Tidal PowerTidal PowerMethods of ExtractionMethods of Extraction

Patrick Dunlap

Definition and Definition and MotivationMotivation

What is Tidal Energy?What is Tidal Energy? Energy contained in a tide, especially Energy contained in a tide, especially

that which can be converted to that which can be converted to electricity.electricity.

Why Tidal Energy?Why Tidal Energy? Declining availability of fossil fuels and Declining availability of fossil fuels and

global climate change.global climate change.

Tidal TheoryTidal Theory

Energy Energy SourceSource

Tidal CycleTidal Cycle

AmplitudeAmplitude

Traditional MethodTraditional Method

Harnesses Harnesses Potential Energy Potential Energy within tidewithin tide

Current PlantsCurrent Plants

CountryCountry SiteSite Installed Installed Power Power (MW)(MW)

Basin Area Basin Area (km(km2)2)

Mean Tide Mean Tide (m)(m)

FranceFrance La RanceLa Rance 240240 2222 8.558.55

RussiaRussia Kislaya GubaKislaya Guba .4.4 1.11.1 2.32.3

CanadaCanada AnnapolisAnnapolis 1818 1515 6.46.4

ChinaChina JiangxiaJiangxia 3.93.9 1.41.4 5.085.08

DisadvantagesDisadvantages

EnvironmentalEnvironmental

EconomicalEconomical

DesignDesign

New MethodNew Method

Involves extraction Involves extraction of kinetic energy of kinetic energy from a tide, given in from a tide, given in KE FluxKE Flux

Mechanical Mechanical processes for processes for extraction are based extraction are based on the hydrofoil.on the hydrofoil.

Actual Power Output Actual Power Output

Energy Flux Energy Flux equation is equation is multiplied by a multiplied by a Constant CConstant Cpp

The differential dA The differential dA is now is now representative of representative of the sweep are of the sweep are of the bladesthe blades

Site SelectionSite Selection

High average High average velocity (currently velocity (currently looking at > 3 looking at > 3 m/s)m/s)

High local energy High local energy demanddemand

Within Current Within Current Technical LimitsTechnical Limits

Comparison to WindComparison to Wind

AdvantagesAdvantages DensityDensity PredictabilityPredictability AestheticsAesthetics

DisadvantagesDisadvantages ScaleScale ConstructionConstruction

Current ProjectsCurrent Projects

In August SeaGen, In August SeaGen, a 1.2 MW, dual a 1.2 MW, dual turbine unit will be turbine unit will be connected to the connected to the power gridpower grid

2.25 MW turbine 2.25 MW turbine will supply Portugalwill supply Portugal

Last December two Last December two turbines installed in turbines installed in NY’s East RiverNY’s East River

ReferencesReferences

Tidal Energy, AM Gorlov, 2001Tidal Energy, AM Gorlov, 2001 Choosing and Evaluating sites for Tidal Choosing and Evaluating sites for Tidal

Energy Evaluation, Byrden, Proceeding of the Energy Evaluation, Byrden, Proceeding of the Institute of Mechanical Engineers, V 218Institute of Mechanical Engineers, V 218

Tapping the Power of the Seas, Economist, Tapping the Power of the Seas, Economist, V383V383

Tidal Current Energy Extraction: Tidal Current Energy Extraction: Hydrodynamic Resource Evaluation, Couch, Hydrodynamic Resource Evaluation, Couch, Proceeding of the Institute of Mechanical Proceeding of the Institute of Mechanical Engineers, V 220Engineers, V 220

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