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10/12/2015 PhotovoltaicsystemWikipedia,thefreeencyclopedia

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Photovoltaicpowersystemsandcomponents:

Top:solarstringinverterandotherBOScomponentsSolararrayonrooftopinHonkong,ChinaBIPVonbalconyinHelsinki,FinlandMiddle:rooftopsysteminBoston,UnitedStatesWestmillsolarparkintheUnitedKingdomDualaxistrackerwithCPVmodulesTopaz,oneoftheworldslargestsolarpowerstation,asseenfromspaceBottom:commercialrooftopPVsystemofabout400kWpPowerplantonMt.Komekura,JapanSolarPVsystemonGermany'shighestmountaintop

PhotovoltaicsystemFromWikipedia,thefreeencyclopedia

Aphotovoltaicsystem,alsosolarPVpowersystem,orPVsystem,isapowersystemdesignedtosupplyusablesolarpowerbymeansofphotovoltaics.Itconsistsofanarrangementofseveralcomponents,includingsolarpanelstoabsorbandconvertsunlightintoelectricity,asolarinvertertochangetheelectriccurrentfromDCtoAC,aswellasmounting,cablingandotherelectricalaccessoriestosetupaworkingsystem.Itmayalsouseasolartrackingsystemtoimprovethesystem'soverallperformanceandincludeanintegratedbatterysolution,aspricesforstoragedevicesareexpectedtodecline.Strictlyspeaking,asolararrayonlyencompassestheensembleofsolarpanels,thevisiblepartofthePVsystem,anddoesnotincludealltheotherhardware,oftensummarizedasbalanceofsystem(BOS).Moreover,PVsystemsconvertlightdirectlyintoelectricityandshouldn'tbeconfusedwithothertechnologies,suchasconcentratedsolarpowerorsolarthermal,usedforheatingandcooling.

PVsystemsrangefromsmall,rooftopmountedorbuildingintegratedsystemswithcapacitiesfromafewtoseveraltensofkilowatts,tolargeutilityscalepowerstationsofhundredsofmegawatts.Nowadays,mostPVsystemsaregridconnected,whileoffgridorstandalonesystemsonlyaccountforasmallportionofthemarket.

Operatingsilentlyandwithoutanymovingpartsorenvironmentalemissions,PVsystemshavedevelopedfrombeingnichemarketapplicationsintoamaturetechnologyusedformainstreamelectricitygeneration.Arooftopsystemrecoupstheinvestedenergyforitsmanufacturingandinstallationwithin0.7to2yearsandproducesabout95percentofnetcleanrenewableenergyovera30yearservicelifetime.[1]:30[2][3]

Duetotheexponentialgrowthofphotovoltaics,pricesforPVsystemshaverapidlydeclinedinrecentyears.However,theyvarybymarketandthesizeofthesystem.In2014,pricesforresidential5kilowattsystemsintheUnitedStateswerearound$3.29perwatt,[4]whileinthehighlypenetratedGermanmarket,pricesforrooftopsystemsofupto100kWdeclinedto1.24perwatt.[5]Nowadays,solarPVmodulesaccountforlessthanhalfofthesystem'soverallcost,[6]leavingtheresttotheremainingBOScomponentsandtosoftcosts,whichincludecustomeracquisition,permitting,inspectionandinterconnection,installationlaborandfinancingcosts.[7]:14

Contents

1Modernsystem1.1Overview1.2Gridconnection1.3Scaleofsystem1.4Performance

2Components2.1Solararray2.2Mounting2.3Cabling2.4Tracker2.5Inverter2.6Battery2.7Monitoringandmetering

3Othersystems3.1CPV3.2Hybrid3.3Floatovoltaics



Diagramofthepossiblecomponentsofaphotovoltaicsystem

3.4Directcurrentgrid3.5Standalone

4Costsandeconomy4.1Systemcost2013

5Regulation5.1Standardization5.2Planningandpermit5.3Nationalregulations

6Seealso7References8Externallinks

Modernsystem

Overview

Aphotovoltaicsystemconvertsthesun'sradiationintousableelectricity.Itcomprisesthesolararrayandthebalanceofsystemcomponents.PVsystemscanbecategorizedbyvariousaspects,suchas,gridconnectedvs.standalonesystems,buildingintegratedvs.rackmountedsystems,residentialvs.utilitysystems,distributedvs.centralizedsystems,rooftopvs.groundmountedsystems,trackingvs.fixedtiltsystems,andnewconstructedvs.retrofittedsystems.Otherdistinctionsmayinclude,systemswithmicroinvertersvs.centralinverter,systemsusingcrystallinesiliconvs.thinfilmtechnology,andsystemswithmodulesfromChinesevs.EuropeanandU.S.manufacturers.

About99percentofallEuropeanand90percentofallU.S.solarpowersystemsareconnectedtotheelectricalgrid,whileoffgridsystemsaresomewhatmorecommoninAustraliaandSouthKorea.[8]:14PVsystemsrarelyusebatterystorage.Thismaychangesoon,asgovernmentincentivesfordistributedenergystoragearebeingimplementedandinvestmentsinstoragesolutionsaregraduallybecomingeconomicallyviableforsmallsystems.[9][10]AsolararrayofatypicalresidentialPVsystemisrackmountedontheroof,ratherthanintegratedintotherooforfacadeofthebuilding,asthisissignificantlymoreexpensive.Utilityscalesolarpowerstationsaregroundmounted,withfixedtiltedsolarpanelsratherthanusingexpensivetrackingdevices.Crystallinesiliconisthepredominantmaterialusedin90percentofworldwideproducedsolarmodules,whilerivalthinfilmhaslostmarketshareinrecentyears.[1]:1720About70percentofallsolarcellsandmodulesareproducedinChinaandTaiwan,leavingonly5percenttoEuropeanandUSmanufacturers.[1]:1112Theinstalledcapacityforboth,smallrooftopsystemsandlargesolarpowerstationsisgrowingrapidlyandinequalparts,althoughthereisanotabletrendtowardsutilityscalesystems,asthefocusonnewinstallationsisshiftingawayfromEuropetosunnierregions,suchastheSunbeltintheU.S.,whicharelessopposedtogroundmountedsolarfarmsandcosteffectivenessismoreemphasizedbyinvestors.[8]:43

Drivenbyadvancesintechnologyandincreasesinmanufacturingscaleandsophistication,thecostofphotovoltaicsisdecliningcontinuously.[3]ThereareseveralmillionPVsystemsdistributedallovertheworld,mostlyinEurope,with1.4millionsystemsinGermanyalone[1]:5aswellasNorthAmericawith440,000systemsintheUnitedStates,[11]Theenergyconversionefficiencyofaconventionalsolarmoduleincreasedfrom15to20percentoverthelast10years[1]:17andaPVsystemrecoupstheenergyneededforitsmanufactureinabout2years.Inexceptionallyirradiatedlocations,orwhenthinfilmtechnologyisused,thesocalledenergypaybacktimedecreasestooneyearorless.[1]:3033Netmeteringandfinancialincentives,suchaspreferentialfeedintariffsforsolargeneratedelectricity,havealsogreatlysupportedinstallationsofPVsystemsinmanycountries.[12]ThelevelisedcostofelectricityfromlargescalePVsystemshasbecomecompetitivewithconventionalelectricitysourcesinanexpandinglistofgeographicregions,andgridparityhasbeenachievedinabout30differentcountries.[13][14][15]

Asof2015,thefastgrowingglobalPVmarketisrapidlyapproachingthe200GWmarkabout40timestheinstalledcapacityof2006.[16]Photovoltaicsystemscurrentlycontributeabout1percenttoworldwideelectricitygeneration.TopinstallersofPVsystemsintermsofcapacityarecurrentlyChina,JapanandtheUnitedStates,whilehalfoftheworld'scapacityisinstalledinEurope,withGermanyandItalysupplying7%to8%oftheirrespectivedomesticelectricityconsumptionwithsolarPV.[17]TheInternationalEnergyAgencyexpectssolarpowertobecometheworld'slargestsourceofelectricityby2050,withsolarphotovoltaicsandconcentratedsolarthermalcontributing16%and11%totheglobaldemand,respectively.[7]

Gridconnection



SchematicsofatypicalresidentialPVsystem

PerovoSolarParkinUkraine

RooftopsystemnearBoston,USA.

Mainarticle:Gridconnectedphotovoltaicpowersystem

Agridconnectedsystemisconnectedtoalargerindependentgrid(typicallythepublicelectricitygrid)andfeedsenergydirectlyintothegrid.Thisenergymaybesharedbyaresidentialorcommercialbuildingbeforeoraftertherevenuemeasurementpoint.Thedifferencebeingwhetherthecreditedenergyproductioniscalculatedindependentlyofthecustomer'senergyconsumption(feedintariff)oronlyonthedifferenceofenergy(netmetering).Gridconnectedsystemsvaryinsizefromresidential(210kWp)tosolarpowerstations(upto10sofMWp).Thisisaformofdecentralizedelectricitygeneration.ThefeedingofelectricityintothegridrequiresthetransformationofDCintoACbyaspecial,synchronisinggridtieinverter.InkilowattsizedinstallationstheDCsidesystemvoltageisashighaspermitted(typically1000VexceptUSresidential600V)tolimitohmiclosses.Mostmodules(60or72crystallinesiliconcells)generate160Wto300Wat36volts.Itissometimesnecessaryordesirabletoconnectthemodulespartiallyinparallelratherthanallinseries.Onesetofmodulesconnectedinseriesisknownasa'string'.[18]

Scaleofsystem

Photovoltaicsystemsaregenerallycategorizedintothreedistinctmarketsegments:residentialrooftop,commercialrooftop,andgroundmountutilityscalesystems.Theircapacitiesrangefromafewkilowattstohundredsofmegawats.Atypicalresidentialsystemisaround10kilowattsandmountedonaslopedroof,whilecommercialsystemsmayreachamegawattscaleandaregenerallyinstalledonlowslopeorevenflatroofs.Althoughrooftopmountedsystemsaresmallanddisplayahighercostperwattthanlargeutilityscaleinstallations,theyaccountforthelargestshareinthemarket.Thereis,however,agrowingtrendtowardsbiggerutilityscalepowerplants,especiallyinthe"sunbelt"regionoftheplanet.[8]:43[19]

Utilityscale

Mainarticle:Photovoltaicpowerstation

Largeutilityscalesolarparksorfarmsarepowerstationsandcapableofprovidinganenergysupplytolargenumbersofconsumers.Generatedelectricityisfedintothetransmissiongridpoweredbycentralgenerationplants(gridconnectedorgridtiedplant),orcombinedwithone,ormany,domesticelectricitygeneratorstofeedintoasmallelectricalgrid(hybridplant).Inrarecasesgeneratedelectricityisstoredoruseddirectlybyisland/standaloneplant.[20][21]PVsystemsaregenerallydesignedinordertoensurethehighestenergyyieldforagiveninvestment.SomelargephotovoltaicpowerstationssuchasSolarStar,WaldpolenzSolarParkandTopazSolarFarmcovertensorhundredsofhectaresandhavepoweroutputsuptohundredsofmegawatts.

Rooftop

Mainarticle:Rooftopphotovoltaicpowerstation

AsmallPVsystemiscapableofprovidingenoughACelectricitytopowerasinglehome,orevenanisolateddeviceintheformofACorDCelectric.Forexample,militaryandcivilianEarthobservationsatellites,streetlights,constructionandtrafficsigns,electriccars,solarpoweredtents,[22]andelectricaircraftmaycontainintegratedphotovoltaicsystemstoprovideaprimaryorauxiliarypowersourceintheformofACorDCpower,dependingonthedesignandpowerdemands.In2013,rooftopsystemsaccountedfor60percentofworldwideinstallations.However,thereisatrendawayfromrooftopandtowardsutilityscalePVsystems,asthefocusofnewPVinstallationsisalsoshiftingfromEuropetocountriesinthesunbeltregionoftheplanetwhereoppositiontogroundmountedsolarfarmsislessaccentuated.[8]:43

Buildingintegrated

Mainarticle:Buildingintegratedphotovoltaics

Inurbanandsuburbanareas,photovoltaicarraysarecommonlyusedonrooftopstosupplementpoweruseoftenthebuildingwillhaveaconnectiontothepowergrid,inwhichcasetheenergyproducedbythePVarraycanbesoldbacktotheutilityinsomesortofnetmeteringagreement.Someutilities,suchasSolvayElectricinSolvay,NY,usetherooftopsofcommercialcustomersandtelephonepolestosupporttheiruseofPVpanels.[23]Solartreesarearraysthat,asthenameimplies,mimicthelookoftrees,provideshade,andatnightcanfunctionasstreetlights.



BAPVwallnearBarcelona,Spain

ThebalanceofsystemcomponentsofaPVsystem(BOS)balancethepowergeneratingsubsystemofthesolararray(leftside)withthepowerusingsideoftheAChouseholddevicesandtheutilitygrid(rightside).

Performance

Uncertaintiesinrevenueovertimerelatemostlytotheevaluationofthesolarresourceandtotheperformanceofthesystemitself.Inthebestofcases,uncertaintiesaretypically4%foryeartoyearclimatevariability,5%forsolarresourceestimation(inahorizontalplane),3%forestimationofirradiationintheplaneofthearray,3%forpowerratingofmodules,2%forlossesduetodirtandsoiling,1.5%forlossesduetosnow,and5%forothersourcesoferror.IdentifyingandreactingtomanageablelossesiscriticalforrevenueandO&Mefficiency.Monitoringofarrayperformancemaybepartofcontractualagreementsbetweenthearrayowner,thebuilder,andtheutilitypurchasingtheenergyproduced.Recently,amethodtocreate"syntheticdays"usingreadilyavailableweatherdataandverificationusingtheOpenSolarOutdoorsTestFieldmakeitpossibletopredictphotovoltaicsystemsperformancewithhighdegreesofaccuracy.[24]Thismethodcanbeusedtothendeterminelossmechanismsonalocalscalesuchasthosefromsnow[25][26]ortheeffectsofsurfacecoatings(e.g.hydrophobicorhydrophilic)onsoilingorsnowlosses.[27]AccesstotheInternethasallowedafurtherimprovementinenergymonitoringandcommunication.Dedicatedsystemsareavailablefromanumberofvendors.ForsolarPVsystemthatusemicroinverters(panellevelDCtoACconversion),modulepowerdataisautomaticallyprovided.Somesystemsallowsettingperformancealertsthattriggerphone/email/textwarningswhenlimitsarereached.Thesesolutionsprovidedataforthesystemownerandtheinstaller.Installersareabletoremotelymonitormultipleinstallations,andseeataglancethestatusoftheirentireinstalledbase.

Components

Aphotovoltaicsystemforresidential,commercial,orindustrialenergysupplyconsistsofthesolararrayandanumberofcomponentsoftensummarizedasthebalanceofsystem(BOS).ThetermoriginatesfromthefactthatsomeBOScomponentsarebalancingthepowergeneratingsubsystemofthesolararraywiththepowerusingside,theload.BOScomponentsincludepowerconditioningequipmentandstructuresformounting,typicallyoneormoreDCtoACpowerconverters,alsoknownasinverters,anenergystoragedevice,arackingsystemthatsupportsthesolararray,electricalwiringandinterconnections,andmountingforothercomponents.

Optionally,abalanceofsystemmayincludeanyorallofthefollowing:renewableenergycreditrevenuegrademeter,maximumpowerpointtracker(MPPT),batterysystemandcharger,GPSsolartracker,energymanagementsoftware,solarirradiancesensors,anemometer,ortaskspecificaccessoriesdesignedtomeetspecializedrequirementsforasystemowner.Inaddition,aCPVsystemrequiresopticallensesormirrorsandsometimesacoolingsystem.

Theterms"solararray"and"PVsystem"areoftenusedinterchangeably,despitethefactthatthesolararraydoesnotencompasstheentiresystem.Moreover,"solarpanel"isoftenusedasasynonymfor"solarmodule",althoughapanelconsistsofastringofseveralmodules.Theterm"solarsystem"isalsoanoftenusedmisnomerforaPVsystem.

Solararray

Furtherinformation:PVmodule

ConventionalcSisolarcells,normallywiredinseries,areencapsulatedinasolarmoduletoprotectthemfromtheweather.Themoduleconsistsofatemperedglassascover,asoftandflexibleencapsulant,arearbacksheetmadeofaweatheringandfireresistantmaterialandanaluminiumframearoundtheouteredge.Electricallyconnectedandmountedonasupportingstructure,solarmodulesbuildastringofmodules,oftencalledsolarpanel.Asolararrayconsistsofoneormanysuchpanels.[28]Aphotovoltaicarray,orsolararray,isalinkedcollectionofsolarpanels.Thepowerthatonemodulecanproduceisseldomenoughtomeetrequirementsofahomeorabusiness,sothemodulesarelinkedtogethertoformanarray.MostPVarraysuseaninvertertoconverttheDCpowerproducedbythemodulesintoalternatingcurrentthatcanpowerlights,motors,andotherloads.ThemodulesinaPVarrayareusuallyfirstconnectedinseriestoobtainthedesiredvoltagetheindividualstringsarethenconnectedinparalleltoallowthesystemtoproducemorecurrent.SolarpanelsaretypicallymeasuredunderSTC(standardtestconditions)orPTC(PVUSAtestconditions),inwatts.[29]Typicalpanelratingsrangefromlessthan100wattstoover400watts.[30]Thearrayratingconsistsofasummationofthepanelratings,inwatts,kilowatts,ormegawatts.

Moduleandefficiency



FixedtiltsolararrayinofcrystallinesiliconpanelsinCanterbury,NewHampshire,UnitedStates

SolararrayofasolarfarmwithafewthousandsolarmodulesontheislandofMajorca,Spain

Globalsolarpotential

Atypical"150watt"PVmoduleisaboutasquaremeterinsize.Suchamodulemaybeexpectedtoproduce0.75kilowatthour(kWh)everyday,onaverage,aftertakingintoaccounttheweatherandthelatitude,foraninsolationof5sunhours/day.Inthelast10years,theefficiencyofaveragecommercialwaferbasedcrystallinesiliconmodulesincreasedfromabout12%to16%andCdTemoduleefficiencyincreasedfrom9%to13%duringsameperiod.Moduleoutputandlifedegradedbyincreasedtemperature.Allowingambientairtoflowover,andifpossiblebehind,PVmodulesreducesthisproblem.Effectivemodulelivesaretypically25yearsormore.[31]ThepaybackperiodforaninvestmentinaPVsolarinstallationvariesgreatlyandistypicallylessusefulthanacalculationofreturnoninvestment.[32]Whileitistypicallycalculatedtobebetween10and20years,thefinancialpaybackperiodcanbefarshorterwithincentives.[33]

Duetothelowvoltageofanindividualsolarcell(typicallyca.0.5V),severalcellsarewired(alsoseecopperusedinPVsystems)inseriesinthemanufactureofa"laminate".Thelaminateisassembledintoaprotectiveweatherproofenclosure,thusmakingaphotovoltaicmoduleorsolarpanel.Modulesmaythenbestrungtogetherintoaphotovoltaicarray.In2012,solarpanelsavailableforconsumerscanhaveanefficiencyofuptoabout17%,[34]whilecommerciallyavailablepanelscangoasfaras27%.IthasbeenrecordedthatagroupfromtheTheFraunhoferInstituteforSolarEnergySystemshavecreatedacellthatcanreach44.7%efficiency,whichmakesscientists'hopesofreachingthe50%efficiencythresholdalotmorefeasible.[35][36][37][38]

Shadinganddirt

Photovoltaiccellelectricaloutputisextremelysensitivetoshading.Theeffectsofthisshadingarewellknown.[39][40][41]Whenevenasmallportionofacell,module,orarrayisshaded,whiletheremainderisinsunlight,theoutputfallsdramaticallyduetointernal'shortcircuiting'(theelectronsreversingcoursethroughtheshadedportionofthepnjunction).Ifthecurrentdrawnfromtheseriesstringofcellsisnogreaterthanthecurrentthatcanbeproducedbytheshadedcell,thecurrent(andsopower)developedbythestringislimited.Ifenoughvoltageisavailablefromtherestofthecellsinastring,currentwillbeforcedthroughthecellbybreakingdownthejunctionintheshadedportion.Thisbreakdownvoltageincommoncellsisbetween10and30volts.Insteadofaddingtothepowerproducedbythepanel,theshadedcellabsorbspower,turningitintoheat.Sincethereversevoltageofashadedcellismuchgreaterthantheforwardvoltageofanilluminatedcell,oneshadedcellcanabsorbthepowerofmanyothercellsinthestring,disproportionatelyaffectingpaneloutput.Forexample,ashadedcellmaydrop8volts,insteadofadding0.5volts,ataparticularcurrentlevel,therebyabsorbingthepowerproducedby16othercells.[42]Itis,thusimportantthataPVinstallationisnotshadedbytreesorotherobstructions.

SeveralmethodshavebeendevelopedtodetermineshadinglossesfromtreestoPVsystemsoverbothlargeregionsusingLiDAR,[43]butalsoatanindividualsystemlevelusingsketchup.[44]Mostmoduleshavebypassdiodesbetweeneachcellorstringofcellsthatminimizetheeffectsofshadingandonlylosethepoweroftheshadedportionofthearray.Themainjobofthebypassdiodeistoeliminatehotspotsthatformoncellsthatcancausefurtherdamagetothearray,andcausefires.Sunlightcanbeabsorbedbydust,snow,orotherimpuritiesatthesurfaceofthemodule.Thiscanreducethelightthatstrikesthecells.IngeneraltheselossesaggregatedovertheyeararesmallevenforlocationsinCanada.[25]Maintainingacleanmodulesurfacewillincreaseoutputperformanceoverthelifeofthemodule.Googlefoundthatcleaningtheflatmountedsolarpanelsafter15monthsincreasedtheiroutputbyalmost100%,butthatthe5%tiltedarrayswereadequatelycleanedbyrainwater.[26][45]

Insolationandenergy

Solarinsolationismadeupofdirect,diffuse,andreflectedradiation.TheabsorptionfactorofaPVcellisdenedasthefractionofincidentsolarirradiancethatisabsorbedbythecell.[46]Athighnoononacloudlessdayattheequator,thepowerofthesunisabout1kW/m,[47]ontheEarth'ssurface,toaplanethatisperpendiculartothesun'srays.Assuch,PVarrayscantrackthesunthrougheachdaytogreatlyenhanceenergycollection.However,trackingdevicesaddcost,andrequiremaintenance,soitismorecommonforPVarraystohavefixedmountsthattiltthearrayandfacesolarnoon(approximatelyduesouthintheNorthernHemisphereorduenorthintheSouthernHemisphere).Thetiltangle,fromhorizontal,canbevariedforseason,[48]butiffixed,



A23yearold,groundmountedPVsystemfromthe1980sonaNorthFrisianIsland,Germany.Themodulesconversionefficiencywasonly12%.

A1998modelofapassivesolartracker,viewedfromunderneath.

shouldbesettogiveoptimalarrayoutputduringthepeakelectricaldemandportionofatypicalyearforastandalonesystem.Thisoptimalmoduletiltangleisnotnecessarilyidenticaltothetiltangleformaximumannualarrayenergyoutput.[49]Theoptimizationoftheaphotovoltaicsystemforaspecificenvironmentcanbecomplicatedasissuesofsolarflux,soiling,andsnowlossesshouldbetakenintoeffect.Inaddition,recentworkhasshownthatspectraleffectscanplayaroleinoptimalphotovoltaicmaterialselection.Forexample,thespectralalbedocanplayasignificantroleinoutputdependingonthesurfacearoundthephotovoltaicsystem[50]andthetypeofsolarcellmaterial.[51]FortheweatherandlatitudesoftheUnitedStatesandEurope,typicalinsolationrangesfrom4kWh/m/dayinnorthernclimesto6.5kWh/m/dayinthesunniestregions.AphotovoltaicinstallationinthesouthernlatitudesofEuropeortheUnitedStatesmayexpecttoproduce1kWh/m/day.Atypical1kWphotovoltaicinstallationinAustraliaorthesouthernlatitudesofEuropeorUnitedStates,mayproduce3.55kWhperday,dependentonlocation,orientation,tilt,insolationandotherfactors.[52]IntheSaharadesert,withlesscloudcoverandabettersolarangle,onecouldideallyobtaincloserto8.3kWh/m/dayprovidedthenearlyeverpresentwindwouldnotblowsandontotheunits.TheareaoftheSaharadesertisover9millionkm.90,600km,orabout1%,couldgenerateasmuchelectricityasalloftheworld'spowerplantscombined.[53]

Mounting

Mainarticle:Photovoltaicmountingsystem

Modulesareassembledintoarraysonsomekindofmountingsystem,whichmaybeclassifiedasgroundmount,roofmountorpolemount.Forsolarparksalargerackismountedontheground,andthemodulesmountedontherack.Forbuildings,manydifferentrackshavebeendevisedforpitchedroofs.Forflatroofs,racks,binsandbuildingintegratedsolutionsareused.Solarpanelracksmountedontopofpolescanbestationaryormoving,seeTrackersbelow.Sideofpolemountsaresuitableforsituationswhereapolehassomethingelsemountedatitstop,suchasalightfixtureoranantenna.Polemountingraiseswhatwouldotherwisebeagroundmountedarrayaboveweedshadowsandlivestock,andmaysatisfyelectricalcoderequirementsregardinginaccessibilityofexposedwiring.Polemountedpanelsareopentomorecoolingairontheirunderside,whichincreasesperformance.Amultiplicityofpoletoprackscanbeformedintoaparkingcarportorothershadestructure.Arackwhichdoesnotfollowthesunfromlefttorightmayallowseasonaladjustmentupordown.

Cabling

Mainarticles:SolarcableandElectricalwiring

Duetotheiroutdoorusage,solarcablesarespecificallydesignedtoberesistantagainstUVradiationandextremelyhightemperaturefluctuationsandaregenerallyunaffectedbytheweather.AnumberofstandardsspecifytheusageofelectricalwiringinPVsystems,suchastheIEC60364bytheInternationalElectrotechnicalCommission,insection712"Solarphotovoltaic(PV)powersupplysystems",theBritishStandardBS7671,incorporatingregulationsrelatingtomicrogenerationandphotovoltaicsystems,andtheUSUL4703standard,insubject4703"PhotovoltaicWire".

Tracker

Mainarticle:Solartracker

Asolartrackingsystemtiltsasolarpanelthroughouttheday.Dependingonthetypeoftrackingsystem,thepaneliseitheraimeddirectlyatthesunorthebrightestareaofapartlycloudedsky.Trackersgreatlyenhanceearlymorningandlateafternoonperformance,increasingthetotalamountofpowerproducedbyasystembyabout2025%forasingleaxistrackerandabout30%ormoreforadualaxistracker,dependingonlatitude.[54][55]Trackersareeffectiveinregionsthatreceivealargeportionofsunlightdirectly.Indiffuselight(i.e.undercloudorfog),trackinghaslittleornovalue.Becausemostconcentratedphotovoltaicssystemsareverysensitivetothesunlight'sangle,trackingsystemsallowthemtoproduceusefulpowerformorethanabriefperiodeachday.[56]Trackingsystemsimproveperformancefortwomainreasons.First,whenasolarpanelisperpendiculartothesunlight,itreceivesmorelightonitssurfacethanifitwereangled.Second,directlightisusedmoreefficientlythanangledlight.SpecialAntireflectivecoatingscanimprovesolarpanelefficiencyfordirectandangledlight,somewhatreducingthebenefitoftracking.[57]



CentralinverterwithACandDCdisconnects(ontheside),monitoringgateway,transformerisolationandinteractiveLCD.

Stringinverter(left),generationmeter,andACdisconnect(right).Amodern2013installationinVermont,UnitedStates.

Trackersandsensorstooptimisetheperformanceareoftenseenasoptional,buttrackingsystemscanincreaseviableoutputbyupto45%.[58]PVarraysthatapproachorexceedonemegawattoftenusesolartrackers.Accountingforclouds,andthefactthatmostoftheworldisnotontheequator,andthatthesunsetsintheevening,thecorrectmeasureofsolarpowerisinsolationtheaveragenumberofkilowatthourspersquaremeterperday.FortheweatherandlatitudesoftheUnitedStatesandEurope,typicalinsolationrangesfrom2.26kWh/m/dayinnorthernclimesto5.61kWh/m/dayinthesunniestregions.[59][60]

Forlargesystems,theenergygainedbyusingtrackingsystemscanoutweightheaddedcomplexity(trackerscanincreaseefficiencyby30%ormore).Forverylargesystems,theaddedmaintenanceoftrackingisasubstantialdetriment.[61]Trackingisnotrequiredforflatpanelandlowconcentrationphotovoltaicsystems.Forhighconcentrationphotovoltaicsystems,dualaxistrackingisanecessity.[62]Pricingtrendsaffectthebalancebetweenaddingmorestationarysolarpanelsversushavingfewerpanelsthattrack.Whensolarpanelpricesdrop,trackersbecomealessattractiveoption.

Inverter

Mainarticles:Solarinverter,SolarmicroinverterandPowerinverter

Systemsdesignedtodeliveralternatingcurrent(AC),suchasgridconnectedapplicationsneedaninvertertoconvertthedirectcurrent(DC)fromthesolarmodulestoAC.GridconnectedinvertersmustsupplyACelectricityinsinusoidalform,synchronizedtothegridfrequency,limitfeedinvoltagetonohigherthanthegridvoltageanddisconnectfromthegridifthegridvoltageisturnedoff.[63]Islandinginvertersneedonlyproduceregulatedvoltagesandfrequenciesinasinusoidalwaveshapeasnosynchronisationorcoordinationwithgridsuppliesisrequired.

Asolarinvertermayconnecttoastringofsolarpanels.Insomeinstallationsasolarmicroinverterisconnectedateachsolarpanel.[64]ForsafetyreasonsacircuitbreakerisprovidedbothontheACandDCsidetoenablemaintenance.ACoutputmaybeconnectedthroughanelectricitymeterintothepublicgrid.[65]ThenumberofmodulesinthesystemdeterminesthetotalDCwattscapableofbeinggeneratedbythesolararrayhowever,theinverterultimatelygovernstheamountofACwattsthatcanbedistributedforconsumption.Forexample,aPVsystemcomprising11kilowattsDC(kWDC)

worthofPVmodules,pairedwithone10kilowattAC(kWAC)inverter,willbelimitedtotheinverter'soutputof10kW.Asof2014,conversionefficiencyforstateoftheartconvertersreachedmorethan98percent.WhilestringinvertersareusedinresidentialtomediumsizedcommercialPVsystems,centralinverterscoverthelargecommercialandutilityscalemarket.Marketshareforcentralandstringinvertersareabout50percentand48percent,respectively,leavinglessthan2percenttomicroinverters.[66]

Maximumpowerpointtracking(MPPT)isatechniquethatgridconnectedinvertersusetogetthemaximumpossiblepowerfromthephotovoltaicarray.Inordertodoso,theinverter'sMPPTsystemdigitallysamplesthesolararray'severchangingpoweroutputandappliestheproperresistancetofindtheoptimalmaximumpowerpoint.[67]

AntiislandingisaprotectionmechanismthatimmediatelyshutsdowntheinverterpreventingitfromgeneratingACpowerwhentheconnectiontotheloadnolongerexists.Thishappens,forexample,inthecaseofablackout.Withoutthisprotection,thesupplylinewouldbecomean"island"withpowersurroundedbya"sea"ofunpoweredlines,asthesolararraycontinuestodeliverDCpowerduringthepoweroutage.Islandingisahazardtoutilityworkers,whomaynotrealizethatanACcircuitisstillpowered,anditmaypreventautomaticreconnectionofdevices.[68]



AcomputergeneratedimageoftheTeslaPowerwall

Inverter/ConverterMarketin2014

Type Power Efficiency(a)MarketShare(b)

Remarks

Stringinverter

upto100kWp(c)

98% 50% Cost(b)0.15perwattpeak.Easytoreplace.

Centralinverter

above100kWp 98.5% 48%0.10perwattpeak.Highreliability.Oftensoldalongwithaservicecontract.

Microinverter

modulepowerrange 90%95% 1.5%

0.40perwattpeak.Easeofreplacementconcerns.

DC/DCconverterPoweroptimizer

modulepowerrange 98.8% n.a.

0.40perwattpeak.Easeofreplacementconcerns.Inverterisstillneeded.About0.75GWPinstalledin2013.

Source:databyIHS2014,remarksbyFraunhoferISE2014,from:PhotovoltaicsReport,updatedasper8September2014,p.35,PDF[66]

Notes:(a)bestefficienciesdisplayed,(b)marketshareandcostperwattareestimated,(c)kWp=kilowattpeak

Battery

Mainarticles:RechargeablebatteryandBattery(electricity)

Althoughstillexpensive,PVsystemsincreasinglyuserechargeablebatteriestostoreasurplustobelaterusedatnight.Batteriesusedforgridstoragealsostabilizetheelectricalgridbylevelingoutpeakloads,andplayanimportantroleinasmartgrid,astheycanchargeduringperiodsoflowdemandandfeedtheirstoredenergyintothegridwhendemandishigh.

Commonbatterytechnologiesusedintoday'sPVsystemsincludethevalveregulatedleadacidbatteryamodifiedversionoftheconventionalleadacidbattery,nickelcadmiumandlithiumionbatteries.Comparedtotheothertypes,leadacidbatterieshaveashorterlifetimeandlowerenergydensity.However,duetotheirhighreliability,lowselfdischargeaswellaslowinvestmentandmaintenancecosts,theyarecurrentlythepredominanttechnologyusedinsmallscale,residentialPVsystems,aslithiumionbatteriesarestillbeingdevelopedandabout3.5timesasexpensiveasleadacidbatteries.Furthermore,asstoragedevicesforPVsystemsarestationary,thelowerenergyandpowerdensityandthereforehigherweightofleadacidbatteriesarenotascriticalas,forexample,inelectrictransportation[9]:4,9OtherrechargeablebatteriesthatareconsideredfordistributedPVsystemsincludesodiumsulfurandvanadiumredoxbatteries,twoprominenttypesofamoltensaltandaflowbattery,respectively.[9]:4In2015,TeslamotorslaunchedthePowerwall,arechargeablelithiumionbatterywiththeaimtorevolutionizeenergyconsumption.[69]

PVsystemswithanintegratedbatterysolutionalsoneedachargecontroller,asthevaryingvoltageandcurrentfromthesolararrayrequiresconstantadjustmenttopreventdamagefromovercharging.[70]BasicchargecontrollersmaysimplyturnthePVpanelsonandoff,ormaymeteroutpulsesofenergyasneeded,astrategycalledPWMorpulsewidthmodulation.MoreadvancedchargecontrollerswillincorporateMPPTlogicintotheirbatterychargingalgorithms.Chargecontrollersmayalsodivertenergytosomepurposeotherthanbatterycharging.RatherthansimplyshutoffthefreePVenergywhennotneeded,ausermaychoosetoheatairorwateroncethebatteryisfull.

Monitoringandmetering

Mainarticles:Netmetering,EnergymeteringandSmartmeter

Themeteringmustbeabletoaccumulateenergyunitsinbothdirectionsortwometersmustbeused.Manymetersaccumulatebidirectionally,somesystemsusetwometers,butaunidirectionalmeter(withdetent)willnotaccumulateenergyfromanyresultantfeedintothegrid.[71]Insomecountries,forinstallationsover30kWpafrequencyandavoltagemonitorwithdisconnectionofallphasesisrequired.Thisisdonewheremoresolarpowerisbeinggeneratedthancanbeaccommodatedbytheutility,andtheexcesscannoteitherbeexportedorstored.Gridoperatorshistoricallyhaveneededtoprovidetransmissionlinesandgenerationcapacity.Nowtheyneedtoalsoprovidestorage.Thisisnormallyhydrostorage,butothermeansofstorageareused.Initiallystoragewasusedsothatbaseloadgeneratorscouldoperateatfulloutput.Withvariablerenewableenergy,storageisneededtoallowpowergenerationwheneveritisavailable,andconsumptionwheneveritisneeded.



ACanadianelectricitymeter

Concentratorphotovoltaic(CPV)inCatalonia,Spain

Thetwovariablesagridoperatorhavearestoringelectricityforwhenitisneeded,ortransmittingittowhereitisneeded.Ifbothofthosefail,installationsover30kWpcanautomaticallyshutdown,althoughinpracticeallinvertersmaintainvoltageregulationandstopsupplyingpoweriftheloadisinadequate.Gridoperatorshavetheoptionofcurtailingexcessgenerationfromlargesystems,althoughthisismorecommonlydonewithwindpowerthansolarpower,andresultsinasubstantiallossofrevenue.[72]Threephaseinvertershavetheuniqueoptionofsupplyingreactivepowerwhichcanbeadvantageousinmatchingloadrequirements.[73]

Photovoltaicsystemsneedtobemonitoredtodetectbreakdownandoptimizetheiroperation.Thereareseveralphotovoltaicmonitoringstrategiesdependingontheoutputoftheinstallationanditsnature.Monitoringcanbeperformedonsiteorremotely.Itcan

measureproductiononly,retrieveallthedatafromtheinverterorretrieveallofthedatafromthecommunicatingequipment(probes,meters,etc.).Monitoringtoolscanbededicatedtosupervisiononlyorofferadditionalfunctions.Individualinvertersandbatterychargecontrollersmayincludemonitoringusingmanufacturerspecificprotocolsandsoftware.[74]Energymeteringofaninvertermaybeoflimitedaccuracyandnotsuitableforrevenuemeteringpurposes.Athirdpartydataacquisitionsystemcanmonitormultipleinverters,usingtheinvertermanufacturer'sprotocols,andalsoacquireweatherrelatedinformation.IndependentsmartmetersmaymeasurethetotalenergyproductionofaPVarraysystem.Separatemeasuressuchassatelliteimageanalysisorasolarradiationmeter(apyranometer)canbeusedtoestimatetotalinsolationforcomparison.[75]DatacollectedfromamonitoringsystemcanbedisplayedremotelyovertheWorldWideWeb,suchasOSOTF.[76][77][78][79]

Othersystems

Thissectionincludessystemsthatareeitherhighlyspecializedanduncommonorstillanemergingnewtechnologywithlimitedsignificance.However,standaloneoroffgridsystemstakeaspecialplace.Theywerethemostcommontypeofsystemsduringthe1980sand1990s,whenPVtechnologywasstillveryexpensiveandapurenichemarketofsmallscaleapplications.Onlyinplaceswherenoelectricalgridwasavailable,theywereeconomicallyviable.Althoughnewstandalonesystemsarestillbeingdeployedallaroundtheworld,theircontributiontotheoverallinstalledphotovoltaiccapacityisdecreasing.InEurope,offgridsystemsaccountfor1percentofinstalledcapacity.IntheUnitedStates,theyaccountforabout10percent.OffgridsystemsarestillcommoninAustraliaandSouthKorea,andinmanydevelopingcountries.[8]:14

CPV

Mainarticle:Concentratorphotovoltaics

Concentratorphotovoltaics(CPV)andhighconcentratorphotovoltaic(HCPV)systemsuseopticallensesorcurvedmirrorstoconcentratesunlightontosmallbuthighlyefficientsolarcells.Besidesconcentratingoptics,CPVsystemssometimeusesolartrackersandcoolingsystemsandaremoreexpensive.

EspeciallyHCPVsystemsarebestsuitedinlocationwithhighsolarirradiance,concentratingsunlightupto400timesormore,withefficienciesof2428percent,exceedingthoseofregularsystems.VariousdesignsofCPVandHCPVsystemsarecommerciallyavailablebutnotverycommon.However,ongoingresearchanddevelopmentistakingplace.[1]:26

CPVisoftenconfusedwithCSP(concentratedsolarpower)thatdoesnotusephotovoltaics.Bothtechnologiesfavorlocationsthatreceivemuchsunlightandaredirectlycompetingwitheachother.

Hybrid

AhybridsystemcombinesPVwithotherformsofgeneration,usuallyadieselgenerator.Biogasisalsoused.Theotherformofgenerationmaybeatypeabletomodulatepoweroutputasafunctionofdemand.Howevermorethanonerenewableformofenergymaybeusede.g.wind.Thephotovoltaicpowergenerationservestoreducetheconsumptionofnonrenewablefuel.Hybridsystemsaremostoftenfoundonislands.PellwormislandinGermanyandKythnosislandinGreecearenotableexamples(botharecombinedwithwind).[80][81]TheKythnosplanthasreduceddieselconsumptionby11.2%.[82]

In2015,acasestudyconductedinsevencountriesconcludedthatinallcasesgeneratingcostscanbereducedbyhybridisingminigridsandisolatedgrids.However,financingcostsforsuchhybridsarecrucialandlargelydependontheownershipstructureofthepowerplant.Whilecostreductionsforstateownedutilitiescanbesignificant,thestudyalsoidentifiedeconomic



AwindsolarPVhybridsystem

benefitstobeinsignificantorevennegativefornonpublicutilities,suchasindependentpowerproducers.[83][84]

TherehasalsobeenrecentworkshowingthatthePVpenetrationlimitcanbeincreasedbydeployingadistributednetworkofPV+CHPhybridsystemsintheU.S.[85]Thetemporaldistributionofsolarflux,electricalandheatingrequirementsforrepresentativeU.S.singlefamilyresidenceswereanalyzedandtheresultsclearlyshowthathybridizingCHPwithPVcanenableadditionalPVdeploymentabovewhatispossiblewithaconventionalcentralizedelectricgenerationsystem.Thistheorywasreconfirmedwithnumericalsimulationsusingpersecondsolarfluxdatatodeterminethatthenecessarybatterybackuptoprovideforsuchahybridsystemispossiblewithrelativelysmallandinexpensivebatterysystems.[86]Inaddition,largePV+CHPsystemsarepossibleforinstitutionalbuildings,whichagainprovidebackupforintermittentPVandreduceCHPruntime.[87]

PVTsystem(hybridPV/T),alsoknownasphotovoltaicthermalhybridsolarcollectorsconvertsolarradiationintothermalandelectricalenergy.Suchasystemcombinesasolar(PV)modulewithasolarthermalcollectorinancomplementaryway.CPVTsystem.Aconcentratedphotovoltaicthermalhybrid(CPVT)systemissimilartoaPVTsystem.Itusesconcentratedphotovoltaics(CPV)insteadofconventionalPVtechnology,andcombinesitwithasolarthermalcollector.CPV/CSPsystem.AnovelsolarCPV/CSPhybridsystemhasbeenproposedrecently,combiningconcentratorphotovoltaicswiththenonPVtechnologyofconcentratedsolarpower(CSP),oralsoknownasconcentratedsolarthermal.[88]

PVdieselsystem.Itcombinesaphotovoltaicsystemwithadieselgenerator.[89]

Combinationswithotherrenewablesarepossibleandincludewindturbines.[90]

Floatovoltaics

FloatovoltaicsarePVsystemsthatfloatonthesurfaceofdrinkingwaterreservoirs,quarrylakes,irrigationcanalsorremediationandtailingponds.AsmallnumberofsuchsystemsexistinFrance,India,Japan,Korea,theUnitedKingdomandtheUnitedStates.[91][92][93][94]

InMay2008,theFarNienteWineryinOakville,California,pioneeredtheworld'sfirstfloatovoltaicsystembyinstalling994solarPVmoduleswithatotalcapacityof477kWonto130pontoonsandfloatingthemonthewinery'sirrigationpond.[95]Theprimarybenefitofsuchasystemisthatitavoidstheneedtosacrificevaluablelandareathatcouldbeusedforanotherpurpose.InthecaseoftheFarNienteWinery,itsavedthreequartersofanacrethatwouldhavebeenrequiredforalandbasedsystem.[96]Anotherbenefitofafloatovoltaicsystemisthatthepanelsarekeptatacoolertemperaturethantheywouldbeonland,leadingtoahigherefficiencyofsolarenergyconversion.ThefloatingPVarrayalsoreducestheamountofwaterlostthroughevaporationandinhibitsthegrowthofalgae.[97]

UtilityscalefloatingPVfarmsarestartingtobebuilt.ThemultinationalelectronicsandceramicsmanufacturerKyocerawilldeveloptheworld'slargest,a13.4MWfarmonthereservoiraboveYamakuraDaminChibaPrefecture[98]using50,000solarpanels.[99]ItisexpectedtobeonlineinMarch2016.Saltwaterresistantfloatingfarmsarealsobeingconstructedforoceanuse.[100]Thelargestsofarannouncedfloatovoltaicprojectisa350MWpowerstationintheAmazonregionofBrazil.[101]

Directcurrentgrid

DCgridsarefoundinelectricpoweredtransport:railwaystramsandtrolleybuses.Afewpilotplantsforsuchapplicationshavebeenbuilt,suchasthetramdepotsinHannoverLeinhausen,usingphotovoltaiccontributors[102]andGeneva(BachetdePesay).[103]The150kWpGenevasitefeeds600VDCdirectlyintothetram/trolleybuselectricitynetworkwhereasbeforeitprovidedabout15%oftheelectricityatitsopeningin1999.

Standalone

Astandaloneoroffgridsystemisnotconnectedtotheelectricalgrid.Standalonesystemsvarywidelyinsizeandapplicationfromwristwatchesorcalculatorstoremotebuildingsorspacecraft.Iftheloadistobesuppliedindependentlyofsolarinsolation,thegeneratedpowerisstoredandbufferedwithabattery.Innonportableapplicationswhereweightisnotanissue,suchasinbuildings,leadacidbatteriesaremostcommonlyusedfortheirlowcostandtoleranceforabuse.

Achargecontrollermaybeincorporatedinthesystemtoavoidbatterydamagebyexcessivechargingordischarging.Itmayalsohelptooptimizeproductionfromthesolararrayusingamaximumpowerpointtrackingtechnique(MPPT).However,insimplePVsystemswherethePVmodulevoltageismatchedtothebatteryvoltage,theuseofMPPTelectronicsisgenerally



AnisolatedmountainhutinCatalonia,Spain

SolarparkingmeterinEdinburgh,Scotland

consideredunnecessary,sincethebatteryvoltageisstableenoughtoprovidenearmaximumpowercollectionfromthePVmodule.Insmalldevices(e.g.calculators,parkingmeters)onlydirectcurrent(DC)isconsumed.Inlargersystems(e.g.buildings,remotewaterpumps)ACisusuallyrequired.ToconverttheDCfromthemodulesorbatteriesintoAC,aninverterisused.

Inagriculturalsettings,thearraymaybeusedtodirectlypowerDCpumps,withouttheneedforaninverter.Inremotesettingssuchasmountainousareas,islands,orotherplaceswhereapowergridisunavailable,solararrayscanbeusedasthesolesourceofelectricity,usuallybychargingastoragebattery.Standalonesystemscloselyrelatetomicrogenerationanddistributedgeneration.

PicoPVsystems

Thesmallest,oftenportablephotovoltaicsystemsarecalledpicosolarPVsystems,orpicosolar.Theymostlycombinearechargeablebatteryandchargecontroller,withaverysmallPVpanel.Thepanel'snominalcapacityisjustafewwattpeak(110Wp)anditsarealessthanatenthofasquaremeter,oronesquarefoot,insize.Alargerangeofdifferentapplicationscanbesolarpoweredsuchasmusicplayers,fans,portablelamps,securitylights,solarlightingkits,solarlanternsandstreetlight(seebelow),phonechargers,radios,orevensmall,seveninchLCDtelevisions,thatrunonlessthantenwatts.Asitisthecaseforpowergenerationfrompicohydro,picoPVsystemsareusefulinsmall,ruralcommunitiesthatrequireonlyasmallamountofelectricity.Sincetheefficiencyofmanyapplianceshaveimprovedconsiderably,inparticularduetotheusageofLEDlightsandefficientrechargeablebatteries,picosolarhasbecomeanaffordablealternative,especiallyinthedevelopingworld.[104]Themetricprefixpicostandsforatrillionthtoindicatethesmallnessofthesystem'selectricpower.

Solarstreetlights

Solarstreetlightsraisedlightsourceswhicharepoweredbyphotovoltaicpanelsgenerallymountedonthelightingstructure.ThesolararrayofsuchoffgridPVsystemchargesarechargeablebattery,whichpowersafluorescentorLEDlampduringthenight.Solarstreetlightsarestandalonepowersystems,andhavetheadvantageofsavingsontrenching,landscaping,andmaintenancecosts,aswellasontheelectricbills,despitetheirhigherinitialcostcomparedtoconventionalstreetlighting.Theyaredesignedwithsufficientlylargebatteriestoensureoperationforatleastaweekandevenintheworstsituation,theyareexpectedtodimonlyslightly.

Telecommunicationandsignaling

SolarPVpowerisideallysuitedfortelecommunicationapplicationssuchaslocaltelephoneexchange,radioandTVbroadcasting,microwaveandotherformsofelectroniccommunicationlinks.Thisisbecause,inmosttelecommunicationapplication,storagebatteriesarealreadyinuseandtheelectricalsystemisbasicallyDC.Inhillyandmountainousterrain,radioandTVsignalsmaynotreachastheygetblockedorreflectedbackduetoundulatingterrain.Attheselocations,lowpowertransmittersareinstalledtoreceiveandretransmitthesignalforlocalpopulation.[105]

Solarvehicles

Solarvehicle,whetherground,water,airorspacevehiclesmayobtainsomeoralloftheenergyrequiredfortheiroperationfromthesun.Surfacevehiclesgenerallyrequirehigherpowerlevelsthancanbesustainedbyapracticallysizedsolararray,soabatteryisusedtomeetpeakpowerdemand,andthesolararrayrechargesit.Spacevehicleshavesuccessfullyusedsolarphotovoltaicsystemsforyearsofoperation,eliminatingtheweightoffuelorprimarybatteries.

Solarpumps

Oneofthemostcosteffectivesolarapplicationsisasolarpoweredpump,asitisfarcheapertopurchaseasolarpanelthanitistorunpowerlines.[106][107][108]Theyoftenmeetaneedforwaterbeyondthereachofpowerlines,takingtheplaceofawindmillorwindpump.Onecommonapplicationisthefillingoflivestockwateringtanks,sothatgrazingcattlemaydrink.Anotheristherefillingofdrinkingwaterstoragetanksonremoteorselfsufficienthomes.

Spacecrafts

SolarpanelsonspacecrafthavebeenoneofthefirstapplicationsofphotovoltaicssincethelaunchofVanguard1in1958,thefirstsatellitetousesolarcells.ContrarytoSputnik,thefirstartificialsatellitetoorbittheplanet,thatranoutofbatterieswithin21daysduetothelackofsolarpower,mostmoderncommunicationssatellitesandspaceprobesintheinnersolarsystemrelyontheuseofsolarpanelstoderiveelectricityfromsunlight.[109][110]



Doityourselfcommunity

Withagrowinginterestinenvironmentallyfriendlygreenenergy,anincreasingnumberofhobbyistsintheDIYcommunityhaveendeavoredtobuildtheirownsolarPVsystemsfromkits[111]orpartlyDIY.[112]Usually,theDIYcommunityusesinexpensive[113]orhighefficiencysystems[114](suchasthosewithsolartracking)togeneratetheirownpower.Asaresult,theDIYsystemsoftenendupcheaperthantheircommercialcounterparts.[115]Often,thesystemisalsohookedupintotheregularpowergrid,usingnetmeteringinsteadofabatteryforbackup.Thesesystemsusuallygeneratepoweramountof~2kWorless.Throughtheinternet,thecommunityisnowabletoobtainplansto(partly)constructthesystemandthereisagrowingtrendtowardbuildingthemfordomesticrequirements.

Galleryofstandalonesystems

Seealso:ListofsolarpoweredproductsandStandalonepowersystem

Profilepictureofamobilesolarpoweredgenerator

Solarpanelsonasmallyachttocharge12voltbatteriesup

to9amps

AmobilechargingstationforelectricvehiclesinFrance

Asolarpoweredrepeaterusedintelecommunications

Artist'sconceptoftheJunospacecraftorbitingJupiter

Alateralmark,OtagoHarbour,NZ

Solarpoweredelectricfence,inHarwoodNorthumberland,UK.

Solarsailorboat,DarlingHarbour,Sydney,Australia.

PoweringaYurtinMongolia

Asolarcalculator

Asolarnavigationlight



Solarpathwaylightinginwinter(SteamboatSprings,US).

SolarpoweredlighthouseinScotland

Asmallsolarwaterpumpsystem

Solarcar.TheJapanesewinnerof2009WorldSolarChallengein

Australia.

Asolarcellphonecharger

Asolarfan

Solarpoweredwatch

Asolarpoweredtrashcompactor,JerseyCity,U.S.

AsolarsewagetreatmentplantinSantuarideLluc,Spain

SolarImpulse,anelectricaircraft

Rentalstationforebikes,Budapest,Hungary

Costsandeconomy

Thecostofproducingphotovotaiccellshavedroppedduetoeconomiesofscaleinproductionandtechnologicaladvancesinmanufacturing.Forlargescaleinstallations,pricesbelow$1.00perwattarenowcommon.[118]Apricedecreaseof50%hadbeenachievedinEuropefrom2006to2011andthereisapotentialtolowerthegenerationcostby50%by2020.[119]Crystalsiliconsolarcellshavelargelybeenreplacedbylessexpensivemulticrystallinesiliconsolarcells,andthinfilmsiliconsolarcellshavealsobeendevelopedrecentlyatlowercostsofproduction.Althoughtheyarereducedinenergyconversionefficiencyfromsinglecrystalline"siwafers",theyarealsomucheasiertoproduceatcomparablylowercosts.[120]

ThetablebelowshowsthetotalcostinUScentsperkWhofelectricitygeneratedbyaphotovoltaicsystem.[121][122]Therowheadingsontheleftshowthetotalcost,perpeakkilowatt(kWp),ofaphotovoltaicinstallation.Photovoltaicsystemcostshave

beendecliningandinGermany,forexample,werereportedtohavefallentoUSD1389/kWpbytheendof2014.[123]ThecolumnheadingsacrossthetoprefertotheannualenergyoutputinkWhexpectedfromeachinstalledkWp.Thisvariesbygeographicregionbecausetheaverageinsolationdependsontheaveragecloudinessandthethicknessofatmospheretraversedbythesunlight.Italsodependsonthepathofthesunrelativetothepanelandthehorizon.Panelsareusuallymountedatananglebasedonlatitude,andoftentheyareadjustedseasonallytomeetthechangingsolardeclination.Solartrackingcanalsobeutilizedtoaccessevenmoreperpendicularsunlight,therebyraisingthetotalenergyoutput.

ThecalculatedvaluesinthetablereflectthetotalcostincentsperkWhproduced.Theyassumea10%totalcapitalcost(forinstance4%interestrate,1%operatingandmaintenancecost,[124]anddepreciationofthecapitaloutlayover20years).Normally,photovoltaicmoduleshavea25yearwarranty.[125][126]



MedianinstalledsystempricesforresidentialPVSystemsinJapan,

GermanyandtheUnitedStates($/W)

Historyofsolarrooftoppricessince2006.ComparisoninUS$perinstalledwatt.[116][117]

Japan

UnitedStates

Germany

CostofgeneratedkilowatthourbyaPVSystem(US/kWh)dependingonsolarradiationandinstallationcostduring20yearsofoperation

Installationcostin

$perwatt

InsolationannuallygeneratedkilowatthoursperinstalledkWcapacity(kWh/kWpy)

2400 2200 2000 1800 1600 1400 1200 1000 800

$0.20 0.8 0.9 1.0 1.1 1.3 1.4 1.7 2.0 2.5$0.60 2.5 2.7 3.0 3.3 3.8 4.3 5.0 6.0 7.5$1.00 4.2 4.5 5.0 5.6 6.3 7.1 8.3 10.0 12.5$1.40 5.8 6.4 7.0 7.8 8.8 10.0 11.7 14.0 17.5$1.80 7.5 8.2 9.0 10.0 11.3 12.9 15.0 18.0 22.5

$2.20 9.2 10.0 11.0 12.2 13.8 15.7 18.3 22.0 27.5

$2.60 10.8 11.8 13.0 14.4 16.3 18.6 21.7 26.0 32.5$3.00 12.5 13.6 15.0 16.7 18.8 21.4 25.0 30.0 37.5$3.40 14.2 15.5 17.0 18.9 21.3 24.3 28.3 34.0 42.5$3.80 15.8 17.3 19.0 21.1 23.8 27.1 31.7 38.0 47.5$4.20 17.5 19.1 21.0 23.3 26.3 30.0 35.0 42.0 52.5

$4.60 19.2 20.9 23.0 25.6 28.8 32.9 38.3 46.0 57.5

$5.00 20.8 22.7 25.0 27.8 31.3 35.7 41.7 50.0 62.5

USA Japan Germany Smallrooftopsystemcostandavg.insolationappliedtodatatable,in2013

Notes:

1. Costperwattforrooftopsystemin2013:Japan$4.64,[116]UnitedStates$4.92,[116]andGermany$2.05[117]

2. Generatedkilowatthourperinstalledwattpeak,basedonaverageinsolationforJapan(1500kWh/m/year),UnitedStates(5.0to5.5kWh/m/day),[127]andGermany(1000to1200kWh/m/year).

3. A2013studybytheFraunhoferISEconcludesLCOEcostforasmallPVsystemtobe$0.16(0.12)ratherthan$0.22perkilowatthourasshownintable(Germany).

Systemcost2013



Inits2014editionofthe"TechnologyRoadmap:SolarPhotovoltaicEnergy"report,theInternationalEnergyAgency(IEA)publishedpricesinUS$perwattforresidential,commercialandutilityscalePVsystemsforeightmajormarketsin2013.[7]

TypicalPVsystempricesin2013inselectedcountries(USD)

USD/W Australia China France Germany Italy Japan UnitedKingdomUnitedStates

Residential 1.8 1.5 4.1 2.4 2.8 4.2 2.8 4.9Commercial 1.7 1.4 2.7 1.8 1.9 3.6 2.4 4.5Utilityscale 2.0 1.4 2.2 1.4 1.5 2.9 1.9 3.3

Source:IEATechnologyRoadmap:SolarPhotovoltaicEnergyreport[7]:15

Regulation

Standardization

Increasinguseofphotovoltaicsystemsandintegrationofphotovoltaicpowerintoexistingstructuresandtechniquesofsupplyanddistributionincreasesthevalueofgeneralstandardsanddefinitionsforphotovoltaiccomponentsandsystems.ThestandardsarecompiledattheInternationalElectrotechnicalCommission(IEC)andapplytoefficiency,durabilityandsafetyofcells,modules,simulationprograms,plugconnectorsandcables,mountingsystems,overallefficiencyofinvertersetc.[128]

Planningandpermit

Whilearticle690oftheNationalElectricCodeprovidesgeneralguidelinesfortheinstallationofphotovoltaicsystems,theseguidelinesmaybesupersededbylocallawsandregulations.Oftenapermitisrequirednecessitatingplansubmissionsandstructuralcalculationsbeforeworkmaybegin.Additionally,manylocalesrequiretheworktobeperformedundertheguidanceofalicensedelectrician.CheckwiththelocalCity/CountyAHJ(AuthorityHavingJurisdiction)toensurecompliancewithanyapplicablelawsorregulations.

IntheUnitedStates,theAuthorityHavingJurisdiction(AHJ)willreviewdesignsandissuepermits,beforeconstructioncanlawfullybegin.ElectricalinstallationpracticesmustcomplywithstandardssetforthwithintheNationalElectricalCode(NEC)andbeinspectedbytheAHJtoensurecompliancewithbuildingcode,electricalcode,andfiresafetycode.Jurisdictionsmayrequirethatequipmenthasbeentested,certified,listed,andlabeledbyatleastoneoftheNationallyRecognizedTestingLaboratories(NRTL).Despitethecomplicatedinstallationprocess,arecentlistofsolarcontractorsshowsamajorityofinstallationcompanieswerefoundedsince2000.[129]

Nationalregulations

UnitedKingdom

IntheUK,PVinstallationsaregenerallyconsideredpermitteddevelopmentanddon'trequireplanningpermission.Ifthepropertyislistedorinadesignatedarea(NationalPark,AreaofOutstandingNaturalBeauty,SiteofSpecialScientificInterestorNorfolkBroads)thenplanningpermissionisrequired.[130]

UnitedStates

IntheUS,manylocalitiesrequireapermittoinstallaphotovoltaicsystem.Agridtiedsystemnormallyrequiresalicensedelectriciantomaketheconnectionbetweenthesystemandthegridconnectedwiringofthebuilding.[131]Installerswhomeetthesequalificationsarelocatedinalmosteverystate.[129]TheStateofCaliforniaprohibitshomeowners'associationsfromrestrictingsolardevices.[132]

Spain

AlthoughSpainusesabout20%ofitsenergyviaphotovoltaicsascitiessuchasHuelvaandSevilleboastnearly3,000hoursofsunshineperyear,SpainhasissuedasolartaxtoaccountforthedebtcreatedbytheinvestmentdonebytheSpanishgovernment.Thosewhodonotconnecttothegridcanfaceuptoafineof30millioneuros($40millionUSD).[133][134]

Seealso

Listofphotovoltaicpowerstations



ListofrooftopphotovoltaicinstallationsPhotovoltaicpowerstationsRenewableenergyRooftopphotovoltaicpowerstationSolarenergySolarvehicle

References1. "PhotovoltaicsReport"(PDF).FraunhoferISE.28July2014.Archivedfromtheoriginalon31August2014.Retrieved31August2014.2. ServiceLifetimePredictionforEncapsulatedPhotovoltaicCells/Minimodules(http://www.nrel.gov/docs/legosti/fy97/22572.pdf),A.W.

CzandernaandG.J.Jorgensen,NationalRenewableEnergyLaboratory,Golden,CO.3. M.Bazilian,I.Onyeji,M.Liebreichetal.(2013)."Reconsideringtheeconomicsofphotovoltaicpower"(PDF).RenewableEnergy

(53).Archivedfromtheoriginalon31August2014.Retrieved31August2014.4. "PhotovoltaicSystemPricingTrendsHistorical,Recent,andNearTermProjections,2014Edition"(PDF).NREL.22September2014.

p.4.Archivedfromtheoriginalon29March2015.5. "PhotovoltaikPreisindex"[SolarPVpriceindex].PhotovoltaikGuide.Retrieved30March2015."TurnkeynetpricesforasolarPV

systemofupto100kilowattsamountedtoEuro1,240perkWp."6. FraunhoferISELevelizedCostofElectricity(http://www.ise.fraunhofer.de/en/publications/veroeffentlichungenpdfdateienen/studien

undkonzeptpapiere/studylevelizedcostofelectricityrenewableenergies.pdf)Study,November2013,p.197. http://www.iea.org(2014)."TechnologyRoadmap:SolarPhotovoltaicEnergy"(PDF).IEA.Archivedfromtheoriginalon7October

2014.Retrieved7October2014.8. "GlobalMarketOutlookforPhotovoltaics20142018"(PDF).www.epia.org.EPIAEuropeanPhotovoltaicIndustryAssociation.

Archivedfromtheoriginalon12June2014.Retrieved12June2014.9. JoernHoppmann,JonasVolland,TobiasS.Schmidt,VolkerH.Hoffmann(July2014)."TheEconomicViabilityofBatteryStoragefor

ResidentialSolarPhotovoltaicSystemsAReviewandaSimulationModel".ETHZrich,HarvardUniversity.RetrievedMarch2015.10. FORBES,JustinGerdes,SolarEnergyStorageAboutToTakeOffInGermanyandCalifornia

(http://www.forbes.com/sites/justingerdes/2013/07/18/solarenergystorageabouttotakeoffingermanyandcalifornia/),18July201311. http://www.greentechmedia.com/articles/read/u.s.solarmarketgrows41hasrecordyearin201312. RenewableEnergyPolicyNetworkforthe21stcentury(REN21),Renewables2010GlobalStatusReport

(http://www.ren21.net/REN21Activities/GlobalStatusReport.aspx),Paris,2010,pp.180.13. Branker,K.Pathak,M.J.M.Pearce,J.M.(2011)."AReviewofSolarPhotovoltaicLevelizedCostofElectricity".Renewableand

SustainableEnergyReviews15(9):4470.doi:10.1016/j.rser.2011.07.104.hdl:1974/6879.14. "LevelizedCostofElectricityRenewableEnergyTechnologies"(PDF).http://www.ise.fraunhofer.de.FraunhoferISE.November

2013.p.4.Archivedfromtheoriginalon3August2014.Retrieved3August2014.15. "CrossingtheChasm"(PDF).DeutscheBankMarketsResearch.27February2015.p.9.Archivedfromtheoriginalon1April2015.16. TamHunt(9March2015)."TheSolarSingularityIsNigh".GreentechMedia.Retrieved29April2015.17. "SnapshotofGlobalPV19922014"(PDF).http://www.ieapvps.org/index.php?id=32.InternationalEnergyAgencyPhotovoltaic

PowerSystemsProgramme.30March2015.Archivedfromtheoriginalon30March2015.18. "Photovoltaic...Cell,Module,String,Array"(PDF).WordPowerIanWoofenden.2006.RetrievedAugust2015.19. NREL.govResidential,Commercial,andUtilityScalePhotovoltaic(PV)SystemPricesintheUnitedStates

(http://www.nrel.gov/docs/fy12osti/53347.pdf),p.6February201220. TypesofPVsystems(http://www.fsec.ucf.edu/en/consumer/solar_electricity/basics/types_of_pv.htm).FloridaSolarEnergyCenter

(FSEC),aresearchinstituteoftheUniversityofCentralFlorida.21. Rahmani,R.Fard,M.Shojaei,A.A.Othman,M.F.Yusof,R.,AcompletemodelofstandalonephotovoltaicarrayinMATLAB

Simulinkenvironment,2011IEEEStudentConferenceonResearchandDevelopment(SCOReD),pp4651,2011.22. Armyevaluatingtransportablesolarpoweredtents|Article|TheUnitedStatesArmy(http://www.army.mil/article/49138/army

evaluatingtransportablesolarpoweredtents/).Army.mil(20101208).Retrievedon20130717.23. [1](http://www.9wsyr.com/news/local/story/SolvayElectricusingsolarpanelsonutility/4fFgF35JP0yyCmRElazAQg.cspx)24. RobAndrews,AndrewPollard,JoshuaM.Pearce,"Improvedparametricempiricaldeterminationofmoduleshortcircuitcurrentfor

modellingandoptimizationofsolarphotovoltaicsystems",SolarEnergy86,22402254(2012).DOI(http://dx.doi.org/10.1016/j.solener.2012.04.016),openaccess(http://mtu.academia.edu/JoshuaPearce/Papers/1853740/Improved_parametric_empirical_determination_of_module_short_circuit_current_for_modelling_and_optimization_of_solar_photovoltaic_systems)

25. RobAndrewsandJoshuaM.Pearce,"PredictionofEnergyEffectsonPhotovoltaicSystemsduetoSnowfallEvents(http://www.ieeepvsc.org/ePVSC/manuscripts/MePVSC566_0521131900.pdf)"in:201238thIEEEPhotovoltaicSpecialistsConference(PVSC).Presentedatthe201238thIEEEPhotovoltaicSpecialistsConference(PVSC),pp.003386003391.Available:DOI(http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6318297)openaccess(http://mtu.academia.edu/JoshuaPearce/Papers/1990041/Prediction_of_Energy_Effects_on_Photovoltaic_Systems_due_to_Snowfall_Events)

26. Andrews,RobW.Pollard,AndrewPearce,JoshuaM.(2013)."TheEffectsofSnowfallonSolarPhotovoltaicPerformance".SolarEnergy92(8497).doi:10.1016/j.solener.2013.02.014.

27. RobW.Andrews,AndrewPollard,JoshuaM.Pearce,Anewmethodtodeterminetheeffectsofhydrodynamicsurfacecoatingsonthesnowsheddingeffectivenessofsolarphotovoltaicmodules(http://dx.doi.org/10.1016/j.solmat.2013.01.032).SolarEnergyMaterialsandSolarCells113(2013)7178.openaccess(http://www.academia.edu/2937014/A_new_method_to_determine_the_effects_of_hydrodynamic_surface_coatings_on_the_snow_shedding_effectiveness_of_solar_photovoltaic_modules)

28. PVEducation.orgModuleMaterials(http://pveducation.org/pvcdrom/modules/modulematerials)29. KeyFactorsinselectingsolarcomponents(http://www.millenniumplanet.com/solarbuyersguide.html)



30. ListofEligibleSB1GuidelinesCompliantPhotovoltaicModules(http://www.gosolarcalifornia.ca.gov/equipment/pv_modules.php)31. "SolarPower(Photovoltaic,PV)".AgricultureandAgriFoodCanada.Retrieved5February2010.32. TheWorstMetricinRenewables:'ThePaybackPeriod'(http://www.renewableenergyworld.com/rea/blog/post/2010/04/theworstmetric

inrenewablesthepaybackperiod).RenewableEnergyWorld(20100419).Retrievedon20121001.33. It'spaybacktimeforhomegeneration(http://news.bbc.co.uk/2/hi/science/nature/8751862.stm).BBCNews(20100622).Retrievedon

20120423.34. "SolarPanelComparisonTable".Retrieved20121021.35. Andresen,BjarneR.StephenBerry(May1977)."Thermodynamicsinfinitetime.I.ThestepCarnotcycle".PhysicalReviewA.

doi:10.1103/PhysRevA.15.2086.36. FraunhoferInstituteforSolarEnergySystems."WorldRecordSolarCellwith44.7%Efficiency".FraunhoferISE.37. "ConcentrixSolar:ConcentratorModules".Retrieved20081203.38. CPVSolarCellReach27%SystemEfficiency(http://www.renewableenergyfocususa.com/view/16037/cpvsolarcellreach27system

efficiency/)39. Kajihara,Atsushi,andA.T.Harakawa."Modelofphotovoltaiccellcircuitsunderpartialshading."IndustrialTechnology,2005.ICIT

2005.IEEEInternationalConferenceon.IEEE,2005.40. Drif,M.Perez,P.J.Aguilera,J.Aguilar,J.D.(2008)."AnewestimationmethodofirradianceonapartiallyshadedPVgeneratorin

gridconnectedphotovoltaicsystems".RenewableEnergy33(9):20482056.doi:10.1016/j.renene.2007.12.010.41. VENTRE,JERRYAUTOR.Photovoltaicsystemsengineering.CRCpress,2004.42. UrsulaEicker,SolarTechnologiesforBuildings,Wiley2003,ISBN047148637X,page22643. H.T.NguyenandJ.M.Pearce,IncorporatingShadingLossesinSolarPhotovoltaicPotentialAssessmentattheMunicipalScale,Solar

Energy86(5),pp.12451260(2012).Source:http://www.academia.edu/1499891/Incorporating_Shading_Losses_in_Solar_Photovoltaic_Potential_Assessment_at_the_Municipal_Scale

44. Z.Dereli,C.YcedaandJ.M.Pearce,SimpleandLowCostMethodofPlanningforTreeGrowthandLifetimeEffectsonSolarPhotovoltaicSystemsPerformance,SolarEnergy,95,pp.300307(2013).Available:http://www.academia.edu/4074627/Simple_and_lowcost_method_of_planning_for_tree_growth_and_lifetime_effects_on_solar_photovoltaic_systems_performance

45. Shouldyouspringcleanyoursolarpanels?(http://googleblog.blogspot.com/2009/07/shouldyouspringcleanyoursolar.html)46. Santbergen,RR.J.C.vanZolingen(22October2007)."TheabsorptionfactorofcrystallinesiliconPVcells:Anumericaland

experimentalstudy".SolarEnergyMaterials&SolarCells.47. ElSharkawi,MohamedA.(2005).Electricenergy.CRCPress.pp.8788.ISBN9780849330780.48. OptimumTiltofSolarPanels(http://www.macslab.com/optsolar.html)49. StandAlonePhotovoltaicLightingSystems(http://www.fsec.ucf.edu/en/publications/pdf/FSECRR54982.pdf)50. Andrews,RobW.Pearce,JoshuaM.(2013)."Theeffectofspectralalbedoonamorphoussiliconandcrystallinesiliconsolar

photovoltaicdeviceperformance".SolarEnergy91:233241.doi:10.1016/j.solener.2013.01.030.51. Brennan,M.P.Abramase,A.L.Andrews,R.W.Pearce,J.M.(2014)."Effectsofspectralalbedoonsolarphotovoltaicdevices".Solar

EnergyMaterialsandSolarCells124:111116.doi:10.1016/j.solmat.2014.01.046.52. "Howmuchenergywillmysolarcellsproduce?".Retrieved20120530.53. Sahara'ssolarpowerpotentialunderlined(http://social.csptoday.com/taxonomy/term/83/saharassolarpowerpotentialunderlined)54. APerformanceCalculator(http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/).Rredc.nrel.gov.Retrievedon20120423.55. Technologicaladvantages(http://www.mecasolar.com/_bin/ventajas_2_ejes.php).Mecasolar.com.Retrievedon20120423.56. AlMohamad,Ali(2004)."EfficiencyimprovementsofphotovoltaicpanelsusingaSuntrackingsystem".AppliedEnergy79(3):345

354.doi:10.1016/j.apenergy.2003.12.004.57. ReflectiveCoatingSiliconSolarCellsBoostsAbsorptionOver96Percent

(http://www.scientificblogging.com/news_releases/reflective_coating_silicon_solar_cells_boosts_absorption_over_96_percent).Scientificblogging.com(20081103).Retrievedon20120423.

58. Beginners'GuidetoSolarTrackers:HowtoIncreaseOutputforYourHomeSolarPanelSystem(http://www.solartown.com/learning/solarpanels/beginnersguidetosolartrackershowtoincreaseoutputforyourhomesolarpanelsystem/),17August2011(archived(http://www.webcitation.org/6Sqbm9QvL))

59. InsolationLevels(Europe)(http://www.apricus.com/html/insolation_levels_europe.htm)60. 10yearsAverageInsolationData(http://www.portaenergy.com/Insolation_USA.htm)61. UtilityScaleSolarPowerPlants

(http://www1.ifc.org/wps/wcm/connect/04b38b804a178f13b377ffdd29332b51/SOLAR%2BGUIDE%2BBOOK.pdf?MOD=AJPERES)62. ShouldYouInstallaSolarTracker?(http://www.helmholz.us/smallpowersystems/Intro.pdf)63. GridTiedInverterSafety(http://homepower.com/article/?file=HP130_pg28_ATE_2).Homepower.com.Retrievedon20120423.64. Trendwatch:Microinvertersinvadesolar(http://www.smartplanet.com/blog/intelligentenergy/trendwatchmicroinvertersinvade

solar/9707)65. ServicesandSolutionsforPhotovoltaicSystems

(http://www.schurter.com/content/download/244246/7047074/version/3/file/Solar_Technology_wp_us.pdf)66. FraunhoferISEreport,archivedversionasperSeptember2014(archivedPDF)(http://www.webcitation.org/6TTjaprUM)67. http://www.solarelectric.comAllAboutMaximumPowerPointTracking(MPPT)(http://www.solarelectric.com/mpptsolarcharge

controllers.html)68. EDN.comSolarpowerantiislandingandcontrol(http://www.edn.com/design/systemsdesign/4391907/ProductHowToSolarpower

antiislandingandcontrol),7August201269. "TeslalaunchesPowerwallhomebatterywithaimtorevolutionizeenergyconsumption".AssociatedPress.May1,2015.70. DanFink,www.homepower.comChargeControllerBuyer'sGuide(http://www.homepower.com/articles/solarelectricity/equipment

products/2012chargecontrollerbuyersguide),January201271. ResidentialPhotovoltaicMeteringandInterconnectionStudy

(http://www.solarelectricpower.org/media/84144/sepa%20pv%20metering.pdf)72. IntegratingVariableRenewableEnergyinElectricPowerMarkets(http://www.nrel.gov/docs/fy12osti/53732.pdf)



73. SmartPVInverterBenefitsforUtilities(http://www.renewableenergyworld.com/rea/news/article/2012/01/smartpvinverterbenefitsforutilities)

74. EnphaseTechnology(http://enphase.com/explore/enphasetechnology/)75. SolarIrradianceMeasurements(https://buildingsfieldtest.nrel.gov/solar_irradiance_measurements)76. Pearce,Joshua.MAdegboyegaBabasolaRobAndrews(2012)."OpenSolarPhotovoltaicSystemsOptimization".Proceedingsofthe

16thAnnualNationalCollegiateInventorsandInnovatorsAllianceConference(NCIIA):17.77. CSIMeteringandPerformanceMonitoring

(http://www.pge.com/myhome/saveenergymoney/solarenergy/csi/csimeteringperformancemonitoring/)78. SolarEnergy(http://www.campbellsci.com/solarenergy)79. SolarGuard(http://www.solarcity.com/residential/solarguardsystemmonitoring.aspx)80. PVresourceswebsite(http://www.pvresources.com/en/hybrid.php),Hybridpowerstationaccessed10Feb0881. DatenundFakten(https://web.archive.org/web/20110719072419/http://www.pellworm.de/energieversorgung.0.html)attheWayback

Machine(archivedJuly19,2011).Pellwormislandwebsite(inGerman)82. Darula,IvanStefanMarko(2007)."Largescaleintegrationofrenewableelectricityproductionintothegrids"(PDF).Journalof

EelectricalEngineering58(1):5860.ISSN13353632.Retrieved20080210.83. "Newstudy:HybridisingelectricitygridswithsolarPVsavescosts,especiallybenefitsstateownedutilities".SolarServer.com.31May

2015.84. "RenewableEnergyinHybridMiniGridsandIsolatedGrids:EconomicBenefitsandBusinessCases".FrankfurtSchoolUNEP

CollaboratingCentreforClimate&SustainableEnergyFinance.May2015.85. J.M.Pearce(2009)."ExpandingPhotovoltaicPenetrationwithResidentialDistributedGenerationfromHybridSolarPhotovoltaic+

CombinedHeatandPowerSystems".Energy34:19471954.doi:10.1016/j.energy.2009.08.012.86. P.DerewonkoandJ.M.Pearce,"OptimizingDesignofHouseholdScaleHybridSolarPhotovoltaic+CombinedHeatandPower

SystemsforOntario"(http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5411247&isnumber=5411118),PhotovoltaicSpecialistsConference(PVSC),200934thIEEE,pp.12741279,712June2009.

87. M.Mostofi,A.H.Nosrat,andJ.M.Pearce,"InstitutionalScaleOperationalSymbiosisofPhotovoltaicandCogenerationEnergySystems"InternationalJournalofEnvironmentalScienceandTechnology8(1),pp.3144,2011.Availableopenaccess:[2](http://www.ijest.org/?_action=articleInfo&article=473)

88. Phys.orgAnovelsolarCPV/CSPhybridsystemproposed(http://phys.org/news/201502solarcpvcsphybrid.html),11February201589. AmandaCain(22January2014)."WhatIsaPhotovoltaicDieselHybridSystem?".RenewableEnergyWorld.com.90. "HybridWindandSolarElectricSystems".http://energy.gov.DOE.2July2012.91. "Kyocera,partnersannounceconstructionoftheworld'slargestfloatingsolarPVPlantinHyogoprefecture,Japan".SolarServer.com.4

September2014.92. "RunningOutofPreciousLand?FloatingSolarPVSystemsMayBeaSolution".EnergyWorld.com.7November2013.93. "VikramSolarcommissionsIndiasfirstfloatingPVplant".SolarServer.com.13January2015.94. "SunflowerFloatingSolarPowerPlantInKorea".CleanTechnica.21December2014.95. "WinerygoessolarwithFloatovoltaics".SFGate.29May2008.Retrieved31May2013.96. "NapaValley'sFarNienteWineryIntroducesfirsteverFloatovoltaicsolararray"(PDF).FarNiente.97. "NapaWineryPioneersSolarFloatovoltaics".Forbes.18April2012.Retrieved31May2013.98. "YamakuraDaminChibaPrefecture".TheJapanDamFoundation.Retrieved1February2015.99. KyoceraandCenturyTokyoLeasingtoDevelop13.4MWFloatingSolarPowerPlantonReservoirinChibaPrefecture,Japan

(http://global.kyocera.com/news/2014/1205_dfsp.html),Kyocera,December22,2014100. SolarPanelsFloatingonWaterCouldPowerJapan'sHomes(http://news.nationalgeographic.com/news/energy/2015/01/150116floating

solarpowerjapanyamakura/),NationalGeographic,BryanLufkin,January16,2015101. AnandUpadhyay(6April2015)."BrazilAnnouncesHuge350MWFloatingSolarPowerPlant".CleanTechnica.com.102. InnovativeElectricalConcepts(https://web.archive.org/web/20090318231142/http://www.ieapvps.org/products/download/rep7_07.pdf)

attheWaybackMachine(archivedMarch18,2009).InternationalEnergyAgency(2001)103. site7(http://www.ecotourisme.ch/site/7/site7.htm).Ecotourisme.ch.Retrievedon20120423.104. "PicoSolarPVSystemsforRemoteHomesAnewgenerationofsmallPVsystemsforlightingandcommunication"(PDF).IEA

PVPS.January2014.105. B.HKhan,'NonConventionalEnergyResources',TMHPublications01012006106. 'Paybillfor4months,getpowerfor25years'(http://daily.bhaskar.com/article/RAJJPRpaybillfor4monthsgetpowerfor25years

3491363.html)107. "PumpingWaterwithSunshine".Retrieved7January2014.108. "SolarWellPumps".Retrieved7January2014.109. "SpaceBasedSolarPower".energy.gov.6March2014.Retrieved29April2015.110. "HistoryofSolarEnergy".http://exploringgreentechnology.com/.Retrieved29April2015.111. Peoplebuildingtheirownsolarsystemsfromkits(http://www.greenplanet4energy.com).Greenplanet4energy.com.Retrievedon2012

0423.112. ExampleofdiyPVsystemwithpictures(http://www.instructables.com/id/SolarPowerSystem/).Instructables.com(20071105).

Retrievedon20120423.113. Graham,Michael.(20051015)LowcostPVsolarkitpreferredbydiycommunities

(http://www.treehugger.com/files/2005/10/inexpensive_diy.php).Treehugger.com.Retrievedon20120423.114. KenDarrowandMikeSaxenianAppropriateTechnologySourcebook

(https://web.archive.org/web/20100922115732/http://www.villageearth.org/pages/Appropriate_Technology/ATSourcebook/)attheWaybackMachine(archivedSeptember22,2010).villageearth.org

115. "AlternativeEnergyDevelopment:MichiganwillbeNationsLeaderinAlternativeEnergyTechnology,Jobs"(PDF).StateofMichigan,OfficeOfTheGovernor.RetrievedFebruary22,2012.

116. "ComparingPhotovoltaic(PV)CostsandDeploymentDriversintheJapaneseandU.S.ResidentialandCommercialMarkets"(PDF).http://www.nrel.gov/.NREL.gov.June2014.pp.16,27.Archivedfromtheoriginalon24September2014.Retrieved24September2014.



117. "HistoryofaverageturnkeypricesforrooftopPVsystemsupto100kWpinGermany.photovoltaikguide.de,pvpreisindexsince2009(http://www.photovoltaikguide.de/pvpreisindex),usingmonthofJanuaryfigures,andBundesverbandSolarwirtschafte.V.(BSWSolar),September2009,page4(http://www.solarwirtschaft.de/fileadmin/content_files/Faktenblatt_PV_Okt09.pdf),quarterlyfiguresfromEUPDResearchfor,dataforyears20062008.Usedexchangerateof0.74eurocentsperUS$.

118. JohnQuiggin(January3,2012)."TheEndoftheNuclearRenaissance|".NationalInterest.119. "Solarphotovoltaics:Competingintheenergysector".EuropeanPhotovoltaicIndustryAssociation(EPIA).20110901.Retrieved

20140405.120. AComparisonofPVTechnologies(http://quantumsp.com/en/solarenergy/acomparisonofpvtechnologies/)

121.

122. WhatisLevelizedCost?(http://www.solarestimate.org/showfaq.php?id=261)123. PVpriceindexGermany(http://www.photovoltaikguide.de/pvpreisindex)124. PVoperationandmaintenancecosts(http://www1.eere.energy.gov/solar/pdfs/46025.pdf).(PDF).Retrievedon20120423.125. SolarPVwarranties(http://solarconsumerreporting.webs.com/warranties.htm)126. UnderstandingSolarPanelWarrantees(https://www.cleanenergyexperts.com/2011/02/01/understandingsolarpanelwarranties/)127. MapPhotovoltaicResourceoftheUnitedStates(http://www.nrel.gov/gis/images/eere_pv/national_photovoltaic_201201.jpg)128. ReganArndtandDr.IngRobertPuto.BasicUnderstandingofIECStandardTestingForPhotovoltaicPanels.Available:

http://tuvamerica.com/services/photovoltaics/ArticleBasicUnderstandingPV.pdf129. SolarPowerWorld(http://www.solarpowerworldonline.com/top250solarcontractors/)130. SolarPanels(http://www.planningportal.gov.uk/permission/commonprojects/solarpanels/).PlanningPortal.Retrievedon20130717.131. "RequirementsforSolarInstallations".bootsontheroof.com.2011.RetrievedMarch31,2011.132. "CaliforniaSolarRightsAct".RetrievedFebruary25,2012.133. Hunt,Tam."SpainandPortugalLeadtheWayonRenewableEnergyTransformation".RenewableEnergyWorld.134. PhillipsErb,Kelly(19August2013)."OutOfIdeasAndInDebt,SpainSetsSightsOnTaxingTheSun".Forbes.Retrieved

20November2014.

Externallinks

Solar/PhotovoltaicResource(http://sunmetrix.com)PhotovoltaicEnergyFactsheet(http://css.snre.umich.edu/css_doc/CSS0708.pdf)bytheUniversityofMichigan'sCenterforSustainableSystems(http://www.css.snre.umich.edu/)HomePowerMagazinehttp://www.homepower.com/Solarprojectmanagement(http://www.vectorcuatro.es/index.php?option=com_content&view=article&id=150&Itemid=218&lang=en)PhotovoltaicSystemsEngineering(http://www.renovierungeneupen.be/PhotovoltaikSchienensysteme/)BestPracticesforSitingSolarPhotovoltaicsonMunicipalSolidWasteLandfills:AStudyPreparedinPartnershipwiththeEnvironmentalProtectionAgencyfortheREPoweringAmericasLandInitiative:SitingRenewableEnergyonPotentiallyContaminatedLandandMineSites(http://purl.fdlp.gov/GPO/gpo41519)NationalRenewableEnergyLaboratory

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