Table Of ContentElectricity from Wave
and Tide
Electricity from Wave
and Tide
An Introduction to Marine Energy
Paul A. Lynn,
BSc (Eng), PhD
formerly
Imperial College London, UK
Thiseditionfirstpublished2014
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LibraryofCongressCataloging-in-PublicationData
Lynn,PaulA.
Electricityfromwaveandtide:anintroductiontomarineenergy/PaulA.Lynn.
pagescm
Includesbibliographicalreferencesandindex.
ISBN978-1-118-34091-2(hardback)
1.Tidalpower-plants. 2.Oceanwavepower. 3.Tidalpower. I.Title.
TK1081.L952014
621.31(cid:2)2134–dc23
2013019102
AcataloguerecordforthisbookisavailablefromtheBritishLibrary.
ISBN:9781118340912
Typesetin10/12ptTimesNewRomanbyLaserwordsPrivateLimited,Chennai,India
12014
Contents
Preface.........................................................ix
Acknowledgements............................................xi
1. Introduction...............................................1
1.1 MarineenergyandPlanetEarth..................................1
1.2 Marineresources................................................5
1.2.1 Wavesoftheworld.......................................5
1.2.2 Tidesoftheworld.......................................11
1.3 Apieceofhistory..............................................18
1.3.1 Workingwithwaves.....................................18
1.3.2 Tappingtides...........................................23
1.4 Power,energyandperformance.................................27
1.5 Intothefuture..................................................34
References.....................................................37
2. Capturingmarineenergy.................................39
2.1 Oceanwaves...................................................39
2.1.1 Linearwaves............................................39
2.1.2 Randomwaves..........................................43
2.1.3 Wavespectra............................................48
2.1.4 Wavemodification......................................52
2.1.5 Wavemeasurement......................................56
2.2 Waveenergyconversion........................................59
2.2.1 Introductory.............................................59
2.2.2 Typesofwaveenergyconverter..........................60
2.2.3 Principlesofwaveenergycapture........................62
2.2.3.1 Floatingdevices................................62
v
Contents
2.2.3.2 Tuninganddamping...........................64
2.2.3.3 WhenwavesmeetWECs.......................68
2.3 Tidalstreams...................................................71
2.3.1 Hydrodynamics.........................................71
2.3.2 Tidalharmonics.........................................76
2.3.3 Predictingtidalstreams..................................83
2.4 Tidalstreamenergyconversion.................................86
2.4.1 Introductory.............................................86
2.4.2 Tidalstreamturbines....................................89
2.4.2.1 Turbinesizesandpowerratings.................89
2.4.2.2 Extractingenergy:theBetzLimit...............93
2.4.2.3 Liftanddrag...................................96
2.4.2.4 Rotorspeedandpowercoefficient.............102
2.4.3 Turbinesiting..........................................105
2.5 Researchanddevelopment....................................108
2.5.1 Modelsandtesttanks..................................108
2.5.2 TheEuropeanMarineEnergyCentre(EMEC)...........111
2.5.2.1 Waveandtidaltestsites.......................111
2.5.2.2 Researchactivities............................121
References....................................................124
3. Generatingelectricity...................................125
3.1 Introductory..................................................125
3.2 Powertake-off................................................126
3.3 ACelectricity.................................................130
3.4 Generators....................................................141
3.4.1 Introductory...........................................141
3.4.2 Synchronousgenerators................................147
3.4.3 Asynchronousgenerators...............................151
3.4.3.1 Squirrel-cageandwound-rotorinduction
machines.....................................151
3.4.3.2 Doubly-fedinductiongenerators...............157
3.4.4 Linearmotiongenerators...............................162
3.5 Connectingtothegrid.........................................166
3.5.1 Settingthescene.......................................166
3.5.2 Gridstrengthandfaultlevels...........................169
3.5.3 Electricalquality.......................................173
3.6 Large-scalerenewableenergy..................................175
3.6.1 Introductory...........................................175
3.6.2 Intermittencyandvariability............................176
3.6.3 Capacitycreditandbackupgeneration..................179
References....................................................183
vi
Contents
4. Casestudies:Waveenergyconverters.................185
4.1 Introductory..................................................185
4.2 Casestudies..................................................186
4.2.1 Pelamis................................................186
4.2.2 Oyster.................................................192
4.2.3 LimpetandMutriku....................................199
4.2.4 WaveDragon..........................................205
®
4.2.5 PowerBuoy ..........................................211
4.2.6 Penguin...............................................216
References....................................................221
5. Casestudies:Tidalstreamenergyconverters.........223
5.1 Introductory..................................................223
5.2 Casestudies..................................................224
5.2.1 AndritzHydroHammerfest.............................224
5.2.2 AtlantisResources.....................................229
5.2.3 MarineCurrentTurbines...............................234
5.2.4 OpenHydro............................................240
5.2.5 PulseTidal............................................245
5.2.6 ScotrenewablesTidalPower............................251
5.2.7 TidalGeneration.......................................258
References....................................................262
Index.........................................................263
vii
