PVInstaller’sCourse:TheSiteVisitApril2016

2.1--The Site Visit

1

April 2016 PV Installer's Course: Introduction 2

Cryingoutforsolarpanels

Tooshadedforsolarpanels

Beforevisi*ng,lookatGoogleEarthphotos

PVInstaller’sCourse:TheSiteVisitApril2016

SiteSurveyKit

• Checklist• 100’tapemeasure,25’tapemeasure• solarpathfinder,compass• camera• notepadandpen• ladder• flashlight,flatheadscrewdriver• magneGcprotractor

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PVInstaller’sCourse:TheSiteVisitApril20164

TheSiteVisitFindaplacewherethereisnoshadefrom9Ato4P. Noshadeisguaranteedwhentheobjectis3Gmes asfarawayasitistall. Theroofisthebestplaceunlessitisshaded. Trytokeepground-mountswithin100feetofhouse

Shadeproblem

April 2016 PV Installer's Course: Introduction 5

SolarAccess

Photovoltaicsystemperformancewillbegreatlyreducedifevenasmallpartofthearrayisshaded

NYSERDAwillderateincenGveifshadelossexceeds20%

April 2016 PV Installer's Course: Introduction 6

TheSolarPathfindershowsyouwhatstructuresortreesshadetheareayouareconsidering

UsetheSolarPathfinderatthe2lowestcorners

ofproposedroof-toparraysite

April 2016 PV Installer's Course: Introduction 7

SolarPathfinderChart

April 2016 PV Installer's Course: Introduction 8

Dec:4+5+6+7+7+8=37Jan:4+5+6+7+7+8=37

Nov:4+5+6+7+7+8=37Feb:5+6+7+7+7=32

Oct:6+6+7+7=26

Shadingatcustomer’sroof

April 2016 PV Installer's Course: Introduction 9

FindingSun-hourslost:

NRELsun-hoursperdayxnumberofdayspermonthxpercentlostfromsolarpathfinder

convert37%todecimalbydividingby100.37%=0.37

0.37x30daysx2.4sun-hoursperday=26.64sun-hourslost

Reminder:a“sun-hour”=1kWh/m2i.e.anequivalenthourof1kW/m2

SolarAccess=availablesun-hours-sun-hourslost

April 2016 PV Installer's Course: Introduction 10

FiguringoutlostSun-hoursduetoshading

1. Computehourslostforeachmonth2. Addthemup3. Subtractfromyearlytotal

April 2016 PV Installer's Course: Introduction 11

Nowusethereducednumberoffull-sun-hoursinourperformanceformula

FullsunhoursxsystemefficiencyxPVsizeinkW=kWhgenerated

Example1425HoursofFullSunx0.75efficiencyx2.4kW=2565kWh

Insteadof2825kWhwithnoshade.

April 2016 PV Installer's Course: Introduction 12

Howmanyfull-sun-hoursperyearwillthisshadingtakeawayifthesiteisinSyracuse?

Full-sun-hoursperdayinSyracuseforasouthroofof28°slope(6.4”risefor12”run)City: SYRACUSE State: NY

Lat(N): 43.12

LAT-15 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YearAverage 2.4 3.3 4.2 5 5.6 5.9 6 5.5 4.7 3.5 2.1 1.8 4.2

Practice problem #5

April 2016 PV Installer's Course: Introduction 13

SolmetricSuneyeautomatesyourshademeasurement

Solmetric:• 100-TSRFisshadeandorientaGonloss

• TOFisorientaGonloss• Shadelossaloneis1-(TSRF/TOF)• EnterthatinPVWATTS

PVInstaller’sCourse:TheSiteVisitApril201614

SiteMeasurements

TheSiteVisit

PVInstaller’sCourse:TheSiteVisitApril201615

Measureroofup-slope

TheSiteVisitOldshingles:5”perrowNewShingles:5.5”perrow

PVInstaller’sCourse:TheSiteVisitApril201616

Up-slopedimensioncrosscheck:measureslope,dotrig

hypotenuse

angle

TheSiteVisit

PVInstaller’sCourse:TheSiteVisitApril201617

Trigreview

Opposite(Y)

Adjacent(X)

AngleA

TangentA=opposite/adjacentSineA=opposite/hypotenuseCosineA=adjacent/hypotenuseAngleB=AngleA(RuleofSimilarAngles)

Hypotenuse(H)B

PVInstaller’sCourse:TheSiteVisitApril201618

TheSiteVisit

Lookintheapc,measureraqerspacingandsize

PVInstaller’sCourse:TheSiteVisitApril201619

TheSiteVisitWhatkindofroofsupportIsthere?

PVInstaller’sCourse:TheSiteVisitApril201620

TheSiteVisit

Whereisthemeter?TheincominguGlitylines?(Ifany)

“SitePlan”

PVInstaller’sCourse:TheSiteVisitApril201621

IfyouhavetodoGlt-upsonroof,spacetherowssoonedoesnotshadeanother.FindY,thenfindX

Tangent(18) = opposite over adjacent = Y/X = 24”/X Solve for X

X = 24”/tan(18) = 73.46” = 6 feet

PVInstaller’sCourse:TheSiteVisitApril201622

Tilt-uponNWrooftofacePVSouth

PVInstaller’sCourse:TheSiteVisitApril201623

IfyoudomulGplepole-mounts,placepolessoonePVarraydoesnotshadetheotherSun-angle

PVInstaller’sCourse:TheSiteVisitApril201624

Pole-topPVmount

PVInstaller’sCourse:TheSiteVisitApril201625

Chooseaplaceforthebarerybank. Ba-eriesliketobewarm Theinvertermustbewithin20;oftheba-ery

MeasurethedistancefromthatspottothebarerylocaGon

TheSiteVisit

PVInstaller’sCourse:TheSiteVisitApril201626

Chooseaplacefortheinverteranddisconnects

BareryboxPowerpanel

vent

PVInstaller’sCourse:TheSiteVisitApril201627

Recordthesizeandtypeofcabincircuitbox(loadcenter) Ifthereisnocircuitbox,makeanoteofthatand recordthenumberofcircuits(orpotenGalnumber)

TheSiteVisit

SumoftheMainbreakerandPVbreakermustbelessthanorequalto1.2xbusbarraGng

Example:n 200Amainon200Abusbarmeans 200+PVbreaker≤1.2x200=≤240.

n ThelargestPVbreakercanbe40A