HomeMy WebLinkAboutStebbins Wind Feasibility and Conceptual Design Report with Appendices - Sep 2013 - REF Grant 7071068
STEBBINSWINDPROJECT
CONCEPTDESIGNREPORT
PreparedFor:
AlaskaVillageElectricCooperative
4831EagleStreet
Anchorage,Alaska99503
PreparedBy:
MarkSwenson,P.E.
3335ArcticBlvd.,Ste.100
Anchorage,AK99503
Phone:907.564.2120
Fax:907.564.2122
September6,2013
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
September6,2013i
1.0EXECUTIVESUMMARY
ThisreporthasbeenpreparedfortheAlaskaVillageElectricCooperative(AVEC)toprovidea
conceptualdesignandcostanalysisforthedevelopmentofwindpowergenerationinthe
communityStebbins,Alaska.Stebbinsisarural,coastalcommunityofapproximately585
residentslocatedonSt.MichaelIsland,125airmilessouthofNome.AVECiscurrently
constructinganewpowerplantandbulkfuelfacilityinStebbinstoaccommodatethecombined
electricalloadingforStebbinsandtheneighboringcommunityofSt.Michael.An11Ͳmilelong
electricalintertieisplannedalongtheroadthatconnectsthetwovillages.Integrationofwind
turbinepowerintotheproposedelectricalpowergenerationsystemwilloffsetdiesel
consumptionandprovidearenewableenergyresourceforthetworuralcommunities.A
ProjectLayoutPlan(SheetG1.03ofAppendixA)showstheprojectlocation,components,and
proposedintertieroute.
OnJuly11,2010,ameteorological(met)towerwasinstalledonasteepvolcanicrockoutcrop,
orcindercone,approximatelymidwayalongtheintertieroutebetweenStebbinsandSt.
Michael.Themettowerwasequippedwithinstrumentationanddataloggerstoevaluateand
recordthewindresourceonSt.MichaelIsland.ThemettowerwasfunctionaluntilSeptember
19,2011.Inthewinterof2011,themettowerwasrelocatedtoapotentialwindtower
locationclosertoStebbins,neartheintersectionoftheStebbinsLandfillAccessRoadandthe
StebbinsͲSt.MichaelRoad.Thetowerwasrelocatedtobettercorrelatetherecordedwinddata
onthecinderconesitetothepotentialwindtowerlocationnearStebbins.Themettoweris
stillrecordingdataatthenewlocationatthetimeofthisreport.Theresultsofthedata
acquisitionandanalysisofthewindresourceareincludedintheStebbinsͲSt.MichaelWindͲ
DieselFeasibilityAnalysisdatedSeptember2013(AppendixB).
OnSeptember19,2011,AVEC,HattenburgDilley&Linnell(HDL),andV3Energyperformeda
sitevisittoSt.MichaelIslandtoidentifypossiblewindturbinelocations.Multiplewindturbine
siteswereinvestigatedalongtheintertierouteandonesitewasselectedforevaluationforthis
report.Thesite(StebbinsSite1)islocatednorthofStebbinsonaridgelinenearthe
intersectionoftheStebbinslandfillaccessroad(neartheStebbinsmettower).Thesiteis
locatedinaClass6windresourceandisapproximately1.25milesfromthenewpowerplantin
Stebbins.
Forthisreport,AVECselectedthreewindturbineconfigurationsforevaluation.
•Thefirstconfigurationincludes(4)NorthernPower100Arcticturbines(NP100),formerly
knownastheNorthwind100.TheNorthernPower100Arcticturbineisa37meter(121Ͳ
foot),100kWpermanentmagnet,directdrivewindpowergeneratorthatAVECpreviously
installedin10othervillagesinruralAlaska.The(4)NorthernPower100Arctictowerarray
hasamaximumpowergenerationoutputof400kW.
•Thesecondturbineconfigurationconsistsof(5)VestasV17turbines.TheVestasV17
turbineisa26meter(85Ͳfoot),90kW,inductiongenerator.Thisconfigurationhasa
maximumpowergenerationoutputof450kWandrequiresacoldweatherkitmodification
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foruseinStebbins.Thegeneratorswillbecontrolledusingasimpleinverterwithsoftstart
andsoftbreakingcapabilitiesoramorecomplexvariablespeeddrive(VSD)inverterateach
turbine.Theturbinebladesarefixedpitch.
•Thethirdturbineconfigurationconsistsof(2)AeronauticaAW33Ͳ225turbines.The
AW33Ͳ225turbineisa40meter(131Ͳfoot),225kW,inductiongenerator.Thisconfiguration
hasamaximumpowergenerationoutputof450kW.Thegeneratorswillbecontrolled
usingasimpleinverterwithsoftstartandsoftbreakingcapabilitiesoramorecomplex
variablespeeddrive(VSD)inverterateachturbine.Theturbinebladesarestall
regulatedtolimitrotationinextremewindevents.
Eachturbinewouldbeinstalledonamonopoletowerwithprecastconcreteandrockanchor
foundation.AcomparisonofthethreeturbineconfigurationsinstalledatStebbinsSite1
presentedinTablesEXͲ1andEXͲ2below.
TableEXͲ1:TurbineAlternativeComparisonSummary
Alt
TurbineSelection
Site
Generation
Capacity(kW)
Estimated
CapitalCost
Estimated
CapitalCost
perInstalled
kW
Estimated
AnnualEnergy
Production
@100%
Availability
1
(4)NP100s
Stebbins1400$4.03M$10,077
1,383MWh
2
(5)V17s
Stebbins1450$3.79M$8,420
1,178MWh
3
(2)AW33Ͳ225s
Stebbins1450$3.95M$8,769
1,700MWh
Source:AnnualEnergyProductiondatatakenfromV3Energy’sSeptember2013DraftStebbinsͲSt.Michael
WindͲDieselFeasibilityAnalysis
TableEXͲ2:EconomicAnalysisSummary
Alt
AnnualWind
Generation@
80%Availability
(kWh)
WindEnergyFor
Power(kWh/yr)
Wind
EnergyFor
Heat
(kWh/yr)
Windas%
TotalPower
Production(%)
Windas%
TotalThermal
Production(%)
HeatingFuel
DisplacedBy
WindEnergy
(gal/yr)
1
1,106,9201,009,59097,330332.9
2,488
2
942,572855,58586,987292.6
2,224
3
1,360,2371,131,538228,699406.6
5,846
Source:AnnualEnergyProductiondatatakenfromV3Energy’sSeptember2013DraftStebbinsͲSt.Michael
WindͲDieselFeasibilityAnalysis
Basedontheanalysispresentedabove,werecommendAVECproceedwithdesignand
permittingforinstallationoftwoAW33Ͳ225turbinesatStebbinsSite1.
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TableofContents
1.0EXECUTIVESUMMARY............................................................................................................i
2.0INTRODUCTION................................................................................................................1
2.1BACKGROUND.....................................................................................................................1
2.2LOCATION........................................................................................................................2
2.3CLIMATE...........................................................................................................................3
2.4EXISTINGELECTRICALPOWERSYSTEMS............................................................................3
2.5NEWELECTRICALPOWERSYSTEMS..................................................................................4
2.6ELECTRICALDEMAND.......................................................................................................5
2.7STEBBINSRECOVEREDHEATPOTENTIAL...........................................................................6
2.8CONTRIBUTORSANDSOURCESOFINFORMATION..........................................................11
2.9LIMITATIONS..................................................................................................................11
3.0WINDDATAACQUISITIONANDMODELING..........................................................................11
3.1DATAACQUISITION........................................................................................................11
3.2WINDMODELINGRESULTS.............................................................................................12
4.0STEBBINSWINDSITEANALYSIS.............................................................................................13
4.1WINDSITEINVESTIGATION.............................................................................................13
4.1.1St.MichaelSite1..................................................................................................14
4.1.2St.MichaelSite2..................................................................................................14
4.1.3StebbinsSite1......................................................................................................15
4.1.4StebbinsSite2......................................................................................................16
5.0WINDTURBINESYSTEMALTERNATIVES...............................................................................17
5.1STEBBINSWINDTURBINEANALYSIS...............................................................................17
5.1.1NorthernPower100Arctic...................................................................................17
5.1.2VestasV17...........................................................................................................18
5.1.3AeronauticaAW33Ͳ225........................................................................................18
5.2ALTERNATIVE1Ͳ(4)NP100TURBINESINSTALLEDATSTEBBINSSITE1...........................19
5.3ALTERNATIVE2Ͳ(5)V17TURBINESINSTALLEDATSTEBBINSSITE1..............................19
5.4ALTERNATIVE3Ͳ(2)AW33Ͳ225TURBINESINSTALLEDATSTEBBINSSITE1....................20
5.5ALTERNATIVECOMPARISONSUMMARY.........................................................................20
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6.0ECONOMICEVALUATION.....................................................................................................21
6.1METHODOLOGYANDAPPROACH...................................................................................21
6.2ECONOMICEVALUATIONRESULTS..................................................................................21
7.0PREFERREDALTERNATIVE.....................................................................................................21
8.0ENVIRONMENTALREQUIREMENTS.......................................................................................22
8.1HISTORICANDARCHAEOLOGICAL:ALASKASTATEHISTORICPRESERVATIONOFFICE
(SHPO)............................................................................................................................22
8.2WETLANDS:DEPARTMENTOFTHEARMY(DA)...............................................................22
8.3FEDERALAVIATIONADMINISTRATION(FAA)..................................................................23
8.4BIOTICRESOURCESANDFEDERALLYLISTEDTHREATENEDANDENDANGEREDSPECIES:
UNITEDSTATESFISH&WILDLIFESERVICE(USFWS)........................................................23
8.5CONTAMINATEDSITES,SPILLS,ANDUNDERGROUNDSTORAGETANKS..........................24
8.6ANADROMOUSFISHSTREAMS.......................................................................................24
8.7STATEREFUGES,CRITICALHABITATAREASANDSANCTUARIES.......................................24
8.8LANDOWNERSHIP..........................................................................................................24
8.9SUBSISTENCEACTIVITIES................................................................................................24
8.10AIRQUALITY...................................................................................................................25
8.11NATIONALENVIRONMENTALPOLICYACTREVIEW(NEPA)..............................................25
8.12ENVIRONMENTALSUMMARYANDRECOMMENDATIONS..............................................25
9.0CONCLUSIONSANDRECOMMENDATIONS............................................................................27
10.0REFERENCES...................................................................................................................28
Figures
Figure1:AEAWindResourceMap...................................................................................................................1
Figure2:SiteMap.............................................................................................................................................2
Figure3:StebbinsMetTower.........................................................................................................................12
Figure4:AlternativeSiteLocations.................................................................................................................13
Figure5:St.MichaelSite1..............................................................................................................................14
Figure6:St.MichaelSite2..............................................................................................................................15
Figure7:StebbinsSite1(StebbinsMetTower)..............................................................................................16
Figure8:StebbinsSite2..................................................................................................................................17
Figure9:NP100TurbineInstalledinEmmonak..............................................................................................18
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Tables
Table1:EnergyConsumptionDataFY2012.....................................................................................................6
Table2:AlternativeComparisonSummary....................................................................................................20
Table3:EconomicEvaluationSummary.........................................................................................................21
Table4:EnvironmentalSummaryTable.........................................................................................................26
Appendices
AppendixA:WindProjectConceptualDesignDrawings(12sheets)
AppendixB:V3Energy’sSeptember2013DraftStebbinsͲSt.MichaelWindͲDieselFeasibility
Analysis
AppendixC:Stebbins,AlaskaHeatRecoveryStudy
AppendixD:PreliminaryOfficeResearchMemoandSiteInvestigationTripReport
AppendixE:CapitalCostEstimates
AppendixF:CRCMemotitled“KnownArchaeologicalandHistoricalSitesintheStebbinsArea”
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ABBREVIATIONS
AACAlaskaAdministrativeCode
ADECAlaskaDepartmentofEnvironmentalConservation
ADF&GAlaskaDepartmentofFishandGame
ADNRAlaskaDepartmentofNaturalResources
AEAAlaskaEnergyAuthority
AVECAlaskaVillageElectricCooperative
B/CBenefitͲtoͲCostRatio
CRCCulturalResourceConsultants,LLC
DADepartmentofArmy
EAEnvironmentalAssessment
EREnvironmentalReview
FAAFederalAviationAdministration
FYFiscalYear
FONSIFindingofNoSignificantImpact
°FDegreesFahrenheit
HDLHattenburgDilley&Linnell
ISERInstituteforSocialandEconomicResearch
kWKilowatt
kWhKilowattHour
MMillion
MetMeteorological
MphMilesperhour
MWhMegawatthour
NLURNorthernLandUseResearch
NP100NorthernPower100Arctic
NWINationalWetlandsInventory
NWPNationwidePermit
OEAAAObstructionEvaluation/AirportAirspaceAnalysis
PCEPowerCostEqualization
PCNPreͲConstructionNotification
PLCProgrammableLogicController
PMParticularMatter
SCADASupervisoryControlandDataAcquisition
SecSection
SMNCSt.MichaelNativeCorporation
USFWSUnitedStatesFish&WildlifeServices
USGSUnitedStatesGeologicalServices
WAsPWindAtlasandApplicationProgram
YrYear
StebbinsWindProject
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2.0INTRODUCTION
2.1BACKGROUND
ThisreporthasbeenpreparedfortheAlaskaVillageElectricCooperative(AVEC)toevaluate
alternativesforincorporatingwindpowerintothenewpowergenerationsysteminStebbins,
Alaska.
UpgradestoAVEC’spowergenerationfacilitiesarecurrentlyunderwayinStebbins.The
upgradesincludeconstructionofanewtankfarmandpowerplantwithsufficientstorageand
capacitytoaccommodateelectricalloadingfromStebbinsandtheneighboringcommunityof
St.Michael.AnelectricalintertiebetweenStebbinsandSt.Michaelisplannedtofollowthe
alignmentofthe11Ͳmilelongroadconnectingthetwovillages.Thenewpowerplantandtank
farmwillbecollocatedinStebbinsandconfiguredtoaccommodatefuturewindturbine
generatorsinstalledinthepreferredlocationalongtheintertieroute.Thewindturbinesare
necessarytoreduceAVEC’sdependenceonimporteddieselfuelandprovideanalternate
sourceofrenewableenergytoruralcommunities.PreliminaryfindingsincludedintheAlaska
EnergyAuthority(AEA)Alaskahighresolutionwindresourcemap(Figure1)indicatethatthe
StebbinsregionhasaClass3windregimesuitableforwindpowerdevelopment.
ThepurposeofthisreportistoprovideAVECwithalternativeconceptualdesignandcost
informationfordevelopingthewindenergyresourceinStebbins.Thisreportincludesan
assessmentofthewindresource,investigationofpotentialwindturbinelocations,wind
turbinegeneratorcomparison,andeconomicanalysisoftheturbinealternatives.
Figure1:AEAWindResourceMap
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2.2 LOCATION
TheproposedwindturbineprojectislocatednearthevillageofStebbinsonSt.MichaelIsland.
Stebbinsislocatedapproximately430milesnorthwestofAnchorage,onthesouthsideof
NortonSoundonAlaska’swestcoast.Itlies8airmilesnorthwestofthevillageofSt.Michael
andapproximately125airmilessoutheastofNome.Stebbinsissituatedatapproximately
63°31’02.16”NorthLatitudeandͲ162°17’04.57WestLongitude(Sec.02,T023S,R019W,Kateel
RiverMeridian).YearͲroundaccessbetweenStebbinsandSt.Michaelisprovidedbyan11Ͳmile
longgravelroad(SeeFigure2).StebbinsisaccessiblebybargeservicebetweenJuneand
October.YearͲroundaircraftaccessisalsoavailableviaa3,000Ͳfootlongby60Ͳfootwide
gravelrunwayinStebbinsanda4,000Ͳfootlongby75ͲfootwidegravelrunwayinSt.Michael.
BothrunwaysareownedandmaintainedbytheAlaskaDepartmentofTransportationand
PublicFacilities(ADOT&PF).
Stebbinshasapopulationof585residents(2010U.S.CensusPopulation),with95.3%being
AlaskaNativeorAmericanIndian.St.Michaelhasaslightlysmallerpopulationof401residents
(2010U.S.CensusPopulation).Thelocalresidentsofbothcommunitiesdependheavilyonthe
subsistenceharvestoffish,seals,belugawhales,walrus,andreindeer.Localeconomiesare
basedonamixofcommercialfisheriesandlocalwagepositionsatschool,City,andNative
Cooperationfacilities.
Figure2:SiteMap
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2.3 CLIMATE
StebbinsandSt.MichaelhaveamaritimeͲinfluencedsubarcticclimate.NortonSoundisiceͲfree
fromJunetoNovemberandaveragesummertemperaturesrangefrom40to60°F.Therecord
hightemperaturefortheregionis77°F.Wintersaretypicallycoldanddry;however,windand
blowingsnowcancreatethepotentialforicingconditionsathigherelevations.Averagewinter
temperaturesrangefromͲ4to16°F,withanextremelowtemperatureofͲ55°F.Annual
precipitationaverages12inches,with38inchesofsnowfall.
2.4 EXISTINGELECTRICALPOWERSYSTEMS
ExistingStebbinsPowerPlant
AVEC’sexistingStebbinspowerplantislocatedsouthofthecommunityontheStebbins
Airport.TheStebbinsairportisownedandmaintainedbyADOT&PF.Theplantwasfirst
energizedin1970andconsistsofa15Ͳfootby36Ͳfoot“ButlerBuilding”,wooddock,control
module,storagevan,crewmodule,andthreepadͲmountedtransformers.Thebuildingand
modulesareconstructedonamixtureofelevatedtimberpost,gradebeam,andcrib
foundations.The“ButlerBuilding”containsthefollowingCumminsgeneratorsets:
(1) Cummins499kWdieselgeneratorͲ(Overhauledin2007)
(1)Cummins350kWdieselgeneratorͲ(Ageunknown)
(1)Cummins250kWdieselgeneratorͲ(Overhauledin2000)
1,099kWTotalGenerationCapacity
Thepowerplantalsoincludesgeneratorappurtenances,daytank,miscellaneoustoolsand
equipment,transferpump,startingbatteries,andstationserviceequipment.Thebuilding
containsanexhausthoodandradiatorstandforeachgenerator.Thecontrolmodulecontains
switchgear,generatorcontrols,desk,andfilestorage.AccordingtohistoricAVECrecordsand
PowerCostEqualization(PCE)data,thepowerplantgeneratedatotalof1,316,100kWhin
2011withanaverageefficiencyof13.75kWhpergallonofdieselconsumed.
Theexistingpowerplantisold,outͲdated,andlocatedonairportproperty.ADOT&PFis
planninganexpansionoftheexistingStebbinsairportandrequirestheAVECpowerplanttobe
removedfromtheairportassoonaspossible.AVEChasbegunconstructionofanewpower
plantadjacenttotheirnewlyconstructedtankfarmontheeasternedgeofthecommunity.
Theoldpowerplantandtankfarmarescheduledtobedecommissionedinthefallof2013.
ExistingSt.MichaelPowerPlant
TheSt.MichaelpowerplantiscentrallylocatedinthecommunityalongBakerStreetandthe
coastofSt.Michael’sBay.Theplantconsistsofthreemodularpowergenerators,separate
crewquartersmodule,andastoragemoduleconstructedonwoodensleeperfoundations.The
powerplantgeneratorsconsistofthefollowing:
(1)Cummins499kWdieselgeneratorͲ(7yearsold)
(1)DetroitDiesel314kWdieselgeneratorͲ(Overhauledin2006)
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(1)DetroitDiesel207kWdieselgeneratorͲ(Overhauledin2006)
1,020kWTotalGenerationCapacity
Thepowerplantwasfirstenergizedin1970,andthelastmajorgeneratorupgradeoccurred
whenthegeneratorswereoverhauledin2006.Thepowerplantgenerated1,683,181kWhof
electricityin2011withanaverageefficiencyof14.26kWhpergallonofdieselconsumed.There
isnorecoveredheatloopassociatedwiththispowerplant.
TheSt.MichaelpowerplantwasinspectedbyHattenburgDilley&Linnell(HDL)andAVEC
representativesonJuly11,2012.Theexteriormetalsurfacesofthemodules,pipes,andtanks
wereaged,pitted,andshowedsignsofcorrosion.Theexistingpowerplantandassociatedtank
farmareplannedfordecommissioningin2014oncethenewStebbinspowerplantand
electricalintertieareoperational.Anewstandbymodulewillbeinstalledneartheexisting
schooltoprovidetemporarypowergenerationforSt.Michaelintheeventofadisruptionin
theStebbinspowerintertie.
2.5 NEWELECTRICALPOWERSYSTEMS
NewStebbinsPowerPlant
ThenewStebbinspowerplantwillconsistofa30Ͳfootby72Ͳfootprefabricatedmetalbuilding
onanelevatedsteelpipepilefoundationwithaconcreteslabͲonͲdeckfloorsystem.Theplant
willbeinitiallyequippedwithfourCaterpillar3456dieselgenerators.Theenginesareratedat
450kWforprimepowerandhavethehighestfuelefficiencyintheirclass.Twooftheengines
willberetrofitwithamarinemanifoldandturbocharger.Themarineconversionapproximately
doublestheamountofrecoverablejacketwaterheat.Thesystemwillbeconfiguredtorunthe
marineconversionenginesinthewinterandtheothertwoenginesinthesummer.Theplant
structurehasbeendesignedtoallowfuturereplacementofuptotwoofthe3456engineswith
1,050kWratedCaterpillar3512units.Thepowerplantisunderconstructionandisscheduledto
comeonlineinthefourthquarterof2013.
ThenewswitchgearwillhaveatotalofsixsectionsͲoneforeachdieselgenerator;onefor
mastercontrol;andonefordistributionfeederbreakers.Theswitchgearwillbefullyautomatic
withparallelingcapabilityandwillutilizeaprogrammablelogiccontroller(PLC)toautomatically
matchtherunninggenerator(s)tothecommunityload,includingmonitoringthewind
generation.ThenewswitchgearwillincludeaSCADAsystemforremotemonitoringofthe
generationanddistributionsystems.Afiberopticdatacommunicationcablefromtheremote
windturbinewillallowmonitoringandcontrolofthepowergeneration.
Thenewswitchgearwillprovideautomaticparallelingandloadcontrolofthefourgenerating
units.Theloadcontrolsystemwillmonitortheelectricaldemandonthegeneratorsalongwith
windgenerationoutputandautomaticallyselectthenumberofgeneratingunitsrequiredto
meetthedemand.Theswitchgearwillautomaticallystartthemostefficientcombinationof
engines,bringthemuptospeed,automaticallysynchronizetheunits,andclosethegenerator
circuitbreakers.Whenaunitistakenoffline,eitherformaintenanceorduetoareductionin
electricload,theswitchgearwillautomaticallyremovetheunitfromthebusandallowthe
enginetocooldownbeforeshutdown.Generatorcontrolsandrelayingwillprovidecomplete
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protectionandmonitoringofeachengineͲgeneratorandthefeeders.AsimplisticoneͲline
diagramoftheintegrationbetweenthenewpowerplantandthewindturbinesisincluded
onSheetE.1,AppendixA.
Intertie
TheproposedelectricalintertiebetweenStebbinsandSt.Michaelconsistsofapproximately11
milesofnewoverheadinstalledparalleltotheexistingroadalignment.Thelinewillbe
designedandbuiltto24.9/14.4kVstandardsandenergizedat12.47/7.2kVasis
standardforAVECoperations.Approximately170newdirectͲsetpowerpoleswillbe
constructedalong6milesoftheroadfromthenewStebbinspowerplanttotheexistingfresh
waterpumphouselocatedattheSt.Michaelwatersource,approximately1.9mileswestof
theSt.MichaelAirport.Theintertiewillconnecttotheexistingpowerpolesatthepump
housethatextendtotheSt.Michaelpowergrid.Newlinepolesareanticipatedtobe
40Ͳfoothigh,Class1,timberpolesembedded8feetbelowgradetoresistmovementfrom
seasonalfrostjacking.NewdeadͲendorriserpolesareanticipatedtobe45Ͳfoothigh,Class1,
timberpolesembeddedtoadepthof9feetbelowgrade.Thepoleswillbespaced
approximately200feetapartandwillbeequippedwith8Ͳfootcrossarmstoaccommodate
thenewconductors.TheexistingpowerpolesextendingfromthepumphousetotheSt.
Michaelpowergridwillberetrofittedwithnewcrossarmsandbracedasrequiredtocarrythe
newconductors.Theintertiedesigniscurrently95%completeandconstructiongrantfunding
hasbeendedicatedbytheDenaliCommission.Theprojectisanticipatedtobebidinfall2013
withconstructionbeginninginthespring2014.
St.MichaelStandͲbyGenerator
Theproposedintertieprojectalsoincludesinstallationofanewstandbygeneratoradjacentto
theexistingSt.MichaelSchooltankfarm.ThestandbyunitwillprovidetemporarypowertoSt.
MichaelintheeventofadisruptioninpowerthroughtheStebbinsintertie.Theproposed
generatorisanticipatedtobea750kW,1020Hpgensetwithappropriateswitchgear,heat
exchanger,radiator,andexhaustsystem.Thegeneratorwillconnecttoanexisting30,000
gallondiesel,doubleͲwalled,skidͲmountedtanklocatedintheschooldistrict’stankfarm.Use
ofthistankissharedbetweentheBeringStraitSchoolDistrict(BSSD)andAVECpera2008
MemorandumofUnderstanding.Thememorandumstipulatesthat15,000gallonsofdieselin
thetankisavailableforAVEC’sstandͲbygenerator.
2.6 ELECTRICALDEMAND
HistoricaldatafromAVECandtheAEAAlaskaPowerCostEqualizationProgram(PCE)report
wasanalyzedtodeterminetrendsintheStebbinsandSt.Michaelenergyconsumption.ThePCE
programisareliablesourceofhistoricpower,fuelconsumption,andenergycostinformation
forruralcommunitiesthroughoutthestate.ThePCEprogramprovidesfundingsubsidiesto
electricutilitiesinruralAlaskancommunitiesinordertolowerenergycoststocustomers.This
programpaysforaportionofthekilowatthourssoldbytheparticipatingutility.Theexact
amountpaidvariesperlocationandisdeterminedbytheamountofenergygeneratedand
sold,theamountoffuelusedtogenerateelectricity,andfuelcosts.
Eachyear,AEApublishesPCEprograminformationincludingfuelconsumption,power
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generationandsales,andelectricityratesforeligiblecommunities.Duringthefiscalyear2012
(July1,2011toJune302012),150residentialandcommunityfacilitiesinStebbinswereeligible
toreceivePCEassistance.Stebbinscustomersreceivedfundingfor46.5%ofkilowatthours
soldandhadelectricityratesreducedfromanaverageof$0.62perkilowatthourto$0.22per
kilowatthour.St.Michaelcustomersreceivedfundingfor40.9%ofkilowatthourssoldandhad
electricityratesreducedfromanaverageof$0.65perkilowatthourto$0.22perkilowatthour.
V3EnergyfurtheranalyzedtheelectricalloadingintheirStebbinsͲSaintMichaelWindͲDiesel
FeasibilityAnalysis(AppendixB).TheanalysisincludedreviewofAVEC’s15minuteinterval
loadingdataforStebbinsandSt.MichaelfromJanuary2012toAugus2013.SeeAppendixBfor
loadingprofiles.Thecalculatedaverageloadwas367kW,withapeakrecordedloadof662kW,
andanaveragedailydemandof8,806kWh.Table1providesadditionalenergyconsumption
dataforbothcommunities.Assumingthatthecombinedcommunitydemandforpowerwill
increaselinearlywitha2%averagepopulationgrowthrate,itisestimatedthatthepower
generationsystemwillexperienceanaveragepowerdemandof547kW,apeakpowerdemand
of983kW,andanaveragedailyenergydemandof13,086kWhintheyear2032.
Table1:EnergyConsumptionDataFY2012
Community
Gross
KWhs
Generated
DieselFuelUsedAverage
kWhLoad
PeakkWh
Load
Customers
(Residential
and
Community
Facilities)
Gallons
Cost($)Average
FuelPrice
($/gallon)
Diesel
Efficiency
(kWh/gallon)
Stebbins
1,428,234
104,466
403,0153.8613.67165
299
150
St.Michael
1,853,882
131,689
515,1084.1814.08210
414
111
*Source:2012AVECAnnualGenerationReport,AVEC Operations Personnel, and Annual PCE ReportFY2012
2.7 STEBBINSRECOVEREDHEATPOTENTIAL
TheAlaskaNativeTribalHealthConsortium(ANTHC),incooperationwithAVEC,has
investigatedtheexistingandproposedthermalloadsforcommunityfacilitieswithin600feetof
thenewStebbinspowerplant.ANTHCmodeledthethermalloadsandpreparedastudyfor
heatrecoveryfromthenewpowerplant.ANTHC’sHeatRecoveryStudyisincludedinAppendix
C. Asummaryoftheaverage,minimum,andmaximumthermalloadsisincludedinV3Energy’s
StebbinsͲSaintMichaelWindͲDieselFeasibilityAnalysis(AppendixB)andisusedasthebasisfor
thecostprojectionsincludedintheeconomicmodeling.Belowisasummarydescriptionofthe
proposedheatrecoverysystem.
x TheheatrecoverysystemwillcapturejacketwaterheatgeneratedbytheAVECdiesel
generatorsthatwouldotherwiseberejectedtotheatmospherebytheradiators.The
heatwillbeusedtooffsetheatingfuelconsumptionatcommunityfacilities,referredto
asendͲuserbuildings.
x TheproposedsystemwillproviderecoveredheattoatotalofsixendͲuserbuildings,
includingtheexistingwatertreatmentplant,newwatertreatmentplant,washeteria,
clinic,headstartbuilding,andschool.
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x Hotenginecoolantwillbepumpedthroughheatexchangerslocatedatthepowerplant.
Heatwillthenbetransferredtotherecoveredglycolheatloop.
x Heatrecoverysupplyandreturnarcticpipewillberoutedaboveandbelowgradeas
requiredtoreachtheenduserbuildings.Thearcticpipewillhavea4Ͳinchdiameter
fluidpipewhilethebranchpipingwillhavea2Ͳinchdiameterfluidpipe.Arcticpipewill
consistofsteelfluidpipesinsulatedwithpolyurethanefoamandcoveredwithanHDPE
orcorrugatedsteeljacket.
x Theconnectionateachenduserbuildingwillconsistofaheatexchangerbetweenthe
recoveredheatloopandthebuildinghydronicsystem.Theconnectionpointwillbeat
theheatingreturnmain,upstreamoftheboiler,toallowthesystemto“preͲheat”boiler
returnwater.Eachenduserconnectionwillalsoincludeisolationvalves,controls,
instrumentation,andanenergymetertomeasureandrecordtheheattransfer.
BasedontheanalysisperformedbyANTHC,thesixendͲuserbuildingshaveatotalestimated
fuelconsumptionofapproximately69,000gallonsperyearanditisestimatedtheproposed
heatrecoverysystemcanoffsetapproximately57,000gallonsoffuelperyear.
2.8 CONTRIBUTORSANDSOURCESOFINFORMATION
PhysicalsiteinformationcontainedinthisreportwasgatheredbyHDLduringfield
investigationsandthroughtheuseofGPSdata,UnitedStatesGeologicalSurvey(USGS)
topographicmaps,andaerialimagery.Powerplantcontrols,integrationassistance,and
historicalelectricalloaddatawasprovidedbyAVECEngineeringandOperationsdepartments.
V3EnergyprovidedtheStebbinsͲSaintMichaelWindͲDieselFeasibilityAnalysis.ANTHC
providedtheStebbins,AlaskaRecoveredHeatStudy.Thermalloadconversionsandpower
plantengineeringassistancewasprovidedbyAlaskaEnergyandEngineering.Economicanalysis
wasprovidedbyV3Energy.St.MichaelandStebbinsCommunitydatawasobtainedfromthe
AlaskaCommunityDatabaseavailableatwww.commerce.state.ak.us/dca/commdb/CF_CIS.htm
2.9 LIMITATIONS
Thisreport,titledStebbinsWindProjectConceptDesignReport,waspreparedinsupportof
agrantfundingrequestfordesignandpermittingawindtowerprojectinStebbins,Alaska.
Designinformationcontainedhereinisconceptualforplanningandbudgetarycostestimation
purposesonly.
3.0WINDDATAACQUISITIONANDMODELING
3.1 DATAACQUISITION
OnJuly21,2010,AVECinstalleda30metertallmeteorological(met)towerontopofasteep
volcanicrockoutcrop,orcindercone,locatedadjacenttotheroadattheapproximatemidpoint
betweenStebbinsandSt.Michael(SeeSheetG1.03,AppendixA).Themettowerlocationis
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ownedbySt.MichaelNativeCorporation(SMNC)andisusedasagravelsourceforSt.Michael.
ThetowercollectedwinddataatthislocationuntilSeptember19,2011(14months).Themet
towerwasequippedwiththreeseparateanemometers,awindvane,andatemperature
sensor.Twooftheanemometerswereinstalled28.4metersabovegroundlevelandonewas
installed18.6metersabovegroundlevel.Thecollecteddatawasstoredonadatalogger
mountedtothebaseofthemettower.Storeddatawasdownloadedevery3to6months
duringsitevisitstoinspecttheequipment.Thequalityofthedatawasgenerallygoodwith
above95%datarecovery.AVECcontractedwithV3Energytoanalyzethecollectedwindand
temperaturedataandcalculatewindspeed,airdensity,prevailingwinddirection,windshear,
andotherfactorseffectingwindenergyproduction.
InJanuary2012,themettowerwasreinstalledatthepotentialturbinelocationatthe
intersectionoftheStebbinsͲSt.MichaelRoadandtheStebbinsLandfillAccessRoad(Stebbins
Site1).ThemettowerwasrelocatedbecausetheSt.Michaelmettowersiteisusedasagravel
sourcebySMNCandthecorporationisunwillingtoreleasethelandforwindfarm
development.Atthetimeofthisreport,themettowerisstillrecordingdata.Thequalityofthe
datawasgenerallygoodwithabove95%datarecovery.Thedatacollectionprocessand
modelingresultsarefurtherdefinedinV3Energy’sSeptember2013StebbinsͲSt.Michael
WindͲDieselFeasibilityAnalysis(AppendixB).
Figure3:StebbinsMetTower
3.2 WINDMODELINGRESULTS
TheresultsofV3’swindmodelingarepresentedintheStebbinsͲSt.MichaelWindͲDiesel
FeasibilityAnalysis(AppendixB).ThecollectedwinddatadepictedaClass6(outstanding)wind
resourceattheStebbinsmettowersite.ThemodelingwasdonewithWAsPmodelingsoftware
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topredictthequalityofthewindresourceatothernearbylocationsonSt.MichaelIslandby
analyzingthecharacteristicsofthetopographyandterrain.Thisinformationisusedtoidentify
optimallocationsforwindtowerconstructionandtoanalyzetheeffectivenessofwindturbine
alternativesontheproposedpowergenerationsystem.
4.0STEBBINSWINDSITEANALYSIS
4.1 WINDSITEINVESTIGATION
OnSeptember19,2011,MarkSwenson(HDL),JohnThornley(HDL),MattMetcalf(AVEC),and
DougVaught(V3Energy)traveledtoStebbinstoinvestigatealternativewindtowersitesfor
turbineinstallation.Thepurposeofthesitevisitwastoinvestigatepotentialwindsites
identifiedthroughanofficeevaluationofsiteaccess,permitrequirements,landownership,and
thepotentialstrengthofthewindresourceusingaerialimageryandtopographicmaps.During
thereconnaissance,threesiteswerepreliminarilyevaluatedforaccess,terrain,surface
geology,andwindpatterns.ThethreesitesinvestigatedincludeSt.MichaelSite1,St.Michael
Site2,andStebbinsSite1,asshownonSheetG1.03,AppendixA.Amemosummarizingthe
preliminaryofficeresearchandthetripreportforthesiteinvestigationisincludedinAppendix
D.
Followingthefieldinvestigation,afourthsitewasidentifiedbythewindmodelingashavinga
strongpotentialwindresource.ThissiteislocatedontheCapeStephensBluffnorthof
StebbinsandisshownasStebbinsSite2onSheetG1.03,AppendixA.Anofficeevaluationof
thissitewasperformedtoidentifythewindturbineconstruction,permitting,andsitecontrol
feasibility,butnofieldinvestigationwasperformed.Belowisasummaryoftheinvestigationat
eachpotentialwindturbinesite.
Figure4:AlternativeSiteLocations
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4.1.1 St.MichaelSite1
St.MichaelSite1islocatedat63ȗ30’09.56”northlatitude,162ȗ11’23.81’westlongitude,atan
elevationofapproximately130feet.Thissiteislocatedonariseoflandtothesouthofthe
Stebbins–St.MichaelRoad,approximately0.70milessoutheastoftheSt.Michaelmettower.
Groundcoverconsistsoftundraandsparselowaldersondryground.Subsurfaceconditions
mayincludeshallowtosignificantsoildepositswithwarmpermafrost.Anyrockencountered
wouldlikelybefrostfracturestovaryingdepthsbelowthesurfaceandmaybeweatheredand
friabletodepth.Possiblefoundationtypesforwindtowersatthissiteincludemassgravitymat
foundations.Rockanchorsmaybenecessaryifvolcanicsareencounteredatshallowdepths.
AccesstothesitefromtheStebbinsͲSt.Michaelroadcouldbeeasilyconstructedwithnodeep
fillsorsignificantterrainfeaturestoovercome.WindmodelingdepictsapotentialClass2/3
windresourceatthissite.SeeV3Energy’sSeptember2013StebbinsͲSt.MichaelWindͲDiesel
FeasibilityAnalysis(AppendixB)forwindmodelinginformation.Therelativelylowpotential
windresourceatthissitemakesitanundesirablewindfarmlocation.Therefore,no
constructionalternativeswereanalyzedforSt.MichaelSite1.
Figure5:St.MichaelSite1
4.1.2 St.MichaelSite2
St.MichaelSite2islocatedat63ȗ30’46.54”northlatitude,162ȗ10’56.31’westlongitude,atan
elevationofapproximately175feet.Thesiteislocatedonaridgelineextendingnortheastfrom
thecindercone(St.Michaeloriginalmettowerlocation).Theridgewaslikelyformedbya
basaltflowfrompastvolcanicevents.Thereconnaissancegroupviewedthesitefromthe
SMNCgravelsourceatthetopofthecindercone.Theridgeislikelycomposedofshallow
organicsandsoilsabovebasaltandothervolcanics.Theunderlyingrockmaybefrostfractured
atvaryingdepthsbelowthesurfaceandmaybeweatheredandfriabletodepth.Apossible
foundationforwindtowersatthissiteincludesamassgravitymatfoundation.Rockanchors
maybeneededifvolcanicsareencounteredatshallowdepths.Constructionatthissitealso
includesclearingdensepatchesofaldersandconstructinga0.5mileaccesstrailfromthetopof
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thecinderconetotheproposedsite.Accesstraildevelopmentrequiresfillinga20Ͳfootdeep
ravinebetweenthecinderconeandtheridgeline.Also,accesseasementsarerequiredwith
SMNCforshareduseoftheexistingroadtotheSMNCmaterialsourcetothetopofthecinder
cone.
Figure6:St.MichaelSite2
WindmodelingdepictsapotentialClass4/5windresourceatthissite.SeeV3Energy’s
September2013StebbinsͲSt.MichaelWindͲDieselFeasibilityAnalysis(AppendixB)forwind
modelinginformation.Thewindresourcewassufficientforpowergeneration.Thissiteisnota
preferredwindfarmlocationduetothevariableterrainandtheadditionalfillvolumesrequired
foraccesstrailconstruction.Therefore,noconstructionalternativeswereanalyzedforthissite.
4.1.3 StebbinsSite1
StebbinsSite1islocatedat63ȗ31’56.58”northlatitude,162ȗ16’50.64”westlongitude,atan
elevationofapproximately155feet.Thesiteislocatedonaridgelineadjacenttotheexisting
StebbinsͲSt.MichaelRoad,neartheintersectionoftheStebbinsͲSt.MichaelRoadandthe
StebbinsLandfillAccessRoad.Gravelforwindtowerroadandpadconstructionisreadily
availableattheStebbinsNativeCorporationgravelsource,approximately0.85mileswestof
theproposedsite.Thereconnaissancegroupwalkedtheterrainandinspectedthesite.The
groundcoveratthesiteiscomposedoftundraandnopondingorexcessmoisturewas
observed.Thesubsurfaceconditionsmayconsistoforganicsandshallowsoilsoverlyingbasalt
andothervolcanics.FrostͲfracturedrockcouldbeencounteredatvaryingdepthsbelowthe
surfaceandmaybeweatheredandfriabletodepth.Amassgravitymatfoundationmaybea
viablealternativeatthissite.Rockanchorsmaybenecessaryifthevolcanicsareencountered
atshallowdepths.
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Figure7:StebbinsSite1(StebbinsMetTower)
StebbinsSite1wasselectedasthepreferredsiteforwindfarmconstructionduetotheeven,
dryterrain,closeproximitytothepowerplantandgravelsource,andeasyaccesstrail
construction.Alternatives1through3presentedinSection5.0belowincludewindturbine
optionsinstalledatthissite.TheextrapolatedwinddatafromtheSt.MichaelMetTower
depictedapotentialClass3/4windresourceatStebbinsSite1,whichissufficientforpower
generation.Thenewmettowererectedatthesiteddatameasureda Class5/6wind
resourceatthislocationwhichexceededthemodeledresults.SeeV3Energy’s
September2013StebbinsͲSt.MichaelWindͲDieselFeasibilityAnalysis(AppendixB)forwind
modelinginformation.
4.1.4 StebbinsSite2
Followingthesitevisit,StebbinsSite2wasselectedasanotherpotentialwindturbinelocation
basedonthefindingsofthepreliminarywindmodeling.Thesiteislocatedat63ȗ32’10.43”
northlatitude,162ȗ18’14.52”westlongitude,andatanapproximateelevationof140feet.The
siteislocatedalongtheCapeStephensBluffonthenorthwesterntipofSt.MichaelIsland,
approximately0.20mileswestoftheStebbinsGravelSource.Accesstothesiteisfroman
existinggraveltrailextendingfromtheStebbinsGravelSourcetothebluff.Aneasementor
leasewillberequiredfromthelandowner,theStebbinsNativeCorporation.
ThewindmodelingresultsshowthatStebbinsSite2isanoptimalwindturbinelocationto
maximizetheavailablewindresource.TheextrapolatedwinddatafromtheSt.MichaelMet
TowerdepictedapotentialClass5windresourcefortheStebbinsSite2.Nositeinvestigation
hasoccurredandtherehasbeennopreliminarygeotechnicalanalysisofthearea.Aerial
photographydepictsthesiteasdrywithtundraandlowbrushgroundcover.Thesiteappears
feasibleforwindfarmconstructionduetothedryterrain,closeproximitytothepowerplant
andgravelsource,andeasyaccesstrailconstruction.However,discussionswithAlaska
DepartmentofFishandWildlife(ADF&W)indicatedthataavianstudywouldberequiredprior
todevelopmentinthislocationandtheturbineswouldlikelyberequiredtoshutdownduring
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StellarEidermigrationperiods.Sincethemigrationperiodscoincidewithsomeofthetypically
windytimesoftheyear,theseasonalshutdownwouldhavealargeaffectonwindenergy
production.Therefore,noconstructionalternativeswereanalyzedforthissite.
Figure8:StebbinsSite2
5.0WINDTURBINESYSTEMALTERNATIVES
5.1 STEBBINSWINDTURBINEANALYSIS
AVECselectedthefollowingthreeturbinealternativesforevaluationatStebbinsSite1:
NorthernPower100Arctic,VestasV17,andAeronauticaAW33Ͳ225.Theseconfigurationsare
classifiedasmediumwindͲdieselpenetrationsystemshavingagoaltooffset20%to50%ofthe
community’senergydemandwithwindpower.Amediumpenetrationsystemprovidesa
balancebetweentheamountofenergyprovidedandthecomplexityofthewindgeneration
andintegrationsystems.
5.1.1 NorthernPower100Arctic
Thefirstturbineconfigurationconsistsof(4)NorthernPower100Arctic(NP100)turbines.The
NP100’saremanufacturedbyNorthernPowerSystemsinBarre,Vermont.TheNP100isa
37Ͳmeterhigh,100kW,permanentmagnet,synchronous,directdrivewindpowergenerator,
witha21Ͳmeterrotordiameterand3bladesthatAVEChaspreviouslyinstalledinthefollowing
ruralAlaskavillages:
x ChevakͲ 400kW
x Emmonak–400kW
x Gambell–300kW
x HooperBay–300kW
x Kasigluk–300kW
x Mekoryuk–200kW
x Quinhagak–300kW
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x Savoonga–200kW
x Shaktoolik–200kW
x ToksookBay–400kW
AVECTotal=3,000kW
Eachturbineisequippedwithactiveyawcontrol,butdoesnothavebladepitchcontrol
capability.The(4)proposedNorthernPower100Arcticgeneratorshaveamaximumcumulative
powergenerationoutputof400kWatawindspeedof32.4mph.Theturbinesareequipped
witha21Ͳmeterdiameterrotor.
Figure9:NP100TurbineInstalledinEmmonak
5.1.2 VestasV17
Thesecondoptionisinstalling(5)remanufacturerVestasWindSystemsA/SV17turbines.The
V17isa90kW,fixedpitchturbinewithactiveyawandahighspeedrotorwiththreeblades.
VestasisaninternationalturbinemanufacturerbasedinDenmark,withtheirAmerican
operationsbasedinPortland,Oregon.TheV17’swerecommonlyusedassmallscaleindustrial
windturbinesinthe1980’sand1990’s.Morerecently,theseturbineshavebeenreplacedin
windfarmswithnewlargescaleturbineswith1megawattcapacityorgreater.The
decommissionedV17sweresoldtoindependentcontractors,suchasHalusPowerSystemsin
SanLeandro,CA,forrefurbishmentandresale.TheV17isa26Ͳmeter(85Ͳfoot)high,90kW,
inductiongenerator.Theturbinesareequippedwitha17Ͳmeterdiameterrotor.Installingfive
V17sinStebbinswouldproduceamaximumoutputof450kWatawindspeedof15mph.The
generatorpoweroutputcanbecontrolledusingasimpleinverterandsoftbreakingora
variablespeeddrive(VSD)complexinverter.V17turbineshavebeenpreviouslyinstalledin
AlaskaatKokhanok.
5.1.3 AeronauticaAW33Ͳ225
ThethirdturbineoptionisinstallingtwoAeronauticaAW33Ͳ225turbines.Aeronautica
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WindpowerInc.startedin2008asaturbinerefurbishmentcompany.In2010theypurchased
therightstomanufactureandselltheNorwin225andNorwin750turbinesundertheirname.
TheAW33Ͳ225turbineisa40Ͳmeter(131Ͳfoot)high,225kW,inductiongenerator.The
turbinesareequippedwitha33Ͳmeterdiameterrotor.Thisconfigurationhasa
maximumpowergenerationoutputof450kW.Thebladesarefixedpitchandstallregulatedat
highwindspeeds.Thebladesareaerodynamicallydesignedtostallduringextremewind
eventsinordertomaintainasafeoperatingspeed.Thismethodofcontroleliminatesthe
mechanicalandelectricbladecontrolsystemsinvolvedwithpitchcontrolledturbines.
TherearenoAeronauticaturbinesinstalledinAlaskaatthistime.
5.2 ALTERNATIVE1Ͳ(4)NP100TURBINESINSTALLEDATSTEBBINSSITE1
Thisalternativeproposesinstallationof(4)NP100turbinesatStebbinsSite1foratotal
cumulativegenerationcapacityof400kW.Theprojectincludesconstructionof1,300feetof
16Ͳfootwidegravelaccesstrailand(4)2,600squarefootgravelpadsatthewindtower
locations.Theproposedtrailandwindtowerpadsareanticipatedtobe4feetthickandconsist
oflocallyavailablesandsandgravelscompactedto90%maximumdensity.Thedrivablesurface
oftheembankmentisconstructedwith6Ͳinchesofcrushedaggregatesurfacecourse.Topsoil
andseedisplannedfortheembankmentslopestominimizeerosionoftheplacedfill.The
turbinesareinstalledona37Ͳmeterhigh,conical,monopoletower.Thetowerfoundationis
anticipatedtoincludeprecastconcretegravityaboveshallowvolcanicbedrock.Powerfrom
thewindturbineswillbeconnectedtothegridthroughthenewStebbinsͲSt.Michaelsintertie
whichisscheduledforconstructionin2014.ReferenceSheetC1.02,AppendixAforasiteplanof
Alternative1.
ThewindfarmmodelingincludedV3Energy’sSeptember2013StebbinsͲSt.MichaelWindͲ
DieselFeasibilityAnalysis(AppendixB)predictsthatthisalternativewilladd1,106MWh/year
ofannualenergyproductiontotheStebbinsandSt.Michaelpowergenerationsystemat80%
turbineavailability.Theconstructioncostforthisalternativeisestimatedtobe$10,077per
installedkWassumingthenewpowerplantiscompleteandoperational.SeeCapitalCost
EstimateincludedinAppendixE.
5.3 ALTERNATIVE2Ͳ(5)V17TURBINESINSTALLEDATSTEBBINSSITE1
Thisalternativeproposesinstallationof(5)V17turbinesatStebbinsSite1foratotalcumulative
generationcapacityof450kW.Theprojectincludesconstructionof1,600feetof16Ͳfootwide
gravelaccesstrailand(5)2,600squarefootgravelpadsatthewindtowerlocations.The
proposedtrailandwindtowerpadsareanticipatedtobe4feetthickandconsistoflocally
availablesandsandgravelscompactedto90%maximumdensity.Thedrivablesurfaceofthe
embankmentisconstructedwith6Ͳinchesofcrushedaggregatesurfacecourse.Embankments
andfoundationsareanticipatedtobethesameaspreviouslydescribedinAlternative1.The
turbinesareanticipatedtobeinstalledonmonopoletowers.Latticetowerswillalsobe
consideredfortheseturbinesifthisalternativeisadvancedtofinaldesign.Reference
SheetC1.03,AppendixAforasiteplanofAlternative2.
ThewindfarmmodelingincludedV3Energy’sSeptember2013StebbinsͲSt.MichaelWindͲ
DieselFeasibilityAnalysis(AppendixB)andpredictsthatthisalternativewilladd943MWh/year
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ofannualenergyproductiontotheStebbinsandSt.Michaelpowergenerationsystemat80%
turbineavailability.Theconstructioncostforthisalternativeisestimatedtobe$8,419per
installedKWassumingthenewpowerplantiscompleteandoperational.SeeCapitalCost
EstimateincludedinAppendixE.
5.4 ALTERNATIVE3Ͳ(2)AW33Ͳ225TURBINESINSTALLEDATSTEBBINSSITE1
Thisalternativeproposesinstallationof(2)AW33Ͳ225turbinesatStebbinsSite1forapotential
generationcapacityof450kW.Theprojectincludesconstructionofa750Ͳfootgravelaccess
trailand(2)2,600squarefootwindtowerpads.Theproposedtrailandwindtowerpadsare
anticipatedtobe4feetthickandconsistoflocallyavailablesandsandgravelscompactedto
90%maximumdensity.Thedrivablesurfaceoftheembankmentisconstructedwith6Ͳinchesof
crushedaggregatesurfacecourse.Topsoilandseedisplannedfortheembankmentslopesto
minimizeerosionoftheplacedfill.Theturbineisinstalledona40Ͳmeterhigh,conical,
monopoletower.Thetowerfoundationisanticipatedtoincludeprecastconcretegravitymats
withrockanchorstoresisttheincreasedoverturningmoment.TheAW33Ͳ225towersare
anticipatedtorequirelargerfoundationsthantheNP100turbinesduetolargerreactionforces
fromtheincreasedtowerweight,longerbladediameters,andincreasedsweptarea.
ReferenceSheetC1.05,AppendixA,forasiteplanofAlternative3.
ThewindfarmmodelingincludedV3Energy’sSeptember2013StebbinsͲSt.MichaelWindͲ
DieselFeasibilityAnalysis(AppendixB)andpredictsthatthisalternativewilladd1,360
MWh/yearofannualenergyproductiontotheStebbinsandSt.Michaelpowergeneration
systemat80%turbineavailability.Theconstructioncostforthisalternativeisestimatedtobe
$8,769perinstalledKWassumingthenewpowerplantiscompleteandoperationaland450
kWofpowerisdeliveredfromthenewturbine.SeeCapitalCostEstimateincludedinAppendix
E.
5.5 ALTERNATIVECOMPARISONSUMMARY
Table2belowsummarizesthecapitalcostsandestimatedannualenergyproductionforeach
turbinealternative.
Table2:AlternativeComparisonSummary
Alt
TurbineSelection
Site
Generation
Capacity(kW)
Estimated
CapitalCost
EstimatedCapital
CostperInstalled
kW
EstimatedAnnual
EnergyProduction
@80%
Availability
1
(4)NP100s
Stebbins1400$4.03M$10,077
1,107MWh
2
(5)V17s
Stebbins1450$3.79M$8,420
943MWh
3
(2)AW33Ͳ225
Stebbins1450$3.95M$8,769
1,360MWh
*Source:AnnualEnergyProductiondatatakenfromV3Energy’sSeptember2013DraftStebbinsͲSt.MichaelWindͲDiesel
FeasibilityAnalysis
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6.0ECONOMICEVALUATION
6.1 METHODOLOGYANDAPPROACH
TheStebbinsͲSt.MichaelsWindDieselFeasibilityAnalysispreparedbyV3Energy(AppendixB)
includesawindpoweranalysisofthecombinedStebbinsͲSt.Michaelpowergenerationsystem
usingHOMERenergymodelingsoftwarewiththepreviouslydescribedwindturbine
alternatives.Thesoftwarewasconfiguredforamediumtohighpenetrationsystem,withthe
firstprioritytomeetthecommunity’selectricaldemandsandthesecondprioritytoservethe
recoveredheatsystemthroughasecondaryloadcontroller(electricboiler).Theanalysis
consideredanaveragedieselfuelpriceof$5.23pergallonfortheprojected20Ͳyearprojectlife.
ThemodelingassumptionsandresultsofV3’sanalysisarepresentedinAppendixB.
V3insertedthepowergenerationandfuelconsumptionresultsfromtheHOMERmodelinginto
theeconomicmodelingprogramdevelopedbytheInstituteforSocialandEconomicResearch
(ISER).AEAusestheISEReconomicmodelasthestandardapproachforscoringwindproject
designandconstructiongrantapplications.TheISERmodelconsidersthecapitalcostof
constructionandannualcostofoperatingandmaintainingthewindturbinesandweighsthem
againstthebenefitcostsavingsrealizedfromthevolumeofdisplaceddieselfuelrequiredfor
powergenerationandheatingpublicfacilities.Theanalysisdevelopsabenefit/costratiothat
canbeusedtocomparewindturbinealternatives.SeeV3’seconomicanalysisresultsin
AppendixB.
6.2 ECONOMICEVALUATIONRESULTS
Table3belowsummarizesthefindingsoftheV3’seconomicevaluationforeachturbine
alternative.
Table3:EconomicEvaluationSummary
Alt
Annual
Wind
Generation
@80%
Availability
(kWh)
Wind
Energy
ForPower
(kWh/yr)
Wind
Energy
ForHeat
(kWh/yr)
Windas%
Total
Power
Production
(%)
Windas%
Total
Thermal
Production
(%)
Power
Generation:
Fuel
Displacedby
WindEnergy
(gal/yr)
Thermal
Generation:
HeatingFuel
Displacedby
WindEnergy
(gal/yr)
Benefit/Cost
Ratio
1
1,106,920
1,009,590
97,330332.968,9082,488
1.24
2942,572
855,585
86,987292.658,5122,224
1.12
3
1,360,237
1,131,538
228,699406.680,2895,846
1.50
*Source:V3Energy’sSeptember2013DraftStebbinsͲSt.MichaelWindͲDieselFeasibilityAnalysis
7.0PREFERREDALTERNATIVE
Basedonthefindingsofthesiteanalysis,windmodeling,andeconomicevaluation,Alternative
3isthepreferredalternativeforStebbinswindturbinedevelopment.Thisalternativeconsists
ofconstructionof(2)AW33Ͳ225turbinesatStebbinsSite1.Eachturbinehasthepotentialto
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generate225kW,foranaggregatetotalpowergenerationof450kW.TheAW33Ͳ225turbineis
thepreferredalternativebecauseitmaximizespoweroutputwhileminimizingtheamountof
turbinesthatneedtobeoperatedandmaintained.Also,thelargersweptareaoftheturbine
allowsforefficientpowergenerationthroughawiderangeofwindspeeds.Thetwoturbine
installationwouldallowforredundancyinthesystemandtheabilitytoperformturbine
maintenancewithouteliminatingwindpowergenerationfromthesystem.Theeconomic
evaluationaboveassumesthattheturbinearrayoperatesatthe450kWenergyoutputlevel.
However,forbettersystemperformance,theturbineshouldbemodulatedusingaVSDdown
toanenergyoutputlevelthatprovidesmediumpenetrationtotheStebbinsͲSt.Michaelgrid
andadequateexcessenergytomeetrecoveredheatdemands.Therecommendedenergy
outputlevelwillbedeterminedduringfinaldesignofthecontrolsystem.
8.0ENVIRONMENTALREQUIREMENTS
8.1 HISTORICANDARCHAEOLOGICAL:ALASKASTATEHISTORICPRESERVATIONOFFICE
(SHPO)
CulturalResourceConsultants,LLC(CRC)conductedareviewoftheAlaskaHeritageResource
Survey(AHRS)filesatStebbinsSite1(RidgeSite).AccordingtotheAHRSfilesthereareno
knownAHRSsiteswithintheprojectareasforthesesites.However,thereareknownsensitive
siteslocatedadjacenttotheprojectareasofinterest,includingonesitelistedontheNational
RegisterofHistoricPlaces.In2009NorthernLandUseResearch(NLUR)completedan
archaeologicalsurveyofpotentialmaterialssourcesinStebbinsandSt.Michael.Theirresearch
includedtwositeslocatednorthofStebbinsintheimmediatevicinityoftheprojectareasof
interest.AccordingtoNLUR’sfindings,noknownculturalresourceswerefoundinthesites
investigated.BasedonexistingAHRSinformationandthefindingsofNLUR’ssiteinvestigation,
thereisarelativelylowprobabilityofundiscoveredarchaeologicalandhistoricsiteswithinthe
actualprojectareasofinterest.PertherecommendationofCulturalResourceConsultants,LLC,
theundertakingwouldneedtobereviewedbytheStateHistoricPreservationOffice,but
furtherfieldsurveyswilllikelynotberequiredateitherofthesetwosites.CRCAnalysisis
includedinAppendixF.
8.2 WETLANDS:DEPARTMENTOFTHEARMY(DA)
Section404oftheCleanWaterActrequiresapermitforplacementoffillinwetlandsand
watersoftheUnitedStates.TheNationalWetlandsInventory(NWI)databasedoesnothave
datafortheStebbinsarea.
Satelliteimageryandnotesfromfieldreconnaissanceofthreesites(StebbinsSite1andSt.
MichaelSites1&2)inSeptember,2011indicatethosesitesaredrierthansurroundingtundra.
StebbinsSite2wasnotinvestigatedatthattime,buttopographyandsatelliteimagerysuggest
relativelydryconditions.However,theDAwilllikelyrequireawetlandsdelineationwith
currentwetlanddatabeforeprovidingaJurisdictionalDetermination.IftheDAconcludesthe
projectsitecontainswetlandsundertheirjurisdiction,anewNationwidePermit(NWP)issued
in2012forLandBasedRenewableEnergyGenerationFacilities(NWP51)authorizesdischarge
offillforwindtowerconstructioniflossofwetlandsdoesnotexceed1/2acre.Submittal
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201323
requirementsforNWP51includeaPreͲConstructionNotification(PCN)andwetland
delineationreportdocumentingprojectimpacts.NWP51alsocoversutilitylines,roads,and
parkinglotswithinthewindgenerationfacility.Accessroadsandtransmissionlinesnotwithin
thefacilityandusedtoconnectthefacilitytoexistinginfrastructurerequireseparate
permitting.NWP12(Utilitylines)and14(Lineartransportation)maybeusedforthispurposeif
lossofwetlandsdoesnotexceedoneͲhalfacreforeachpermittype.
Ifawetlandsdelineationisrequired,theDArecommendsthatitiscompletedwithinthe
designatedgrowingseasonforspecificregions.StebbinsislocatedwithinAlaska’sSubarctic
CoastalPlainsEcoͲregion,whichhasagrowingseasonthatbeginsonMay23rdandendson
October3rd.
8.3 FEDERALAVIATIONADMINISTRATION(FAA)
BasedonpreliminaryreviewoftheonlineObstructionEvaluation/AirportAirspaceAnalysis
(OEAAA)tool,allsitesunderconsiderationexceedCFRTitle14Part77NoticeCriteriaforslope
ratio.Part77regulationsrequireanairspacestudyandfilingform7460Ͳ1fortheproposed
towerlocationstodeterminethatthereisnohazardtoairnavigation.Preliminarycoordination
hasalreadyoccurredwiththeFAAconcerningthemettoweratStebbinsSite1.TheFAAissued
a“DeterminationofNoHazardtoAirNavigationforaTemporaryStructure”onOctober27,
2011fortheStebbinsmettower.Furthercoordinationwillberequiredandmayinclude
modificationstothepublishedtrafficproceduresattheStebbinsAirporttokeeppatterning
aircraftsouthoftheairportandawayfromtheproposedtowerlocations.
8.4 BIOTICRESOURCESANDFEDERALLYLISTEDTHREATENEDANDENDANGERED
SPECIES:UNITEDSTATESFISH&WILDLIFESERVICE(USFWS)
TheUSFWSliststhespectacledeiderasathreatenedspecies.ReviewoftheUSFWSEndangered
SpeciesActConsultationGuideindicatesallwindtowersitesunderconsiderationarelocatedin
azonedesignatedasspectacledeiderbreedinghabitat;however,nositesarewithinthezone
designatedasCriticalHabitat.Spectacledeiderstypicallynestoncoastaltundranearshallow
pondsorlakes,usuallywithin10feetofthewater.StebbinsSite1and2arelocatedinupland
habitatatelevationsabovenestingareas.A2006reportpreparedbyABRforAVECstudiedbird
movementsalongaproposedpowerlineintertiecorridorbetweenthevillagesofStebbinsand
St.Michaelandpotentialwindturbinelocations.Thereportconcludedlowriskofinjuryor
deathtobirdsattheStebbinsSite1(RidgeSite),whichisapproximatelyonemilesoutheastof
StebbinsSite2(BluffSite).Birdmovementinthisareaconsistsprimarilyoflowflying(<20
metersaboveground)passerinesandhighflying(>50metersabovegroundlevel)cranesand
swans,whichisaboveandbelowtheproposedtowerheight.TowerconstructionatSt.Michael
Site1and2arenotrecommendedduetotheirproximitytoeiderhabitatinClearLakesarea.
TowerconstructionatStebbinsSite2isnotrecommendedduetotheproximitytotheSt.
StephensBluffandpossibleeiderflyways.
TowerconstructionatStebbinsSite1wouldrequireinformalconsultationwithUSFWSto
identifypotentialeffectstolistedspeciesanddeterminewhethermeasurestoavoidand
minimizeeffectsarenecessary.BecauseanaviansurveyhasbeencompletedfortheStebbinsͲ
St.MichaelintertierouteareaitisunlikelyUSFWSwillrequestadditionalsurveysdocumenting
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201324
avianspeciespresenceandflightpatternsatStebbinsSite1.
St.MichaelSite1,St.MichaelSite2,andStebbinsSite2wouldrequireformalconsultation,
whichmayincludeaBiologicalAssessmentandBiologicalOpinionfromtheUSFWS.Becausean
aviansurveyhasbeencompletedfortheStebbinsareaitisunlikelyUSFWSwillrequest
additionalsurveysdocumentingavianspeciespresenceandflightpatterns.Additionalavian
surveyswouldberequiredatthesesites.
TheproposedStebbinswindtowerlocationsarealsoadjacenttopolarbearcriticalhabitat.The
probabilityofencounteringpolarbearislow,buttheUSFWSwouldlikelyadvisemaintaininga
voluntarypolarbearmonitoringplan.
USFWSrecommendsavoidingvegetationclearingforregionsthroughoutthestateofAlaska.
FortheYukonͲKuskokwimDeltaregionthefollowingavoidanceperiodsapply:
x ShrubandOpenHabitat–May5ththroughJuly25th(exceptinhabitatthatsupports
Canadageese,swan,andblackscoter)
x Canadageeseandswanhabitat–April20ththroughJuly25th
x Blackscoterhabitat–May5ththroughAugust10th
8.5 CONTAMINATEDSITES,SPILLS,ANDUNDERGROUNDSTORAGETANKS
AsearchoftheAlaskaDepartmentofEnvironmentalConservation’s(ADEC)contaminatedsites
databaserevealednocontaminatedsiteswithinanyofthesitesconsidered.
8.6 ANADROMOUSFISHSTREAMS
TherearenocatalogedanadromousstreamslocatedbetweenthevillagesofStebbinsandSt.
Michael,accordingtotheAlaskaDepartmentofFishandGame(ADF&G)AnadromousWaters
Catalog.
8.7 STATEREFUGES,CRITICALHABITATAREASANDSANCTUARIES
AreviewoftheADF&G’spublicationregardingStateofAlaskaRefuges,CriticalHabitat
Areas,andSanctuaries,foundthatnosuchareasarelocatedinthevicinityofanyofthesites
considered.
8.8 LANDOWNERSHIP
TheAlaskaDivisionofCommunityandRegionalAffairsStebbinsAreaUseMapandAlaska
DepartmentofNaturalResources(ADNR)SpecialManagementLandsDivisionindicateStebbins
Site1and2arelocatedonlandownedbytheStebbinsNativeCorporationwithintheStebbins
Cityboundary.St.MichaelSite1and2arelocatedonlandownedbySt.MichaelsNative
Corporation.NegotiationswiththeStebbinsNativeCorporationwillberequiredforsitecontrol
ofStebbinsSite1andStebbinsSite2.
8.9 SUBSISTENCEACTIVITIES
CoordinationwithStebbinscommunitymemberswillbeneededtoensurethereislittletono
disruptionofhuntingandharvestingactivitiesfromwindfarmdevelopment.Preliminary
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201325
discussionswithcommunitymembersindicatethatStebbinsSite1isnotusedforsubsistence
activities.ThereisreportedberrypickingactivitiesintheareaofStebbinsSite2.Thefinal
locationofthetowerswillbecoordinatedwiththecommunityduringdesigntominimize
impactstosubsistenceactivities.
8.10 AIRQUALITY
AccordingtoAlaskaAdministrativeCode(AAC)18AAC50,thecommunitiesofStebbinsandSt.
MichaelareconsideredClassIIareas.Assuch,therearedesignatedmaximumallowable
increasesforparticulatematter10(PMͲ10)micrometersorlessinsize,nitrogendioxide,and
sulfurdioxide.Activitiesintheseareasmustoperateinsuchawaythattheydonotexceed
listedairqualitycontrolsforthesecompounds.Thenatureandextentoftheproposedproject
isnotlikelytoincreaseemissionsorcontributetoaviolationofanambientairqualitystandard
orcauseamaximumallowableincreaseforaClassIIarea.
8.11 NATIONALENVIRONMENTALPOLICYACTREVIEW(NEPA)
AnEnvironmentalReview(ER)documentwillberequirediffederalfundingisusedfor
constructionofthewindturbineproject.SimilartoanEnvironmentalAssessment(EA),anER
willprovideanassessmentofpotentialenvironmentalimpactsandidentifyavoidance,
minimization,andmitigationmeasures.AFindingofNoSignificantImpact(FONSI)
determinationbythefundingagencywillbeneeded.
8.12 ENVIRONMENTALSUMMARYANDRECOMMENDATIONS
Table4belowsummarizesenvironmentaldataandpermitrequirementsfordevelopmentof
windturbinesoneachsiteinvestigated.
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201326
Table4:EnvironmentalSummaryTable
StebbinsSite1
(Ridge)
StebbinsSite2
(Bluff)
St.MichaelSite1
St.MichaelSite2
HistoricandArchaeological
Lowpotentialforimpact;
SHPOreviewrequired
NoAHRSinfo;
SHPOreviewrequired
Wetlands
WetlanddelineationandJurisdictionalDeterminationneeded;
NWP12,14,&51ifwetlandsimpactedandimpactslessthan½acre.Anindividual
permitwillberequiredforimpactsgreaterthan½acre.
FederalAviationAdministration
Form7460Ͳ1;
Trafficpatternedalteredto
accommodateMETtower
Form7460Ͳ1
Threatened&EndangeredSpecies
Lowrisktoflying
birds;Informal
consultation
required
Moderatetohighrisktobirds;
Willrequireformalconsultation
ContaminatedSites
Nonelocatedwithinprojectareas
AnadromousFishStreams
NonebetweenvillagesofStebbinsandSt.Michael
StateRefuges,CriticalHabitat,and
Sanctuaries
Nonelocatednearprojectareas
LandOwnership
StebbinsNativeCorporationSt.MichaelNativeCorporation
Subsistence
AVECwillcoordinatewithcommunitiestoidentifyareasimportanttosubsistence
activities.
AirQuality
ClassIIarea;Projectnotlikelytoincreaseemissions,contributetoaviolationof
ambientairqualitystandards,orcausemaximumallowableincreasesforPmͲ10and
nitrogenandsulfurdioxide.
NationalEnvironmentalPolicyAct
EnvironmentalAssessmentandFindingofNoSignificantImpactneededfrom
fundingagency
PermitRecommendations
1. InitiateSection106consultationforpreferredsite,inaccordancewiththeNational
HistoricPreservationAct,assoonaspossible.
2. FileFAAform7460Ͳ1forwindtowersatleast45dayspriortoconstruction.
3. PerformwetlandsdelineationandobtainJurisdictionalDeterminationforthepreferred
sitetodeterminewhetherSection404permittingisnecessary.
4. InitiateconsultationwithUSFWStoidentifypotentialeffectsatthepreferredsiteto
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201327
threatenedorendangeredspeciesandpossiblemitigation.
5. Schedulevegetationclearingactivitiesoutsideappropriatetimeperiodsofavoidance,
pertheUSFWS’srecommendations.
9.0CONCLUSIONSANDRECOMMENDATIONS
ThehighcostofdieselfuelandstrongwindresourceonSt.MichaelIslandmakeswindpower
anattractivecomponentofAVEC’snewcombinedelectricalpowergenerationsystemfor
StebbinsandSt.Michael.Thewindsiteinvestigationandsubsequentwindmodelinganalysis
determinedthatStebbinsSite1hasaClass6windresourceandiswellͲsuitedforwindpower
generation.Economicevaluationoftheturbinealternativespresentedinthisreportand
discussionswithAVECOperationspersonnelresultedinapreferredturbineconfigurationof(2)
AW33Ͳ225turbinesinstalledatStebbinsSite1.Theeconomicevaluationprojectedthatthis
preferredalternativewillcontributetoapproximately40%oftotalpowerproductionandwill
offsetapproximately69,000gallonsoffuelforpowergenerationand6,000gallonsofheating
oilperyear.Windpowercouldprovideapproximately6.6%oftheenergyneededforheat
recovery.Integrationofthewindpowerintothenewdieselpowerplantwillrequirealarge
secondaryloadcontrollertopreventoverloadingthegridwithexcessenergyandtrippingthe
generatorsoffline.
Thefollowingactionsarerecommendedtocontinuetheprogressofwindturbinedevelopment
inStebbins:
Recommendations
1. EnterintonegotiationswiththeStebbinsNativeCorporationforsitecontrolandaccess
rightstoStebbinsSite1.
2. ConsultwithStebbinscommunityleaderstominimizetheimpactstosubsistenceactivities
fromwindprojectdevelopmentatStebbinsSite1.
3. ProceedwithpermittingperthepermittingrecommendationsincludedinSection8.
4. Performasitespecificgeotechnicalinvestigationoftheproposedturbinelocation.
5. DesignshouldincludeVSDsateachturbinealongwithasecondaryloadcontrollerand
associatedcontrolsatthenewStebbinsPowerplant.
6. Ifcomplicationsresultingfromsitecontrol,permitting,orthegeotechnicalinvestigation
makedevelopmentofStebbinsSite1notfeasible,relocatetheproposedwindturbineproject
toStebbinsSite2andreinitiatetheactionsstatedabove.
7. Coordinatewithwindtowermanufacturerforsitespecificenvironmental,powercontrol,
andpowerqualityrequirementstoensureselectedwindturbinesarewarranteedtoperformas
anticipated.
8. Performfinaldesignofthepreferredalternativeandapplyforconstructiongrantfunds.
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201328
10.0REFERENCES
AlaskaCommunityDatabase,CommunityInformationSummaries(CIS)
http://www.commerce.state.ak.us/dca/commdb/CIS.cfm?Comm_Boro_Name=Stebbins,
accessedon11/15/2011
WesternRegionalClimateCenter,http://www.wrcc.dri.edu/CLIMATEDATA.html,accessedon
12/5/2011
AlaskaEnergyAuthority(AEA).2012.StatisticalReportofthePowerCostEqualizationProgram,
FiscalYear2011.TwentyThirdEdition.April2012.
AlaskaDepartmentofEnvironmentalConservation(ADEC).18AAC50AirQualityControl:As
AmendedthroughAugust1,2012.
http://dec.alaska.gov/commish/regulations/pdfs/18%20AAC%2050.pdf.Lastaccessed
onSeptember8,2012.
ADEC.DivisionofSpillPreventionandResponse.LastaccessedonSeptember6,2012.
http://dec.alaska.gov/applications/spar/CSPSearch/results.asp.
AlaskaNativeTribalHealthConsortium(ANTHC)DivisionofEnvironmentalHealthand
Engineering.Stebbins,AlaskaHeatRecoveryStudy.September10,2012.
AlaskaDepartmentofFish&Game(ADF&G).WildlifeActionPlanSectionIIIB:Alaska’s32EcoͲ
regionshttp://www.adfg.alaska.gov/static/species/wildlife_action_plan/section3b.pdf.
LastaccessedonSeptember6,2012.
ADF&G.AnadromousWatersCatalog.http://www.adfg.alaska.gov/sf/SARR/AWC/.Last
accessedonSeptember6,2012.
ADF&G.Refuges,Sanctuaries,CriticalHabitatAreasandWildlifeRefuges.
http://www.adfg.alaska.gov/index.cfm?adfg=protectedareas.locator.Lastaccessedon
September7,2012.
ADNR.DivisionofSpecialManagementLands.
http://www.navmaps.alaska.gov/specialmanagementlands/.Lastaccessedon
September7,2012.
CRC.KnownArchaeologicalandHistoricalSitesintheStebbinsArea.August28,2012.
FAA.ObstructionEvaluation/AirportAirspaceAnalysis(OE/AAA).
https://oeaaa.faa.gov/oeaaa/external/portal.jsp012.LastaccessedonAugust26,2012.
USACE.RegionalSupplementtotheCorpsofEngineersWetlandDelineationManual:Alaska
Region(Version2.0).
http://www.usace.army.mil/Portals/2/docs/civilworks/regulatory/reg_supp/erdcͲel_trͲ
07Ͳ24.pdf.LastaccessedonSeptember6,2012.
USFWS.UnitedStatesFishandWildlifeServiceEndangeredSpecies:ListedandCandidate
SpeciesinAlaska,SpectacledEider(Somateriafischeri).
StebbinsWindProject
ConceptDesignReport
AlaskaVillage
ElectricCooperative
August30,201329
http://alaska.fws.gov/fisheries/endangered/species/spectacled_eider.htm.Last
accessedonSeptember6,2012.
USFWS.YukonDeltaNationalWildlifeRefuge.
http://www.fws.gov/refuges/profiles/index.cfm?id=74540.LastaccessedonSeptember
6,2012.
USFWS.U.S.FishandWildlifeServiceLandClearingGuidanceforAlaska:RecommendedTime
PeriodstoAvoidVegetationClearing.
http://alaska.fws.gov/fisheries/fieldoffice/anchorage/pdf/vegetation_clearing.pdf.Last
accessedonSeptember7,2012.
USFWS.U.S.FishandWildlifeServiceNationalWetlandsInventory.
http://107.20.228.18/Wetlands/WetlandsMapper.html#.LastaccessedonSeptember6,
2012.
V3Energy.StebbinsͲSt.MichaelWindDieselFeasibilityAnalysis.September6,2013.
AppendixA
StebbinsWindProjectConceptDesignDrawings
STEBBINS WIND PROJECTCONCEPT DESIGN DRAWINGSSTEBBINS, ALASKA4831 Eagle StreetAnchorage, Alaska 99503
4831 Eagle StreetAnchorage, Alaska 99503
EXISTINGLANDFILLEXISTINGSEWAGELAGOONNORTONSOUNDNORTONSOUNDEXISTINGSTEBBINS / ST.MICHAEL ROADST. MICHAEL MET TOWER(CINDER CONE)ST. MICHAELSITE 2ST. MICHAELSITE 1PROPOSEDELECTRICALINTERTIEST. MICHAELAIRPORTN O R T O N S O U N DNORTONSOUNDST. MICHAELBAYSTEBBINSAIRPORTEXISTINGSTEBBINSPOWER PLANTNEW STEBBINSPOWER PLANTSTEBBINS LANDFILLACCESS ROADSTEBBINSGRAVELSOURCESTEBBINSSITE 1STEBBINSMET TOWEREXISTING ST.MICHAELPOWER PLANTNEW ST. MICHAELSTAND BYGENERATORST. MICHAELWATER SOURCEPUMP HOUSEN O R T O N S O U N DSTEBBINSSITE 24831 Eagle StreetAnchorage, Alaska 99503
4831 Eagle StreetAnchorage, Alaska 99503
WIND ACCESS TRAILEXISTINGSEWAGELAGOONNP 100WIND TOWER 2NP 100WIND TOWER 4NP 100WIND TOWER 3ALTERNATIVE 1:NP 100'sSITE 1BLUFF ACCESS TRAILNP 100WIND TOWER 14831 Eagle StreetAnchorage, Alaska 99503
4831 Eagle StreetAnchorage, Alaska 99503
WIND ACCESS TRAILEXISTINGSEWAGELAGOONBLUFF ACCESS TRAILALTERNATIVE 2:V-17'sV-17WIND TOWER 1V-17WIND TOWER 2V-17WIND TOWER 3V-17WIND TOWER 4V-17WIND TOWER 54831 Eagle StreetAnchorage, Alaska 99503
4831 Eagle StreetAnchorage, Alaska 99503
EXISTINGSTEBBINSLANDFILLTO STEBBINSTO SAINT MICHAELSN O R
T
O
N
S
O
U
N
DN O R T O N S O U N DWIND ACCESS TRAILEXISTINGSEWAGELAGOONAW33-225WIND TOWER #2ALTERNATIVE 3:AW33-225STEBBINS SITE 1STEBBINS LANDFILLACCESS ROADEXISTINGSTEBBINSGRAVELSOURCESTEBBINSMET TOWERSITE BBLUFF ACCESS TRAILAW33-225WIND TOWER #14831 Eagle StreetAnchorage, Alaska 99503
4831 Eagle StreetAnchorage, Alaska 99503
4831 Eagle StreetAnchorage, Alaska 99503
AppendixB
StebbinsͲSaintMichaelWindͲDieselFeasibilityStudy
Stebbins-Saint Michael Wind-Diesel
Feasibility Analysis
AVEC Photo
September 6, 2013
Douglas Vaught, P.E.
dvaught@v3energy.com
V3 Energy, LLC
Eagle River, Alaska
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | i
This report was prepared by V3 Energy, LLC under contract to Alaska Village Electric Cooperative, Inc. to
assess the technical and economic feasibility of installing wind turbines in the village of Stebbins to serve
a combined Stebbins-St. Michael load. This analysis is part of a conceptual design report funded by the
Renewable Energy Fund, which is administered by the Alaska Energy Authority.
Contents
Introduction.................................................................................................................................................. 1
Stebbins and Saint Michael....................................................................................................................... 1
Stebbins Wind Resource............................................................................................................................... 2
Measured Wind Speeds............................................................................................................................ 3
Temperature and Density......................................................................................................................... 4
Wind Roses................................................................................................................................................ 5
Extreme Winds.............................................................................................................................................. 6
Wind-Diesel Hybrid System Overview.......................................................................................................... 6
Low Penetration Configuration................................................................................................................. 7
Medium Penetration Configuration.......................................................................................................... 7
High Penetration Configuration................................................................................................................ 8
Wind-Diesel System Components............................................................................................................. 9
Wind Turbine(s) .................................................................................................................................... 9
Supervisory Control System.................................................................................................................. 9
Synchronous Condenser....................................................................................................................... 9
Secondary Load...................................................................................................................................10
Deferrable Load ..................................................................................................................................10
Interruptible Load...............................................................................................................................11
Storage Options ..................................................................................................................................11
Wind Turbine Options................................................................................................................................. 12
Northern Power Systems 100 ARCTIC.....................................................................................................12
Vestas V17...............................................................................................................................................13
Aeronautica 33-225 ................................................................................................................................13
Homer Software Wind-Diesel Model..............................................................................................................14
Diesel Power Plant..................................................................................................................................14
Wind Turbines.........................................................................................................................................14
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | ii
Electric Load............................................................................................................................................15
Thermal Load ..........................................................................................................................................16
Diesel Generators ...................................................................................................................................16
Economic Analysis.......................................................................................................................................17
Wind Turbine Costs................................................................................................................................. 17
Fuel Cost..................................................................................................................................................17
Modeling Assumptions ...........................................................................................................................18
Economic Valuation ................................................................................................................................19
Sensitivity Analysis......................................................................................................................................22
Conclusion and Recommendations ............................................................................................................22
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 1
Introduction
Alaska Village Electric Cooperative (AVEC) is the electric utility for the City of Stebbins and the City of
Saint Michael. AVEC was awarded a grant from the Alaska Energy Authority (AEA) to complete
conceptual design work for installation of wind turbines, with planned construction in 2015.
Stebbins and Saint Michael
Stebbins has a population of 585 people while Saint Michael has a population of 401 people (2010
census). Both villages are located on Saint Michael Island in Norton Sound, 125 miles southeast of
Nome and 48 miles southwest of Unalakleet. The villages have a subarctic climate with maritime
influences during the summer. Summer temperatures average 40° to 60 °F; winters average -4° to 16 °F.
Extremes from -55° to 70 °F have been recorded. Annual precipitation averages 12 inches, with 38
inches of snow. Summers are rainy and fog is common. Norton Sound is typically ice free from early
June to mid-November.
A fortified trading post called "Redoubt St. Michael" was built by the Russian-American Company at
Saint Michael in 1833; it was the northernmost Russian settlement in Alaska. The Native village of
"Tachik" stood to the northeast. When the Russians left Alaska in 1867, several of the post's traders
remained. "Fort St. Michael," a U.S. military post, was established in 1897. During the gold rush of 1897,
it was a major gateway to the interior via the Yukon River. As many as 10,000 persons were said to live
in Saint Michael during the gold rush. Saint Michael was also a popular trading post for Eskimos to trade
their goods for Western supplies.Centralization of many Yup'iks from the surrounding villages
intensified after the measles epidemic of 1900 and the influenza epidemic of 1918. The village remained
an important trans-shipment point until the Alaska Railroad was built. The city government was
incorporated in 1969.
A federally-recognized tribe is located in Saint Michael, the Native Village of Saint Michael. In Stebbins,
the analogous entity is the Stebbins Community Association. Stebbins’ and Saint Michael's population is
largely Yup'ik Eskimo and many residents are descendants of Russian traders. Seal, beluga whale,
moose, caribou, fish, and berries are important staples. The sale and importation of alcohol is banned in
both villages.
Stebbins and Saint Michael are accessible only be air and sea but are connected to each other with a
10.5 mile road. Both villages have airports and a seaplane base is available. Regular and charter flights
are available from Nome and Unalakleet. Saint Michael is near the Yukon River Delta and has a good
natural harbor but no dock. Lighterage service is provided on a frequent basis from Nome. Both villages
receive at least one annual shipment of bulk cargo. At present Saint Michael and Stebbins are not
connected electrically with a power distribution intertie, but a project to do so is planned for the near
future. The electrical intertie will follow the road connecting the two villages.
Note: Information above obtained from Alaska Community Database Community Information
Summaries at www.commerce.state.ak.us/dca/commdb/CF_CIS.htm.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 2
Stebbins Wind Resource
A met tower was installed on a plateau area located on Stebbins Native Corporation land near the road
that connects Stebbins to the village of Saint Michael to the east. The site is large enough to
accommodate several or more wind turbines and in many respects is ideal for wind power development
with close proximity to an existing road and planned new electrical distribution connecting Stebbins to
Saint Michael. Additionally, geotechnical conditions at the site appear to be highly suitable for turbine
foundation construction.
Note that the Stebbins met tower is the second wind site in the Stebbins-Saint Michael area studied. A
met tower had been in service from July 2010 to September 2011 on the summit of an old, eroded
cinder cone nearer Saint Michael. This met tower was removed in September 2011 and re-located to
the Stebbins site where it has been in service since January 2012.
A synopsis of Stebbins met tower data is presented below. The wind project site will be at or very near
this location. For reference, a synopsis of the Saint Michael met tower data is also presented below.
Both sites exhibit outstanding potential for wind power development.
Stebbins (Site 0070) met tower data synopsis
Data dates 1/19/2012 to 8/13/2013(19 months; in service)
Wind power class Class 6 (outstanding)
Power density mean (MoMM), 30 m 490 W/m
2
Wind speed mean (MoMM), 30 m 7.08 m/s
Max. 10-min wind speed average 25.9 m/s
Maximum wind gust 30.6 m/s (Feb. 2012)
Weibull distribution parameters k = 1.77, c = 7.55 m/s
Wind shear power law exponent 0.236 (moderate)
Roughness class 3.02 (many trees)
IEC 61400-1, 3rd ed. classification Class III-C
Turbulence intensity, mean 0.081 (at 15 m/s)
Calm wind frequency, 30 m 26% (wind speeds <4 m/s)
Saint Michael (Site 0021) met tower data synopsis (for reference)
Data dates 07/21/2010 to 09/19/2011 (14 months)
Wind power class Class 5 (excellent)
Power density mean (MoMM), 30 m 435 W/m
2
Wind speed mean (MoMM), 30 m 6.73 m/s
Max. 10-min wind speed average 24.7 m/s
Maximum wind gust 29.8 m/s (Feb. 2011)
Weibull distribution parameters k = 2.03, c = 7.70 m/s
Wind shear power law exponent 0.116 (low)
Roughness class 0.60 (snow surface)
IEC 61400-1, 3rd ed. classification Class III-C
Turbulence intensity, mean 0.081 (at 15 m/s)
Calm wind frequency, 30 m 26% (wind speeds <4 m/s)
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 3
Topographic map
Google Earth image
Measured Wind Speeds
Anemometer data collected from the Stebbins met tower, from the perspectives of mean wind speed
and mean wind power density, indicates an outstanding wind resource. Note that cold temperatures
contributed to a higher wind power density than otherwise might have been expected for the mean
wind speeds.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 4
Anemometer data summary
Variable Speed 30 m A Speed 30 m B Speed 21 m
Measurement height (m) 30 30 21
Mean wind speed (m/s) 6.73 6.72 6.19
MoMM wind speed (m/s) 7.08 7.06 6.51
Max 10 min avg wind speed (m/s) 25.9 25.9 25.0
Max gust (m/s) 30.2 30.6 29.8
Weibull k 1.77 1.80 1.79
Weibull c (m/s) 7.55 7.56 6.97
Mean power density (W/m²) 428 425 343
MoMM power density (W/m²) 490 487 396
Mean energy content (kWh/m²/yr) 3,747 3,724 3,005
MoMM energy content (kWh/m²/yr) 4,291 4,264 3,469
Energy pattern factor 2.16 2.16 2.22
Frequency of calms (%) 27.4 27.7 32.2
Time series graph
Temperature and Density
The Stebbins met tower site experiences cool summers and cold winters with a resulting air density that
is higher than standard for that altitude. Calculated air density during the met tower test period
exceeds standard air density at 46 meters elevation (1.220 Kg/m
3) by 6.0 percent. The winter of
2012/2013 was colder than average, however, and it’s likely that long term average air density at the
Stebbins met tower site is slightly less than measured.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 5
Temperature and density table
Temperature Density
Month Mean Min Max Mean Min Max
(°C) (°C) (°C) (kg/m³) (kg/m³) (kg/m³)
Jan -13.1 -34.1 5.2 1.350 1.219 1.468
Feb -12.2 -33.3 5.1 1.346 1.261 1.463
Mar -12.7 -31.0 4.6 1.349 1.264 1.449
Apr -5.5 -21.2 6.7 1.312 1.254 1.393
May 1.3 -14.3 18.0 1.280 1.206 1.356
Jun 10.2 -0.6 28.6 1.239 1.163 1.288
Jul 13.7 6.4 23.0 1.224 1.185 1.256
Aug 13.8 5.1 21.3 1.223 1.176 1.261
Sep 7.5 -1.6 14.9 1.251 1.218 1.293
Oct 2.4 -4.9 13.1 1.274 1.226 1.308
Nov -8.1 -18.3 -1.1 1.325 1.290 1.377
Dec -13.4 -30.6 2.8 1.352 1.272 1.447
-1.3 -34.1 28.6 1.294 1.163 1.468
Wind Roses
Wind frequency rose data indicates highly directional northeasterly winds at the project site with a
minor occurrence of southwesterly winds. The wind energy rose indicates that for wind turbine
operations the majority of power-producing winds will be north-northeast to northeast. Calm frequency
(percent of time that winds at the 30 meter level are less than 4 m/s) was 26 percent during the met
tower test period.
Wind Frequency Rose Total Value (power density) Rose
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 6
Extreme Winds
The relatively short duration of Stebbins met tower data should be considered minimal for calculation of
extreme wind probability, but nevertheless it can be estimated with a Gumbel distribution analysis
modified for entry of monthly versus annual data. Analysis indicates that the Stebbins met tower site
experiences relatively low extreme wind events and by reference to International Electrotechnical
Commission (IEC) 61400-1, 3rd edition (2005), classifies as IEC Class III for extreme wind probability, the
lowest defined. All wind turbines are designed to meet this criterion.
Extreme wind speed probability table
Vref Gust IEC 61400-1, 3rd ed.
Period (years)(m/s) (m/s) Class Vref, m/s
2 25.8 30.9 I 50.0
10 30.8 36.9 II 42.5
15 32.0 38.4 III 37.5
30 34.2 40.9 S designer-
specified5035.8 42.8
100 37.9 45.4
average gust factor:1.20
Wind-Diesel Hybrid System Overview
Wind-diesel power systems are categorized based on their average penetration levels, or the overall
proportion of wind-generated electricity compared to the total amount of electrical energy generated.
Commonly used categories of wind-diesel penetration levels are low penetration, medium penetration,
and high penetration. The wind penetration level is roughly equivalent to the amount of diesel fuel
displaced by wind power. Note however that the higher the level of wind penetration, the more
complex and expensive a control system and demand-management strategy is required.
Categories of wind-diesel penetration levels
Penetration PenetrationLevel Operating characteristics and system requirements
Instantaneous Average
Low 0% to 50% Less than
20%
Diesel generator(s)run full time at greater than minimum
loading level. Requires minimal changes to existing diesel
control system. All wind energy generated supplies the
village electricload; wind turbines function as “negative
load” with respect to diesel generator governor response.
Medium 0% to 100+% 20% to
50%
Diesel generator(s)run full time at greater than minimum
loading level. Requires control system capable of
automatic generator start, stop and paralleling. To control
system frequency during periods of high wind power input,
system requires fast acting secondary load controller
matched to a secondary load such as an electric boiler
augmenting a generator heat recovery loop. At high wind
power levels, secondary (thermal) loads are dispatched to
absorb energy not used by the primary (electric) load.
Without secondary loads, wind turbines must be curtailed
to control frequency.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 7
Penetration PenetrationLevel Operating characteristics and system requirements
Instantaneous Average
High
(Diesels-off
Capable)
0% to 150+% Greater
than 50%
Dieselgenerator(s)can be turned off during periods of
high wind power levels. Requires sophisticated new
control system, significant wind turbine capacity, secondary
(thermal)load,energy storage such as batteries or a flywheel,
and possibly additional components such as demand-
managed devices.
Low Penetration Configuration
Low-penetration wind-diesel systems require the fewest modifications to a new or existing power
system in that maximum wind penetration is never sufficient to present potential electrical stability
problems. But, low penetration wind systems tend to be less economical than higher penetration
systems due to the limited annual fuel savings compared to a relatively high total wind system
installation costs. This latter point is because all of the fixed costs of a wind power project – equipment
mobilization and demobilization, distribution connection, new road access, permitting, land acquisition,
etc. – are spread across fewer turbines, resulting in relatively high per kW installed costs.
Medium Penetration Configuration
Medium penetration mode is very similar to high penetration mode except that no electrical storage is
employed in the system and wind capacity is designed for a moderate and usable amount of excess wind
energy that must be diverted to thermal loads. All of AVEC’s modern wind power systems are designed
as medium penetration systems.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 8
High Penetration Configuration
Other communities, such as Kokhanok, are more aggressively seeking to offset diesel used for thermal
and electrical energy. They are using configurations which will allow for the generator sets to be turned
off and use a significant portion of the wind energy for various heating loads. The potential benefit of
these systems is the highest, however currently the commissioning for these system types due to the
increased complexity, can take longer.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 9
Wind-Diesel System Components
Listed below are the main components of a medium to high-penetration wind-diesel system:
x Wind turbine , plus tower and foundation
x Supervisory control system
x Synchronous condenser
x Secondary load
x Deferrable load
x Interruptible load
x Storage
Wind Turbine(s)
Village-scale wind turbines are generally considered as 50 kW to 250 kW rated output. This turbine size
once dominated with worldwide wind power industry but has been left behind in favor of much larger
1,000 kW plus capacity turbines for utility grid-connected projects. Conversely, many turbines are
manufactured for home or farm application, but generally these are 10 kW or smaller. Consequently,
few new manufacture village size-class turbines are on the market, although a large supply of used
and/or remanufactured turbines are available. The latter typically result from the repower of older wind
farms in the Continental United States and Europe with new, larger wind turbines.
Supervisory Control System
Medium- and high-penetration wind-diesel systems require fast-acting real and reactive power
management to compensate for rapid variation in village load and wind turbine power output. The new
Stebbins power plant, designed to serve both Stebbins and Saint Michael, will be equipped with a new,
wind-ready supervisory control system (per Brian Gray of Gray Stassel Engineering).
Synchronous Condenser
A synchronous condenser, sometimes called a synchronous compensator, is a specialized synchronous
electric motor with an output shaft that spins freely. Its excitation field is controlled by a voltage
regulator to either generate or absorb reactive power as needed to support the grid voltage or to
maintain the grid power factor at a specified level. This is necessary for diesels-off wind turbine
operations, but generally not required for wind systems that maintain a relatively large output diesel
generator online at all times.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 10
Synchronous condenser in Kokhanok
Secondary Load
To avoid curtailing wind turbines during periods of high wind/low load demand, a secondary or “dump”
load is installed to absorb excess system (principally wind) power beyond that required to meet the
electrical load. The secondary load converts excess wind energy into heat via an electric boiler typically
installed in the diesel generator heat recovery loop. This heat can be for use in space and water heating
through the extremely rapid (sub-cycle) switching of heating elements, such as an electric boiler
imbedded in the diesel generator jacket water heat recovery loop. As seen in Figure 16, a secondary
load controller serves to stabilize system frequency by providing a fast responding load when gusting
wind creates system instability.
An electric boiler is a common secondary load device used in wind-diesel power systems. An electric
boiler (or boilers), coupled with a boiler grid interface control system, inside the new Stebbins power
plant building, would need to be able to absorb up to 450 kW of instantaneous energy (full output of the
wind turbines). The grid interface monitors and maintains the temperature of the electric hot water
tank and establishes a power setpoint. The wind-diesel system master controller assigns the setpoint
based on the amount of unused wind power available in the system. Frequency stabilization is another
advantage that can be controlled with an electric boiler load. The boiler grid interface will automatically
adjust the amount of power it is drawing to maintain system frequency within acceptable limits.
Deferrable Load
A deferrable load is electric load that must be met within some time period, but exact timing is not
important. Loads are normally classified as deferrable because they have some storage associated with
them. Water pumping is a common example - there is some flexibility as to when the pump actually
operates, provided the water tank does not run dry. Other examples include ice making and battery
charging. A deferrable load operates second in priority to the primary load and has priority over
charging batteries, should the system employ batteries as a storage option.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 11
Interruptible Load
Electric heating either in the form of electric space heaters or electric water boilers should be explored
as a means of displacing stove oil with wind-generated electricity. It must be emphasized that electric
heating is only economically viable with excess electricity generated by a renewable energy source such
as wind and not from diesel-generated power. It is typically assumed that 41 kWh of electric heat is
equivalent to one gallon of heating fuel oil.
Storage Options
Electrical energy storage provides a means of storing wind generated power during periods of high
winds and then releasing the power as winds subside. Energy storage has a similar function to a
secondary load but the stored, excess wind energy can be converted back to electric power at a later
time. There is an efficiency loss with the conversion of power to storage and out of storage. The
descriptions below are informative but are not currently part of the planned design.
Flywheels
A flywheel energy system has the capability of short-term energy storage to further smooth out short-
term variability of wind power, and has the additional advantage of frequency regulation. However, the
flywheel system is designed for much larger load systems and would not be economical for Stebbins.
Batteries
Battery storage is a generally well-proven technology and has been used in Alaskan power systems
including Fairbanks (Golden Valley Electric Association), Wales and Kokhanok, but with mixed results in
the smaller communities. Batteries are most appropriate for providing medium-term energy storage to
allow a transition, or bridge, between the variable output of wind turbines and diesel generation. This
“bridging” period is typically 5 to 15 minutes long. Storage for several hours or days is also possible with
batteries, but this requires higher capacity and cost. In general, the disadvantages of batteries for utility-
scale energy storage, even for small utility systems, are high capital and maintenance costs and limited
lifetime. Of particular concern to rural Alaska communities is that batteries are heavy and expensive ship
and most contain hazardous substances that require special removal from the village at end of service
life and disposal in specially-equipped recycling centers.
There are a wide variety of battery types with different operating characteristics. Advanced lead acid
and zinc-bromide flow batteries were identified as “technologically simple” energy storage options
appropriate for rural Alaska in an Alaska Center for Energy and Power (ACEP) July, 2009 report on
energy storage. Nickel-cadmium (NiCad) batteries have been used in rural Alaska applications such as
the Wales wind-diesel system. Advantages of NiCad batteries compared to lead-acid batteries include a
deeper discharge capability, lighter weight, higher energy density, a constant output voltage, and much
better performance during cold temperatures. However, NiCads are considerably more expensive than
lead-acid batteries and one must note that the Wales wind-diesel system had a poor operational history
and has not been functional for over ten years.
Because batteries operate on direct current (DC), a converter is required to charge or discharge when
connected to an alternating current (AC) system. A typical battery storage system would include a bank
of batteries and a power conversion device. The batteries would be wired for a nominal voltage of
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 12
roughly 300 volts. Individual battery voltages on a large scale system are typically 1.2 volts DC. Recent
advances in power electronics have made solid state inverter/converter systems cost effective and
preferable a power conversion device. The Kokhanok wind-diesel system is designed with a 300 volts DC
battery bank coupled to a grid-forming power converter for production of utility-grade real and reactive
power. Following some design and commissioning delays, the solid state converter system in Kokhanok
should be operational by late 2013 and will be monitored closely for reliability and effectiveness.
Wind Turbine Options
Several village-scale wind turbines are considered suitable for Stebbins/St. Michael. The guiding criteria
are turbine output rating in relation to electric load, simplicity of design, AVEC Operations department
preferences, redundancy, and cost considerations. The turbines chose for review in this CDR are the
Northern Power Systems NPS 100, the Vestas V17, and the Windmatic WM17S.
Northern Power Systems 100 ARCTIC
The Northern Power 100 ARCTIC (NPS100), formerly known as the Northwind 100 (NW100) Arctic, is
rated at 100 kW and is equipped with a permanent magnet, synchronous generator, is direct drive (no
gearbox), and is equipped with heaters and has been tested to ensure operation in extreme cold
climates. The turbine has a 21 meter diameter rotor and is available with a 30 meter or 37 meter
monopole tower. The rotor blades are fixed pitch for stall control but the turbine is also and inverter
regulated for maximum 100 kW power output. For Stebbins, the NPS100 will be equipped with an arctic
package enabling a minimum operating temperature of -40° C. The Northern Power 100 ARCTIC is the
most widely represented village-scale wind turbine in Alaska with a significant number of installations in
the Yukon-Kuskokwim Delta and on St. Lawrence Island. The Northern Power 100 ARCTIC wind turbine
is manufactured in Barre, Vermont, USA. More information can be found at
http://www.northernpower.com/.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 13
Vestas V17
The Vestas V17 was originally manufactured by Vestas Wind Systems A/S in Denmark and is no longer in
production. It is, however, available as a remanufactured unit from Halus Power Systems in California
(represented in Alaska by Marsh Creek, LLC) and from Talk, Inc. in Minnesota. The V17 is a higher
output version of the two Vestas V17 wind turbines installed in Kokhanok in 2011. The V17 has a fixed-
pitch, stall-regulated rotor coupled to an asynchronous (induction) generator via a gearbox drive. The
original turbine design included low speed and high speed generators in order to optimize performance
at low and high wind speeds. The two generators are connected to the gearbox with belt drives and a
clutch mechanism. In some installations though – especially sites with a high mean wind speeds – the
low speed generator is removed to eliminate a potential failure point.
Vestas V17 wind turbines in Kokhanok
Aeronautica 33-225
The Aeronautica AW33-225 wind turbine is manufactured new by Aeronautica in Durham, New
Hampshire. This turbine was originally designed by the Danish-manufacturer Norwin in the 1980’s with
a 29 meter rotor diameter and had a long and successful history in the wind industry before being
replaced by larger capacity turbines for utility-scale grid-connect installations. The original 29 meter
rotor diameter design is available as the AW29-225 for IEC Class IA wind regimes, which the AW33-225 is
a new variant designed for IEC Class II and III winds. The AW225 turbine is stall-regulated, has a
synchronous (induction) generator, active yaw control, is rated at 225 kW power output, and is available
with 30, 40, or 50 meter tubular steel towers. The AW33-225 is fully arctic-climate certified to -40° C
and is new to the Alaska market with no in-state installations at present. While the AW29-225 has a
typical cut-out wind speed of 25 m/s, the larger rotor diameter AW33-225 is designed for a cut-out
speed of 22 m/s. More information can be found at http://aeronauticawind.com/aw/index.html and in
Appendix D of this report.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 14
Aeronautica AW 33-225 wind turbine (29-225 version shown)
Homer Software Wind-Diesel Model
Homer energy modeling software was used to analyze the new Stebbins powerplant presently under
construction, serving a combined Stebbins and Saint Michael load which will be realized when an
electrical intertie connecting the two villages is complete. Homer software was designed to analyze
hybrid power systems that contain a mix of conventional and renewable energy sources, such as diesel
generators, wind turbines, solar panels, batteries, etc. and is widely used to aid development of Alaska
village wind power projects. It is a static energy balance model, however, and is not designed to model
the dynamic stability of a wind-diesel power system, although it will provide a warning that renewable
energy input is potential sufficient to result in system instability.
Diesel Power Plant
Electric power (comprised of the diesel power plant and the electric power distribution system) in
Stebbins is provided by Alaska Village Electric Cooperative. A new powerplant is presently under
construction in Stebbins with four identically configured Caterpillar 3456 diesel generators, rated at 450
kW each maximum electrical power output. The new generators will be equipped with wet
turbochargers and after-coolers for a high efficiency co-generation power system.
The new powerplant is considered “wind ready” in that it will be equipped with a new Kohler SCADA
that can be readily programmed to accommodate wind turbines. Also, the powerplant heat recovery
system was designed for eventual installation of an electric boiler to absorb excess wind energy.
Wind Turbines
This CDR evaluates installation of four new Northern Power Systems Northern Power 100 ARCTIC
turbines for 400 kW installed capacity, five remanufactured Vestas V17 turbines for 450 kW installed
capacity, or five remanufactured Windmatic WM17S turbines for 450 KW installed capacity. Standard
temperature and pressure (STP) power curves are shown below. Note that for the Homer analysis,
power curves were adjusted to reflect the measured site mean annual air density of 1.294 kg/m3.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 15
Northern Power 100 ARCTIC power curve Vestas V17 Power Curve
Aeronautica AW33-225
Electric Load
Stebbins and Saint Michael load data, collected from December 2010 to December 2011, was received
from Mr. Bill Thompson of AVEC. These data are in 15 minute increments and represent total electric
load demand during each time step. The data were processed by adjusting the date/time stamps nine
hours from GMT to Yukon/Alaska time, multiplying each value by four to translate kWh to kW (similar to
processing of the wind turbine data), and creating a January 1 to December 31 hourly list for export to
HOMER software. The resulting load is shown graphically below. Average load is 367 kW with a 662 kW
peak load and an average daily load demand of 8,806 kWh.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 16
Electric load
Thermal Load
The new Stebbins power plant will include recovered heat to serve thermal loads which will include the
village water plant. The thermal load was described by Brian Gray of Alaska Energy and Engineering, Inc.
in the table below and incorporated into the Homer model.
Stebbins thermal load (planned)
Month
Max
Avg
Temp,
°F
Min Avg
Load,
kW
Mean
Temp,
°F
Mean
Load,
kW
Min Avg
Temp,
°F
Max
Avg
Load,
kW
Jan 9.9 323 3.1 363 -3.7 403
Feb 10.3 321 2.9 364 -5.1 411
Mar 16.9 282 8.2 333 -0.5 384
Apr 29.3 209 21 258 12.7 307
May 45.8 113 38.1 158 30.4 203
Jun 54.6 61 48 100 41.4 138
Jul 61 23 54.3 63 47.6 102
Aug 59.8 30 52.9 71 46.1 111
Sep 51.2 81 43.9 124 36.7 166
Oct 33 188 26.9 223 20.8 259
Nov 19.1 269 13.2 304 7.3 338
Dec 8.4 332 1.8 370 -4.8 409
Diesel Generators
The HOMER model was constructed with the four new Stebbins generators that will eventually power
both Stebbins and Saint Michaels once the intertie connecting the two villages is complete. Diesel
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 17
generator information pertinent to the HOMER model is shown below. Cat 3456 fuel curve information
from Alaska Energy Authority was used in the Homer model.
Diesel generator HOMER modeling information
Diesel generator Caterpillar 3456
Power output (kW) 450
Intercept coeff. (L/hr/kW rated) 0.007307
Slope (L/hr/kW output) 0.2382
Minimum electric
load (%)
11.0%
(50 kW)
Heat recovery ratio (percent of
waste heat that can serve the
thermal load); data point from
Brian Gray of Gray Stassel
Engineering, Inc.
40%
Intercept coefficient – the no-load fuel consumption of the generator divided by its capacity
Slope – the marginal fuel consumption of the generator
Economic Analysis
Installation of four Northern Power Systems NPS100 ARCTIC wind turbines, five remanufactured Vestas
V17 wind turbines, or two Aeronautica AW33-225 wind turbines in medium-to-high penetration mode
without electrical storage are evaluated to demonstrate the economic benefit of the project options.
Note that in the analyses turbines are connected to the electrical distribution system with first priority
to serve the electrical load, and second priority to serve the thermal load via a secondary load controller
and electric boiler. For this CDR, Homer modeling is used to determine system performance and energy
balance, but economic valuation is accomplished with use of the Renewable Energy Fund Round 7
economic valuation spreadsheet developed by University of Alaska’s Institute for Social and Economic
Research (ISER) for use by the Alaska Energy Authority.
Wind Turbine Costs
Project capital and construction costs for the three evaluated wind turbines were obtained from HDL,
Inc. and are presented below. Detailed information regarding HDL’s cost estimates is available in their
portion of this conceptual design report.
Project cost estimates
Turbine Project Cost
Installed
kW
Cost per kW
Capacity Tower Type
Tower Height
(meters)
Northern Power
NPS100 ARCTIC $4,030,650 400 $10,076 Monopole 37
Vestas V17 $3,788,750 450 $8,419 Monopole 26
Aeronautica AW33-225 $3,946,050 450 $8,769 Monopole 40
Fuel Cost
A fuel price of $5.23/gallon ($1.40/Liter) was chosen for the initial HOMER analysis by reference to
Alaska Fuel Price Projections 2013-2035, prepared for Alaska Energy Authority by the Institute for Social
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 18
and Economic Research (ISER), dated June 30, 2103 and the 2013_06_R7Prototype_final_07012013
Excel spreadsheet, also written by ISER. The $5.23/gallon price reflects the average value of all fuel
prices between the 2015 (the assumed project start year) fuel price of $4.34/gallon and the 2034 (20
year project end year) fuel price of $6.36/gallon using the medium price projection analysis with an
average social cost of carbon (SCC) of $0.61/gallon included.
By comparison, the fuel price for Stebbins (without social cost of carbon) reported to Regulatory
Commission of Alaska for the 2012 PCE report is $3.86/gallon ($1.02/Liter), without inclusion of the SCC.
Assuming an SCC of $0.40/gallon (ISER Prototype spreadsheet, 2013 value), the 2012 Stebbins fuel price
was $4.26/gallon ($1.13/Liter).
Heating fuel displacement by excess energy diverted to thermal loads is valued at $6.32/gallon
($1.67/Liter) as an average price for the 20 year project period. This price was determined by reference
to the 2013_06_R7Prototype_final_07012013 Excel spreadsheet where heating oil is valued at the cost
of diesel fuel (with SCC) plus $1.05/gallon, assuming heating oil displacement between 1,000 and 25,000
gallons per year.
Fuel cost table (SCC included)
ISER medium
cost projection
2015
(/gal) 2034 (/gal)
Average
(/gallon)
Average
(/Liter)
Diesel fuel $4.34 $6.29
$5.23 $1.38
Heating oil $5.39 $7.34
$6.28 $1.66
Modeling Assumptions
As noted previously, HOMER energy modeling software was used to analyze a combined the Stebbins
wind-diesel hybrid power plant that will also serve the nearby village of Saint Michael. HOMER is
designed to analyze hybrid power systems that contain a mix of conventional and renewable energy
sources, such as diesel generators, wind turbines, solar panels, batteries, etc. and is widely used to aid
development of Alaska village wind power projects.
Modeling assumptions are detailed in the table below. Assumptions such as project life, discount rate,
operations and maintenance (O&M) costs, etc. are AEA default values and contained in the ISER
spreadsheet model. Other assumptions, such as diesel overhaul cost and time between overhaul are
based on general rural Alaska power generation experience.
The base or comparison scenario is the new Stebbins power plant presently under construction that will
be equipped with four identically configured Caterpillar 3456 diesel engines with 450 kW generators.
Although the existing Stebbins does not have a heat recovery loop to offset thermal loads in the village,
the new powerplant will have this capability.
Note that wind turbines installed in Stebbins will operate in parallel with the diesel generators. Excess
energy will serve thermal loads via a secondary load controller and electric boiler. Installation cost of
wind turbines assumes construction of three phase power distribution to the selected site, plus civil,
permitting, integration and other related project costs.
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 19
Homer and ISER modeling assumptions
Economic Assumptions
Project life 20 years (2015 to 2034)
Discount rate 3% (reference: ISER 2013 Prototype spreadsheet)
Operating Reserves
Load in current time step 10%
Wind power output 100% (Homer setting to force diesels on)
Fuel Properties (no. 2 diesel for
powerplant)
Heating value 46.8 MJ/kg (140,000 BTU/gal)
Density 830 kg/m
3 (6.93 lb./gal)
Price (20 year average; ISER 2013,
medium projection plus social cost of
carbon)
$5.23/gal ($1.38/Liter)
Fuel Properties (no. 1 diesel to serve
thermal loads)
Heating value 44.8 MJ/kg (134,000 BTU/gal)
Density 830 kg/m
3 (6.93 lb./gal)
Price (20 year average; ISER 2013,
medium projection plus social cost of
carbon)
$6.28/gal ($1.66/Liter)
Diesel Generators
Generator capital cost $0 (new generators already funded)
O&M cost $0.02/kWh (reference: ISER 2013 Prototype spreadsheet)
Minimum load 50 kW; based on AVEC’s operational criteria of 50 kW
minimum diesel loading with their wind-diesel systems
Schedule Optimized
Wind Turbines
Availability 80%
O&M cost $0.049/kWh (reference: ISER 2013 Prototype spreadsheet)
Wind speed 7.08 m/s at 30 m, 100% turbine availability
6.22 m/s at 30 m, 80% turbine availability
Density adjustment 1.293 kg/m^3 (mean of monthly means of 19 months of
Stebbins met tower data); note that standard air density is
1.225 kg/m^3; Homer wind resource elevation set at -590
meters to simulate the Stebbins air density
Energy Loads
Electric 8.80 MWh/day average combined Stebbins-Saint Michael
power plant load
Thermal 5.44 MWh/day average new Stebbins thermal load
Economic Valuation
Homer software was used in this feasibility analysis to model the wind resource, wind turbine energy
production, effect on the diesel engines when operated with wind turbines, and excess wind energy that
could be used to serve thermal loads. Although Homer software is designed to evaluate economic
valuation by ranking alternatives, including a base or “do nothing” alternative by net present cost, AEA
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 20
economic valuation methodology differs somewhat in its assumptions of O&M costs, fuel costs each
year of the project life, and disposition of excess energy.
In an effort to align economic valuation of project alternatives with Alaska Energy Authority methods,
this feasibility analysis uses AEA’s economic evaluation methods. Although ISER developed the cost
evaluation spreadsheet, AEA determined the assumptions and methods of the model. The model is
updated every July in preparation for the next round of Renewable Energy Fund requests for proposals
in the form of an explanation report and an Excel spreadsheet. The latest version of the spreadsheet
has a file name of 2013_06-R7Prototype_final_07012013 and is available on ISER’s website.
Stebbins-Saint Michael Wind-Diesel Feasibility AnalysisPage| 21Project Economic ValuationHomer Model Input ISER Model ResultsTurbine TypeWind Capacity (kW)Diesel Efficiency (kWh/gal)Wind Energy (kWh/yr)Excess Electricity (kWh/yrNet Wind Energy (kWh/yr)Project Capital CostNPV BenefitsNPV Capital CostsDiesel #2 Displaced (gal/yr)B/C RatioNPV Net BenefitNPS100 400 15.2 1,106,920 97,330 1,009,590 $4,030,650 $4,447,229 $3,581,180 68,908 1.24 $866,049 V17 450 15.2 942,572 86,987 855,585 $3,788,750 $3,778,522 $3,366,255 58,512 1.12 $412,267 AW33 450 15.2 1,360,237 228,699 1,131,538 $3,946,050 $5,241,559 $3,506,014 80,289 1.50 $1,735,545 Note: wind energy at 80% availabilityNote: NPV benefits and capital costs at 3% discount rate; base year is 2012 (ISER spreadsheet)Additional InformationTurbine TypeHub Height (m)No. TurbinesWind Energy to Thermal (kWh/yr)Heating Fuel Equiv. (gal)Wind Penetration (% electrical)Wind Penetration (% thermal)Excess thermal (%)NPS100 37 4 97,330 2,488 33.0 2.9 0.5V17 26 5 86,987 2,224 29.0 2.6 0.5AW33 40 2 228,699 5,846 40.0 6.6 1.9Note: wind energy at 80% availability
Stebbins-Saint Michael Wind-Diesel Feasibility Analysis Page | 22
Sensitivity Analysis
In general, the economic valuation (benefit-to-cost ratio) of a project increases when, all other things
being equal, project capital cost decreases, fuel price increases, fuel displacment increases, or wind
turbine annual energy production (AEP) increases.
Wind energy projects in rural Alaska are expensive compared to Lower 48 or urban Alaska projects for
several reasons, principally difficult logistics, isolation of the project villages, relatively high expense of
small compared to large wind turbines, and complex powerplant integration requirements. The reality
is that project costs are high and opportunities for significant reduction are constrained.
The amount of fuel displaced by wind energy and the value of that fuel significantly impacts the
economic valuation of a project. For Stebbins, the wind resource was measured at the proposed turbine
site and hence accurate within the confines of the relatively short study timeframe of 19 months. The
wind resource dictates, for a given type and number of turbines, the annual energy production of the
turbines and this energy displaces fuel that otherwise would be burned by the diesel engines to meet
the load demand. Wind turbine energy production cannot of course be higher than 100 percent
availability (wind turbines on-line and available to produce power 100 percent of the time), but
adoption of a historic turbine availability is problematic as comprehensive data from existing rural
Alaska projects is difficult to obtain. For this reason, this feasibility analysis adopts the Alaska Energy
Authority’s default 80 percent wind turbine availability assumption. If wind turbine availability greater
than 80 percent is accomplished, then the economic value of the project will increase.
Conclusion and Recommendations
Three wind turbine project alternatives were presented in this feasibility analysis: four Northern Power
Systems NPS100-21 wind turbines, five Vestas V17 wind turbines, or two Aeronautica AW33-225 wind
turbines. Modeling shows that over a 20 year project life all three alternatives would have a benefit-to-
cost ratio greater than unity. Of the three, however, clearly the Aeronautica AW33-225 alternative
presents the superior economic benefit as reflected by a benefit-to-cost ratio of 1.50 and a net present
value net benefit over the 20 year project life that exceeds $1.7 million. The AW33-225 is a solid turbine
based on a proven design with a long track record in Europe and North America and should perform well
at Stebbins. For this reason, a two turbine Aeronautica AW33-225 configuration is the recommended
project alternative for Stebbins and Saint Michaels.
AppendixC
HeatRecoveryStudy
STEBBINS, ALASKA HEAT RECOVERY STUDY
PREPARED BY:
Alaska Native Tribal Health Consortium
Division of Environmental Health and Engineering
1901 Bragaw St, Ste 200, Anchorage AK 99508
Phone (907) 729-3600 / Fax (907) 729-4090
September 10, 2012
EXECUTIVE SUMMARY
The future Stebbins power plant, new water treatment plant (WTP), existing WTP,
washeteria, clinic, and head start building and School were evaluated for heat recovery
potential. The total estimated annual heating fuel used by all six buildings is approximately
57,000 gallons. The expected annual savings is $240,000 in fuel costs.
The payback is based on a 2011 fuel price of $4.21/gallon and an estimated 2011 project cost
of $1,243,000.
Assuming construction in 2014, the design and construction cost with 2 years of 3%
escalation is $1,319,000.
The AVEC power plant is currently in design with site work already started. It is expected to
provide most of the recovered heat necessary to serve the nearby public buildings. An
expected intertie to St. Michael is currently in planning. AVEC is considering integration of
wind power generation into its new power plant at some point in the future. The impact of the
wind power is unknown at this point, but with an intertie to St. Michael (necessary for wind
power), it is expected that there will still be substantial recoverable heat available.
1.0 INTRODUCTION
The Alaska Native Tribal Health Consortium (ANTHC) reviewed the feasibility of providing
recovered heat from the future AVEC power plant (construction beginning in 2012) to the new
WTP (construction beginning in 2013), existing WTP, community school, and adjacent
community buildings in Stebbins. ANTHC also developed a budgetary project cost estimate
based on Force Account Construction, including Engineering and Construction
Administration.
The new WTP is designed to integrate recovered heat to heat the building, preheat the
incoming raw water, and heat two water storage tanks (WSTs). Space has been allocated for
a heat recovery heat exchanger and pumps, piping connections have been provided, and the
control system is designed for easy integration.
The existing WTP provides heat to the circulating water lines and heat to one of the WSTs.
The system was not designed for waste heat and will require controls and installation of new
heat transfer equipment, including a new heat exchanger and new circulating pumps. Once
the water treatment functions have been moved to the new WTP, space will be available for
new equipment to be added.
The existing washeteria building is hydronically heated. The city reports fuel consumption of
7,400 gallons/year and importantly, much of this load is present in the summer as well as
winter. New equipment will include a large brazed plate heat exchanger, a new circulator
pump, and controls to prevent back feeding of heat to the generator facility.
The existing head start building and community clinic also are hydronically heated. It is
anticipated that recovered heat could also be used in these buildings as well.
The existing school has a reported fuel consumption of approximately 46,500 gal / year and is
hydronically heated with oil fired boilers. A site investigation of the facility has not been done
at this time, but it is anticipated that space can be found for a heat recovery heat exchanger,
associated pumps and controls.
This report assumes that space for heat recovery equipment at the power plant will be
included in the construction of the power plant, with necessary controls and heat exchangers
in place.
Additional assumptions have been made in the development of this report, including, but not
limited to, the proposed arctic piping route, building heating loads, and flow rates and
pressure drops of the power plant heat recovery system. It is anticipated that refinements in
arctic pipe size and routing, pump and heat exchanger sizing, and other design elements will
be required as the project progresses to final design.
Available as-built information was obtained from AVEC regarding the 2011 power plant
electrical loads. End-user annual fuel use was obtained from a variety of sources, including
the City, Alaska Rural Utility Cooperative (ARUC), and engineering estimates. Where
possible, reported fuel consumption was used to validate engineering estimates. Site visits
were made to the existing WTP and washeteria to confirm accuracy of information obtained.
2.0 OVERVIEW
The purpose of this study is to provide an estimate of the heat that can be recovered from the
AVEC power plant diesel engines and used to offset heating oil consumption at the nearby
public buildings. Useable recovered heat is quantified in gallons of heating fuel saved using a
gross heating value of 134,000 BTU per gallon of #1 arctic diesel fuel and an overall boiler
efficiency of 75% for a net heating value of 100,000 BTU per gallon.
The public buildings eligible for heat recovery are located within 600-foot radius of the AVEC
power plant. This analysis evaluates the potential to provide recovered heat to the nearby
public buildings. The estimated average annual heating fuel consumption for the nearby
public buildings is 22,800 gallons.
3.0 ESTIMATED RECOVERED HEAT UTILIZATION
A heat recovery utilization spreadsheet has been developed to estimate the recoverable heat
based on monthly total electric power production, engine heat rates, building heating
demand, washeteria loads, heating degree days, passive losses for power plant heat and
piping, and arctic piping losses. The spreadsheet utilizes assumed time-of-day variations for
electric power production and heat demand. Power generation data from AVEC for fiscal year
2011 is used in the spreadsheet. The estimated heat rejection rate for the power plant
gensets, Caterpillar 3456 series with marine jackets, were used to estimate available
recovered heat. Heating degree-days for Stebbins were utilized for this site. All arctic piping is
assumed to be routed below grade. All power plant hydronic piping is assumed to be
insulated with 2 in of insulation. The proposed conceptual generator plant design was used to
estimate the heating load for the power plant, which includes the power house, an insulated
storage module, and one living quarters module.
The spreadsheet uses monthly heating degree-days to distribute annual fuel consumption by
month. The washeteria commercial heating loads are field verified as approximately 80% of
maximum utilization for 8 hours a day, 5 days a week. The end-user hourly heat load is
compared to the hourly available heat from the power plant, less power plant heating loads
and parasitic piping losses, and the net delivered heat to the end-user is determined.
Following is a summary of annual fuel use and estimated heat utilization in equivalent gallons
of fuel for each building:
Facility Estimated
Annual Fuel
Use (Gallons)
Estimated Heat
Delivered W/ Intertie
(Gallons)
Old Water Treatment Plant 4,815 4,815
New Water Treatment Plant 5,318 5,318
Washeteria 7,452 2,653
Stebbins School 46,474 39,437
Clinic 2,353 2,353
Head Start Building 2,353 2,353
Total 68,765 56,929
4.0 HEAT RECOVERY SYSTEM DESCRIPTION AND OPERATION:
The heat recovery system captures jacket water heat generated by the AVEC power plant
that is typically rejected to the atmosphere by the radiators. The recovered heat is transferred
via below-grade arctic piping to the end users. The objective is to reduce the consumption of
expensive heating fuel by utilizing available recovered heat.
Although heat recovery is an excellent method of reducing heating fuel costs,
recovered heat is a supplementary heat source and it is imperative that the end-user
facility heating systems are operational at all times.
Hot engine coolant is piped through a plate heat exchanger located at the power plant. Heat is
transferred from the engine coolant to the recovered heat loop without mixing the fluids.
Controls at the power plant are used to prevent subcooling of the generator engines and
reducing electric power production efficiency. The recovered heat fluid is pumped through
buried insulated pipe to the end-user facilities, and is typically tied into the end-user heating
system using a plate heat exchanger.
4.1 AVEC PLANT TIE-IN
Because the AVEC plant is being designed for recovered heat, no modifications to the AVEC
power plant cooling system are included or anticipated, except those required to connect the
arctic piping to the power plant heat exchangers.
All heat recovery piping will be insulated with a minimum of 2-in insulation and have an
aluminum jacket where exposed to the weather. All valves will be either bronze ball valves or
lug style butterfly valves with seals compatible with 50/50 glycol/water mixtures at 200F. Air
vents, thermometers, pressure gauges, drain valves, and pressure relief valves will also be
provided.
4.2 ARCTIC PIPING (Recovered Heat Loop)
The proposed arctic piping is based on Rovanco’s Rhinoflex preinsulated pipe design with a
4-in PEX-A carrier pipe, 1-in polyurethane foam insulation, and HDPE outer jacket. The
piping will be buried approximately 2 ft deep and run from the AVEC plant within existing
rights-of-way to the end-user buildings.
Because multiple users are connected to the system, a variable speed pump located at the
new power plant will circulate heating fluid to each user from the AVEC facility. When users
are not actively consuming recovered heat, their systems will throttle down heating fluid flow
to minimize power consumption. Electric charges for the circulation pump will be shared
based on use of recovered heat.
The recovered heat fluid will be a 50/50 Propylene Glycol/Water solution to provide freeze
protection to the piping.
4.3 END-USER BUILDING TIE-INS
End-user building tie-ins typically consist of brazed plate heat exchangers with motorized
bypass valves to prevent back feeding heat to AVEC or other users. Plate heat exchangers
located in the end-user mechanical rooms will be tied into the boiler return piping to preheat
the boiler water prior to entering the boiler. Where required, a heat injection pump will be used
to avoid introducing excessive pressure drop in the building heating system. The maximum
anticipated delivered recovered heat supply temperature is about 190F. When there is
insufficient recovered heat to meet the building heating load, the building heating system
(boiler or heater) will fire and add heat. Off the shelf controls will lock out the recovered heat
system when there is insufficient recovered heat available.
Typical indoor piping will be type L copper tube with solder joints. Isolation valves will be
solder end bronze ball valves or flanged butterfly valves. All piping will be insulated with a
minimum of 1-in insulation with an all-service jacket. Flexibility will be provided where
required for thermal expansion and differential movement. Air vents, thermometers, pressure
gauges, drain valves, and pressure relief valves will also be provided.
Each facility will also receive a BTU meter to provide recovered heat use totalization and
instantaneous use.
4.4 PRIORITIZATION OF RECOVERED HEAT
Recovered heat prioritization is accomplished by setting the minimum recovered heat
temperature for each user, with successive load shedding as the recovered heat loop
temperature falls. The user with the highest allowable recovered heat temperature will be
removed from the system first. The user with the lowest allowable recovered heat
temperature will be removed from the system last.
The system will also provide freeze protection in the event a user’s boiler system temperature
falls below a minimum temperature, typically 50-100 degrees F.
4.5 RIGHTS-OF-WAY ISSUES
There are no apparent conflicts with rights-of-ways for the arctic piping between the power
plant and the end-user buildings, as the route is entirely within existing road rights-of-ways
and on city, school and AVEC property.
A Heat Sales/Right-of-Entry Agreement will be required between AVEC and the end users to
define the parties’ responsibilities, detail the cost of recovered heat, and authorize the
connection to the power plant heat recovery equipment.
4.1 POTENTIAL RISKS AND UNKNOWNS
The location of heating pumps and organization of the piping system is dependent on
community, school and AVEC negotiating maintenance and rate structures. The cost
estimate included in this feasibility study assumes that there will be two independent heating
loops, one for the school and one for the community buildings. This is a conservative
approach since a single district heating system would be preferred. If a single heating
system can be agreed upon, the benefit would be substantially better than reflected by the
costs and fuel savings used in this feasibility study.
The AVEC power plant may incorporate wind power but a final determination has not been
made.
Incorporation of wind turbines to reduce generator power consumption would most likely
reduce the amount of recovered heat available, though if marine jacketed engines are used,
there is still likely to be sufficient recovered heat available to provide a benefit for the facilities
proposed in this study.
5.0 PRELIMINARY EQUIPMENT SELECTIONS
The following initial equipment selections are sized and selected based on preliminary data
and will require minor modifications to reflect final design.
5.1 Heat Exchangers
Based on initial selected flow rates, brazed plate heat exchangers appear to be adequate for
all locations. Initial heat exchanger selections are as follows.
HX-1: (Power Plant). 1800 MBH capacity
Primary: 200 GPM 195F EWT (50% ethylene glycol), 2.0 PSI max WPD
Secondary: 200 GPM 190F LWT (50% propylene glycol) 2.0 PSI max WPD
HX-2: (Old WTP). 150 MBH capacity.
Primary: 17 GPM 185F EWT (50% propylene glycol), 1.0 PSI max WPD
Secondary: 17 GPM 180F LWT (50% propylene glycol) 1.5 PSI max WPD
HX-3: (New WTP). 150 MBH capacity.
Primary: 17 GPM 185F EWT (50% propylene glycol), 1.0 PSI max WPD
Secondary: 17 GPM 180F LWT (50% propylene glycol) 1.5 PSI max WPD
HX-4: (Washeteria). 500 MBH capacity.
Primary: 55 GPM 185F EWT (50% propylene glycol), 1.0 PSI max WPD
Secondary: 55 GPM 180F LWT (50% propylene glycol) 1.5 PSI max WPD
HX-5: (Clinic). 100 MBH capacity.
Primary: 11 GPM 185F EWT (50% propylene glycol), 1.0 PSI max WPD
Secondary: 11 GPM 180F LWT (50% propylene glycol) 1.5 PSI max WPD
HX-6: (Head Start Building). 100 MBH capacity.
Primary: 11 GPM 185F EWT (50% propylene glycol), 1.0 PSI max WPD
Secondary: 11 GPM 180F LWT (50% propylene glycol) 1.5 PSI max WPD
HX-7: (Stebbins School). 850 MBH capacity.
Primary: 95 GPM 185F EWT (50% propylene glycol), 1.0 PSI max WPD
Secondary: 95 GPM 180F LWT (50% propylene glycol) 1.5 PSI max WPD
5.2 Arctic Piping
The round trip length of heat recovery loop piping between the power plant and most distant
facility is approximately 1,100 ft. The arctic piping utilizes 4-in carrier pipe to minimize
pressure drop and reduce pumping energy. The pipe itself consists of a 4-in PEX-A carrier
pipe with 1-in polyurethane foam insulation and an HDPE outer jacket. The specified product
is durable enough for direct bury. The piping and excavated soil will be will be wrapped in
geotextile fabric to hold the pipe in the ground in the event of flooding (a big concern in
Stebbins).
5.3 Circulating Pumps
P-HR1A & 1B: Heat recovery loop to end-user buildings
Flow = 200 GPM, Head = 45 ft
Initial Selection: Grundfos TPE series with integrated VFD and differential pressure
controller. Approximately 3 HP
P-HR2: Heat injection loop in Old WTP
Flow = 17 GPM, Head = 15 ft
Initial Selection: Grundfos UPS 26-99.
P-HR3: Heat injection loop in New WTP
Flow = 17 GPM, Head = 15 ft
Initial Selection: Grundfos UPS 26-99
P-HR4: Heat injection loop in Washeteria
Flow = 55 GPM, Head = 15 ft
Initial Selection: Grundfos Magna.
P-HR5: Heat injection loop in Clinic
Flow = 11 GPM, Head = 15 ft
Initial Selection: Grundfos UPS 26-99
P-HR6: Heat injection loop in Head Start Building
Flow = 11 GPM, Head = 15 ft
Initial Selection: Grundfos UPS 26-99
P-HR7: Heat injection loop in School Building
Flow = 95 GPM, Head = 15 ft
Initial Selection: Grundfos Magna series
5.4 Expansion Tanks
Total heat recovery loop volume is approximately 1000 gallons. Pressure relief at the power
plant heat exchanger will be 45 PSIG and the maximum normal operating pressure will be 40
PSIG.
ET-1, ET-2, ET-3: System requirements: 200 gallon tank and 100 gallon acceptance
Select:three Extrol AX-144V, 77 gallon tank and 34 gallon acceptance
5.5 GLYCOL MAKEUP
A glycol make-up system at the new power house will be provided to accommodate filling the
system and adding additional glycol.
GT-1:Select AXIOM SF100 55 Gal Glycol make-up tank.
5.6 CONTROLS
Heat recovery system in each building will use an off the shelf differential temperature
controller to actuate a 3-way valve and start/stop heat injection pump (if used). Control will
provide load shedding, freeze protection, and prevent backfeeding of boiler heat into heat
recovery system. In addition, A BTU meter will be provided at each facility using recovered,
displaying instantaneous temperatures and heat transfer, as well as totalizing BTUs used.
Differential Controllers: 6 required Tekmar Model 155 differential temperature control
Control Valves:
CV-1, CV-2: Old & New WTP-: 1-1/2” 3-way motorized control valve with 24v Actuator
CV-3: Washeteria 2-1/2” 3 way motorized control valve with 24v Actuator.
CV-4, CV-5: Clinic & Head Start-: 1-1/4” 3-way motorized control valve with 24v Actuator
CV-6: School Building: 3” 3 way motorized control valve with 24v Actuator
BTU Meters:
BTU-1,2 Old & New WTP,: KEP BTU meter with 1-1/2” magnetic flow meter and matching
temperature elements.
BTU-3 Washeteria: KEP BTU meter with 2-1/2” magnetic flow meter and matching
temperature elements.
BTU-4,5 Clinic & Head Start: KEP BTU meter with 1-1/4” magnetic flow meter and matching
temperature elements.
BTU-6 School: KEP BTU meter with 3” magnetic flow meter and matching temperature
elements.
6.0 CONCLUSIONS AND RECOMMENDATIONS
Estimated construction costs were determined based on prior recent heat recovery project
experience, and include materials, equipment, freight, labor, design, construction
management, and startup and testing. All work at the power plant and WTP, along with
design and construction management/administration for the complete project, is included in
the Base Project cost. Incremental costs for arctic pipe, end-user building renovations, and
overhead and freight are estimated individually for each of the other end-user buildings (refer
to attached cost estimate).
The estimated project cost is $1,243,000. Estimated fuel savings are:
x 56,900 gallons ($237,700) for a simple payback of 5.2 years.
Payback is based on a 2011 fuel price of $4.21/gallon. Funding for design and construction
isn’t expected before fall 2013, with construction occurring summer of 2014.
With 2 years of escalation at 3%, the estimated project cost in 2014 is $1,319,000.
6008001000120014001600MBTU/HRStebbinsRecoveredHeatUtilizationW/Intertie0200400January February March April May June July Aug Sept Oct Nov DecMONTHWasheteriaCommercialLoad(MBH)WasheteriaSeasonalHeatingDemand(MBH)HeadStartHeatingDemand(MBH)ClinicHeatingDemand(MBH)NewWTPHeatingDemand(MBH)OldWTPHeatingDemand(MBH)Schoolload(MBH)AvailableRecoveredHeat
50006000700080009000LStebbinsRecoveredHeatUtilizationW/IntertieGalavoidedfueluseGalfueluse01000200030004000January February March April May June July Aug Sept Oct Nov DecGALMONTH
ANTHC DEHEDivision of Environmental Health & EngineeringAlaska Native Tribal Health Consortium1901 Bragaw Street, Suite 200oject Name:Stebbins Heat Recovery ProjectANCHORAGE, AK 99503ct Number:TBD(907) 729-3609Engineer:WLFChecked:________FAX (907) 729-3729vision Date:e-mail: william.fraser@anthc.orgPrint:File: C:\Documents and Settings\william.fraser\Application Data\OpenText\DM\Temp\[DEHE-#199326-v1-Stebbins_Heat_Recovery_Feasibility_Calcs.XLSX]Sheet1Find:FeasibilityofHeatRecoveryfromStebbinsGeneratorFacilitytoexistingWTP,newWTP,Clinic,Washeteria,andHeadStartresidenceGiven:Monthly KWH produced by existing Stebbins generator plant in 2011WasheteriareportedFuelconsumption7,400Gal/YearSchoolreportedfuelconsumptioin46,500Gal/YearHeatingDegreedaysforStebbinsAssumptions:Estimated Peak heat loss for 3 WSTs:90,000BTU/HrEstimated peak Heat loss for Clinic80,000BTU/HrEstimated Peak heat loss for Old WTP120,000BTU/Hr EstimatedpeakheatlossforWasheteria80,000BTU/HrEstimated Peak heat loss for New WTP80,000Btu/HrEstimatedpeakheatlossforSchool1,580,000BTU/HrDesign Air Temperature:-40DegF EstimatedpeakWasheteriaDryerAirflow1,200CFMDesign Water Temperature40DegF EstimatedDryerAirTemperature180DegFWTP Space Temperature60DegF EstimatedpeakWasheteriaHotwaterload110,000BTU/Hr(40GPHx4)Public Bldg Space Temperature72DegF ClinicSpaceTemperature72DegF3000 BTU to radiators / KW Power Generated (Based on Marine Deisel jackets)EstimatedBoilerAFUE:75%(Optimistic)New power Plant will serve Stebbins (St. Micheal in future)CommunityEstimatedFuelPrice:$4.21pergalHeat loss per below calculationsAVECEstimatedFuelPrice$4.21pergalHeat loads per below calculationsAVECHeatSalesAgreement:30%AvoidedfuelcostatAVEC'sPriceRaw water production occuring in summer months only (seasonal water supply)FrozenSoilConductivity0.12(Between0.05&0.15BTUH/Ft)Above Ground Heat Recovery System in Arctic PipeCalculations:ExistingWaterPlantHeatLoss:GeneratorModuleHeatLoadsBuildingdesignheatingloss:120,000BTU/HHeatloss/degreeofOSAtemp 1,200.0BTH/H*DegFNewWaterPlantHeatLoss:Buildingdesignheatingloss:80,000BTU/HHeatloss/degreeofOSAtemp 800.0BTH/H*DegF Livingquartersdesignheatloss30000BTU/HrControlmoduleHeatLoss0BTU/HrExistingWasheteriaHeatLoss:StoragemodulesHeatLoss30000BTU/HrBuildingdesignheatingloss:80,000BTU/HGeneratorModulesHeatLoss0BTU/HrHeatloss/degreeofOSAtemp 714.3BTH/H*DegFTotal 60000 BTU/HrHeatloss/degreeofOSAtemp: 545 BTU/Hr*degFExistingClinicHeatLoss:Buildingdesignheatingloss:80,000BTU/HHeatloss/degreeofOSAtemp 714.3BTH/H*DegFExistingHeadStartHeatLoss:Buildingdesignheatingloss:80,000BTU/HExistingSchoolHeatLoss:Heatloss/degreeofOSAtemp 714.3BTH/H*DegFBuildingdesignheatingloss:1,580,000BTU/HHeatloss/degreeofOSAtemp 14,107.1BTH/H*DegF09-Sep-129-Sep-12Theheatingloadfromstoragebuildingsisapproximate.Adesignloadofapproximately50BTU/SFatdesignconditionswasassumedbasedonsmallfootprintbuildingswithpoorinsulationandhighinfiltration.DesignconditionswerebasedonOSAtempofͲ50F
ANTHC DEHEDivision of Environmental Health & EngineeringAlaska Native Tribal Health Consortium1901 Bragaw Street, Suite 200oject Name:Stebbins Heat Recovery ProjectANCHORAGE, AK 99503ct Number:TBD(907) 729-3609Engineer:WLFChecked:________FAX (907) 729-3729vision Date:e-mail: william.fraser@anthc.orgPrint:File: C:\Documents and Settings\william.fraser\Application Data\OpenText\DM\Temp\[DEHE-#199326-v1-Stebbins_Heat_Recovery_Feasibility_Calcs.XLSX]Sheet109-Sep-129-Sep-12Calculations(Continued)BuriedWaterMainHeatLoss:ParasiticGeneratorCoolingSystemLossesDesignAirTemperatureͲ40DegreesFDesignAirTemperature:Ͳ40DegFDesignGroundSurfaceTemperatureͲ10DegreesF AMOTvalveleakRate(average)Maynotapply0GPMDesignCirculatingWaterLoopTemp40DegreesFHotCoolantTemperature180DegFInsulation:4Inchfoamins. DesignHeatLoss: 0 BTU/HrCarrierPipe:6PipeOD(Inches)Heatloss/DegreeofOSAtemp: 0.0InsulationKvalue0.0133BTUH/(ftxDegF)GroundKvalue0.12BTUH/(ftxDegF)AboveGroundHeatRecoveryPipeHeatLoss:Rvalue= 10.140 FtxhrxDegFDepthofBury=2.0feet DesignHeatRecoveryloopTemperature180DegreesFBuriedPipe2000FtDesignAirTemperature:Ͳ40DegreesFDesignHeatLoss: 10,515BTU/hr Insulation:4Inchfoamins.HeatLoss/DegreeOSAtemp 131BTU/hr Pipe:4PipeOD(Inches)InsulationKvalue0.16BTUxin/(ft^2xhrxDegF)Rvalue= 13.114 Ft^2xhrxDegFPeakStorageTankHeatLoss(3storageTanks):90,000BTU/HrLengthofAbovegroundPipe200FtHeatLoss/degreeofOSAtemp: 1125 BTU/Hr DesignHeatLoss: 10,540BTU/hrHeatLoss/Foot 52.70BTUH/FtRawWaterHeatingLoad(JunethroughSeptemberOnly)HeatLoss/DegreeOSAtemp 47.9 BTUH/DegFRawwateranticipatedflowrate19.3GPMRawwatertemperature:35DegFBuriedHeatRecoveryPipeHeatLoss:TreatmentProcessTemperature40DegFDesignAirTemperatureͲ40DegreesFRawwaterheatingload: 48250 BTU/Hr DesignGroundSurfaceTemperatureͲ10DegreesFInsulation:1.05Inchfoamins.WasheteriaCommercialLoadsCarrierPipe:4PipeOD(Inches)WasheteriaLoadsreflectoperationfor8hoursaday,5daysaweek,withaverageloadatInsulationKvalue0.017BTUH/(ftxDegF)80%ofdesign.It'sworthnotingthatloadswillapproach100%ofdesignifusers GroundKvalue0.12BTUH/(ftxDegF)fromSt.MichaelcometoStebbinsforcheaperlaundryuse. PipeRvalue= 3.951 FtxhrxDegFPeakWasherLoad(forwasteheatcapacityestimation:DepthofBury=2.0feetPeakDryerload(forwasteheatcapacityestimation):286,440 BTUH BuriedPipe3000FtServiceFactor75%DesignHeatLoss: 138,936BTU/hrDryerloadperDesigndegreeday(withserviceFactor) 1074 BTUH/DegF HeatLoss/Foot 46.31BTU/hrHotwaterload(withservicefactor) 82500 BTUH HeatLoss/DegreeOSAtemp632Averagehourspermonth(forfuelsavingsestimation:160
ANTHC DEHEDivision of Environmental Health & EngineeringAlaska Native Tribal Health Consortium1901 Bragaw Street, Suite 200oject Name:Stebbins Heat Recovery ProjectANCHORAGE, AK 99503ct Number:TBD(907) 729-3609Engineer:WLFChecked:________FAX (907) 729-3729vision Date:e-mail: william.fraser@anthc.orgPrint:File: C:\Documents and Settings\william.fraser\Application Data\OpenText\DM\Temp\[DEHE-#199326-v1-Stebbins_Heat_Recovery_Feasibility_Calcs.XLSX]Sheet109-Sep-129-Sep-12Calculations(Continued)MonthKWH/Month(Stebbins)KWH/Month(StMichael) Days/Month AvKWHtgDegreeDays/Month(40F)HtgDegreeDays/Month(60F)HtgDegreeDays/Month(180F)HeatrejectedW/Ointertie(MBH)HeatrejectedW/intertie(MBH)ParasiticCoolingSystemLosses(MBH)AvailableHeatW/OIntertie(MBH)AvailableHeatW/Intertie(MBH)January136550 192457 31442 1,2431,8635,5835511327Ͳ5511,327February 132756 167880 29404 1,1481,7285,2085351212Ͳ5351,212March 118303 170554 30388 1,0771,6775,2774771165Ͳ4771,165April 119721 147744 30359 7111,3114,9114831078Ͳ4831,078May 107014 137150 31328 2058254,545432985Ͳ432985June 83575 110549 30261Ͳ5134,113337783Ͳ337783July 97029 115154 31285Ͳ3204,040391856Ͳ391856Aug99037 121572 31297Ͳ3734,093399890Ͳ399890Sept 109701 131971 30325 246244,224442974Ͳ442974Oct 119668 142589 31352 5581,1784,8984831057Ͳ4831,057Nov 130086 167677 30400 9451,5455,1455251201Ͳ5251,201Dec 134112 175477 31416 1,2181,8385,5585411248Ͳ5411,248MonthAVECFacilityHeatingload(MBH/Hr)BuriedPipeLoss(MBTUH)AboveGroundPipeLoss(MBTUH)SumTransmissionLosses(MBTUH)NewWTPBuildingHeatLoss(MBH/Hr)OldWTPBuildingHeatLoss(MBH/Hr)WSTHeatLoss(MBH/Hr)RawWaterHeatAdd(MBH/Hr)CircLoopHeatAdd(MBTU/H)SumHeatDemandJanuary33114915548 72 4505171February33113915548 72 4505169March30111815045 67 4005157April24103813535 52 2703117May1593711421 32 70162June987710214 21Ͳ48.25 082July682694812Ͳ48.25 069Aug78369610 14Ͳ48.25 072Sept1189710717 25 148.25 091Oct21100812830 46 200299Nov28108814541 62 3504143Dec32113915447 71 4405168RecoveredHeatTransmissionLosses:AVECAvailableRecoveredHeatEstimateWTPHeatingDemand
ANTHC DEHEDivision of Environmental Health & EngineeringAlaska Native Tribal Health Consortium1901 Bragaw Street, Suite 200oject Name:Stebbins Heat Recovery ProjectANCHORAGE, AK 99503ct Number:TBD(907) 729-3609Engineer:WLFChecked:________FAX (907) 729-3729vision Date:e-mail: william.fraser@anthc.orgPrint:File: C:\Documents and Settings\william.fraser\Application Data\OpenText\DM\Temp\[DEHE-#199326-v1-Stebbins_Heat_Recovery_Feasibility_Calcs.XLSX]Sheet109-Sep-129-Sep-12Calculations(Continued)MonthBuildingHeatLossDryerLoad(MBH)WasherLoad(MBH) Total(MBH)January48 19382.5324February48 19382.5323March45 18982.5316April35 17682.5293May21 15782.5261June14 14782.5243July8 14082.5231Aug10 14282.5234Sept17 15182.5250Oct30 17082.5283Nov41 18482.5308Dec47 19382.5323MonthAvailableHeatW/OIntertie(MBH/Hr)AvailableHeatW/Intertie(MBH/Hr)OldWTPHeatingDemand(MBH)NewWTPHeatingDemand(MBH)ClinicHeatingDemand(MBH)HeadStartHeatingDemand(MBH)SchoolHeatingDemand(MBH)WasheteriaSeasonalHeatingDemand(MBH)WasheteriaCommercialLoad(MBH)TotalHeatDemand(MBH)RecoveredHeatBenefitW/OIntertie(MBH)RecoveredHeatBenefitW/Intertie(MBH)January 3951,17192 78 43 43 848 48 2761428 395 1171February 3811,05892 77 43 43 841 48 2751418 381 1058March 3271,01585 72 40 40 789 45 2711342 327 1015April 34894364 53 31 31 616 35 2581089 348 943May 31787035 26 19 19 375 21 240736 317 736June 23568021 62 12 12 241 14 230592 235 592July 29776112 57 7 7 146 8 222460 297 460Aug 30379314 58 9 9 170 10 224493 303 493Sept 33586725 65 15 15 293 17 234664 335 664Oct 35492955 44 27 27 536 30 252972 354 929Nov 3801,05678 65 37 37 727 41 2671251 380 1056Dec 3871,09491 77 42 42 836 47 2751412 387 1094Total:WasheteriaCommercialLoadsAvailableRecoveredHeat
ANTHC DEHEDivision of Environmental Health & EngineeringAlaska Native Tribal Health Consortium1901 Bragaw Street, Suite 200oject Name:Stebbins Heat Recovery ProjectANCHORAGE, AK 99503ct Number:TBD(907) 729-3609Engineer:WLFChecked:________FAX (907) 729-3729vision Date:e-mail: william.fraser@anthc.orgPrint:File: C:\Documents and Settings\william.fraser\Application Data\OpenText\DM\Temp\[DEHE-#199326-v1-Stebbins_Heat_Recovery_Feasibility_Calcs.XLSX]Sheet109-Sep-129-Sep-12Calculations(Continued)MonthOldWTP(Gal)NewWTP(Gal) Clinic(Gal)HeadStart(Gal) School(Gal)Washeteria(Gal)TotalFuelDemand(gal)RecoveredHeatFuelSavings(Gal)RecoveredHeatFuelSavings(Dollars)RecoveredHeatCharges(Dollars)SavingstoCommunity(Dollars)RecoveredHeatFuelSavings(Gal)RecoveredHeatFuelSavings(Dollars)RecoveredHeatCharges(Dollars)SavingstoCommunity(Dollars)January684 579 318 318 6,276 7958970 7069$29,761 $8,928 $20,8321324$5,574$1,672 $3,902February634 536 295 295 5,821 7698349 5856$24,655 $7,397 $17,2591168$4,918 $1,476 $3,443March611 513 286 286 5,650 7538098 5757$24,238 $7,271 $16,967830$3,496 $1,049 $2,447April462 378 224 224 4,417 6626365 5319$22,395 $6,718 $15,6761051$4,426 $1,328 $3,098May261 194 141 141 2,779 5404056 4056$17,076 $5,123 $11,953955$4,021 $1,206 $2,814June147 444 88 88 1,728 4642958 2958$12,452 $3,736 $8,716400$1,683 $505 $1,178July92 418 55 55 1,078 4152113 2113$8,894 $2,668 $6,226906$3,816 $1,145 $2,671Aug107 428 64 64 1,257 4282348 2348$9,883 $2,965 $6,918940$3,958 $1,187 $2,771Sept182 469 106 106 2,102 4913457 3457$14,555 $4,367 $10,1891100$4,631 $1,389 $3,242Oct405 325 201 201 3,969 6275727 5415$22,796 $6,839 $15,9571158$4,877 $1,463 $3,414Nov557 464 264 264 5,205 7207473 6079$25,595 $7,678 $17,9161236$5,202 $1,561 $3,642Dec674 569 314 314 6,192 7898851 6502$27,372 $8,212 $19,1611264$5,320 $1,596 $3,7244815 5318 2353 2353 46474 7452 68765 56929 $239,672 $71,902 $167,770 12333 $51,922 $15,577 $36,345FuelSavingsWithIntertie FuelSavingsWithoutIntertieEstimatedFuelSavingsEstimatedFuelDemand
Qty Rate 130 106 117 115 127 126 85 108 35 35 35 LaborCivil200 8 25.020,000$ Site Visit 1 1,100$ 1,100$ Mechanical500 8 62.550,000$ Site Visit 2 1,100$ 2,200$ Electrical200 8 25.020,000$ Site Visit 1 1,100$ 1,100$ DesignTotal hours 771.7 628.3 196.2 76.5 155.0 608.8 34.0 0.0 #### 195.7 613.3MobilizationEquipment Shipping 0.0 1-$ -$ -$ Camp set up 1 0.2 5.0 16,500$ -$ -$ Shop Set up 1 1 1.0 11,300$ -$ -$ Takeoffs 1 1 1.0 11,300$ -$ -$ Training 1 1 1.0 1350$ -$ -$ Materials Receiving and Inventory 2 1 2.0 0.5 0.2 0.5 0.5 0.24,630$ -$ -$ Set up Materials Storage/Yard 2 1 2.0 0.5 1 0.2 25,380$ -$ -$ Expediting to Const Site 0.0-$ -$ -$ -$ -$ -$ 0.0-$ -$ -$ ## of feet 200 200 1.0 1 1 0.1 2 13,695$ Pipe 200 50$ 10,000$ 2,000$ 12,000.00$ Bridge Crossing 0.0-$ Fittings 20 200$ 4,000$ 600$ 4,600.00$ Supports 200 200 1.0 1 0.1 22,085$ Materials -$ -$ Road Crossings 0.0-$ Clamps/ Ins 20 75$ 1,500$ 1,000$ 2,500.00$ -$ -$ -$ -$ -$ -$ ## of feet 2000 300 6.7 1 0.2 1 1 122,547$ -$ -$ Bridge Crossing 0.0-$ -$ -$ Bedding Material 0.0-$ Gravel -$ -$ Road Crossings 6 2.5 2.4 0.5 0.5 1 14,644$ -$ -$ Geo-textile 2000 400 5.0 2 15,250$ Geotextile 5000 5$ 25,000$ 1,000$ 26,000.00$ -$ -$ -$ -$ ## of feet 2200 400 5.5 1 1 1 0.1 0.1 2 0.525,883$ Pipe 2200 38$ 83,600$ 8,000$ 91,600.00$ Bridge Crossing 0.0-$ Fittings 100 100$ 10,000$ 1,500$ 11,500.00$ Bedding Material 0.0-$ -$ -$ Road Crossings 4 2 2.0 0.3 1 24,520$ -$ -$ -$ -$ -$ ## of feet 1000 400 2.5 1 0.5 0.2 0.5 0.1 0.57,513$ Pipe 1000 30$ 30,000$ 500$ 30,500.00$ Bridge Crossing 0.0-$ Materials 80 75$ 6,000$ 500$ 6,500.00$ Bedding Material 0.0-$ Road Crossings 2 2 1.0 0.3 1 22,260$ -$ -$ -$ -$ ## of feet2000 400 5.0 0.1 0.1 2 16,325$ Insulation 5000 4$ 20,000$ 2,000$ 22,000.00$ No. Cost Ea Total Cost90,000$ Fixed estimate @ 100 /hr.FreightMaterials+ FreightFixed estimate @ 100 /hr.ProductionRate*Note2" Rino-flex (buried)PlumbershippingELEMENTTrench Excavation and BackfillEngineerDesignOperatorAbove Ground Arctic PipeFixed estimate @ 100 /hr.Local PlumberTotalLocalLabor Local OperatorInsulation "Blueboard layer"4" Rino-flex (buried)Crew LeadStebbins Heat Recovery Cost EstimateMechanicItemElectricianStebbins Heat Recovery Cost EstimateMATERIALSLABORDays(60hr.Week)Super
-$ -$ -$ Cooling sys modifications 2 0.15 13.3 0.2 0.2 1 127,760$ Pipe & Fittin 1 20,000$ 20,000$ 1,500$ 21,500.00$ HX installation 0.01-$ HX 2 7,000$ 14,000$ 3,000$ 17,000.00$ Controls 2 1 2.0 0.5 0.52,330$ Controls 2 10,000$ 20,000$ 200$ 20,200.00$ Make-up / Expansion Tanks 2 1 2.0 1 13,220$ Tank 4 3,500$ 14,000$ 800$ 14,800.00$ Insulation Upgrades 1 0.3 3.3 0.25 12,050$ Insulation 500 5$ 2,500$ 100$ 2,600.00$ Pump 4 2,000$ 8,000$ 400$ 8,400.00$ Air Sep 2 3,500$ 7,000$ 300$ 7,300.00$ -$ -$ -$ Heating sys modifications 1 0.1 5.0 0.5 1 111,300$ Pipe & Fittin 1 6,500$ 6,500$ 1,000$ 7,500.00$ HX installation 1 1 1.0 1 0.1 11,695$ HX 1 4,000$ 4,000$ 400$ 4,400.00$ Controls 1 0.5 2.0 1 13,240$ Controls 1 2,000$ 2,000$ 350$ 2,350.00$ Insulation Upgrades 1 1 1.0 2700$ Pump 3 2,000$ 6,000$ 900$ 6,900.00$ -$ Insulation 600 3$ 1,800$ 150$ 1,950.00$ -$ -$ Heating sys modifications 1 0.25 4.0 0.5 1 1 110,440$ Pipe & Fittin 1 8,000$ 8,000$ 1,000$ 9,000.00$ HX installation 1 1 1.0 1 0.1 11,695$ HX 1 4,000$ 4,000$ 400$ 4,400.00$ Controls 1 0.5 2.0 1 13,240$ Controls 1 2,000$ 2,000$ 350$ 2,350.00$ Insulation Upgrades 1 1 1.0 1350$ Pump 1 1,000$ 1,000$ 150$ 1,150.00$ -$ Insulation 200 3$ 600$ 50$ 650.00$ -$ -$ Heating sys modifications 1 0.25 4.0 0.5 1 1 110,440$ Pipe & Fittin 1 10,000$ 10,000$ 1,000$ 11,000.00$ HX installation 1 1 1.0 1 0.1 11,695$ HX 1 3,000$ 3,000$ 400$ 3,400.00$ Controls 1 0.5 2.0 1 13,240$ Controls 1 2,000$ 2,000$ 350$ 2,350.00$ Insulation Upgrades 1 1 1.0 1350$ Pump 1 1,000$ 1,000$ 150$ 1,150.00$ -$ Insulation 100 3$ 300$ 50$ 350.00$ -$ -$ Heating sys modifications 1 0.25 4.0 0.5 1 1 110,440$ Pipe & Fittin 1 10,000$ 10,000$ 1,000$ 11,000.00$ HX installation 1 1 1.0 1 0.1 11,695$ HX1 3,000$ 3,000$ 400$ 3,400.00$ Controls 1 0.5 2.0 1 13,240$ Controls 1 2,000$ 2,000$ 350$ 2,350.00$ Insulation Upgrades 1 1 1.0 1350$ Pump 1 1,000$ 1,000$ 150$ 1,150.00$ -$ Insulation 100 3$ 300$ 50$ 350.00$ -$ -$ Heating sys modifications 1 0.2 5.0 0.5 1 1 113,050$ Pipe & Fittin 1 15,000$ 15,000$ 2,000$ 17,000.00$ HX installation 1 1 1.0 1 0.1 11,695$ HX 1 6,000$ 6,000$ 400$ 6,400.00$ Controls 1 0.5 2.0 1 13,240$ Controls 1 2,000$ 2,000$ 350$ 2,350.00$ Insulation Upgrades 1 0.5 2.0 1700$ Pump 1 1,500$ 1,500$ 150$ 1,650.00$ -$ Insulation 200 5$ 1,000$ 100$ 1,100.00$ -$ -$ Heating sys modifications 1 0.1 10.0 0.5 1 1 126,100$ Pipe & Fittin 1 20,000$ 20,000$ 2,000$ 22,000.00$ HX installation 1 1 1.0 1 0.1 11,695$ HX 1 6,000$ 6,000$ 400$ 6,400.00$ Controls 1 0.5 2.0 1 13,240$ Controls 1 2,000$ 2,000$ 350$ 2,350.00$ Insulation Upgrades 1 0.5 2.0 1700$ Pump 3 2,000$ 6,000$ 900$ 6,900.00$ -$ Insulation 500 5$ 2,500$ 150$ 2,650.00$ -$ -$ Connection and install 6 2 3.0 0.2 0.5 0.5 0.1 1 16,930$ BTU Meter 6 3,500$ 21,000$ 500$ 21,500.00$ Programming and interface 6 2 3.0 0.1 13,570$ Flow meter 7 1,700$ 11,900$ 500$ 12,400.00$ AVEC Link 6 3,000$ 18,000$ 300$ 18,300.00$ -$ -$ Surveying / SHIPO 1 0.1 10.0 110,600$ -$ -$ Glycol 1 1 1.0 0.2170$ Glycol 30 1,100$ 33,000$ 33,000.00$ Old WTP ConnectionHead Start ConnectionSchool Building ConnectionWasheteria Building ConnectionWTP ConnectionSupport ActivitiesClinic ConnectionBTU Meter installPower Plant connections
Equipment Maintenance 5 2 2.5 0.41,150$ -$ -$ Fuel and Lubricants 5 10 0.5 0.5 1 1638$ Fuel 1500 6$ 9,000$ 9,000.00$ Fusing Machine 5 8 0.6 1219$ -$ -$ -$ -$ -$ Literature and References 6 0.25 24.0 125,440$ Publishing 4 500$ 2,000$ 100$ 2,100.00$ Training 1 0.25 4.0 1 1 212,240$ -$ -$ -$ -$ -$ -$ Preliminary Clean Up 1 0.2 5.0 0.2 0.25 26,375$ -$ -$ Final Inspection Punch List 1 0.3 3.3 1 3 217,267$ -$ -$ Final Clean Up 1 0.2 5.0 1 210,000$ -$ -$ -$ -$ -$ Pack Up and Crate 1 0.1 10.0 1 220,000$ 1 1 5,000$ 5,000$ 5,000.00$ Shipping 1 0.5 2.0 1 24,000$ -$ 10,000$ 10,000.00$ -$ -$ -$ -$ -$ Financial Close out/ Auditing 1 0.5 2.0 12,120$ -$ -$ As builting 1 0.25 4.0 1 1 0.2510,700$ -$ -$ -$ -$ -$ 385,489$506,000$ M+F total 556,250.00$479,889$941,739$ 1,036,139$1,243,367$2 years escalation @ 3% / year 75,721$ Total 1,319,088$$239,672.005.19 yrsEstimated annual savings (W/ Intertie)Simple PaybackAssumptions:- Construction team is mobilized and on site for adjacent project.- Trenching with associated project was not included, but availability of equipment, mechanics and operators was for purposes of mobilization and staging.- Civil site visit as part of adjacent project.Superintendant will split time with adjacent work.- Power plant is mostly configure and equiped.- System control can be accomplished w/o a panel.- Crew leader functions will be accomplished by Superentendant, or in lieu of Super.- De-mobilization not required due to adjacent project.With DesignDe-MobeJob Clean Up/ Final InspectionFinal*NoteStartup and Operator Training.All + 20% contingencyLabor + Materials + FreightTotal MatLabor + Mat + Frgt + DesignTotal Labor
AppendixD
September16,2011Memo
September19,2011TripReport
3335 Arctic Boulevard Suite 100 • Anchorage Alaska 99503 • Phone: 907.564.2120 • Fax: 907.564.2122
202 W. Elmwood Avenue Suite 1 • Palmer Alaska 99645 • Phone: 907.746.5230 • Fax: 907.746.5231
CIVIL
ENGINEERING
GEOTECHNICAL
ENGINEERING
TRANSPORTATION
ENGINEERING
ENVIRONMENTAL
SERVICES
PLANNING
MEMORANDUM
DATE:September16,2011FileNo:11Ͳ013
TO:MattMetcalf,ProjectManager
AlaskaVillageElectricalCooperative
FROM:MarkSwenson,P.E.,ProjectEngineer
HattenburgDilley&LinnellEngineeringConsultants
RE:PreliminaryResearchforWindTurbineSitinginStebbins
AttherequestoftheAlaskaVillageElectricalCooperative(AVEC),HattenburgDilley&
Linnell(HDL)EngineeringConsultantsperformedpreliminaryresearchfortwopossiblesites
forwindturbineconstructioninStebbins,Alaska.HDLandAVECselectedtwowindtower
locationsforthefeasibilitystudytoanalyzeforpotentialenvironmentaleffects,landuse,
accessibilitytothesite,constructabilityofthesite,andavailablewindresources.SeeFigure
1forthewindtowerlocations.ThesesiteswillbeevaluatedbyHDLandV3Energyduring
ourupcomingsitevisittoStebbins.Also,duringoursitevisitwewillmeetwithcommunity
memberstogetlocalfeedbackabouttheproposedlocationsandhearsuggestionsabout
anyalternativewindtowersites.Feasiblesitessuggestedbythevillagewillalsobe
investigated.
BackgroundInformation
RelocationoftheexistingAVEC'spowerplantandconstructionofanewAVECbulkfuel
storagefacilityiscurrentlyongoinginStebbins.TheseUpgradesarenecessarytomovethe
powerplantoffStateͲownedlands,elevatethefacilityabovethefloodplain,andincrease
tankagetoprovideadequatecapacityforafuture10Ͳmileintertietotheneighboring
communityofSt.Michaels.Aspartoftheintertieproject,anewprimarypowerplantis
plannedinStebbinswithswitchgearandcontrolsconfiguredtoaccommodatefuturewind
turbinepowergenerators.AfuturewindturbineprojectisplannedinStebbinstoreduce
thecommunity'sdependenceonimporteddieselfuelandprovideanalternatesourceof
renewableenergy.
AccordingtotheAEAAlaskahighresolutionwindresourcemap,theStebbinsregionhasa
class3windregime.Ameteorological(met)towerwasinstalledonSt.Michael'sNative
Corporation(SMNC)landbetweenStebbinsandSt.Michaelsin2010.Themettoweris
currentlycollectingwinddatathatsuggeststheexistingwindregimeisthislocationis
suitableforwindpowergeneration.However,themettowerislocatedclosetoSMNC's
gravelsourceandtheCorporationisunwillingtoreleasethelandforwindfarm
development.Therefore,twoalternatewindtowersiteshavebeenselectedforresearchof
accessibility,constructability,landuse,andenvironmentalpermittingandconcerns.
RE: Preliminary Research for Wind Turbine Siting in Stebbins
September 16, 2011
Page 2 of 4
WindTowerSite1
ThefollowingsubͲsectionsdiscussthesitelocation,availableaccess,environmental
documentationnecessaryforthesiteandthelanduseforthewindtowersite1.
LocationandDescription
Towersite1islocatedapproximately1.2ͲmilesnorthoftheStebbinsAirportarea(Latitude
63ȗ32’01”N,Longitude162ȗ16’40”W)asshowninFigure1.Thesiteislocated
approximately150Ͳfeetabovesealevel,onaplateauadjacenttotheNortonSound.The
terrainsurroundingthetowersiteisrelativelyflatwithgradesthatareapproximately0Ͳ6%.
AccessandConstructability
Towersite1iscurrentlylocatedadjacenttotheroadthattravelsfromStebbinstoSt.
Michaels.Iftowersite1isdeveloped,anestimated200Ͳfootlongaccessroadwouldhave
tobedevelopedfromtheexistingroadwaytothesite.Theaccessroadwouldbe
approximately16Ͳfeetwide.Currentlytherearethreepotentialgravelsourceslocatedon
St.MichaelsIslandasshownonFigure1.Thegradeoftheproposedroadwouldrange
between0and6percent.
LandUse
Towersite1islocatedonalotownedbytheStebbinsNativeCorporation.AVECwill
requestpermissionfromtheStebbinsNativeCorporationtovisitandevaluatethewind
towersiteonSt.MichaelsIsland.UponreceiptofanapprovedStatementofNonͲObjection
AVEC,HDLandV3Energywillcompleteasitevisitandevaluationthesite.
PermittingandEnvironmentalConcerns
Thefollowingliststheenvironmentdocumentationisrequiredtoconstructawindtoweron
site1:
x SubmitalettertoSHPOrequestingadecisiononarchaeologicalresourcesinthe
projectarea.
x SubmitaJurisdictionalDeterminationwiththeCorpsofEngineers(COE)regarding
wetlandsattheprojectsite.Duetotheuplandlocationitisunlikelythatthesiteisa
wetlandarea.
x Fileform7460Ͳ1totheFederalAviationAdministration(FAA)atleast45daysbefore
constructionorwhenconstructionpermitsarefiled,whicheverisearliest.
x SubmitaconsultationlettertotheUSFishandWildlifeServices(USFWS)outlining
theprojectwitharequestforabiologicalopinion.
RE: Preliminary Research for Wind Turbine Siting in Stebbins
September 16, 2011
Page 3 of 4
WindTowerSite2
ThefollowingsubͲsectionsdiscussthesitelocation,availableaccess,environmental
documentationnecessaryforthesiteandthelanduseforthewindtowersite2.
LocationandDescription
Towersite2islocatedapproximately2.1ͲmilessoutheastoftheStebbinsAirport(Latitude63ȗ30’
25”N,Longitude162ȗ12’57”W)asshowninFigure1.Thesiteislocatedapproximately80Ͳfeet
abovesealevel,adjacenttotheClearLakes.Theterrainsurroundingthetowersiteis
relativelyflatwithgradesthatareapproximately0to6percent.
AccessandConstructability
Towersite2iscurrentlylocatedadjacenttoaroadwayaccesstotheClearLakes.Iftower
site2isdeveloped,anestimated100Ͳfootlongaccessroadwouldhavetobedeveloped
fromtheexistingroadwaytothetowersite.Theaccessroadwouldbeapproximately16Ͳ
feetwide.CurrentlytherearethreepotentialgravelsourceslocatedonSt.MichaelsIsland
asshownonFigure1.Thegradeoftheproposedroadwouldrangebetween0and6
percent.
LandUse
Towersite2islocatedonalotownedbytheSt.MichaelsNativeCorporation.AVECwill
requestpermissionfromtheSt.MichaelsNativeCorporationtovisitandevaluatethewind
towersiteonSt.MichaelsIsland.UponreceiptofanapprovedStatementofNonͲObjection
AVEC,HDLandV3Energywillcompleteasitevisitandevaluationthesite.
PermittingandEnvironmentalConcerns
Thefollowingliststheenvironmentdocumentationrequiredtoconstructawindtoweron
site2:
x SubmitalettertoSHPOrequestingadecisiononarchaeologicalresourcesinthe
projectarea.
x SubmitaJurisdictionalDeterminationwiththeCorpsofEngineers(COE)regarding
wetlandsattheprojectsite.Duetotheuplandlocationitisunlikelythatthesiteisa
wetlandarea.
x Fileform7460Ͳ1totheFederalAviationAdministration(FAA)atleast45daysbefore
constructionorwhenconstructionpermitsarefiled,whicheverisearliest.
x SubmitaformalSection7consultationlettertotheUSFWS.Duetothelocationof
windtowersite2beingnearwetlands,mitigationandavoidancemeasuresfor
impactstothreatenedandendangeredspeciesandmigratorybirdswilllikelybe
required.
RE: Preliminary Research for Wind Turbine Siting in Stebbins
September 16, 2011
Page 4 of 4
SummaryandRecommendations
AVEC,HDLandV3EnergywilltraveltoStebbinstoevaluatethetwowindtowersites.HDLwillhave
ageotechnicalengineertodeterminepotentialconflictswiththeinͲsitusoilatthetowersites,anda
civilengineertodeterminepotentialaccesstothesites.V3Energywillhaveanaerospaceengineer
specializinginwindresourcestoassesstheavailablewindresources.Oncethetowerlocationis
selectedamettowerwillbeconstructedtocollectdataanddetermineifawindtowerisfeasiblefor
thelocation.
Attachments:Figure1ͲWindTowerSite1&2Locations
H:\jobs\11Ͳ013StebbinsWindFeasibilityStudy(AVEC)\Memo\StebbinsWindStudyMemo_9Ͳ12Ͳ2011.doc
3335 Arctic Boulevard Suite 100 • Anchorage Alaska 99503 • Phone: 907.564.2120 • Fax: 907.564.2122
202 W. Elmwood Avenue Suite 1 • Palmer Alaska 99645 • Phone: 907.746.5230 • Fax: 907.746.5231
CIVIL
ENGINEERING
GEOTECHNICAL
ENGINEERING
TRANSPORTATION
ENGINEERING
ENVIRONMENTAL
SERVICES
PLANNING
SURVEYING
CONSTRUCTION
ADMINISTRATION
MATERIAL
TESTING
MEMORANDUM
DATE: September 22, 2011
TO:Matt Metcalf, AVEC Project Manager
FROM:Mark Swenson, P.E.
RE: September 19, 2011 Stebbins Wind Site Investigation Report
On Monday September 19, 2011, Mark Swenson (HDL), John Thornley (HDL), Matt Metcalf
(AVEC), and Doug Vaught (V3 Energy) flew to Stebbins to investigate two proposed
preliminary wind tower sites.
We departed Anchorage via Security Aviation charter at 8:00 AM and arrived in Stebbins at
approximately 9:40 AM. Also on the charter were Janie Dusel (HDL), Dana Keene (AVEC)
and Mark Teitzel (AVEC), who were traveling to Stebbins to inspect the progress of the
AVEC and Community bulk fuel facilities that are currently being constructed by STG, Inc.
Kirk with STG met us at the airport with a truck and a 6-wheeler. We drove to STG’s camp
and then walked to the AVEC bulk fuel farm to inspect the construction. Matt, Doug, John
and I left the AVEC site at approximately 10:00 AM and drove to the existing met tower site
located on an elevated cinder cone rock formation between Stebbins and St. Michaels. See
attached Site Map for met tower location. Doug inspected the met tower while John, Matt,
and I inspected the top of the cinder cone. We sampled and inspected the exposed rock
and viewed the surrounding terrain. Doug informed us that the met tower baseline settings
were different than he initially anticipated and the wind data would have to be adjusted to
reflect the field conditions. The cinder cone is not a viable wind tower site because it is a
gravel source owned and operated by the St. Michaels Village Corporation. The
Corporation has stated that it will not relinquish a viable and profitable material source for
wind farm development.
From the cinder cone, we identified two alternative wind tower sites with flat or gently
sloping terrain and good north/south exposure. The sites are identified below and shown on
the attached site map:
x St. Michaels Site 1: Lat: N 63°30'09.56" Long: W 162°11'23.81” Elev:±130'
x St. Michaels Site 2: Lat: N 63°30'46.54" Long: W 162°10'56.31" Elev:±175'
St. Michaels Site 1 is located on a bluff to the south of the road, approximately 0.70 miles
southeast of the met tower. We parked along the road and walked the site. The terrain was
dry and ground cover consisted of tundra with the occasional low alder bush. Subsurface
conditions at the site are anticipated to include shallow to significant soil deposits with warm
permafrost. It should be anticipated that any rock encountered will be frost fractured to
depths of 8 to 10 feet below the surface and may be weathered and friable to depth. The
most likely foundation types for wind turbines at this location are a mass gravity mat
foundation or deep foundation consisting of driven piles or helical piers. This site lies within
the Part 77 airspace of St. Michaels’ Runway 02/20 and further coordination with the FAA is
RE: September 19, 2011 Stebbins Trip Report
September 22, 2011
Page 2 of 2
required prior to erection of a met tower or wind turbines in this location. See attached
preliminary FAA Notice Criteria worksheets.
St. Michaels Site 2 is located approximately 0.4 miles east of the existing met tower. The
site is located on a ridge line extending from the cinder cone that appears to be an old
basalt flow. We viewed the site from the top of the cinder cone but did not walk the terrain.
It is likely that shallow organics and soils overlie basalt and other volcanics in this location.
It should be anticipated that the underlying rock is frost fractured to depths of 8 to 10 feet
below the surface and may be weathered and friable to depth. Possible foundation types for
wind towers at this site include mass gravity mat foundations and rock anchors if the
volcanics are encountered at shallow depths.Construction would also include clearing
dense patches of alders and constructing a 0.5 mile road from the cinder cone access road
to the proposed site. This site lies within the Part 77 airspace of St. Michaels’ Runway 02/20
and further coordination with the FAA is required prior to erection of a met tower or wind
turbines in this location. See attached preliminary FAA Notice Criteria worksheets.
We traveled from St. Michaels Site 2 to Stebbins Site 1 at approximately 12:00 PM. The
Stebbins site is located on a plateau near the city landfill. The location is identified below
and shown on the attached site map:
x Stebbins Site 1: Lat: N 63°31'56.58" Long: W 162°16'50.64” Elev:±155'
We walked the terrain and inspected the site. The site is located adjacent to the existing
road to St. Michaels and gravel is readily available nearby. The ground cover was
composed of tundra and no ponding or excess moisture was observed. The site subsurface
is likely composed of organics and shallow soils overlying basalt and other volcanics. Frost
fractured rock is anticipated to depths of 8 to 10 feet below the surface and may be
weathered and friable to depth. Possible wind tower foundation types include mass gravity
mat foundations and rock anchors if the volcanics are encountered at shallow depths.
Doug identified this site as the preferred location for a met tower, and AVEC agreed. An
existing rebar stake is located in the tundra at the preferred met tower location. Icing and
wind resources will be measured at the met tower to determine the suitability of the site for
wind generation. AVEC plans to have STG install the met tower at the site this fall.
The Stebbins site lies within the Part 77 airspace of Stebbins’ Runway 05/23 and further
coordination with the FAA is required prior to erection of a met tower or wind turbines. FAA
coordination is likely to include petitioning the Stebbins Airport Manager to change the traffic
pattern to “right traffic” for Runway 05. See attached preliminary FAA notice criteria work
sheets.
We departed Stebbins at approximately 1:00 PM. On the way back to Anchorage we
stopped in Shaktoolik to inspect two recently erected wind turbines. We also circled Elim
and Koyuk to get a preliminary view of the landscape for future wind tower siting work in
those communities. The plane refueled in Unalakleet and we arrived back in Anchorage at
approximately 5:00 PM.
H:\jobs\11-013 Stebbins Wind Feasibility Study (AVEC)\Correspondence\September 19, 2011
Stebbins Trip Report.docx
AppendixE
CapitalCostEstimate
ConceptLevelEstimateStebbinsWindFarmConstructionAlternativeCostSummary7/26/13SUMMARYDescription Estimated Construction Installed kW Estimated Construction Tower TypeCost Cost/ Installed kWAlternative 1 - (4) Northern Power 100 Arctic's on Ridge Site $ 4,030,650.00 400 $ 10,076.63 Monopole Alternative 2 - (5) V17's on Ridge Site $ 3,788,750.00 450 $ 8,419.44 Monopole Alternative 3 - (2) AW33-225's on Ridge Site $ 3,946,050.00 450 $ 8,769.00 Monopole
ConceptLevelEstimate
StebbinsWindFarmConstruction
Alternative1
6/26/13
Item Estimated
Quantity UnitPrice($) Subtotal($)
Alternative1Ͳ(4)NorthernPower100Arctic'sonRidgeSite
1 6,000CY Borrow 25150,000
2 610CY SurfacingCourse 7545,750
3 49,500SF Geotextile 299,000
4 350CY Topsoil 258,750
5 3,500SY Seed 517,500
64Each ConcreteGravityMatFoundations104,000416,000
74Each NorthernPower100ArcticWindTurbines 375,0001,500,000
8 1,350LF ElectricalSpurLinetoIntertie 3749,950
91Sum WirelessCommunicationSystem 75,00075,000
10 1Sum WindTurbinePowerIntegration 100,000100,000
11 1Sum Labor 175,000175,000
12 1Sum Equipment 150,000150,000
13 1Sum Freight 518,000518,000
14 1Sum Indirects200,000200,000
SubtotalConstruction 3,504,950$
LandAcquisition $0
ProjectContingency @15%525,700$
0YearsInflation @2%$0
Total 4,030,650$
InstalledGenerationCapacity400kW
TotalCost 4,030,650$
Cost/InstalledkW $10,077
Description
ConceptLevelEstimate
StebbinsWindFarmConstruction
Alternative2
6/26/13
Item Estimated
Quantity UnitPrice($) Subtotal($)
Alternative2Ͳ(5)V17'sonRidgeSite
1 7,600CY Borrow 25190,000
2 770CY SurfacingCourse 7557,750
3 62,300SF Geotextile 2124,600
4 440CY Topsoil 2511,000
5 4,400SY Seed 522,000
65Each ConcreteGravityMatFoundations81,000405,000
75Each VestasV17WindTurbines 200,0001,000,000
8 1,600LF ElectricalSpurLinetoNewIntertie 3759,200
91Sum WirelessCommunicationSystem 75,00075,000
10 1Sum WindTurbinePowerIntegration 350,000350,000
11 1Sum Labor 225,000225,000
12 1Sum Equipment 150,000150,000
13 1Sum Freight 410,000410,000
14 1Sum Indirects215,000215,000
SubtotalConstruction 3,294,550$
LandAcquisition $0
ProjectContingency @15%494,200$
0YearsInflation @2%$0
Total 3,788,750$
InstalledGenerationCapacity450kW
TotalCost 3,788,750$
Cost/InstalledkW $8,419
Description
ConceptLevelEstimate
StebbinsWindFarmConstruction
Alternative3
7/25/13
Item Estimated
Quantity UnitPrice($) Subtotal($)
Alternative3Ͳ(2)AW33Ͳ225'sonRidgeSite
1 2,600CY Borrow 2565,000
2 260CY SurfacingCourse 7519,500
3 21,000SF Geotextile 242,000
4 110CY Topsoil 252,750
5 1,500SY Seed 57,500
62Each ConcreteGravityMatandRockAnchorTowerFoundations275,000550,000
72Each AeronauticaAW33Ͳ225WindTurbines 600,0001,200,000
8 800LF ElectricalSpurLinetoNewIntertie 3729,600
91Sum WirelessCommunicationSystem 75,00075,000
10 1Sum WindTurbinePowerIntegration 300,000300,000
11 1Sum Labor 225,000225,000
12 1Sum Equipment 150,000150,000
13 1Sum Freight 550,000550,000
14 1Sum Indirects215,000215,000
SubtotalConstruction 3,431,350$
LandAcquisition $0
ProjectContingency @15%514,700$
0YearsInflation @2%$0
Total 3,946,050$
InstalledGenerationCapacity450kW
TotalCost 3,946,050$
Cost/InstalledkW $8,769
Description
AppendixF
CRCMemo
CULTURAL RESOURCE CONSULTANTS LLC
3504 East 67th Avenue Anchorage, Alaska 99507 (907) 349-3445
August 28, 2012
Known Archaeological and Historical Sites in the Stebbins Area
The information below is summarized from the Alaska Historic Resources Survey (AHRS).
There are no known sites within either the Bluff or Ridge site areas of interest for the Stebbins
Wind Power Feasibility Study, although there is one site—Atrivik (SMI-017)—just south of the
Bluff Site. Atrivik, a large former Yup’ik village, was occupied about 200 to 500 years ago. On
the bluff to the east of Atrivik is a cemetery (SMI-053) that may be the first Russian Orthodox
cemetery associated with Stebbins.
There is another known site, Teq’errlak (SMI-019), on the coast between the Bluff and Ridge
site areas. Determined eligible for listing on the National Register in 2007, Teq’errlak consists
of an extensive midden, numerous house and cache pits, and at least 24 burials. East of the Ridge
Site, on the northern coast of St. Michael Island, is Cingikegglirmiullret (SMI-020). There is no
information in the AHRS about this site.
In the general area and north of Stebbins village are Armory Stebbins (SMI-098) and the modern
Stebbins cemetery (SMI-090). Stebbins Village (SMI-012) was first mentioned in 1898 by the
U.S. Coast and Geodetic Survey. Its Eskimo name is reported to be “Atroik.” In 1950, there were
about 80 people living in the village whose main livelihood was hunting, fishing, and reindeer
herding. Within the village are the Assembly of God Church (SMI-101), Old Johnson’s House
(SMI-084), two BIA Territorial Schools (SMI-108 and SMI-109), and several historic houses
(SMI-099, SMI-100, SMI-102, SMI-103, SMI-104, SMI-105, SMI-106, SMI-107, and SMI-
110).
About 200 meters (m) east of Stebbins is SMI-050—a series of 500-year old house depressions
located near the northern and northwestern ends of Stebbins Lake. Located near the
western/southwestern corner of Stebbins Lake are four small, shallow, circular depressions
(SMI-051) that date to approximately 1,750 years ago and fall within the Norton Phase of the
Arctic Small Took tradition. On the eastern side of the lake are 13 features (SMI-052) that are
roughly 2,500 years old and range in size from 40 feet in diameter to cache pit size. Along the
beach at the south/southeastern end of the lake are several shallow features (SMI-085), some of
which might be associated with road construction. Three, large, rectangular house features
(SMI-086) are on a beach ridge south of the lake. One has a distinctive long entry tunnel.
Located on the same beach ridge as SMI-051 and at the southwestern corner of the lake are three
very shallow features (SMI-087) of indeterminate age.
CULTURAL RESOURCE CONSULTANTS LLC
3504 East 67th Avenue Anchorage, Alaska 99507 (907) 349-3445
About 0.5 mile south of Stebbins is Pengurmiullret (SMI-018), the initial settlement of migrants
from the south (from Nelson Island and other areas) who came around the first decade of the 20th
century and whose descendants comprise the majority of the contemporary population of
Stebbins.
Previous Survey in the Immediate Project Area
In 2009, Northern Land Use Research (NLUR) archaeologist Andy Higgs conducted an
archaeological survey of potential material sources in the Stebbins/St. Michael area, including
two north of Stebbins in the immediate vicinity of the two wind tower site alternatives (Higgs
2009). One, the Stebbins Rock quarry, is just east of the Bluff Site, adjacent to the Stebbins
landfill. This quarry had also been surveyed in 2005 by NLUR archaeologist Carol Gelvin-
Reymiller (et al. 2005). Higgs examined the active quarry and a 15-acre expansion area to the
south in 2009 and concluded “No known cultural resources exist here and there is no indication
that expansion of the quarry would impact unknown historic resources” (Higgs 2009:7).
Higgs also surveyed the Stephens Hill Quarry, located approximately 0.7 mile east of the Ridge
Site. He noted:
Native place name research for Stephens Hill identifies the general area as
“Cingikeggliq” translated as "point or tip" referring more to the coastal areas
north of the prominent hilltop. In 1988, [Gary] Navarre indicates he examined
Stephens Hill as a potential resource for the Stebbins-St. Michael (BIA) road but
he found no cultural resources. Navarre recommended it for clearance and SHPO
concurred (Higgs 2009:7).
Higgs looked at this 0.2 mile long quarry area along the southern margin of the St. Michael-
Stebbins Road that is used by the City of Stebbins as their main gravel source. He found no
cultural resources and concluded “there is no indication that expansion of the quarry would
impact unknown historic resources” (Higgs 2009:7-8).
Assessment
There are no known cultural resources within the Bluff or Ridge site areas of interest for the
Stebbins Wind Power Feasibility Study, although Atrivik (SMI-017) is just south of the Bluff
area and Teq’errlak (SMI-019) is on the coast between the two areas. However, based on
NLUR’s surveys of material sources in the vicinity, it would seem that there is a relatively low
probability of undiscovered sites within the actual project areas. With the understanding that this
undertaking would still need to be reviewed by archaeologists at the State Office of History and
Archaeology, and the proviso that any previously undiscovered cultural remains should be
immediately reported to the State Historic Preservation Officer, Cultural Resource Consultants
LLC does not recommend a field survey for the Stebbins Wind Power Feasibility Study.
CULTURAL RESOURCE CONSULTANTS LLC
3504 East 67th Avenue Anchorage, Alaska 99507 (907) 349-3445
References Cited
Gelvin-Reymiller, Carol, Sarah McGowan, and Ben A. Potter
2005 Cultural Resource Survey for Proposed Airport Improvements at Stebbins, Alaska.
Report Prepared for DOWL Engineers, Anchorage. Northern Land Use Research, Inc.,
Fairbanks.
Higgs, Andy
2009 St. Michael and Stebbins Material Source Cultural Resource Survey, St. Michael Island,
Alaska. Report prepared for Bristol Environmental & Engineering Services Corporation,
Anchorage. Northern Land Use Research, Inc., Fairbanks.