This book is dedicated to all men and women who believeinabetterfuture,andmakethedailydifference toachieveit Gabriele Zini • Paolo Tartarini Solar Hydrogen Energy Systems Science and Technology for the Hydrogen Economy GabrieleZini PaoloTartarini DipartimentodiIngegneria DipartimentodiIngegneria MeccanicaeCivile MeccanicaeCivile UniversitàdiModenaeReggioEmilia UniversitàdiModenaeReggioEmilia TranslatedfromtheoriginalItalianmanuscriptbyPei-ShuWu ISBN978-88-470-1997-3 e-ISBN978-88-470-1998-0 DOI10.1007/978-88-470-1998-0 LibraryofCongressControlNumber:2011940674 SpringerMilanHeidelbergNewYorkDordrechtLondon ©Springer-VerlagItalia2012 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpart of the material is concerned,specifically therights of translation,reprinting,reuse of illustrations, recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionor informationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissim- ilarmethodologynowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebrief excerptsinconnectionwithreviewsorscholarlyanalysisormaterialsuppliedspecificallyforthepur- poseofbeingenteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthe work.Duplicationofthispublicationorpartsthereofispermittedonlyundertheprovisionsofthe CopyrightLawofthePublisher’slocation,initscurrentversion,andpermissionforusemustalways beobtainedfromSpringer.PermissionsforusemaybeobtainedthroughRightsLinkattheCopyright ClearanceCenter.ViolationsareliabletoprosecutionundertherespectiveCopyrightLaw. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublica- tiondoesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromthe relevantprotectivelawsandregulationsandthereforefreeforgeneraluse. Whiletheadviceand informationinthisbook arebelieved to be true and accurateat thedateof publication,neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityfor anyerrorsoromissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,with respecttothematerialcontainedherein. Coverdesign:BeatriceB,Milan TypesettingwithLATEX:PTP-Berlin,ProtagoTEX-ProductionGmbH,Germany(www.ptp-berlin.eu) PrintingandBinding:GrafichePorpora,Segrate(Mi) PrintedinItaly Springer-VerlagItaliaS.r.l.,ViaDecembrio28,I-20137Milano SpringerisapartofSpringerScience+BusinessMedia(www.springer.com) Foreword Renewable energies will play a very significant role in our energy future. This is why I lead the Laboratory of Solar Systems at INES in France and why Gabriele chosetoworkonphotovoltaicsystemsinthesameteam.Withthedecreasingprices of photovoltaic modules and systems, the grid parity has already been reached in someregionsofSouthernEurope,whichmeansthatsolarelectricityisalreadyable to compete with conventional electricity in terms of selling price. Within the next tenyears,solarphotovoltaicenergywillevenbeabletocompetewithconventional electricityinmanyregions.Asimilarpicturecanbedrawnforwindenergysystems. However,thereisamarketbarriercomingfromabigdifferencebetweenrenew- ableandconventionalenergysources:Solarsystemsonlyproduceenergywhenthe sunisshining.Windenergyvarieswiththewindspeed.Traditionalelectricityopera- tors,especiallyinFrance,thereforetendtocallrenewableenergiesas“fatal”energy sources,becausetheydonothavethetoolstocontrolthem. In times when the market penetration of renewable energy is rather low, these fluctuations are not relevant. However, once this penetration to the grid becomes higher, innovative solutions are needed to assure a reliable grid service to the cus- tomers. This is very important for the energy supply on an island and also crucial forcontinentalgridswithhighrenewableenergypenetration,aswecanseetodayin Germany,forinstance. Afirstsolutionmightbethemassivematchingoftheelectricitydemandwiththe profile of solar energy generation. However, this cannot be done for the complete electricitydemand.Andmatchingthedemandtofastfluctuationsisevenmoredif- ficult.Thisiswhywehavetoprepareasecondsolution–theintegrationofenergy storage.Hydrogenisonepromisingstorageoption,asitcanbeusedforbothstorage andtransportationofenergy.Thisiswhatthebookisexploringandwhattheauthors havebeenresearchingonforyears.Iamcertainthatthereadercanfindhereaninter- estingintroductiononrenewableenergysystemswithhydrogenandhowhydrogen canbeaninterestingvehicletoincreasethemarketpenetrationofrenewableenergies. LeBourgetduLac,November2011 JensMerten HeadofLaboratoryforSolarSystems InstitutNationaldel’EnergieSolaire(INES) Preface Itisjustamatteroftimebeforefossilfuelsbecomecompletelydepletedor toouneco- nomicaltoretrieve.Inlightofthisdevelopment,thecurrentfossilfueleraismeant todrawtoanend.Ifontopofthisproblemofdiminishingavailabilitywealsoadd theenvironmentalpollutionsthefuelshavecaused,itisunderstandablewhywemust soonfindwaystoendthecurrentperiodandenteranewenergyera. Hydrogenisregardedasoneofthemostpromisingcandidatescapableofassum- ingaleadingroleduringthishistoricaltransition.Needlesstosay,theenergyneeded toobtainhydrogencannotbeprovidedbyfossilfuels.Itisthereforenecessarytoturn torenewableenergysourceswhichareinexhaustibleandcauseaslittleenvironmen- talimpactaspossible.Amongstthesesources,theauthorsconsidersolarenergytobe oneofthebestchoicesforreasonsthatwillbeelaboratedinthefollowingofthebook. Theworkisstructuredintoelevenchapterstopresentthereaderswithadvanced knowledge on the functioning and the implementation of a solar hydrogen energy system,whichcombinesdifferenttechnologiesefficientlyandharmoniouslytocon- vertrenewableenergiesintochemicalenergystoredintheformofhydrogenandthen toamuchmoreexploitableformofenergy,electricity. Chapter 1 introduces the macro-economical, technical and historical aspects of thenewhydrogen-basedenergysystem.Chapter2describesthephysicalandchem- icalpropertiesofhydrogen,itsproduction,application,thedegenerativephenomena andthecompatibilityofthematerialsemployedtohandlehydrogenstorageandtrans- portation.Chapter3exploresindetailthebehaviourandthemodellingofelectroly- sersandfuelcells.Chapters4and5describethetechnicalfoundationsofphotovoltaic andwindenergies.Chapter6discussesotherpotentialrenewableenergysourcesfor hydrogenproduction.Chapter7addressesanotherimportantissueofthewholepro- cess:thestorageofhydrogen.Chapter8providesmoreinformationonthechemical storageinstandardbatteriesandothermoreadvancedalternatives.Chapter9finally examinesindetailtheactualcompleteimplementation ofthehydrogensystemand simulates the system behaviour with the help of mathematical models. Chapter 10 proceedstopresentsomeofthemostinterestingreal-lifeapplications,whileChapter 11 draws the final conclusions. At the end of every chapter are listed the relevant referencesforreaderswhowishtofurtherexplorethetopics. VIII Preface This book has been conceived with the goal to share the science and technol- ogyofsolarhydrogenenergysystemsandtohelpbuildinganewsustainableenergy economy.Wehopethatwewillsucceed. WearegratefultoSimonePedrazziforhelpingdevelopethemodelsandthesim- ulationsinpartsofthebook;andtoAndreaZanni,SecretaryoftheBoardofWikime- diaItaly,forverifyingthecorrectuseoftheCreativeCommonslicenceoftheimages takenfromtheWikimediadatabase. TheauthorsarealsoindebtedtoPei-ShuWuwhosetranslationandeditinghave greatlyimprovedthefinaldraftofthebook. Finally,wewouldliketothankFrancescaBonadei,MariaCristinaAcocellaand Pierpaolo Riva from Springer Italia, for their support during the final stages of the publication. Bologna,September2011 GabrieleZini PaoloTartarini Contents 1 Introduction.................................................. 1 1.1 TheCurrentSituation...................................... 1 1.2 ThePeakOilTheory ...................................... 2 1.3 FormsofEnergySourcesandEnvironmentalImpact ........... 4 1.4 SustainabilityofanEnergySystem .......................... 6 1.5 AHydrogenNewEnergySystem............................ 7 1.6 ScenariosfortheFuture.................................... 7 1.7 AlternativestoHydrogen .................................. 9 References.................................................... 10 2 Hydrogen .................................................... 13 2.1 HydrogenasEnergyCarrier ................................ 13 2.2 Properties ............................................... 14 2.3 Production............................................... 16 2.3.1 SteamReforming.................................. 16 2.3.2 SolidFuelGasification ............................. 17 2.3.3 PartialOxidation .................................. 17 2.3.4 WaterElectrolysis ................................. 18 2.3.5 Thermo-Cracking ................................. 18 2.3.6 AmmoniaCracking................................ 18 2.3.7 Other Systems: Photochemical, Photobiological, SemiconductorsandtheirCombinations............... 19 2.4 Usage................................................... 20 2.4.1 DirectCombustion ................................ 20 2.4.2 CatalyticCombustion .............................. 23 2.4.3 DirectSteamProductionfromCombustion ............ 23 2.4.4 FuelCell......................................... 23 2.5 DegenerativePhenomenaandMaterialCompatibility .......... 24 2.5.1 MaterialDegeneration.............................. 24 2.5.2 ChoiceofMaterials................................ 25 2.6 Components:Pipes,JointsandValves........................ 26 X Contents 2.7 Transport................................................ 26 References.................................................... 27 3 ElectrolysisandFuelCells ..................................... 29 3.1 Introduction.............................................. 29 3.2 ChemicalKinetics ........................................ 30 3.3 Thermodynamics ......................................... 31 3.4 ElectrodeKinetics ........................................ 32 3.4.1 ActivationPolarisation ............................. 32 3.4.2 OhmicPolarisation ................................ 33 3.4.3 ConcentrationPolarisation .......................... 33 3.4.4 ReactionPolarisation .............................. 34 3.4.5 TransferPolarisation............................... 34 3.4.6 TransportPhenomena .............................. 34 3.4.7 InfluenceofTemperatureandPressureonPolarisation Losses .......................................... 35 3.5 EnergyandExergyoftheCell .............................. 35 3.6 Electrolyser.............................................. 36 3.6.1 Functioning ...................................... 36 3.6.2 Technology....................................... 37 3.6.2.1 AlkalineElectrolysers ..................... 37 3.6.2.2 Solid Polymer (Polymeric Membrane) Electrolysers.............................. 38 3.6.2.3 High-TemperatureElectrolysers ............. 38 3.6.3 Thermodynamics.................................. 39 3.6.4 MathematicalModel ............................... 40 3.6.5 ThermalModel ................................... 42 3.7 FuelCell ................................................ 43 3.7.1 Functioning ...................................... 43 3.7.2 Technology....................................... 45 3.7.2.1 AlkalineFuelCell ......................... 45 3.7.2.2 PhosphoricAcidFuelCell .................. 45 3.7.2.3 PolymericElectrolyteMembraneFuelCell .... 46 3.7.2.4 MoltenCarbonateFuelCell ................. 46 3.7.2.5 SolidOxideFuelCell ...................... 47 3.7.3 Thermodynamics.................................. 48 3.7.4 MathematicalModel ............................... 50 3.7.5 ThermalModel ................................... 52 References.................................................... 52 4 SolarRadiationandPhotovoltaicConversion .................... 53 4.1 SolarRadiation........................................... 53 4.2 PhotovoltaicEffect,Semiconductorsandthep-nJunction ....... 55 4.3 CrystallineSiliconPhotovoltaicCells ........................ 58 4.4 OtherCellTechnologies ................................... 61 Contents XI 4.5 ConversionLosses ........................................ 61 4.6 ChangesintheI-UCurve .................................. 62 4.7 PhotovoltaicCellsandModules ............................ 63 4.8 TypesofPhotovoltaicPlants................................ 65 4.9 RadiationontheReceivingSurface ......................... 67 4.10 DeterminationoftheOperatingPoint ........................ 68 References.................................................... 71 5 WindEnergy ................................................. 73 5.1 Introduction.............................................. 73 5.2 MathematicalDescriptionofWind .......................... 74 5.3 WindClassification ....................................... 76 5.4 MathematicalModeloftheAerogenerator .................... 77 5.5 PowerControlandDesign ................................. 83 5.6 WindTurbineRating...................................... 86 5.7 ElectricEnergyConversion ................................ 86 5.8 CalculationExample ...................................... 88 5.9 EnvironmentalImpact ..................................... 88 References.................................................... 89 6 OtherRenewableEnergySourcesforHydrogenProduction ....... 91 6.1 SolarThermalEnergy ..................................... 91 6.2 HydroelectricEnergy...................................... 93 6.3 Tidal,WaveandOceanThermalEnergyConversions........... 93 6.4 Biomasses ............................................... 94 References.................................................... 95 7 HydrogenStorage............................................. 97 7.1 IssuesofHydrogenStorage................................. 97 7.2 PhysicalStorage ......................................... 98 7.2.1 CompressionStorage .............................. 98 7.2.1.1 Modelling ............................... 99 7.2.1.2 DimensioningExample..................... 101 7.2.2 LiquefactionStorage .............................. 102 7.2.3 GlassorPlasticContainments ....................... 103 7.3 Physical-ChemicalStorage ................................ 104 7.3.1 Physisorption ..................................... 104 7.3.2 EmpiricalModelsofMolecularInteractions ........... 105 7.3.3 AdsorptionandDesorptionVelocities ................ 107 7.3.4 Experimental Measurements of Adsorption and Desorption ....................................... 109 7.3.5 AdsorptionIsotherms .............................. 109 7.3.6 ThermodynamicsofAdsorption ..................... 111 7.3.7 OtherIsotherms .................................. 112 7.3.8 ClassificationofIsotherms .......................... 112 XII Contents 7.3.9 CarbonMaterialsforthePhysisorptionofHydrogen .... 113 7.3.9.1 Nanotubes................................ 113 7.3.9.2 ActivatedCarbons......................... 114 7.3.10 AlternativestoCarbonPhysisorption ................. 115 7.3.11 Zeolites.......................................... 115 7.3.12 MetallicHydrides ................................. 116 7.4 ChemicalStorage ........................................ 117 7.4.1 ChemicalHydrides ................................ 117 References.................................................... 118 8 OtherElectricityStorageTechnologies .......................... 121 8.1 Introduction.............................................. 121 8.2 ElectrochemicalStorage ................................... 121 8.2.1 ValveRegulatedLead-Acid ......................... 123 8.2.2 Lithium-Ion ...................................... 124 8.2.3 VanadiumRedox.................................. 125 8.3 Ultra-capacitors .......................................... 126 8.4 CompressedAir .......................................... 127 8.5 UndergroundPumpedWater................................ 128 8.6 PumpedHeat............................................. 128 8.7 NaturalGasProduction .................................... 128 8.8 Flywheels ............................................... 129 8.9 SuperconductingMagneticEnergyStorage ................... 130 References.................................................... 130 9 StudyandSimulationofSolarHydrogenEnergySystems ......... 133 9.1 SolarHydrogenEnergySystems ............................ 133 9.2 ControlLogic ............................................ 134 9.3 PerformanceAnalysis ..................................... 136 9.3.1 Sub-SystemsEfficiencies ........................... 136 9.3.1.1 PhotovoltaicModules ...................... 136 9.3.1.2 Aerogenerator ............................ 137 9.3.1.3 Electrolyser .............................. 137 9.3.1.4 FuelCell................................. 138 9.3.1.5 Compressor .............................. 138 9.3.1.6 ElectricSystems .......................... 138 9.3.2 CompleteSystemEfficiencies ....................... 138 9.3.2.1 HydrogenProductionEfficiency ............. 139 9.3.2.2 DirectRouteEfficiency..................... 139 9.3.2.3 HydrogenLoopEfficiency .................. 139 9.3.2.4 CompleteSystemEfficiency ................ 140 9.4 SimulationwithPVConversionandCompressionStorage....... 140 9.5 SimulationwithPVConversionandActivated-CarbonStorage... 147 9.6 SimulationwithWindEnergyConversion,Compressionand Activated-CarbonStorage.................................. 155