Table Of ContentThis 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
