TidalTidal PowerPower CAUSECAUSE 20032003 FinalFinal ProjectProject PetePete ClarkClark RebeccaRebecca KlossnerKlossner LaurenLauren KologeKologe OverviewOverview •• Introduction •• Basic Science of Tides •• Historical Aspects •• New Technology from an Old Idea •• La Rance Case Study •• Severn Project – Will There Ever Be a Barrage? •• Long Island Sound Barrage Case Study for the Future •• Fundy Bay - Case Study – Environmental Impacts of Tidal Energy – Economics of Tidal Energy – Policy Concerns – Other Tidal Schemes •• A More Futuristic Approach –Artificial Reef Program: Offshore Rigs BasicBasic ScienceScience ofof thethe TidesTides LunarLunar TidalTidal DynamicsDynamics TidalTidal BasicsBasics •• MostMost locationslocations havehave twotwo tidaltidal cyclescycles perper day:day: 1212 hours,hours, 2525 minutesminutes •• EssentiallyEssentially causedcaused byby interactioninteraction ofof moon,moon, earth,earth, andand sunsun centrifugalcentrifugal forcesforces •• DiurnalDiurnal tidestides areare generatedgenerated becausebecause thethe maximamaxima andand minimaminima inin eacheach dailydaily rotationrotation areare unequalunequal inin amplitudeamplitude NewtonNewton’’ss LawLaw ofof GravitationalGravitational StateState FF == GG m1m2m1m2 RR2 Particle (Water) Radius of Earth TidalTidal ForceForce == 2Gmm1a2Gmm1a Distance 33 between Earth RR and Moon TidalTidal FactsFacts •• TidalTidal RangeRange == DistanceDistance betweenbetween highhigh tidetide markmark andand lowlow tidetide markmark •• LargestLargest RangesRangesÆÆ CoastalCoastal RegionsRegions withwith extremeextreme depthdepth gradientgradient ((MouzelMouzel == excellentexcellent tidaltidal range)range) •• SmallestSmallest RangesRangesÆÆ OpenOpen OceanOcean (<.5(<.5 m)m) SpringSpring TidesTides •• YearYear roundround •• OccurOccur duringduring fullfull moonmoon andand newnew moonmoon •• DueDue toto thethe linearlinear patternpattern ofof SMESME •• CausesCauses strongerstronger tides:tides: increasedincreased currentcurrent andand tidaltidal rangesranges NeapNeap TidesTides •• MoonMoon andand sunsun areare perpendicularperpendicular toto eacheach otherother •• WeakWeak currents,currents, lowerlower tidaltidal rangesranges •• OccurOccur duringduring quarterquarter moonsmoons NeapNeap TidesTides VersusVersus SpringSpring TidesTides Bulging Effect BarrageBarrage LogisticsLogistics •• LargestLargest surfacesurface area,area, greatestgreatest tidaltidal rangerange –– SquareSquare EffectEffect •• EffectsEffects ofof ecosystemecosystem (fish,(fish, sediment,sediment, etc.)etc.) •• ProximityProximity toto populationpopulation WaterwayWaterway MeasurementMeasurement LogisticsLogistics Mean Tidal Amplitude(m) Basin Area (km2) La Rance, France 4 17 Bay of Fundy, Canada 5.5 240 Annapolis, Nova Scotia 3.2 6 Severn Estuary 4 420 Garolim Bay, South Korea 2.5 85 BayBay ofof FundyFundy VSVS ChesapeakeChesapeake BayBay Greater Friction HistoricalHistorical AspectsAspects AncientAncient TideTide MillsMills •• DuringDuring thethe RomanRoman occupationoccupation ofof England,England, tidetide millsmills werewere builtbuilt toto grindgrind graingrain andand corncorn •• TheseThese tidetide millsmills operatedoperated byby storingstoring waterwater behindbehind aa damdam duringduring highhigh tide.tide. AsAs thethe tidetide recededreceded thethe waterwater waswas slowlyslowly letlet outout fromfrom behindbehind thethe damdam inin orderorder toto powerpower thethe mill.mill. NendrumNendrum MonasticMonastic TidalTidal SiteSite •• DiscoveredDiscovered inin 19991999 •• UnveiledUnveiled waswas aa stonestone builtbuilt tidaltidal millmill andand evidenceevidence ofof anan ancientancient tidaltidal millmill datingdating backback toto 787787 A.D.A.D. ElingEling MillMill •• TheThe millmill waswas includedincluded inin thethe DomesdayDomesday SurveySurvey ofof 10861086 •• OriginallyOriginally milledmilled fourfour tonstons ofof flourflour eacheach dayday atat maximummaximum outputoutput •• RebuiltRebuilt manymany times,times, butbut operatesoperates inin thethe samesame mannermanner ElingEling MillMill –– HowHow itit WorksWorks ElingEling MillMill Tide Pond Tide Mill The Sea NewNew TechnologyTechnology fromfrom anan OldOld IdeaIdea IndustrialIndustrial RevolutionRevolution •• BroughtBrought cheapcheap energyenergy inin thethe formform ofof electricityelectricity •• SmallSmall tidaltidal millsmills werewere replacedreplaced withwith largelarge steamsteam--poweredpowered rollerroller millsmills •• PaleotechnicPaleotechnic periodperiod meansmeans fullfull steamsteam aheadahead withwith littlelittle thoughthough ofof whatwhat waswas happeninghappening toto thethe environmentenvironment FromFrom MillingMilling toto ElectricityElectricity •• MostMost commoncommon generatinggenerating systemsystem isis thethe ebbebb generatinggenerating systemsystem •• DoubleDouble effecteffect turbinesturbines areare nownow becomingbecoming technologicallytechnologically feasiblefeasible ConstructionConstruction •• CaissonsCaissons areare manufacturedmanufactured atat shoreshore--basedbased constructionconstruction yardsyards areare delivereddelivered toto waterwater sitessites byby bargesbarges andand thenthen positionedpositioned byby cranescranes toto allowallow forfor thethe structuresstructures toto correctlycorrectly settlesettle onon thethe marinemarine floor.floor. •• AnotherAnother methodmethod callscalls forfor constructingconstructing diaphragmdiaphragm wallswalls ofof reinforcedreinforced concreteconcrete withinwithin aa temporarytemporary sandsand island.island. LocationLocation •• TidalTidal millsmills werewere usuallyusually builtbuilt onon inletsinlets branchingbranching offoff tidaltidal estuaries.estuaries. •• AnAn estuaryestuary isis aa widewide partpart ofof aa riverriver wherewhere itit meetsmeets thethe sea.sea. •• TidalTidal estuariesestuaries areare characterizedcharacterized byby narrow,narrow, shallowshallow channelschannels withwith aa relativelyrelatively constantconstant widthwidth andand depth.depth. •• TidesTides areare greatlygreatly amplifiedamplified inin thesethese areasareas ofof smallersmaller volume,volume, whichwhich causescauses thethe tidetide toto traveltravel upup thethe river.river. TidalTidal BarrageBarrage •• SimilarSimilar toto aa damdam •• StructureStructure mustmust spanspan thethe entireentire widthwidth andand heightheight ofof thethe estuaryestuary EvolutionEvolution ofof TurbineTurbine TypesTypes •• WaterwheelWaterwheel turbinesturbines werewere usedused inin tidaltidal millsmills Undershot Overshot Breast-shot RecentRecent TurbinesTurbines •• Bulb,Bulb, Rim,Rim, andand TubularTubular Rim Turbine (Copyright Boyle, 1996) Bulb Turbine (Copyright Boyle, 1996) Tubular Turbine (Copyright Boyle, 1996) LaLa RanceRance CaseCase StudyStudy LaLa RanceRance TidalTidal PowerPower PlantPlant •• OnlyOnly fullfull scalescale powerpower stationstation ofof itsits typetype inin thethe worldworld •• LocatedLocated inin northernnorthern FranceFrance onon thethe LaLa RanceRance RiverRiver LaLa RanceRance •• CompletedCompleted inin 19671967 afterafter 2525 yearsyears ofof studiesstudies andand sixsix yearsyears ofof constructionconstruction •• 2424 bulbbulb turbines,turbines, eacheach capablecapable ofof producingproducing tenten megawattsmegawatts ofof powerpower •• TheThe damdam isis 24602460 feetfeet (750(750 meters)meters) long,long, andand 4343 feetfeet (13(13 meters)meters) highhigh •• OneOne ofof thethe greatestgreatest tidaltidal rangesranges inin thethe world,world, atat 13.5m.13.5m. LaLa RanceRance TurbinesTurbines •• BulbBulb turbinesturbines •• TheThe bladesblades ofof thethe turbineturbine cancan changechange directionsdirections dependingdepending onon thethe currentcurrent flow.flow. •• TheThe turbinesturbines weighweigh 470470 tonstons andand havehave aa bladeblade diameterdiameter ofof overover seventeenseventeen feet.feet. •• TheThe plantplant isis alsoalso equippedequipped withwith pumpspumps thatthat allowallow waterwater toto bebe pumpedpumped intointo thethe basinbasin whenwhen thethe seasea isis closeclose toto basinbasin levellevel atat highhigh tide.tide. ThisThis allowsallows forfor moremore electricityelectricity toto bebe generatedgenerated ifif therethere isis anan anticipatedanticipated increaseincrease inin demand.demand. NoNo Drawbacks?Drawbacks? •• NoNo adverseadverse impactimpact onon speciesspecies nativenative toto thethe waterwater •• NoNo floodingflooding hashas occurredoccurred •• RoadRoad waswas createdcreated •• TouristTourist sitesite •• GeneratesGenerates electricityelectricity forfor overover 300,000300,000 homeshomes •• NotNot allall tidaltidal barragesbarrages willwill havehave suchsuch negligiblenegligible affectsaffects SevernSevern ProjectProject SevernSevern BarrageBarrage HistoryHistory •• SecondSecond largestlargest tidaltidal rangesranges inin thethe worldworld •• ProposalsProposals toto damdam thethe SevernSevern havehave existedexisted forfor overover oneone hundredhundred yearsyears •• WhenWhen thethe SevernSevern BarrageBarrage conceptconcept waswas originallyoriginally proposedproposed inin thethe 1840s,1840s, itit waswas toto improveimprove shippingshipping andand preventprevent flooding.flooding. InIn addition,addition, thethe barragebarrage wouldwould createcreate aa roadwayroadway andand railwayrailway acrossacross thethe river.river. PowerPower PlantPlant ProposalsProposals •• Proposal in 1918, but the low cost of coal used to generate electricity did not make the project economically feasible. •• In 1943 the formation Brabazon