design guide n v2-3en

8/2/2019 Design Guide N V2-3EN

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Design GuideSL100 Series Photovoltaic Panels

Solyndra, Inc.47700 Kato Road Fremont, CA www.solyndra.com

DesignGuide_N_V2.3ENEnglish. Version 2.3Release Date: 2010-04-06


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2 SolyndraPhotovoltaicPanelDesignGuide SolyndraConfdentialDocNumber0920-30006-EN-010

Copyright Notice

ThisdocumentprovidesinormationonSolyndraproducts.By issuanceothisdocumentSolyndraassumesno liability.The

rightsandobligationsoSolyndraandanyowneroSolyndrapanelsaregovernedsolelybytheexpresstermsandconditions

containedinthesaleagreementorsuchpanels.ExceptasprovidedinSolyndrasTermsandConditionsoSaleorsuchprod

ucts,Solyndraassumesnoliabilitywhatsoever.

Copyright(circlelogo)SolyndraInc.2009-2010.

PrintedintheUnitedStatesoAmerica.AllRightsReserved.

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trademarksarethepropertyotheirrespectivecompanies.

SolyndraproductsarecoveredbypatentsintheUSandmanyothercountries.

Disclaimer

Solyndradisclaimsanyexpressorimpliedwarranty,relatingtosaleand/oruseoSolyndraproductsincludingliabilityorwar-

rantiesrelatingtoftnessoraparticularpurpose,merchantability,orinringementoanypatent,copyright,orotherintellectua

propertyright.WarrantyrightsaregovernedsolelybytheexpresstermsotheSolyndrawarrantyprovidedtothepurchasero

Solyndrapanels.

Solyndramaymakechangestospecifcations,instructions,andproductdescriptionscontainedinthisdocumentatanytime

withoutnotice.ContactyourlocalSolyndraSalesOcetoobtainthelatestspecifcationsbeoreplacingyourpurchaseorder.

AdvisoryinormationcontainedinSolyndrainstructions,guides,applicationnotes,oranyotherdocumentisadvisoryonly.The

customermustworkwithqualifedpersonneltoensurethatalldesignsaresaeandincompliancewithalllocalcodes.Solyndra

makesnorepresentationthatanyreerencetechniqueormethodisnecessarilysae,legal,orcompliantwithapplicationcodes

Solyndraassumesnolegalliabilityorresponsibilityortheaccuracy,completeness,oruseulnessoanyinormation,appara-

tus,product,orprocessdisclosed,orrepresentsthatitsusewouldnotinringeprivatelyownedrights.Reerencehereintoan

specifccommercialproducts,process,orservicebytradename,trademark,manuacturer,orotherwise,doesnotnecessarily

constituteorimplyitsendorsement,recommendation,oravoringbySolyndra.

TheEnergyYieldForecastToolleveragespastexperience,scientifcmodels,andweatherdatatoestimatetheexpecteduture

perormanceoSolyndraproducts.TherightsandobligationsoSolyndraandanyownero(orinvestorin)projectscontain-

ingSolyndrapanelsaregovernedsolelybytheexpresstermsandconditionscontainedinthesaleagreementorsuchpanels

TheoutputsothistoolshallnotrepresentadepartureromtheTermsandConditionsotheexistingcommercialagreements

Cautions And Warnings

Solyndrapanelsaretypicallyinstalledonhighly-reectiveroosuraces.Thelightcanbebrightenoughtoaectvision.Sun-

glasseswhichflteroutultravioletlightarestronglyrecommended.Personswhoplantoremainontherooormorethanthirty

minutesshoulddressappropriatelyandwearsunscreentoprotectskinromthesun.

Coolroosuracesmaypromoteslipperyconditionsromwaterorsnow.DONOTworkwithin1.6meters(5eet)otheedgeo

aroowithoutappropriatesaetyequipment.

Solyndrapanelsaremaderomglass,andareelectricallylivewheneverlightshinesonthem.Iapanelisbroken,useinsulating

cut-prooglovestohandledebris.ReertoSolyndrassaetyinormationordetailsonclean-upprocedures.TheOpticalCou-

plingAgent(OCAuid)isnon-toxic,butextremelyslippery.Usegreatcarewhenworkingaroundspills.

Contact Information

SolyndraInc.

47700KatoRoadFremont,CA95054

USA

Tel.(510)440-2400

http://www.solyndra.com

[email protected]


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Version2.3SolyndraConfdential SolyndraPhotovoltaicPanelDesignGuide 3

Contents

Chapter1 DesigningwithSolyndra 4

Chapter2 ArrayClearances 5

Chapter3 Sub-ArrayWiringOptions 27

Chapter4 StringSizing 34

Chapter5 Grounding 36

Chapter6 SystemWiring 38

Chapter7 MechanicalDesign 44

Chapter8 SolyndraPanelSystem 46

Chapter9 SitePreparation 56

Chapter10 ToolsandSupplies 59

AppendixA. Reerences 61

AppendixB. DesigninSeismicAreas 62


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Chapter 1 Designing with Solyndra

TepurposeofthisdocumentistoprovidedesignrulesforSolyndraphotovoltaicsystemsTetargetaudienceissystemdesignersandengineerswhoarealreadyskilledinphotovoltaicdesign.TisguidewillhighlighttheuniquepropertiesoftheSolyndratechnologyandtheimpactonsystemdesign,butisnotintendedtocoverallaspectsofsystemdesign.

Solyndrapanelshaveauniqueconstruction.Tepanelsarecomposedof40cylindricalmod-uleswithgapsinbetweeneachmodule.Extensivelaboratoryandreal-worldtestinghascon-rmedthatthisform-factorallowsthewindtopassthroughthepanelswithlittleresistanceandtheweightofthepanelisenoughtokeepitinplaceontherooftopwithoutattachment.Seismicanalysishasbeenperformedtocharacterizepossiblearraydisplacementduringseismiceventsandhasshownthatinseismicallyactiveareasnoattachmentisneeded.

Solyndrapanelsaredesignedbeinstalledonwhite,highreectanceroofswheneverpossible.

CodeCompliance&Saety

Systeminstallationsaresubjecttoarangeofcodesandstandards.Tesewillvarybyjurisdic-tion.Inallcases,codesandstandardsshouldbefollowedcarefully,butitshouldbenotedthaanycodeorstandardprovidesonlyaminimumrequirementforsafety.Codescannotbecom-prehensiveforallspecicsystem.Itistheresponsibilityofthedesignertouseher/hisjudgmentandattimesgobeyondtheseminimumrequirementstoensurethesafetyofthesystem.

Solyndrapanelsaremadeofglassandproducedangerousvoltageswhenevertheyareexposedtosunlight.PleaserefertotheSolyndraInstallationGuideforpanelhandlingsafetyrecom-mendations.

RequiredInormation

Inorderforaneectivedesigntobeproduced,thedesignerneedsseveralpiecesofinformationaboutthesite.Asamplesiteinspectionchecklistisincludedbutthedesignerisencouragedtodeveloptheirowntocoveranyuniquerequirementsintheirparticularjurisdiction.

Forapreliminarydesign,youshouldhave:

Roongmaterialtype,andageofroofmaterial

Roofdeckandloadbearingcapacity

Roofdimensions,includingheight

Seismicrequirements,ifany

LocationsanddimensionsofallroofobstructionsOrientationofbuilding

Shadingconsiderations

Addressofsite


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Chapter 2 Array Clearances

Solyndrapanelsareself-ballasting.Aproperly-assembledarrayhassucientmasstoresistwindliftwithouttheneedforattachmenttotheroof.Tepanelsaredesignedtobeinstalledhorizontally,paralleltotheroof.Becausethepanelsdonotneedtobetiltedforoptimumenergyproduction,itisnotnecessarytoleavespacebetweenarrayrowstoavoidinter-rowshading.Tismakesitpossibletoassemblelargearrayblocksofadjacentpanels,placingmorepanelsontheroofandmaximizingenergyyieldfortheavailablespace.

SetbacksandClearances

Inordertomeetwind,re,safety,access,andseismicrequirementsitsnecessarytoallowspac-esaroundgroupsofpanels.Tischapterwillexplainthedesignguidelinesforthesesetbacksandclearances.

ShadeClearances

Anyshadowfallingacrossthearraywillreduceitsoutput,buttheuniquedesignandlight-

gatheringtechnologyofSolyndrapanelsmakesthemlessaectedbyshadingthana siliconpanel.However,panelsshouldnotbeplacedintheshadowofroofstructuressuchasHVACequipment.

FireClearances

Firecodesvary,butgenerallyrequireaminimumnumberofaccesspathssothatrecrewscanghtresandventilatethestructure.Checkwithlocalauthoritiesbeforedesigningaproject.

SaetyandAccess

Safetycodesmandateaminimumperimeterclearanceinordertoprovideforworkersafety.

Ifpanelsareinstalledtooclosetotheedgeofastructure,workersmayberequiredtousefall-protectionequipmentwhileworking.Independentofanycoderequirement,itmaybeneces-sarytoprovideaccesstoroof-topmachineryorskylightsforservice.

WindClearances

Solyndrapanelsareself-ballastingagainstwinduplift.TeopendesignoftheSolyndrapanelreduceswindeects.Bymechanicallyattachinggroupsofpanels,thetotalweightisincreasedsuchthatpanelliftdoesnotoccur.Inordertoinsurethathighwindsdonotliftthepanels,certainminimumclearancesfrombuildingedgesandotherstructuresmustbemaintained.Inaddition,panelsmustbegroupedintominimumsub-arraysizestoensureadequateself-ballastingeect.

SeismicClearances

Seismicconditionsandbuildingcodesvarywidely.RefertoAppendixBforclearanceallow-ancesinseismiczones.Ifyouareplanninganinstallationinaseismicallyactivearea,contactSolyndra,[email protected],fordesigninformation.


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Sub-ArrayDefnition

Tetermsub-arrayisdenedasagroupofpanelswhicharephysicallyconnectedtogether.Temannerofelectricalconnection(s)isnotrelevanttothisdenition.

Telargerthesub-array,thegreaterthephysicalstabilityofthesystem.

NoteAllpanelswhichtoucheachothershouldbemechanicallyconnected,usinglateralclips,re-gardlessofelectricalarrangement.

String Blocks

Electricalsub-arraysizeisdeterminedbytheseriesstringlength,whichinturnisdeterminedbythechoseninverter.ItsimportantthateveryseriesstringhavethesamenumberofpanelsTusthetotalnumberofpanelswillbeamultipleoftheseriesstringlength.Tisisusuallyintherangeof5to8panels.StringlengthiscoveredinString SizinginChapter3onpage36.

Itspreferabletohaveeachmechanicalsub-arraybeamultipleofthestringlength.Tissimpli-eswiring,byavoidingtheneedtorunconduitacrosswalkways.

Tus,youmustadjustthenumberofpanelsineachmechanicalsub-arraytoobtainanexactmultipleofthestringlength.Teseareasofomittedpanelsaresometimesreferredtoasdead

spacefromstringing.

DesignRulesandExamples

Tefollowingsectionsdiscussandillustrateclearancerequirementsandarraysizerestrictions

A Typical Layout Planning Exercise

Beginwithaplanviewoftheroof,onwhicharemarkedallobstacles,structures,orotherfea-tures.Youwillneedtoknowtheheightaswellasthesizeofallfeatures

Next,beginapplyingthesetbackandplacementrules.Eachoftheclearanceguidelinesex-plainedinthischapteristhenappliedtothesampleroofplan.Teopenareathatremainsafter

allthesetbacksareestablishediscalledtheAvailableRoofSpace.

1. Markthe5-foot(1.52m)setbackline,theZoneAline,andtheZoneBline(describedlaterinthisdocument).

2. Marktheshadowpathofanyroofobjectstallenoughtocastashadow.

3. Markthewindsetbackofanyroofobjectstallerthanthearray.

4. Markthere-clearancelineforaccesstoskylights,hatches,andotherroofobjects.

5. Marktheseismicsetback,ifapplicable.

6. Placegroupsofpanelsintheremainingarea.ypically,adesignerwillplaceonestringblock(e.g.5x3)atatimeuntiltheareaismostlylled,thenaddsinglestingstollanyremainingarea.

Inthefollowingexamples,thesetbackandclearancerulesarerstillustratedindividually,andtheninacombination.Real-worlddesignsmustofcoursemeetallrules,butitiseasiertoun-derstandhowtherulesapplybyexaminingthemindividually.


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TheExampleRoo

oillustratetheclearancerules,theexampleroofshowninFigure1isused.Tisroofhasa24inch(60cm)parapet,andseveralrooftopobjects.

Figure 1. Example Roof

200 (61 m)

161-8 (49.3 m)39-4(12 m)

140(42.7 m)

125(38.1 m)

142 (43.3m) 58 (17.7 m)

39-4(12 m)

265(80.7 m)

225-8(68.8 m)

Skylight8 high(20 cm)

Access Hatch12 high( 30 cm)

DC/ACInverter

Skylights8 high(20 cm)

HVAC unit6 high

(1.82 m)

CoecientsoFriction

Frictionkeepsthepanelsfrommovingunderwindconditions.TestandardSolyndra-sup-pliedpanelmounthasamoderatecoecientoffriction.Addingapadtothefootofthemountcanincreasethis,ifrequired.Solyndrahastestednumerouscombinationsofpanelmountmaterialsandroofmaterialsundervariousconditions,andfoundthatingeneral,coecientsoffrictionrangefrom0.4to1.0,sometimesmore.

Youshoulddeterminethecoecientoffrictionofyourroofmaterialbeforeproceedingwithyourdesign.Solyndrahasvaluesforseveralcommonroongmaterials.


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FirefghterAccessClearance

Itisbeyondthescopeofthisguidetocoverallrecodesforalljurisdictions,however,mostrecodessharesomeprinciplesthatwillaectpanelplacement.TeFireDepartmentwillrequirethatthedesignerleavewalkwaysthroughthearrayandclearancesaroundhatchesandstairways.Checkyourlocalrecodes.

Teexample inFigure2showsaone-storybuildingwithaparapetgreaterthan19inches(0.48m)high.Terecoderequires4feet(1.2m)ofclearanceattheedge.(Notethatthewindrequirementsmandate5feet(1.52m)).Aislesarealongstructuralmembers,andare8feet(2.4m)wide.Inaddition,thereisaisleaccesstoskylights,and4feet(1.2m)ofclearancearoundroofhatches.Tepanelarrangementhas1460panels,andeachofthefoursub-arrayisamultipleofve,thestringlengthinthisexample.

Figure 2. Fire Clearance Example

200 (61 m)

161-8 (49.3 m)

39-4(12 m)

140(42.7 m)

125(38.1 m)

142 (43.3m) 58 (17.7 m)

39-4

(12 m)

265(80.7 m)

225-8(68.8 m)




HVAC unit6 high

(1.82 m)

Detail B

Detail C Detail DStructural Member

Minimum Setback

Detail A

Fire Clearance

Colorcode:

Fire)

Obstruction

MinimumSetback


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Figure 3. Detail A - Fire Clearances

Access Hatch, 12 (30cm) high

4 (1.2 m) clearance for re

4 (1.2 m) walkway for re

Figure 4. Detail B - Fire Clearances


HVAC 6 (1.8 m) high


Figure 5. Detail C - Fire Clearances

Minimum

Setback

Fire

Setback

Figure 6. Detail D - Fire Clearances

Skylight

4 (1.2 m) walkway

for re

Otherarrangementsarepossible.TeCaliforniaFireCode,andotherrecodes,providealter-natearrangementsforreghteraccess,venting,andotherrequirements.Studythesebeforeplanningyourlayout.

Colorcode:

Fire(4)

Obstruction

MinimumSetback(5)


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ShadeClearances

ounderstandtheeectshadingcanhave,itshelpfultounderstandhowtheSolyndrapanelisdierentfromconventionalatplatephotovoltaicsystems.EachSolyndrapaneliscomposedof40cylindricalphotovoltaicmodules,wiredinparallel.Eachmoduleconsistsofanumberofindividualcells,wiredinseries,asshowninFigure7.

Figure 7. Photovoltaic Cell Structure

n-n-

p

+

p

-

i

+

-

+

i

n n

+

-

i

+

-

+

i

TransparentConductive

Layer

CIGS

Back Contact

SubstrateGlass Tube

Cell 1 Cell 2Current Flow

Asinglecellthatisshadedwillstopproducingcurrent.Tisblockscurrentowfromallcellswiredinserieswithit.Tus,shadingonecell(fully)blocksoutputfromtheentiremodule.

However,sincetheSolyndrapanelhas40cylindricalmodulesinparallel,shadingoneofthemcausesonlyasmallreduction-1/40- inthepanelsoutput.Furthermore,becauseSolyndrapanelscollectindirectandreectedlightaswellasdirectlight,itisverydiculttofullyshadeamodule,muchlessafullpanel.Asaresult,Solyndrapanelsarelesssensitivetoshadingthanotherpaneltypes.

Bycomparison,shadingevenasmallportionofatypicalat-platePVmodulecansignicantlyreducetheperformanceoftheentiremodule.Solyndrapanelsarelessaectedbyshadingthanothertechnologies,soitispossibletoplacethemclosertoobstructionsthanotherpanelsandstillmaintaingoodperformance.

ypesofshadingandtheirrelativeeectareshowninFigure8.

Figure 8. Limited, Moderate, and Severe Shading

Limited Shading Moderate Shading Severe Shading

SHADE

SHADE

SHA

DE

SHADE

SH

ADE

SHADE

SHADE

SHADE

Column1showsexampleswhereallorpartofasinglemoduleisshaded.Tisslightamountwillnotsignicantlyaectoutput.Incolumn2,severalmodulesareshaded.Tiscouldcompromisepaneloutput,andmayaectsystemoutput,dependingonthedegreeanddurationoftheshadow.

Column3showssevereshading.Notethatinthelowerdiagram,eectiveshadingisstillseverebecauseallofthemodulesareatleastpartlyshaded.


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ShadeDesignRecommendations

Ifthereareobjectsontheroofornearthebuilding,youshoulddeterminetheamountofshad-ingtheywillcause.Terearetoolsavailableforthispurpose,includingtheSolarPathnder,fromSolarPathways,andtheSun-Eye,fromSolmetric.Eithercanbeusedtodeterminetheareaanddurationofshadows.Itisimportanttomakemeasurementsatmultiplelocationsontheroofandaroundanyroof-topobjectsthatwillcastashadow.

Ifyoucannotmakesuchmeasurements,orthereareveryfewpotentialshade-causingobjects,

youcanestimatethesizeoftheshadowfromable1.Forvariouslatitudes,itshowsthemaxi-mumangularheightofthesunonthewintersolstice,andtheresultinglengthoftheshadowfromanobject10units(feet,meters,etc)high.

Table 1. Shadow Lengths at Winter Solstice

Latitude Sun Angle, Winter Solstice Shadow Length per 10 Units of Height

25 42.5 10.9

30 37.5 13.0

25 32.5 15.7

40 27.5 19.2

45 22.5 24.1

50 17.5 31.7

55 12.5 45.1

(Teformulafortheheightofthesunatthewintersolsticeis67.5-Latitude.)

On-roofobjectswillshadepanelstotheeast,west,andnorth(orsouth,inthesouthernhemi-sphere)oftheobject.Teobjectsshadowwillsweepacrossasectionofroofasthesuntransitsthesky,asshowninFigure9.Earlyinthemorning,andlateintheafternoon,theshadowsarelong.Atmid-day,theshadowisshorter.

Figure 9. Shadow Path Over the Day

Morning

Sun

Noon Sun

Afternoon

Sun

Morning

ShadowNoon

Shadow

Afternoon

Shadow

Shadingeectsaremostcriticalatmid-day,becausethisispeakenergyproductiontime.Atthistime,theshadowfallstothenorth(orsouth,inthesouthernhemisphere).

Estimating Shade

Manydesignersestimateshadeasthepercentageoftotalpanelareathatisshadedduringanyportionoftheday.Tisisaconservativeestimate.Eitherofthetestinstrumentsdescribedear-liercanbeusedtogiveamorepreciseestimate.Youcanalsorenetheestimatebydeterminingtheportionoftubesthatareshaded,ratherthattheportionofarea.


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Shade Clearance Example

TisexampleaddsclearancefortheshadingcausedbytheHVACunit.Arectangularareatothenorthwest,north,andnortheastiskeptfreeofpanels.Tepanelarrangementhas1460panels,andeachofthefoursub-arraysisamultipleofve,thestringlength.

Figure 10. Shade Clearance Example200 (61 m)

161-8 (49.3 m)

39-4(12 m)

140(42.7 m)

125(38.1 m)

142 (43.3m) 58 (17.7 m)

39-4(12 m)

265

(80.7 m)

225-8(68.8 m)

HVAC unit6 high

(1.82 m)

Detail B Clearance for shade

Figure 11. Detail B - Shade Clearance

Shade clearance

HVAC 6 (1.8 m) high

Colorcode:

Obstruction

MinimumSetback


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WindClearance

TeuniquedesignofSolyndrapanelsmeanstheywithstandwindforcesmuchbetterthanstandardat-platemodules.Solyndrapanelshavebeencertiedatwindspeedsupto130mph(208kph)inwindtunnelstudiesandintherealworld.

Windspeedsaredenedasa3-secondgustmeasuredat10meters,perASCE7-05,Figure6.1.TedesignwindspeedforasiteintheUnitedStatesmaybefoundbyconsultingASCE7-05,Chapter6.

RooZones

Windtendstoliftpanelsatthecornersandedgesofthearray,thus,windclearancerulesaredenedaccordingtocorner,edge,andmiddlezonesoftheroof.FollowingtheapproachofASCE7-05,fourroofzoneshavebeendened:

Teminimumsetbackzone,astrip5feet(1.52m)wideallaroundtheperimeter.Panelsareneverpermittedhere.Tiszoneisbasedonextensivewindtestingandanalysis.

Zone(A),astripadjacenttotheminimumsetbackzone.Panelsmaybeplacedhere,withconditions.

Zone(B),anarcsegmentateachroofcorner.Panelsmaybeplacedhere,withconditions.Zone(C),theportionnotincludedinAorB.Panelsmaybeplacedhere,withconditions.

Slopes and Parapets

Roofzonedenitionsdependonbothroofslopeandtheheightoftheparapetwall, ifany.Solyndrapanelsarenotrecommendedforuseonroofslopesgreaterthan2:12(9.5).Tebuildingindustrytypicallyusesthetermlow-slopeforanyrooflessthan2:12.Forinstallationpurposes,Solyndradividesthisintotwosub-categories.Flatroofsarethosewithslopeslessthan1:10(5.7).Roofswithslopesbetween1:10and2:12haveslightlydierentrules.

Lowparapetroofsarethosewithaparapetheightlessthan19inches(0.48m).Parapetsof19

inches(0.48m)ormorehavedierentzoneshapesandless-restrictiverules.

Zonedenitionsforat,high-parapetroofsareshowninFigure12onpage14.Zonedeni-tionsforat,low-parapetroofsareshowninFigure13onpage15.

Zonedenitionsforhigh-parapetroofswithslopesupto2:12areshowninFigure14onpage15.Zonedenitionsforlow-parapetroofswithslopesupto2:12areshownin Figure15onpage15.Notethattheseroofsmayhaveacentralridgeline,i.e.agableroof,andthattheclearancerulesareslightlydierentalongtheridge

Ineachofthefourgures,thered-shadedarearepresentsroofareainwhichpanelsmaynotbeplaced.

DefnitionoBuildingDimensions

Buildingheightisdenedastheheightabovegroundoftheportionoftheroofonwhichthearrayisinstalled.Tereshouldbenosurroundingbuildingstallerthan150%ofroofheightwithinadistanceequalto200%ofroofheight.

Forrectangularbuildings,thedenitionsoflength,width,andheightareclear.Ifthebuildingisnon-rectangular,consultASCE7-05fordenitions.


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Figure 12. Illustration of Roof Zone Denition - Slope


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Figure 13. Illustration of Roof Zone Denition - Slope


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MinimumSub-ArraySizes

able2onpage16denestheminimumsub-arraysizesforroofsupto60feet(18.3m)highandwithaslopelessthan1:10.Itisbasedona100%LoadFactor.

able3onpage17denestheminimumsub-arraysizesforroofsupto60feethighandslopesupto2:12,ata100%LoadFactor.

able4onpage17denestheminimumsub-arraysizesforroofsfrom60feet(18.3m)to600

(183m)high.Itappliesonlytoroofswithslopesupto1:10,ata100%LoadFactor.Design Rules

Panelsshallonlybeplacedoverrmly-attachedroofsurfaces.Loose-laidmembranesorothermaterialsarenotacceptable.

PanelsshallnotberaiseduphigherthanthestandardheightofthesuppliedSolyndrapanemounts.Donotuseblocks,frames,oranyotheritemthatwillliftthepanel.

Terulescitedhereshouldbeconsideredminimums.Whenmorepanelsareconnectedto-getherinanarray,thearrayhasmoreresistancetowindeects.Wheneverpossible,buildar-rayslargerthantheminimum.

Heightisdenedastheheight,abovethesurroundingterrainorground,oftheportionotheroofonwhichthearrayisinstalled.Tereshouldbenosurroundingbuildingstallerthan150%ofbuildingheightwithinadistanceof200%ofbuildingheight.

Atallparapetisonethatis19(0.48m)ormoreinheight.

Table 2. Minimum Sub-Array Sizes:

Buildings 60 Feet (18.3 m) High

Roofs 1:10 Slope

100% Load Factor

Coe

fcientoFriction

Buildings 60 Ft (18.3 m); 1:10 slopeF

cRooZone 85MPH

(137KPH)

95MPH

(153KPH)

130MPH

(208KPH)

0.4

A(Note2,3) 8 15 Notallowed

B,shortparapet 35 50(Note5) Notallowed

B,tallparapet 6 25 Notallowed

C 4 8 Notallowed

0.58

A(Note2,3) 1 4 35(Note2,3)

B,shortparapet 1 8 Notallowed

B,tallparapet 1 1 49

C 1 4 25

0.83

A(Note2,3) 1 1 8

B,shortparapet 1 1 15

B,tallparapet 1 1 4

C 1 1 8

1.0

A(Note2,3) 1 1 8


B,tallparapet 1 1 4

C 1 1 8


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Buildings 60 Feet (18.3 m) High

Roofs 1:10 Slope; 2:10 Slope

100% Load Factor

CoefcientoFriction

Buildings 60 Ft (18.3 m); 2:12 slope

Fc

RooZone 85MPH

(137KPH)

95MPH

(153KPH)

130MPH

(208KPH)

0.4

A(Note2,3) Notallowed Notallowed Notallowed

B,shortparapet Notallowed Notallowed Notallowed

B,tallparapet 48 60 Notallowed

C 75 Notallowed Notallowed

0.58

A(Note2,3) 40 56 Notallowed

B,shortparapet 36 40 Notallowed


C 14 21 84

0.83

A(Note2,3) 6 18 30



C 4 12 21

1.0

A(Note2,3) 5 5 25


B,tallparapet 5 5 5

C 1 1 10


Taller Buildings

1:10 Slope

CoefcientoFriction

60-120 Feet (18.3 m); 1:10 slope 120-180 Feet (36.6-54.9 m); 1:10 slope

Fc

RooZone 85MPH

(137KPH)

95MPH

(153KPH)

130MPH

(208KPH)

85MPH

(137KPH)

95MPH

(153KPH)

130MPH

(208KPH)

0.4

A(Note2,3) 30 55 Notallowed 45 Notallowed Notallowed

B,shortparapet Notallowed Notallowed Notallowed Notallowed Notallowed Notallowed

B,tallparapet Notallowed Notallowed Notallowed Notallowed Notallowed Notallowed

C 20 30 Notallowed 25 49 Notallowed

0.58

A(Note2,3) 9 15 Notallowed 9 25 Notallowed

B,shortparapet 16 55 Notallowed 36 Notallowed Notallowed

B,tallparapet 1 9 Notallowed 4 25 Notallowed


0.83

A(Note2,3) 1 6 49(Note2,3) 4 9 Notallowed

B,shortparapet 1 4 Notallowed 4 4 NotallowedB,tallparapet 1 4 36 4 4 Notallowed

C 1 6 36 4 8 55

1.0

A(Note2,3) 1 4 36 4 5 45

B,shortparapet 1 4 55 4 4 Notallowed

B,tallparapet 1 4 4 4 4 20

C 1 4 25 4 5 35


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Table 4, continued.

CoefcientoFriction

180-240 Feet (54.9-73.2 m); 1:10 slope 240-300 Feet (73.2-91.4 m); 1:10 slope

Fc

RooZone 85MPH

(137KPH)

95MPH

(153KPH)

130MPH

(208KPH)

85MPH

(137KPH)

95MPH

(153KPH)

130MPH

(208KPH)

0.4

A(Note2,3) 55 Notallowed Notallowed Notallowed Notallowed Notallowed


B,tallparapet Notallowed Notallowed Notallowed Notallowed Notallowed Notallowed

C 30 Notallowed Notallowed 30 Notallowed Notallowed

0.58


B,shor tparapet 55 Notallowed Notallowed 55 Notallowed Notallowed



0.83


B,shortparapet 4 9 Notallowed 4 9 Notallowed



1.0

A(Note2,3) 4 6 49 4 6 49

B,shortparapet 4 4 Notallowed 4 4 Notallowed


C 4 7 40 4 7 40

Table 4, continued.

CoefcientoFriction

300-400 Feet (91.4-122 m) 400-500 Feet (122-152 m) 500-600 Feet (152-183 m)

Fc

RooZone 85MPH

(137KPH)

95MPH

(153KPH)

85MPH

(137KPH)

95MPH

(153KPH)

85MPH

(137KPH)

95MPH

(153KPH)

0.4

A(Note2,3) Notallowed Notallowed Notallowed Notallowed Notallowed Notallowed

B,shortparapet Notallowed Notallowed Notallowed Notallowed Notallowed NotallowedB,tallparapet Notallowed Notallowed Notallowed Notallowed Notallowed Notallowed

C 49 Notallowed Notallowed Notallowed Notallowed Notallowed

0.58

A(Note2,3) 25 55 32 Notallowed 35 Notallowed


B,tallparapet 25 Notallowed 49 Notallowed 55 Notallowed

C 20 36 24 45 25 49

0.83

A(Note2,3) 8 16 9 22 9 25

B,shortparapet 4 42 16 49 25 Notallowed


C 7 16 9 20 9 24

1.0

A(Note2,3) 5 9 7 12 8 15

B,shortparapet 4 4 4 16 4 25


C 5 9 7 12 7 15

*Installationisnotpermittedonbuildingsover300eet(91.4m)highinwindzonesover95MPH(153KPH).


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Notes on Tables

Tefollowingnotesapplytoable2,able3,andable4.

1. Powdercoatreferstothepaintnishonthepanelmount,i.e.nopadrequired.

2. Numberofpanelsindirectiontowardscenterofroofmustequalorexceednumberofpanelsalongperimeter.

3. NoarraycanbefullyinsideZoneA.ArrayshallhaveatleasttwotimesasmanypanelsinZoneCasinZoneA(seeFigure16onpage20).

4. ZoneBisdenedbyeitherFigure13onpage15(withparapet


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PanelPlacementatEdgesandOverObstacles

Panelsplacedattheedgeofanarray-thatisinZoneAorB-mustbeconnectedtoaminimimnumberofpanelsinZoneC.

Nosub-arraycanbefullyinsideZoneA.AllarraysshallhaveatleasttwotimesasmanypanelsinZoneCasinZoneA(seeFigure16).Likewise,nosub-arraycanbefullyinsideZoneB.AllarraysshallhaveatleastasmanypanelsinZoneCasinZoneB.

Inaddition,thearraymustbeas deep(or deeper)thanit iswide,Tatis, thenumberofpanelsinthedirectiontowardthecenteroftheroofmustequalorexceedthenumberofpanelsalongperimeter.

Ifyouaresettingupasmallarrayforevaluationpurposes,placeitinthecenteroftheroof;welawayfromZoneAandZoneB.

Figure 16. Rules for Panel Placement at Edges

Zone

C

Roof EdgeAcceptableNot AcceptableNot Acceptable

Zone

A

PlacingPanelsoverRooObjects

Tereareseveralrulesthatmustbefollowedwhenplacingpanelsaroundoroveranyobstruc-tions,conduit,orotheritemsonthesurfaceoftheroof.

First,neverplacepanelsoverobjectsmorethan8inches(20cm)tall.Neverblockuppanelstoclearobjects.

Roof Object Height & Size

Forthepurposesofclearance,roofobjectheightandsizearenotthesame.Objectssuchasconduitrunsaresizedaccordingtothediameteroftheconduit(oranytypeofpipe,etc),notheheightofthetopoftheconduit.Tus,aone-inchconduitwhosetopedgeissixincheabovetheroofsurfaceistreatedasaone-inchobject,notasix-inchobject.Whenseveralpipesareruntogether,eachoneistreatedasanindependentobject.

SeveralexamplesareshowninFigure17onpage21.


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Figure 17. Examples of Roof Object Height Measurements

8(20 cm)

1

(2.5 cm)

3(7.5 cm)

4(10 cm)

6(15 cm)

2(5 cm)

(a) (b) (c) (e)(d)

Objectswhichrestdirectlyontheroof,withnogap,aredenedbytheirheight.Object(a)inFigure17isanexample.

InFigure17,objects(b),(c),(d),and(e)donotrestdirectlyontheroof.Teyare,respectively,1inch(2.5cm),3(7.5cm)inches,4(10cm)inches,and6(15cm)incheshigh.TeyareNO3inches(7.5cm),5inches(12.5cm),6inches(15cm),and8inches(20cm)-itisnotnecessarytoincludethespaceundertheobjectwhendeterminingheight.

Panelarraysmaybeplacedoverobjectslessthan3inches(7.5cm),provided:

(a)theobjectslengthORtheobjectswidthdoesnotexceed12inches(30cm),OR

(b)theobjectisunderthearraysinteriorpanelsandeithertheobjectslengthorwidthdoesnotexceed25%ofthearrayslengthorwidth,respectively.

Notethattheserulesdonotpreventpanelsfrombeingplacedoverconduit,etc,becauseeachconduitislessthan12inches(30cm)across.Tus,rule(a)exemptsconduitandotherpipinginalmostallcases.

Ingeneral,rule(b)permitspanelstobeplacedoverotherrooftopitemsaslongastheitemsareintheinteriorofthearray.

Panelarraysmaybeplacedoverobjectsbetween3inches(7.5cm)and8inches(20cm),pro-vided:

theobjectisbelownomorethantwopanelsontheexteriorofthearray,AND

theobjectisbelownomorethan20%ofthepanelsinthearray,AND

thesub-arraysizeisatleasttwicetheminimumdenedinthetables.

Taller Objects

Objectstallerthan8inches(20cm)shouldnotbecoveredbypanels.

Anybuildingstepsorobstructionsmorethan8inches(20cm)high,suchasoverruns,HVACunitsorskylights,shallhaveaminimumclearanceequaltothelesseroftheobstructionswidthortwiceitsheight.


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WindClearanceExample

Solyndraarraysarehelddownbytheirownweight.Onbuildingswithlowornoparapet,youmustmaintainaminimumsetbackfromthebuildingedge,andatcornersmakesuretherareenoughpanelshookedtogethertoprovideadequatemass.Inaddition,youmustallowfoclearancearoundlargeobstaclesonroofs,duetowindeddies.

Figure18showsatwo-storybuilding,30feet(9m)tall,withaparapetlessthan19inches(0.48m).Tereare1295panelstotal.

Figure 18. Wind Clearance Example

200 (61 m)

161-8 (49.3 m)

39-4(12 m)

140(42.7 m)

125(38.1 m)

142 (43.3m) 58 (17.7 m)

39-4(12 m)

265(80.7 m)

225-8(68.8 m)




HVAC unit6 high

(1.82 m)

Detail B

Detail C Detail D Structural Member

Minimum Setback

Detail A

Fire Clearance

Wind clearance around HVAC

Zone B

Zone B

Zone B

Zone B

Zone B Zone BZone A

Zone A

Zone A

Zone A

Zone A

Zone A

Wind Zone A Border

Colorcode:

Obstruction

Wind

MinimumSetback


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Figure 19. Detail A - Wind Clearance Example


Clearance for wind

Figure 20. Detail B - Wind Clearance Example

HVAC 6 (1.8 m) high

Clearance for wind

Figure 21. Detail C - Wind Clearance Example

Zone B restricted area

Array > 15 panels

Wind clearance

Figure 22. Detail D - Wind Clearance Example

Skylight

Wind clearance

Colorcode:

Obstruction

Wind

MinimumSetback


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AllClearances

Somedesignsmustmeetre,wind,andseismicrulesatthesametime.Itmightseemthatthiswouldseriouslyreducepanelcount,but Figure23showsotherwise.Itshowsthesametwostorybuilding,30feet(9m)tall,withaparapetlessthan19inches(0.48m).Tereare1265panelsinall.

Figure 23. All Clearances Example

200 (61 m)

161-8 (49.3 m)

39-4(12 m)

140(42.7 m)

125(38.1 m)

142 (43.3m) 58 (17.7 m)

39-4(12 m)

265(80.7 m)

225-8(68.8 m)




HVAC unit6 high

(1.82 m)

Detail B

Detail C Detail D Structural Member

Minimum Setback

Detail A

Fire Clearance

Seismic, wind clearance around HVAC

Zone B

Zone BZone B

Zone B

Zone B

Zone BZone A

Zone A

Zone A

Zone A

Zone A

Zone A

Wind Zone A Border

Shade clearance around HVAC

Seismic Clearance

Colorcode:

Fire

Obstruction

Seismic

Wind

MinimumSetback


25/70


Figure 24. All Clearances - Detail A




Clearance for wind

Seismic clearance

Figure 25. All Clearances - Detail B


HVAC 6 (1.8 m) high

Clearance for shade

Clearance for wind

Clearance for seismic

Figure 26. All Clearances - Detail C

Minimum clearanceFire clearance

Zone B restricted areaArray > 15 panels

Wind clearanceSeismic clearance

Figure 27. All Clearances - Detail D

Skylight


Wind clearance

Seismic clearanceColorcode:

Fire

Obstruction

Seismic

Wind

MinimumSetback


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EstimatingEnergyYield

Onceyouhavecompletedyourlayout,youcanuseSolyndrason-lineenergyyieldmodelingtooltodeterminehourly,daily,monthly,andtotalenergyyield. Figure28showsascreenshoofthedataentryportionofthetool.

RefertoForecasting Energy Yieldforinstructionsintheuseofthisprogram.ContactyourSolyndrarepresentativetoobtainaccesstothetool.

Figure 28. Example Screen Shot from Solyndra Energy Yield Tool

Detailedresultsareavailableon-screen, ina downloadable report,and ina downloadableExcel-compatiblespreadsheet.


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Chapter 3 Sub-Array Wiring Options

TheSolyndraConnectorSystem

EachSolyndrapanelhasfourconnectors;twoforpositiveandtwofornegative.Teconnec-torsarearrangedtomakeitpossibletoimplementalmostanydesiredseries,parallel,orseries-parallel.TepanelanditsconnectorsareshowninFigure29.

Figure 29. Solyndra PV Panel and Power Connections

Male, Positive

Male, Negative

Female, Positive

Female, Negative

+ Positive Side

Negative Side

AseriesconnectionisshowninFigure30.

Figure 30. Two Panels Wired in Series

Male,

Positive

Male

Female,

Positive

Female

+ Positive

Side

Negative

Side

Male

+

Male, Negative

Female

+

Female, Negative

+ Positive Side

Negative Side


28/70


Figure31showshowtwopanelscanbeconnectedinparallel.

Figure 31. Two Panels Wired in Parallel

Male, Positive

Male,

Female,

+

Female, Negative

+ Positive Side

Negative Side

Male,

+

Male, Negati

Female, Positiv

Female,

+ Positive Side

Negative Side

Tesearethetwomostcommonpanel-to-panelconnections.Tereisathirdpossiblearrange-ment;aseriesconnectionofpanelswhicharephysicallyend-to-end.Tisisshownin Figure32.

Figure 32. Series Connection, End-to-End Panels

Male, Positive

Male,

Female,

+

Female, Negative

+ Positive Side

Negative Side + Positive Side

Negative Side

Female,

+

Female, Negati

Male Positi

Male,

Do not connect!

Itisimportantwhenconnectingpanelsinseries,asshowninFigure32,thatyouNOcon-necttheotherconnectorpair.Tiscreatesashortcircuit.Acorrectve-panelstringisshowninFigure33.Youmaywishtoplacecapsontheunusedconnectors,toavoidinadvertentuse

Figure 33. Five-Panel Series Connection, End-to-End

+ No Inter-panel Connections

Figure34showsseriesconnectionsbetweenpanels,andatypicalview,fromunderneaththearray,ofseveralseriesconnectioninastringofpanels.

PanelwiringusesUSE-2AWG#12conductors.oconnectpanelsinseries,takethepositiveconnectorandsnapintothenegativeconnectoroftheadjacentpanel.

Figure 34. Interpanel Connection of Positive and Negative Pigtails


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JumperTypes

Mostconnectionscanbedirectlybetweenpanels,usingthepanelpigtails.Tistypeofconnec-tionisshownasablacklineinthefollowingdiagrams.Incertaincases,youwillneedlongerjumperconnection,forbothpositiveandnegativeconnectors.Teseareshownasredorbluelinesinthefollowingdiagrams.

Figure35showsthetypesofjumpers.

Figure 35. Jumper Types

Male, Positive

Male, Negative

Female, Positive

Female, Negative

Positive Jumpers Negative Jumpers

ElectricalSub-Arrays

Panelsaregroupedinseriesstringstoproducesucientvoltagetodrivetheinverter.Aseriesstringisagroupofpanelswhoseelectricalconnectionsareinseries.Teseseriesstringsarethenconnectedinparalleltoincreasethetotalcurrentandreducethenumberofinvertersneeded.

Tenumberofpanelsneededintheseriesstringdependsontheinverterchosenforthedesign,butveisatypicalnumber,andwillbeusedforthefollowingexamples.(Refertopage36fordetailsonstringsizing.)

Similarly,mostdesignshavethreesuchstringsinparallel,foratotalof15panelsperstring-block.Aseriesstringanda5by3arrayareshowninFigure36.

Figure 36. A Typical Series String, and a 5 by 3 Array

Home-run

Connection

Home-run

Connection

Inalloftheseexamples,the locationofthehome-runconnectioncanvary.Ingeneral, thehome-runconnectionshouldbemadetominimizethelengthofwirerequired.


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MoreComplexSub-ArrayArrangements

Insomecases,thestandard5by3string-blockarrangementmaynotbemechanicallycon-venientforagivenrooflocationduetoshape,obstacles,orotherfactors.Figure37showsanalternatemethodofcreatinga5by3string-block.NotetheplaceswhereconnectionsshouldNObemade.

Figure 37. Alternate 5 by 3 Sub-Array Conguration

Home-runConnection

Home-runConnection

No Inter-panel Connections

Roofobstructionsmaymakeitnecessarytoarrangepanelsinarbitraryways.Figure38showsamethodofarrangingpanelstoclearsuchobstructions.(No-connectsomittedforclarity.)

Figure 38. Panel Arrangement to Clear Obstructions

Home-run

Connection

Home-run

Connection

Obstruction

Obstruction


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It isoccasionallynecessary toplacepanelsalongadiagonalorcurvedboundary.Figure39showsamethodofwiringa5by3string-blocktotadiagonaledge.(No-connectsomittedforclarity.)

Figure 39. Panel Arrangement for a Diagonal Boundary

Home-run

Connection

Home-run

Connection


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PanelMatching

Everypanelhasamaximumpowerpoint,theuniquecombinationofvoltageandcurrentthatdeliversthemostenergy.TesevaluesarecalledVmpandImp.Eachpanelsmaximumpowerpointisataslightlydierentpoint,andwillvarywithtemperatureandinsolation.Forasinglepanel,thisisnotanissue,becausetheinverterwillkeepthepanelatitsmaximumpowerpoint.However,thereisasmalllossofeciencywhenmultiplepanelsareconnectedtothesaminverter.Whentwoormorepanelsarewiredinseries,thecurrentineachpanelisthesame,

butthatvalueofcurrentcannotbetheoptimumloadcurrent(Imp)forallpanelsinthestring.

Likewise,whentwoormorepanels(orseriesstrings)arewiredinparallel,allmustoperateatthesamevoltage,butthisvoltagecannotbetheoptimumloadvoltage(Vmp)forallele-ments.

ForSolyndrapanels,itisnotnecessarytoattempttomatchpanelscloselywithinanarray.Temismatchlosscanbekeptunder0.4%.

PanelMatchingRecommendations

Solyndrapanelsareveryinsensitivetooperationatnon-optimumcurrent,andreasonablyinsensitivetooperationatnon-optimumvoltage.Tismeansthatpanelsofdierentpowerratingsdoverywellwhenwiredinseries,butslightlylesswellwhenwiredinparallel.

Panelsfromasmanyasthreedierentpowerratingsmaybemixed,aslongasthepowerrat-ingsareadjacentones.Tus,withnameplatevaluesof150,157,165,173,and182watts,157-165-173ispermissible,but150-165-173isnot.

Wheninstallingpanels,theguidelinesillustratedinFigure40shouldbefollowed.Inthisillustration,panelsofthreedierentpowerratingsarerepresentedbythethreedierentcolorsIneachsub-array,therearevepanelsperseriesstring,andthreestringsinparallel.

Figure 40. Panel Matching and Panel Arrangements

Example(a)showsaninstallationoSolyndrapanels

entirelyothesamepowerrating.Thisisthebest-caseinstallationpractice,butmaynotbeapplicabletovery

largearrays.

Inverter

Inverter

Inverter

InExample(b)thepanelsarepulledromcratessothat

eachseriesstringcontainsasimilarmixopanels,and

allparallelstringscontainsthesamepanelarrange-

ments.Thisistheoptimumcombinationwhenmixing.

Thisarrangementwillkeepmismatchlossbelow0.4%.

Inverter

Inverter

Inverter

InExample(c)theinstallersusedthecontentsoone

crateo16panels,thenproceededtothenextcrate,

andcontinued.Thereisnolossinmoststringsbecause

theyarematched,butthelossinthenon-matchedstringsbringsthetotalmismatchlossto0.8%.

Inverter

Inverter

Inverter

Example(d)istheworst-casearrangement.Byconfn-

ingthemismatchacrossparallelstrings,thelossex-

ceeds1%.Thisarrangementwouldnotoccurduringa

normalinstallationprocess.Itisshownheretoindicate

thatitistheonearrangementthatshouldnotbeused.

Inverter

Inverter

Inverter


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PlanningRecommendations

Youshoulddevelopaspecicwiringandplacementplanforeachelectricalsub-arrayintheoveralllayout,andhaveitavailableduringinstallation.Installerswillneedtoknowwhichwaytoorienteachpanelasitisplaced,sothatwiringconnectionscanbemadeconveniently.

Ifyouareusingpanelsofmorethanonepowerrating,youshouldindicatethecorrectpowerratingforeachpanelonthelayout.

Notethatwhileitisnecessarythatallstringsconnectedtoagiveninverterbethesamelength,itisnotnecessarytohavethesamenumberofstringsinparallelforeveryinverter.

Itiselectricallyandmechanicallyfeasibletohookgroupsofpanelsinparallelrst,andthencombinetheparallelblocksinseries.However,thiscongurationwillslightlyincreasepanelmismatchloss,andisnotrecommended.

Fordetailsonthephysicalwiringandhandlingofpanels,pleaserefertotheSolyndraPhoto-voltaicPanelInstallationManual.


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Chapter 4 String Sizing

SeriesStringLength

Optimumseries string length isabalancebetweenthehighest safevoltageandthe lowestworkableoperatingvoltage.Tehighestvoltageoccurswhenthetemperatureiscoldandtheinverteriso.Teinverterthenseestheopen-circuitvoltageofthepanels.Telowestvoltageoccursonhotdays,typicallylateintheafternoon,whenlightlevelsarefallingbutthetemperatureremainshot.

Tenumberofpanelsthatcanbewiredinseriesisdeterminedbythemaximumsafevoltageoftheelectricalsystemandtheworst-caseopen-circuitvoltageofthepanels.

Temaximumsafevoltageislimitedbyeitherthevoltageratingoftheinverter,ortheratedworkingvoltageofthewiring.IntheUS,mostwiringisratedfor600voltsmaximum;inEuropethemaximumratingis1000volts.

odeterminethemaximumnumberofpanelsyoucanwireinseries,computetheworst-case

panelopen-circuitvoltageatthecoldesttemperaturethesystemwillexperience.Tisiscom-monlytakenastherecord30-yearlow.Tisvoltage,timesthenumberofpanelsinseries,mustnotexceedthemaximumsafevoltageofthesystem

Teminimumnumberofpanelsinseriesissetbythepanelspeakpowervoltage(Vmp),itstemperaturecoecient,theminimumvoltageatwhichtheinverterwilloperate,andthehigh-esttemperatureatthesite.Ifthereisawiderangebetweenthehottestandcoldesttempera-tures,itmaybediculttoselectastringserieslengththatavoidsexcessivelyhighopen-circuitvoltages,yetmaintainssucientvoltageduringhotweathersothatthestringoperatingvoltagewillremainintheinverterspowertrackingwindow.

Allofthestringsconnectedtoaninvertermusthavethesamenumberofpanelsinseries.Tis

ensuresthatparalleledstringshavesimilaroutputvoltages.Itisnotnecessarytoperformancematchpanelswithinanarrayforvoltageorcurrent.

InvertersizingforSolyndrapanelsisthesameasforothertypesofPVpanels.oolsareavail-ableonSolyndraswebsitetoselectthenumberofpanelsforagiveninverter.


35/70


ParallelStrings

Tenumberofstringswhichcanbewiredinparallelislimitedbytheseriesfuserating.Tenumberofsub-arraystringsinasystemislimitedbythemaximuminputcurrentratingoftheinverter.Inordertodeterminethesub-arraystringsizelimit,usetheFaultCurrentEquation.(AfulldiscussionmaybefoundinReferenceDocument5.)

Eqn4.

Ifault =1.56 n Isc + n 1( )1.25Isc

wherenisthenumberofsinglestrings.TersttermistheNECrequiredovercurrentprotec-tiondeviceratingonasinglestring,andmustberoundeduptothenextavailablefusesize.Tesecondtermisthecurrentfromanyotherseriesstringinthesamesub-array.Teyareaddedbecausethestringsarecombinedinparallel.Equation4simpliedis:

Eqn5.

Ifault = (2.81 n -1.25)Isc

Forexample,ifthepanelseriesfuseratingis22A,howmanysinglestringsinparallelcanbecombinedwithoutviolatingtheratinganddestroyingapanelduringafault?Solveforn.

Eqn6.

n =Ifault

Isc

+1.25

1

2.81

PlugintheseriesfuseratingforIfaultandthepanelshortcircuitforI sc(letssay2.60A).Tisgives3.46.Butnmustbeaninteger,sowerounddownto3.NoticethatanincreaseinIscatconstantIfaultleadstosmallern.Whathappensifwetryandusemorethanthreestringsinparallel?Plug4intoEqn.4or5forn.Ifaultis25.97Aslightlyovertheseriesfuserating.

Notethatelectricallyitissafetohavesub-arraystringsoffewerthanthreesinglestringsinparallel,howeverthisismorecostlyintermsoflaborandmaterials.Attimes,thegeometryofarooflayoutmaynecessitatesmallersub-arraystringsthanthemaximum,butthenumberofthesestringsshouldbeminimized.


36/70


Chapter 5 Grounding

Solyndrarecommendsgroundingtheframesofallpanels.SafetyrequiresthatSolyndrapanearraysbeproperlygrounded.Correctgroundingprotectspersonnelintheeventofapanelfailureduetobreakage,anditprotectspersonnelandequipmentfromlightning-relatedeects.

oavoidelectricalshock,groundthepanelassoonasitisplaced,beforedoinganyotherwir-ing.Asthearrayisbuilt,therstpanelofeachcolumnshouldbeconnectedtoearthgroundassoonasitisplaced,usingthesuppliedgroundlugorequivalent.Aseachpanelisaddedconnectagroundstrapbetweenitandthepreviouspanel.Teseconnectionsensurethatthealuminumframeisgrounded.

Useagroundingmethodthatmeetsapplicablenationalandlocalcoderequirements.FortheUSandCanada,theseincludeNECorCSAC22.1SafetyStandardforElectricalInstallations,CanadianElectricalCodePart1.YoumayalsowishtorefertoNECArticle690ongroundingphotovoltaicarraysforspecicrequirements.

Grounding in theSolyndra systemi s accomplished by three primarye lements:1) system

groundlugs(ILSCOGBL4-DB),2)agroundwire,and3)groundstraps.Onegroundlugisinstalledontherstpanelineverycolumn,andevery15rowsthereafter.Eachoftheserowsoflugsisconnectedtogetherandthentogroundvia10AWGsolidcoppergroundwiretosystem(earth)ground.Tedesigngoalistokeepresistancetogroundbelow0.1ohm,perUL1703.

Inaddition,groundlugsmustbeinstalledwheneveranobstructioncreatesaholeinanarrayWhenbuildingaroundobstructions,therstrowaftertheobstructionrequiresagroundwireandlugstoconnecttheobstructedcolumntoeitheroneoftheneighboringcolumns.

Iflocalcodesrequirealargergroundwire,youmayneedtouseadierentgroundlug.

Tethirdcomponentofthegroundsystemisthepanelgroundstrap.ocompletethegroundpath,groundstrapsareusedtoensurethatpanelsineachcolumnareagroundedunit.

Equipmentgroundconductorsmustbeconnectedwithstainlesssteelhardware.Makesurethatthereisnocopper-to-aluminumcontact;thiswillcauserapidgalvaniccorrosion.Astain-lesssteelwashermustbeusedtoisolatecopperwirefromthealuminumframe.

Solyndrapanelscanbegroundedusingagroundingwasherorclip system,providedsuchsystemhasbeentestedandcertiedtomeetUL467requirementsforbondingandgroundingsystems,andareinstalledaccordingtothemanufacturersspecications.AllthreadedholesinaSolyndrapanelaregroundconnections,regardlessoflabeling.

Figure 41. Grounding Connections for Solyndra ArrayGround Lugs

Ground Strap

Ground Bus Wire - 10AWG or Equivalent

Grounding Holes

4 per Frame

Additional

Ground Bus

& Lugs

Roof Obstruction


37/70


ArrayInstallationoverLightningGrids

ASolyndraArrayisnotaLightningGrid

Somerooftopsarettedwithagridofconductorstodealwithlightning.ASolyndraarray,wheninstalled,maybeplacedovertheseconductors.Certainguidelinesshouldbefollowed.

Background

Alightninggridisanarrayofwiresrunninghorizontallyinbothdirectionsacrossaroof.Di-mensionsvary,buttypicallythewiresarespaceafewmetersapart.Teentiregridiscarefullygroundedtoearth.Tesegridsareoccasionallyttedwithverticalconductorsaswell,com-monlycalledlightningrods.

ArrayPlacementGuidelines

1. Inallcases,aqualiedlightning-griddesignershallbeconsultedduringthedesignandinstallationphase.

2. Inallcases,aqualiedelectricalengineershallbeengagedtodesignsystemlead-instotheinverter,equippingthemwithhigh-voltageshuntsorothersafetyequipmentasappropriate.

3. NopartofanySolyndrapanel,includingthepanelmount,shallbeincontactwithanypartofthelightninggrid.

4. TeSolyndrapanelgroundingsystemshallnotbeconnectedtothelightninggridanywhere;and:

5. TeSolyndrapanelgroundshallhaveitsowndedicatedconductordirectlytoearthground.Itshallnotbeconnectedtobuildingelectricalground.

6. Nolightningrodsshallbeplaced,orallowedtoremain,anywhereundertheSolyndraarray.

7. Nolightningrodsshallbeplaced,orallowedtoremain,withinonemeterofthe

Solyndraarray.

8. AllremaininglightningrodsshallbeincreasedinheightbyadistanceequaltotheheightofthetopoftheSolyndraarrayabovetheroof;i.e.approximately25cminmostinstallations.


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Chapter 6 System Wiring

Home-RunWiring

Sub-arraystringsareconnectedinparallelinsideacombinerbox.Justaseachpanelhasfourconnections,eachofthefourcornersofasub-arraystringwillhaveaplusorminuspigtaiavailable.Runapositivehomeruncableandanegativehomeruncablefromthecornersinsuchawaythatminimizescablelength.

Alongedgesofpanels,youmayuseeithertheSolyndra-oeredcabletraysorUV-ratedcabletiestokeepwiresorganizedandpreventthemfromdangling.Solyndrarecommendstheuseofcabletrays,astheyreducethepossibilityofsnaggingawireandoergreaterUVprotectionthancableties.

Cabletraysareavailableforboththeshortsideandthelongsideofthearray.Figure42showsasub-arraywithcabletraysinstalled.

Figure 42. Long and Short Cable Trays

ConnectorsandDustCaps

Whenconnectedtogether,theSolarlokconnectorsusedonSolyndrapanelsformaweather-tightsealdesignedtolastthelifeofthepanel.However,openconnectorsarenotweather-resistant.Terefore,Solyndrastronglyrecommendsthatallunusedconnectorsbecoveredwithdustcapswhenthepanelisinstalled.Tishelpstomaintainconnectorquality.Terearetwooptionsforthis:

Connectbothwirestothenextpanel.Tisincreasesredundancyinthewiringaswell.

UsetheavailableSolyndradustcap(maleorfemaleasappropriate)tocovertheunusedconnector.

Secureanydanglingpigtailstothepanel.

DCConduitDesignandPlacement Conductorsthatconnecteacharraycombinerboxtotheinvertershouldbedesignedandin-

stalledperapplicablecodes.HomerunwireshouldbegradeUSE-2,of12gaugeorlarger,andproperlyprotectedagainstmechanicaldamage.


39/70


InvertersorSolyndraArrays

Solyndrapanelsaredesignedtooperatewithawiderangeofinverters.Stringsofpanelsmaybeconguredforboth500Vand600VinvertersintheUSandfor1000VstringsinEurope.Tetypesofinvertersthathavebeeninvestigatedforproperoperationare:

Centralized inverters:

Solyndrapanelshavebeenveriedforoperationwithstandard300-600VDCinputcentral-

izedinverterswith3-phase,480Voutput.Somecentralinvertersmayrequirea lowvoltagesetting(alsoknownasacentertap)inordertooperatewithintheinputvoltagerangeduringbrightwarmdays.

Distributed or string inverters:

Solyndrapanelshavebeentestedwithawiderangeofdistributedinverters.ContactSolyndrafordetailsandrecommendations.

Micro-inverters:

Atthetimeofpublicationnomicro-inverterswerecommerciallyavailablethatcanoperatewithaSolyndrapanel,duetotheirlowinput-voltagedesign.Solyndraanticipatesthatitspan-elswilloperatesatisfactorilyonmicro-inverterswhentheydobecomeavailableforthehigherinputvoltagesnecessarySolyndrapanels.

Transformerless inverters

Invertermanufacturershaveintroducedvariousinverterdesignsthatemploytransformerlesstopologies.Tesetransformerlessinvertershavethepotentialto resultinhighersysteme-ciencybyeliminatingtheoutputtransformer,whichisasourceofloss.

Solyndrapanelshaveextremelylowcapacitance(500-600pF)fromterminaltoframe;sincethemeasuredleakagecapacitanceisordersofmagnitudelowerthanthatrequiredforatrans-formerlessinverteritmaybeadequateforungroundedoperationwhenconnectedtosuchan

inverter. WhileungroundedarraysaremoreprevalentinEurope,NEC690-2008hasaddressedtheis-

suein690.35.Nevertheless,manyutilityjurisdictionsmaystillrequirePVarraystobeelectri-callygroundedviathegroundingelectrodeintheinverterperUL-1741;accordingly,systemsmaynotbedesignedwithtransformerlessinvertersthatdonotallowthearraytobegrounded.


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ActualPowervsWpRating

TeactualpowerproducedbyapanelisusuallylessthantheWpratedpowerforthreereasons:

Tesunisusuallynotasintenseasthe1000W/m2usedformeasuringWp.

Powerdecreasesastemperatureincreases,andthepanelisusuallywarmerthanthe25CtemperatureusedformeasuringWp.Tisisespeciallylikelytobethecaseinthesummer.

Tepanelisnotaimeddirectlyatthesun;thatis,itisnotperpendiculartothesunlight.

Geometry & Tracking

Teangleofthepanelwithrespecttothedirectionofsunshineaectstheamountofsolarenergywhichstrikesthepanel.Forexample,tiltingaconventionalsolarpanel45degreesawayfromthesunreducestheamountofdirectsolarradiationthatstrikesthepanel,asshowninFigure45.Tepanelonlycapturesabout70%(1meteroutof1.41meters,inthisexample)ofthesunwhentheangleofincidenceis45degrees.

Non-trackingdesignsaresubjecttothis intensity-reductionthroughouttheday.Solyndrasuniqueself-trackinggeometryreducesthiseect,asillustrated.ASolyndrapanelisaone-axistrackingpanel;asthesunmovesacrosstheskyfrommorninguntilevening,thepanelpassively

tracksthismotion.Solyndrapanelsarethusabletoproducemoreenergythanconventionalatplatepanelsinthemorningandafternoonhourswhenthesunisnotdirectlyoverhead.

Figure 45. Geometry Eect & Solyndra Self-Tracking Eect

1-meter panel 1-meter panel

1.0 meter 1.41 meters Solyndra modules

Morning Noon Afternoon

Tisself-trackingfeaturemeansthatSolyndrapanelsdelivermoreenergyinthemorningandevening,comparedtoconventionalatpanels,eventhoughthepeakislower. Figure46showsmeasuredoutputofaSolyndrapanelandaatpanel.TeSolyndrapanelproducesmoretotalenergyduringtheday.TisiswhyaSolyndrapaneldoesnotrequireasmuchinvertercapacityasconventionalpanels.Putdierently,forthesameenergyoutput,aSolyndrasystemworkswellwithasmallerinvertersizethanaconventionalatpanelPVsystem,signicantlyreduc-ingcosts.

Figure 46. Solyndra Energy Yield Curve

6 AM 9 AM Noon 3 PM 6 PM

140120

10080604020

0

Solyndra

SL001-157Sharp

NT180U1

Instantane

ous

Power


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InverterSizing

Becauseofthefactorsdescribedabove,atypicalsolararraywillnevergeneratethenominalWpratedpower.Teinvertercanandshouldbesmaller.Teamountdependsonbothtechnicalfactorsandeconomicfactors.

Technical Factors

Solyndrassolar-energymodelingprogramproducesanhour-by-hourforecastofenergypro-

duction.Fromthis,thepeakpowerproducedbythearraycanbedetermined.Aninvertersizedtothisvaluewillbesucient.Asanexample,anominal250kWarrayinstalledinSacramentoCaliforniawillproduce,forafewdaysaroundJune22nd,amaximumof206kW.Tisisthepeakoutput,soaninverterof210kWpismorethansucientforthisarray.

Economic Factors

Itmaymakeeconomicsensetouseanevensmaller inverterthanthetechnical factoralonesuggest.Invertersarenotharmedbybeingconnectedtoanarraywhichproducesmorewattsthantheinverterrating.Teinvertersimplyignorestheextrapower(ifany),aneectknownasclipping.

Intheaboveexample,a200kWorevena180kWinverterwillresult inasmallamountofenergyloss,butthecostsavingswilljustifyit.TeLevelizedCostofEnergy(LCOE)metricisanusefulindicatoroftheoptimuminvertersize,asitaccountsforboththecostbenetandthelostenergypenalty.

Intheexamplearray,a200kWinverterwillsacriceonly0.2%oftotalenergy.A180kWinverterwillsacriceonly3.6%.TesystemdesignercancomputetheLCOEfordierentin-vertersizes,giventhecostofinverters.Figure5showstheLCOEfordierentinvertersizesforthenominal-250kWexamplesystem.Atthespeciedratioof1.45,theinvertersizeis172.4kW,foralossofonly8.4%.

SolyndraoersanExcelspreadsheettoolthatwillautomaticallyimportthehourlydatafrom

theenergyyieldmodelandevaluatetheperformanceofvariousinvertersizes.Figure 47. LCOE vs DC:AC Ratio

1.00 1.20 1.40 1.60 1.80 2.00

DC:AC Ratio

$0.256

$0.254

$0.252

$0.250

$0.248

$0.246

$0.244

$0.242

LCOE

1.45


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MaximizingValueorAC-LimitedIncentiveApplications

Intheprevioussection,wedeterminedtheoptimuminvertersizeforagivenDCprojectsizetoyieldthelowestLCOE.Tecalculationisbasedonaxedfeed-intari(FI).However,somefeed-intarisaretiedtotheACratingoftheinverter,ratherthantheDCoutputofthearray.TerearebreakpointsintheFIatvariousACsizes.

Tisincentivesystemmeansthattheeconomicgoalistodeterminethemostcost-eectiveDCarraysizeforagivenACinverterrating.TisDC-to-ACratioiscalledtheoversizeratio.Tere

isanoptimumoversizeratiowhichwillmaximizethenetpresentvalue(NPV)oftheprojecttotheinvestor.TehighercapitalcostforthelargerDCarrayisbalancedbythegaininrevenuefromtheextraenergyproducedbytheoversizedDCarray,andsoldatthehigherFIrate.

Figure48showstheeconomically-optimumoversizeratioforanarrayinstalledwherethereisachangeinFIratesfora250kW-ratedinverter.Ata1.75ratio,thearrayis437.5kWp.

Figure 48. NPV vs DC:AC Ratio

1.00 1.20 1.40 1.60 1.80 2.00DC:AC Ratio

$700$600$500$400

$300$200$100

$0

1.75

N

PV

A250kWparrayatthislocationwillyield302MWhofenergy.Byincreasingthearraysizeto437.5kWp,thetotalenergyyieldincreasesto392MWh.TisisillustratedinFigure49.Teareainredistheenergylost;theareaingreenistheenergygainedduetotheoversizearray.

Figure 49. Energy-Cost Trade-o for Oversized Array

Histogram of Hourly Energy Output

1218435652869

1086

1303

1520

1737

1954

2171

2388

2605

2822

3039

3256

3473

3690

3907

4124

4341

400

350

300

250

200

150

100

50

0

kWO

utput 1.2 DC:AC Ratio

Histogram of Hourly Energy Output

1218435652869

1086

1303

1520

1737

1954

2171

2388

2605

2822

3039

3256

3473

3690

3907

4124

4341

400

350

300

250

200

150

100

50

0

kWO

utput

ClippedOptimized

1.2 DC:AC Ratio

Summary

Inallcases,itmakessensetodeterminetheactualpoweroutputofthearray,andsizethein-verteraccordingly.Inmostcases,itwillmakeeconomicsensetoselectaninvertersomewhatsmallerthantheactualpeakpoweroutputofthearray.Tepreciseoversizeratiowilldependonthetariregimen,actualinsolation,andinvertercost.Regardlessofyourtarimodel,youcanuseSolyndrasExceltool,ortheSolyndraDesignServicesteamwillbehappytoassistyouindeterminingtheoptimuminvertersizeforyourarrayandyoureconomicsituation.


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Chapter 7 Mechanical Design

RooLoads

Teroofdeckmaybemadeofanymaterialaslongasitiscoveredbyasecurelyfastenedlight-coloredcool-roofmembrane,hasaslopeof2:12orless,andcansupporttheload.Otherroongmaterialsandcolorsmaybeused,butlower-reectivityroofswillreducearrayoutputSolyndrahasamodelingtoolandanextensivecollectionofreectivitydata;contactSolyndraifyouwishtoinstallpanelsonanon-whiteroof.

Eachpanelcovers1.97m2(21.2ft2)andweighs,withmounts,70pounds(32kg).

Table 5. Roof Loading

Item DeadLoad(USunits) DeadLoad(Metric)

Panelswithmountsandhomerunwiring 3.3pounds/squareoot 16kg/squaremeter

Fromadesignviewpoint,addinganarraytoaroofadds3.3lbs/ft2(16kg/m2)ofloadingtotheroof.However,theroofsliveloadallowanceof20lbs/ft2(100kg/m2)maybeeliminated

becauseitwillnolongerbepossibletoplacematerialsinareasoccupiedbythearray.Tereforemostbuildingandpermittingauthoritieswillaccepttheargumentthataddinganarraywillactuallyreducethecalculatedloadontheroof.

StructuralEngineering

Allroof-topphotovoltaicinstallationsshouldbereviewedbyaqualiedstructuralengineerTefollowingdatashouldbeconsideredasadvisoryonly.

RooMountPressureLoads

Someroofmaterials,suchasmineralwoolandcertaintypesoffoaminsulation,haveaspecic

localpressureloadinglimit.Tesesoftroofsmayrequiredtheuseofapanelmountwithalargerfootprinttoreducelocalizedpressure.

SolyndraoersaLoadDistributionFoot(LDF)forinstallationsituationswhichmustmeetalocalpressureloadinglimit.TeLDFattachestothestandardpanelmount.TeattachmentallowstheLDFtotiltslightlytoaccommodateunevenroofsurfaces.

WhenusedinaccordancewithSolyndrasinstallationguidelines(seenextpage),theLDFlim-itsroofcompressiontolessthan3mm.

Table 6. Standard Panel Mount and Load-Distribution Foot

Standard Mount Load-Distribution Foot

Material Powder-coatedaluminum Powder-coatedaluminum

AreaoFoot 0.0138m2 0.123m2

Weight,each 0.48Kg 0.6Kg

Panel Mount

LDF


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DeterminingPanelMountPressure

Temaximumpressureatthefootofeachmountisshowninable7.

Teseareworst-casevalues,basedonanaverageoftwomountsperpanel.

Table 7. Standard Panel Mount Maximum Loading

Snow Load Total Weight Pressure per Mount, Standard Pressure per Mount, LDF

pas-

calskg/m2 psf kg lbs psi psf kg/m2 pascals psi psf kg/m2 pascals

0 0 0 31.9 70.3 1.69 244 1189 11662 0.20 29 144 1409

500 51.0 10.4 132.1 291.3 6.86 988 4823 47296 0.79 113 553 5420

1000 102 20.9 232.3 512.2 12.0 1732 8457 82930 1.37 197 962 9432

1500 153 31.3 332.6 733.2 17.2 2476 12090 118564 1.95 281 1371 13443

2000 204 41.8 432.8 954.1 22.4 3220 15724 154197 2.53 365 1780 17455

2500 255 52.2 533.0 1175 27.5 3965 19357 189831 3.11 448 2189 21466

2800 286 58.5 593.1 1308 30.6 4411 21538 211211 3.46 499 2434 23873

MinimumPressureRatingorRoofngMaterial

Atthemaximumratedsnowloadof2800Pascals,theminimumroofloadpressurespecica-

tionmustbe8300Pascals.Forapplicationswithlesssnoworsofterroongmaterials,contactSolyndra.

SnowLoads

SolyndrapanelshavebeentestedperSection10.16of IEC61646.Teycanwithstand58poundspersquarefoot(283kg/m2,or2800Pascals)ofsnowload.Inmanycases,snowwillaccumulateonthetubes,althoughlightsnowsometimesfallsthrough.

Solyndrapanelsdonotincreasetheamountofsnowthatwillaccumulateontheroof.

Snowonthetubesshouldbebrushedotoenhanceelectricalyield.Snowontheroofhasex-cellentalbedo,andwillnotdecreasepaneloutput.Tehistoricalsnowloadinginaparticular

regionandthedetailsofthejobsiteshouldbeexaminedtoassesstheriskofexceedingthisvalueontheroofinagivenyear.

ConstructionMaterialsPlacement

Inadditiontodeadloads,theroofmustwithstandliveloadsduringinstallation.Solyndrapan-elsarepackedhorizontallyontopalletsforshipment.Tepalletweighsapproximately1100lbs(500kg).(RefertoSolyndrasshippingdocumentationforexactweightandsize.)Makesurethattheroofsurfaceisnotoverloadedwhenpalletsareplacedontheroof.


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Chapter 8 Solyndra Panel System

TissectiondetailsthepartsinvolvedinaSolyndraPVinstallation.

PartDefnitionsandIdentifcation

Figure50showsthemajorcomponentsofaSolyndraPVpanelandtheirnames.Fastenersandothersmallpartsarelistedinable8.

Figure 50. Panel Parts and Assemblies

SolarLokMale, Positive

SolarLokMale, Negative

SolarLokFemale, Positive

SolarLokFemale, Negative

Lateral Clip HoleLateral Clip Hole

Ground Strap Hole

Ground Strap Hole Ground Strap Hole

Ground Strap Hole

Panel MountGround Lug Hole

(underside)

Ground Lug Hole(underside)

PanelInstallationRates

Panelinstallationsaretypicallydonewithave-personcrew.Ateamoftwopeopleassemblethepanels;asecondtwo-personteamcarriesthemintoposition.Tefthpersonmakesthe

electricalconnections.Anexperiencedcrewcaninstallupto300panelsperdayundergoodconditions.However,ifthepanellayoutiscomplex,orthedistancetocarrythepanelsfromthestagingareaislong,itmayonlybepossibletoinstallaround100panelsperday.


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SolyndraProvidedPartsandAncillaryRecommendedParts

GeneralRecommendations

Tefollowingisalistofgeneralrecommendationstohelptheinstallerchoosetherightma-terials,equipment,andinstallationmethodsthatwillhelpensurethatthesystemwillprovidemanyyearsofreliableservice.Teserecommendationscanbeusedtoevaluatepre-engineeredsystemdesignsandcomparesystemfeaturesfromonesuppliertoanother.

MaterialsRecommendations

DonotsubstituteanySolyndra-speciedpartswithouttheexpresswrittenconsentofSolyndra.

Materialsusedoutdoorsshouldbesunlight/UVresistant.

Followroofmanufacturersguidelinesforsealants.Ifnoguidelinesareprovided,urethanesealantsshouldbeusedforallnon-ashedroofpenetrations.

Materialssuchaswireinsulationandothercomponentsshouldbecertiedtowithstandthetemperaturestowhichtheyareexposed.

Dissimilarmetals(suchassteelandaluminum)shouldbeisolatedfromeachotherusingnon-conductiveshims,washers,orothermethods.

Aluminumshouldnotbeplacedindirectcontactwithconcretematerials.

Onlyhighqualitystainlesssteelfastenersshouldbeused.

Structuralmembersshouldbeeither:

corrosionresistantaluminum,6061or6063.

hotdipgalvanizedsteelperASMA123.

coatedorpaintedsteel(onlyinlowcorrosionenvironmentssuchasdeserts).

stainlesssteel(particularlyforcorrosivemarineenvironments).

EquipmentRecommendationsandInstallationMethods

Allelectricalequipmentshouldbelistedforthevoltageandcurrentratingsnecessaryfortheapplication.

InvertersshouldbelistedtoUL1741.

Allrequiredover-currentprotectionshouldbeincludedinthesystemandshouldbeaccessibleformaintenance.

Allelectricalterminationsshouldbefullytightened,secured,andstrainrelievedperNEC.

Allroofpenetrationsshouldbesealedwithansealingmethodapprovedbytheroongmaterialvendor,andthatdoesnotadverselyimpacttheroofwarranty.Ifpossible,havetheroongcontractorsealallroofpenetrations.

Integralroongproductsshouldbeproperlyrated(e.g.,classAroongmaterials).

Allcables,conduit,exposedconductorsandelectricalboxesshouldbesecuredandsupportedaccordingtocoderequirements.


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SolyndraParts

able8liststhepartswhichareastandardpartoftheBalanceofSystem(BOS)inSolyndrasystems.able9andable10listtheoptionalBOSparts.

Table 8. Panel Installation Hardware - Provided as Balance of System

Item Picture Part Number Description

Panel SL001-XXX Solyndraphotovoltaicpanel.-XXXrepresentsthe

powerratingothepanel.

PanelMount 0040-30175 PanelmountorSolyndraphotovoltaicpanel.

Attachedusing1/4-20screw.Becausepanels

sharepanelmounts,thenumberopanelmounts

requiredwillvarywitheachinstallation.

PanelMount

Screw

(obsolete)

0520-30011 1/4-20x3/4Phillipsheadwithstarwasher,

stainlesssteel,orattachingpanelmounts.One

neededperpanelmount.

GeneralPur-

pose

Screw

(obsolete)

0520-00689 10-32x1/2Phillipsheadwithstarwasher,stain-

lesssteel.Usedorgroundstrap(2),lateralclip

(2),andgroundlug(1).Totalnumberrequired

willvarywithinstallation.

M5Screw 0520-30658 Inmid-2009,Solyndraupgradedallastenersto

ISO-standardmetricscrews.TheM5-0.8x14mm

stainlesssteelscrewreplaces0520-30011and

0520-00689orallholes.

Ground

Strap 0011-30029 10AWGtinnedstrandedwirewithlugsateach

end.UL,greenjacket.Usedbetweenthelong

sideoadjacentpanels.Totalnumberrequired

willvarywithinstallation.

LateralClip 0020-30213 Usedtoconnectramestogetherwith10-32

screws.Hasteethononeside;thesegoagainst

aluminumrametoinsureagoodconnection.

Totalnumberrequiredwillvarywithinstallation.

PanelPrep

Block

0205-30029 Usedtosupportthepanelwhileinstallingpanel

mountsontopanel.

OCAClean-up

Kit

0240-30833 Cleanupkitincaseopanelbreakage.Onekit

neededperbuildingorinstallationsite


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Table 9. Panel Installation Hardware - Optional, from Solyndra


LongCableTray 0020-30198 Usedorroutingthehome-runcablesaround

thearray.ShortCableTray 0020-30199

Load-Distribut-

ingFoot

0024-31632 Usedonmineral-woolorothersotroos.

CableTrayClip

0020-30205 Cabletrayclipsareinstalledontheshortside

othepanel.Theysupportthecabletraythatcontainsthehome-runpowerconnections.

DustCapor

FemaleSolyndra

Connectors

0048-30094 MaybeusedtocoverunusedSolarlokemale

connectors.Notrequired.

DustCapor

MaleSolarlok

Connectors

0048-30100 MaybeusedtocoverunusedSolarlokmale

connectors.Notrequired.Alsoavailablerom

Tyco.

Ground

Lug

0700-30198 Attachestopanelwithascrew.Thewire-

clampingportionisopen-jawed;permitsthe

useoacontinuouslengthogroundingwire.

AlsoavailableasILSCOGBL-4DBT.

Pad,Panel

Mount,TPO

0020-30225 Padorpanelmount-TPOtyperoomem-

branejunction,attheoptionoenduser.

Pad,Panel

Mount,PVC

0020-30226 Padorpanelmount-PVCtyperoomem-


Pad,Panel

Mount,EPDM

0020-30227 Padorpanelmount-EPDMtyperoomem-



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Table 10. Panel Installation Hardware - Optional, from Third-Party Suppliers


Solarlokemale

connector

0710-00075 Keyedpositive.Forpositivelead,markedRed.

Usedtoconnectthehome-runcablestothe

outputconnectionothestringsothearray.

Solarlokemale

connector

0710-00077 Keyednegative.Fornegativelead,marked

Blue.



Solarlokmale

connector

0710-00379 Unkeyed.Canbeusedorpositiveornegative

lead.



DustCapor

MaleSolarlok

Connectors

0048-30100 MaybeusedtocoverunusedSolarlokmale

connectors.Notrequired.

Ground

Lug

0700-30198 Attachestopanelwithascrew.Thewire-

clampingportionisopen-jawed;permitsthe

useoacontinuouslengthogroundingwire

AlsoavailableasILSCOGBL-4DBT.

Foryourconvenience,partnumbersforycoSolarlokconnectorsareshowninable11.Teseconnectorsaresizedfor12AWG(4mm 2)wire.

Table 11. Tyco Solarlok Connector Part Numbers

FemaleCableConnector MaleCableConnector

PlusKeyed MinusKeyed PlusKeyed MinusKeyed

PlusCoupler 1394462-3 - 1394461-3 -

MinusCoupler - 1394462-4 - 1394461-3

Unkeyed

MaleCoupler,Neutral - - 6-1394461-2


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QuantitiesoParts

Solyndrapanelssharemountsandcertainothercomponents.Tereforethenumberofpartsneededisdeterminedbyboththenumberofpanelsandthearrangementofthearrays,i.e.thenumberofrowsandcolumnsofpanels.SpreadsheettoolsareavailablefromSolyndrathatcancalculateabillofmaterialsforaproject.oaidthedesigner,theequationsusedtocalculatetherequirednumberofeachtypeofpartarediscussedbelow.Figure51showsadetailedviewoftheplacementofeachpartandhelpstoillustratehowtocalculatetherequirednumberof

parts.

Figure 51. Parts Arrangement in a Typical Sub-Array

+

-

+

+

+

+

-

-

-

-

Ground Lugs

Ground Strap

Ground Bus Wire

Grounding Holes4 per Frame

Wiring

Polarity

Lateral Clip

Panel Row

Panel Row

Panel Row

Panel Row

Panel Row

Panel Column

(String)

Panel Column

(String)

Panel Column

(String)

ANoteonPanelTerminology

Notethatinmostinstallations,panelsaregroupedelectricallybycolumnrst,thenrow.Tatis,acolumnsrepresentsaseriesstringofpanels,asshownin Figure51.Columnsarethenwiredinparallelwithothercolumns.Ofcourse,otherarrangementarepossibleinconsulta-tionwithyourqualiedsolarsystemdesigner.


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CalculatingPartsCounts

Panelsareheldupbypanelmounts,andtiedtogetherbygroundstrapsandlateralclips.

Panel Mounts:Panelmountsaresharedbetweenpanels.Tenumberofpanelmountsneededisthenumberofpanelsinthearraytimes2,plusanotherpairtostarttherstrow,or:

Eqn1.

Nmounts = 2Ncolumns Nrows +1( )

Ground Straps:Groundstrapsconnectpanelsineachrowtogether.Tepanelattheendoftherowdoesntneedagroundstrap.Terefore,thenumberofgroundstrapsneededisthenumberofpanelsinthearrayminusthenumberofpanelsinthelastrow,or:

Eqn2.

Nstraps = Ncolumns Nrows 1( )

Lateral Clips:Lateralclipsconnectpanelsinadjacentcolumnstogether,Tenalcolumnneedsnogroundstrap.Tenumberoflateralclipsneededisthenumberofpanelsinthesub-arrayminusthepanelsinthelastcolumn,givenby:

Eqn3.

Nclips = Ncolumns 1( ) Nrows( )

Ground Lugs:Tenumberneededisthenumberofcolumnsinasub-array,plusanyopeninginthearraymusthavegroundlugsthatrunalongthenorthendoftheexposedpanels.

Fasteners:Eachpanelmountrequiresonefastener0520-30011.Eachgroundlug,lateralclip,andcabletraycliprequiresonefastener0520-00689.Eachgroundstraprequirestwofastener0520-00689.

Cable Trays:Terequirednumberof longcabletraysistwotimesthenumberofcolumnsTenecessarynumberofshortcabletraysisthenumberofrowsifwiresarerunononlyonesideofthearray.

Cable Tray Clips:wopershortcabletray.Longcabletraysdonotrequireclips;theytinto

tabsonthepanelmounts. Tyco Solarlok Connectors:Tenumberofmaleandfemaleconnectorsneededisthetota

numberofpanelsdividedbythenumberofpanelsinasub-arraystring.Forexample,1500panelsina5seriesby3parallelarrangementwouldrequire100femaleand100maleconnectors.However,extraconnectorswillberequiredifthesame1500panelsarenotallconnected3inparallel,orwhereroofobstructionspreventclosepackingofpanelsandextrajumpersarerequiredtoconnectpanelsthatarenotadjacent.


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ASampleBOMCalculation

able12showsasampleofthespreadsheetavailablefromSolyndratoaidthesystemdesigner.TisspreadsheetisavailableattheSolyndrawebsite.Tistoolallowsthedesignertoinputthenumberofrowsandcolumnsofeachsub-arrayinthesystem,andtheequationsdiscussedintheprevioussectionwillcalculatethequantitiesoftheancillarypartsrequired.Assumingthatsub-arrayA-1intheaboveexamplecorrespondstothesub-arrayshowninFigure51onpage51,a3isplacedundercolumnsanda5isplacedunderrows.Terestoftherowinthe

worksheetiscalculatedbasedonthisgeometry. Teworksheetcomeswithafewexample lineslledin. Editthecolumnsandrowsas

necessary,andcopyandpastethelinesforalargersystemasneeded.EditthecolumnUSE-212AWGasnecessarytogetthecorrectamountofwireforeachsub-array.Forirregularsub-arrays,inputthetotalnumberofcolumnsandrows,andthenedittheequationsforpanels,panelmounts,groundstraps,andlateralclipstogetthecorrectamount.

Table 12. Sample BOM

Subarray

Name

Columns Rows Panels Panel

Mounts

Fastener

0520-

30011

Ground

straps

Fastener

0520-

00689

Ground

lug

Lateral

clip

Cable

tray,

long

Cable

tray,

short

Clip,

cable

tray

A-1 3 5 15 36 36 12 57 3 10 6 5 10

A-2 15 10 150 330 330 135 585 15 140 30 10 20

A-3 15 10 150 330 330 135 585 15 140 30 10 20

A-4 15 10 150 330 330 135 585 15 140 30 10 20

A-5 15 10 150 330 330 135 585 15 140 30 10 20

A-6 15 10 150 330 330 135 585 15 140 30 10 20

A-7 15 10 150 330 330 135 585 15 140 30 10 20

A-8 15 10 150 330 330 135 585 15 140 30 10 20

A-9 15 10 150 330 330 135 585 15 140 30 10 20

B-1 12 5 50 144 144 48 228 12 55 24 5 10

Totals 135 90 1275 2820 2820 1140 4965 135 1185 270 90 180

Forlargerinstallations,youmaywishtoincludeafewextrascrews,lateralclips,groundlugs,andgroundstraps.


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MountingonUnevenRoos

Panelmountsshouldnotbeplacedwhollyorpartiallyonraisedareassuchthatthesurfacecontactareabetweenthemountandroofisreduced,orthatthereisalargeheightdisparitybetweenpanels.Forstability,itisrecommendedthatthemountsbeplacedinthevalleysofanon-atpatternedroof,versusthepeaks.Itisalsorecommendedthattheroofstructuresload-bearingcapabilitybeassessedwhereverthemountsareplaced.

Figure 52. Right and Wrong Ways to Place Panels on Uneven Roofs

Acceptable Unacceptable Unacceptable

UseotheMulti-HoleMount

Solyndraoersapanelmountwithmultipleholes,showninFigure53.Tisallowsthemounttobemovedslightlytowardthemiddle,ortheend,ofthepanel.Tisfeatureisusefulwheninstallingonstandingseammetalroofsorotherroofsthathavearegularpatternofhighandlowplaces.Itisalsousefulonconventionalatroofsincaseswherethereisasmallprojectionorbumpofsomesort,rightwheretheregularmountwouldnormallysit.

Figure 53. Multi-Hole Panel Mount

[993.39]39.110(POR)

[917.19]36.110(POR)

[839.72]33.060

[1069.59]42.110

[1147.06]45.160

[1083.33]43.635

[1032.13]

42.135

[1070.23]42.135

[993.39]39.110

[954.66]37.585

[1031.49]40.610

[955.29]37.610

[917.19]36.110

[878.46]34.585

[916.56]36.085


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MountSpacingOptions

Dependingonthemountingholelocationsselected,anumberofpossiblespacingsareavail-able.Tesearelistedinable13.TePanelMountPitchcolumnsshowthecenter-to-centerspacingofmounts.Teintra-paneldimensionreferstomountsonthesamepanel,andtheinter-paneldimensionreferstomountsonadjacentpanels.Notethatthetotalpitchisalways1819mm,or68-13/16inches.Teintra-panelspacingcolumnshowstheclearspacebetweenthemounts,thatis,itallowsforthewidthofthemount.Teinter-panelspacingcolumn

showstheclearspacebetweenthemountsformountsonadjacentpanels.Tehighlightedlineisthestandardspacing.

Table 13. Possible Panel Mount Pitches

Mount Position Panel Mount Pitch Intra-panel Spacing Inter-panel Spacing

intra-panel inter-panel

mm inches mm inches mm inches mm inches mm inches

+76.8 +3 1147 45-3/16 672 23-5/8 1076 42-3/8 601 23-21/32

+63.5 +2-1/2 1120 44-1/8 699 24-11/16 1049 41-5/16 628 24-23/32

+38.0 +1-1/2 1070 42-1/8 749 26-11/16 999 39-5/16 678 26-23/32

0.0 0 993 39-1/8 826 29-11/16 922 36-5/16 755 29-23/32

-38.0 -1-1/2 917 36-1/8 902 32-11/16 846 33-5/16 831 32-23/32

-63.5 -2-1/2 866 34-1/8 953 34-11/16 795 31-5/16 882 34-23/32

-76.8 -3 840 33-1/16 979 35-3/4 769 30-1/4 908 35-1/4


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Chapter 9 Site Preparation

Tischapteraddresseskeystepsyoushouldtakebeforethepanelsarriveatthesite.Whileitisbeyondthescopeofthismanualtoprovideacompleteguidetoplanningyourphotovoltaicinstallation,itsimportanttounderstandthebasicprinciplesofinstallation.Teseinclude:

ScopeSafety.

Installationofconduitandelectricalequipmentboxes.

Planninginstallationofgroundingwires.

Roofpreparationandcleaning.

Planningpanelplacementandclearances.

Planningpanelwiring.

ools,supplies,andtechniques.

Scope TeinstallationofSolyndrapanelsmusttakeplaceincompliancewithnationalandlocalelec-

tricalandbuildingcodes.Tesearetoonumeroustodescribehere.Teuseofqualiedandexperiencedlocalprofessionalsisthebestwaytoensurecompliancewithsuchcodesaswellasoptimumsystemdesign,installation,andperformance.

ASolyndrapanel ispartofacompletephotovoltaic installation.Aproperly-engineeredin-stallationwillmeetallapplicablerecodes,electricalcodes,buildingcodes,andothersafetycodes.InmostcasescompliancewiththesecodesinvolvesmanycomponentsinadditiontotheSolyndrapanels.

Yourinstallationplanshouldincludeadetaileddescriptionofthewiringmethodstobeusedandadetaileddescriptionofthemechanicalmounting.Teseplansshouldspecify,atamini-mum:

Size,type,andtemperatureratingofallwiringcomponents.WireshouldbetypeUSE-2,12AWG(4mm2),orbetterifrequiredbylocalcodes.Notethatthisisa

design guide n v2-3en

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