光伏发电系统设计与安装手册

PhotovoltaicDesignandInstallationBucknellUniversitySolarScholarsProgramPresenters:ColinDavies‘08EricFournier‘08OutlineWhyRenewableEnergy?TheScienceofPhotovoltaicsSystemConfigurationsPrincipleDesignElementsTheSolarScholarsprogramatBucknell(walkingtour)What’swrongwiththispicture?Pollutionfromburningfossilfuelsleadstoanincreaseingreenhousegases,acidrain,andthedegradationofpublichealth.In2005,theU.S.emitted2,513,609metrictonsofcarbondioxide,10,340metrictonsofsulfurdioxide,and3,961metrictonsofnitrogenoxidesfromitspowerplants.40%85%ofourenergyconsumptionisfromfossilfuels!WhySustainableEnergyMattersTheworld’scurrentenergysystemisbuiltaroundfossilfuels–Problems:FossilfuelreservesareultimatelyfiniteTwo-thirdsoftheworld'sprovenoilreservesarelocatingintheMiddle-EastandNorthAfrica(whichcanleadtopoliticalandeconomicinstability)WhySustainableEnergyMattersDetrimentalenvironmentalimpacts–Extraction(miningoperations)–CombustionGlobalwarming?(couldleadtosignificantchangesintheworld'sclimatesystem,leadingtoariseinsealevelanddisruptionofagricultureandecosystems)ASustainableEnergyFutureDevelopanddeployrenewableenergysourcesonamuchwiderscaleBringdowncostofrenewableenergyMakeimprovementsintheefficiencyofenergyconversion,distribution,anduseThreeMethods:-Incentives-Economyofscale-RegulationMakingtheChangetoRenewableEnergySolarGeothermalWindHydroelectricToday’sSolarPictureGermanyleadssolarproduction(over4.5timesmorethenUSproduction)–Japanis2nd(nearly3timesmorethenUSproduction)–thisismainlyduetoincentivesFinancialIncentives–Investmentsubsidies:costofinstallationofasystemissubsidized–Netmetering:theelectricityutilitybuysPVelectricityfromtheproducerunderamultiyearcontractataguaranteedrate–RenewableEnergyCertificates(RECs)SolarinPennsylvaniaPennsylvaniaisinfactaleaderinrenewableenergyIncentives–Local&stategrantandloanprograms–Taxdeductions–REC’s(in2006:variedfrom$5to$90perMWh,medianabout$20)HarnessingtheSunCommonlyknownassolarcells,photovoltaic(PV)devicesconvertlightenergyintoelectricalenergyPVcellsareconstructedwithsemiconductormaterials,usuallysilicon-basedThephotovoltaiceffectisthebasicphysicalprocessbywhichaPVcellconvertssunlightintoelectricity–WhenlightshinesonaPVcell,itmaybereflected,absorbed,orpassrightthrough.Butonlytheabsorbedlightgenerateselectricity.ElectricityPart2:LearningObjectivesCompareACandDCelectricalcurrentandunderstandtheirimportantdifferencesExplaintherelationshipbetweenvolts,amps,amp-hours,watts,watt-hours,andkilowatt-hoursLearnaboutusingelectricalmetersElectricityTerminologyElectricity=FlowingelectronsDifferencesinelectricalpotentialcreateelectronflowLoadsharnessthekineticenergyoftheseflowingelectronstodoworkFlowingwaterisagoodconceptualtoolforunderstandingElectricityTerminologyVoltage(EorV)–Unitofelectromotiveforce–CanbethoughtofaselectricalpressureAmps(IorA)–Rateofelectronflow–Electricalcurrent–1Amp=1coulomb/second=6.3x1018electrons/secondElectricityTerminologyResistance(RorΩ)–Theoppositionofamaterialtotheflowofanelectricalcurrent–DependsonMaterialCrosssectionalareaLengthTemperatureElectricityTerminologyWatt(W)areameasureofPower–UnitrateofelectricalenergyAmpsxVolts=Watts1Kilowatt(kW)=1000wattsElectricityTerminologyWatt-hour(Wh)isameasureofenergy–Unitquantityofelectricalenergy(consumptionandproduction)–Wattsxhours=Watt-hours1Kilowatt-hour(kWh)=1000WhPowerandEnergyCalculationDrawaPVarraycomposedoffour75wattmodules.Whatsizeisthesysteminwatts?ElectricityTerminologyAmp-hour(Ah)–Quantityofelectronflow–Usedforbatterysizing–Ampsxhours=Amp-hours–Amp-hoursxVolts=Watt-hoursA200AhBatterydelivering1Awilllast_____hours200AhBatterydelivering10Awilllast_____hours100AhBatteryx12V=_____WhTypesofElectricalCurrentDC=DirectCurrent–PVpanelsproduceDC–BatteriesstoreDCAC=AlternatingCurrent–Utilitypower–MostconsumerappliancesuseACMetersandTestingClamponmeterDigitalmultimeterNevertestbatterycurrentusingamultimeter!SystemTypesPart1:LearningObjectivesUnderstandthefunctionsofPVcomponentsIdentifydifferentsystemtypesPhotovoltaic(PV)TerminologyCellModulePanelArrayBattery–storesDCenergyController–sensesbatteryvoltageandregulateschargingInverter–convertsdirectcurrent(DC)energytoalternatingcurrent(AC)energyLoads–anythingthatconsumesenergySystemswithDCLoadsDCSystemOptionsBatterybackupvs.discontinuoususeLVDoptioninchargecontrollerLoadcontrollersSystemswithACloadsACSystemOptionsCombinedACandDCloadsHybridsystemwithbackupgeneratorGridtiedutilityinteractivesystemwithoutbatteriesGridtiedinteractivewithbatterybackup(whymightyouneedthis?)Grid-TiedSystem(WithoutBatteries)Complexity–Low:Easytoinstall(lesscomponents)GridInteraction–Gridcansupplementpower–NopowerwhengridgoesdownGrid-TiedSystem(WithBatteries)Complexity–High:DuetotheadditionofbatteriesGridInteraction–Gridstillsupplementspower–Whengridgoesdownbatteriessupplypowertoloads(akabatterybackup)PVModulesPart3:LearningObjectivesLearnhowaPVcellproduceselectricityfromsunlightDiscussthe3basictypesofPVcelltechnologiesUnderstandtheef