuide”)

Onceyouhavedeterminedyouhavetherightconditionsforawindsystem,youwillneedtoconsiderthebestplaceonyourproperty.Propersitingiscriticaltotheperformanceandlongevityofyourinvestment.Itcanmakethedifferencebetweenyearsoftroublefreeoperationorcontinuousfrustration.

Thisguideisaprecursortoinvestinginasmallresidentialscalewindgenerator.Whetheryourreasonforinvestingisbecauseofyourconcernfortheenvironment,helpingreduceforeignfuelim-portsorpureeconomics,weatSouthwestWindpowerwanttomakesureyougetthemostfromyourwindgenerator.Beforemakinganyinvestmentinsmallwind,besuretoreviewthisguidecarefully,asklotsofquestionsandonceyoufeelconfident,callyourdealer.

dEtErMInInG Your WInd rESourcE“DoIhaveenoughwind?”isoftenthefirstandmostaskedquestion.Generally,ifyoufeellikeyouhaveaverywindysite,youmostlikelyhaveagoodplaceforawindsystem.Itisalwaysagoodideatodoyourhomeworkjusttomakesure.Windresourcescanvaryfromplacedtoplace.Thereareseveralplacesyoucangotoassistyou.

Sitelook Personal Wind Energy Assessment

SouthwestWindpoweroffersafreeonlinewindenergyassessmentforsitesthatalreadyreceiveutilitypowerintheUnitedStates.Ifyouliveoff-gridorinanothercountry,lookforexpandedavailabilitysoon.

Sitelookasksyouforyourlocationandsomeinformationaboutyourenergyconsumption,andproducesawindenergyassessmentcus-tomizedforyourneeds. Go to www.windenergy.com/sitelook.

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Thelastresourceisconductinganactualwindresourceassess-ment.Thisisbyfarthemostaccuratewayofdoingasiteassess-mentbutitisalsothemostexpensiveandtimeconsuming.Itinvolvestheinstallationofasmalltoweronyourpropertywith1-2anemometersandadatacollectinglogger.CompaniessuchasSecondWindoffersuchhardwareandthenchargeamonthlyfeeforconsolidatingthedataandgeneratingareport.

KeepinmindthatmanySouthwestWindpowerdealersalsoperformsite assessments.

Griggs-PutnamIndex. *Probablemeanannualwindspeed.DatapreparedbyE.W.Hewson,J.E.Wade,andR.W.BakerofOregonStateUniversity

0No Deformity

I5-9 mph*

Brush & Slight Flagging

II8-11 mph*

Slight Flagging

III10-13 mph*Moderate Flagging

IV12-16 mph*CompleteFlagging

V14-18 mph*

Partial Throwing

VI15-21 mph*Complete Throwing

VII22-higher mph*

Carpeting

Should I MEtEr MY SItE?

Generally, no, the cost of an accurate data logging system can be almost as much as a small wind system. Hand-held anemometers only measure the reading at arm’s length and certain times of the day. The do not give an accurate overall wind speed for your site at the height that you would install.

Wind Maps

IfyoucannotuseSitelook,windmapsmayofferageneralizedlookatyourwindresource.TheU.S.DepartmentofEnergyprovidesaseriesofhighreso-lutionwindmapsformuchoftheUnitedStatesthatwillgiveyouagoodideawhatyourwindresourceisatyourlocation.Keepinmind,thesemapsareabout80percentaccurateandestimatethewindresourceat

about150feet(46m)offtheground.Windsdecreasetheclosertheyaretotheground.YouwanttomakesurethelocationofyourpropertyonthemapisinaClassIIIwindorbetter.Thesemapshavearesolutionof+/-1km(0.7mile).

Tofindthemapofyourstateorcountry,gotowww.windenergy.com/wind-maps

other Ways to Evaluate Wind

Youmayalsoobtainwinddatafromyourlocalweatherstation,uni-versityoreventelevisionstation.Airportdataisnotrecommended.Airportsaregenerallylocatedinlowerwindareas(valleys)andtheirmeasurementtechniquesdonotproducegooddata.

Ifwindmapsorlocaldatadoesn’twork,anothermethodislookingaroundandobservingofthedeformationofvegetationandtreesonandaroundyourproperty.TheGriggs-PuttnamIndexwasascientificstudythatlookedathowwinddeformedvegetationtodeterminethewindresourceataparticularsite.Comparethedrawingabovewithyourownpropertytodetermineyourwindresource.

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once you have determined you have a good wind resource, you will want to site your wind genera-tor in the most optimum place.

Theidealpositionforawindgeneratorisaflatopenspacewithgoodwindfromatleastonedirection(knownastheprevailingwinddirection),acoastline,orasmoothhilltopwithanopenareaintheprevailingwind.Thewindspeedsupsignificantlynearthetopofthehillandtheairflowshouldbereasonablysmoothandfreefromexcessiveturbulence.

Excessiveturbulenceor“badwind”causesfatiguedamageandshortensagenerator’sworkinglife.Whensiting,keepawayfromlo-calobstructionssuchaslargetreesandhouses,oruseatallertowertoensurethatthegeneratoriswellabovetheobstructions.Windspeedalsoincreaseswithheightsoitisbesttohavethegenerator

ashighasyourzoninglawsandinvestmentpaybackwillallow.Itisrecommendedtositeyougeneratoratleast20feet(6m)aboveanysurroundingobstaclessuchastreesorbuildingsina250foot(76m)radius(seegeneralsitingimageabove).

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Prevailing wind

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SItInG

Prevailing wind

WhAt IS thE “bESt” SItE?

Windresourceisnottheonlyconsiderationwhensiting.Com-ponentssuchastallertowersandrunninglargeamountsofwire–morethan500feet(152m)fromyoursite–canaddsignificantcoststoyourwindsystem.Youwillneedtobalanceenergyachievedinthebestwindsiteoverthecostofinstalla-tiontodeterminethebestoverallplacementofyoursystem.

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1 2 323123A-typical siting Plateau/MesaWindscliffsitetoropsWindofproper-tion,TheleastobjectscVeryfromimportantcloseandfromPrevailing windPrevailing windPrevailing wind

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toWErS

because wind speeds increase with height, a residential wind generator is mounted on a tower. the tower also raises the generator above the air turbulence that can exist close to the ground because of obstructions such as hills, buildings, and trees.

tower heightYourwindresourcewillbecleanerandstrongerthehigheryougo.Thetalleryourtower,thebetteryourenergyoutput.Itisimportantthatthetowerisatleast20feet(6m)abovesurroundingobjects.Whilesomesiteswithveryhighwindandfewobstuctionsmightbesuitedtotowersasshortas33feet(10m),wegenerallyrecom-mendtowersthatareatleast45ft(14m)high,andSouthwestWindpowerofferstowersupto70ft(21m).Whileyoushouldtrytoinstallyoursysteminthetallesttowerallowed,tallertowerscostmore.Itisbesttoevaluateyouroverallenergyandcostpaybackbeforeinvestingintallertowers(seediagramatright,top). types of towers Thetwomostcommontypesoftowersareguyedandmonopole.Bothareavailableinvariousdesigns.Somecanbetilted-downforeasyaccesswhileothersrequireacraneforinstallationandservice(seediagramatright,bottom).

Guyedtowersarelessexpensivethanmonopoletowers.However,be-causetheguyradiusmustbeone-halftothree-quartersofthetowerheight,guyedtowersrequireenoughspacetoaccommodatethem.

Monopoletowersaremoreexpensivebuttheyoffertheconsumeraneasywaytoperformmaintenance.Monopoletowerscanbe

150’ 46m

120’ 37m

90’ 27m

60’ 18m

45‘ 14m

33’ 10m

0 0 20% 41% 75% 100% 124%

Increase in wind power

16 mph7.3m/s

15.5 mph7 m/s

14.7 mph 6.6 m/s

13.5 mph6 m/s

12.8 mph5.7 m/s

12 mph5.4 m/s

Tow

er h

eig

ht

Win

d S

pee

d

Calculations based on Power Law Exponenet 0.02 (In area of tall row crops, hedges, a few trees).

GuyedtowerMonopoletower

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rEcAP

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loweredtothegroundduringhazardousweathersuchashurricanes(seediagramonnextpage).

Installation or MountingAgeneralruleofthumbistoinstallasmallwindgeneratoronatowerwiththebottomoftherotorbladesatleast20feet(6m)aboveanyobstaclethatiswithin250feet(76m)ofthetower,25feet(7.6m)tothehub.

Usingapickuptoraiseandloweramonopoletower.

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determine if you have enough windforawindgeneratorandthebestresourceonyoursite.

try to have clear, smooth access to the prevailingwind,e.g.overopenwaterorsmoothground.Ifpossiblesitethegeneratoronasmooth hill.

Mount the generator on as high a tower as possible and well clear of obstructions,butdonotgotoextremes.Easyaccesswillberequiredforerectionandfoundationsforthetowermaybeneededdependingonthesizeandtowertype.Remember,highertowerswilladdcosttothesystemthatmaynotbecounteredbytheenergyoutputachieved.Itisalsoimportanttoensurethatthewindgeneratorcanbeeasilyloweredforinspectionandmaintenance.

consult your local council astowhetheryouneedplanningpermission.Youshouldtrytomini-mizetheenvironmentalimpactofthegenerator,anditwillbehelpfultoinformyourneighborsofyourplansatearlystage.

If planning an interconnected system, consult with your utility toobtainaninterconnectionagreement.

cAn I Mount thIS on MY roof?

Mountingsmallwindgeneratorsover500wattsonrooftopsisnotrecommended.Largerresidentialwindgeneratorsvibrateandtransmitnoisetothestructureonwhichtheyaremounted.Thisvibrationcanleadtonoiseandstructuralproblemswiththebuilding.Mountingontherooftopcanalsoexposethegeneratortoexcessiveturbulencethatshortensitslife.