8/6/2019 Class d wr

1/12

Bangalore-560074

Department Of Electrical and Electronics

Engineering

Submitted By:

Megha.B.G

1RR07EE021

Under the Guidance of:

Prof.H.L.Dinakar

Head of the Dept,EEE

8/6/2019 Class d wr

2/12

TIDAL POWER

Introduction

Renewable Energy Overview of Tidal Generation

-Tides

-Basic methods ofgeneratingelectricity from

tides

-Pros/Cons

Differenttypes oftidalgenerators-Tidal fence

-Tidallagoons

-Tidalturbines

Conclusions

Renewable energy

Renewableenergysources capturetheirenergy from existingflows ofenergy, from on-going natural processes,suchas

sunshine,wind, flowingwater(hydropower),biological

processes,and geothermalheat flows.Renewableenergy is from

8/6/2019 Class d wr

3/12

anenergyresourcethat isreplaced rapidlybyanaturalprocess

suchaspowergenerated from thesun orfrom thewind.

Examples ofRenewable Energy Sources:

Solar

Wind

hh Hydro Electricity

8/6/2019 Class d wr

4/12

Tides

How do tides change= Electricity?

Asusual,theelectricity isprovided byspinningturbines. Two types oftidalenergy canbeextracted: kinetic energy

of currentsbetweenebbingand surgingtidesand potential

energy from the difference inheight (orhead)betweenhighand lowtides.

Thepotentialenergy contained ina volume ofwateris E=

xMg

8/6/2019 Class d wr

5/12

wherexistheheight ofthetide,Misthe mass of

waterand gistheacceleration dueto gravity.

Therefore,atidalenergygeneratormustbeplaced inalocationwith veryhigh-amplitudetides. Suitablelocations

are found inthe formerUSSR, USA,Canada,Australia,

Korea,the UKand othercountries.

Thegeneration ofelectricity from tides is verysimilartohydroelectric generation,exceptthatwater isableto flow

inboth directionsand this mustbetaken into account inthedevelopment ofthegenerators.

Some Turbine Types

1.Bulb Turbine

InsystemswithaBulb turbine,waterflowsaround the

turbine, makingaccess formaintenance difficult,asthewatermustbeprevented from flowingpasttheturbine.

8/6/2019 Class d wr

6/12

2.Rim Type

Rim turbinesreducetheseproblemsasthegeneratorismounted inthebarrage,atrightanglesto theturbineblades.

Unfortunately, it is difficultto regulatetheperformance ofthese

turbinesand it isunsuitable foruse inpumping.

3.Tubular Type

Tubular turbineshavebeenproposed forusesome UK

projects. Inthis configuration,thebladesare connected to a

longshaftand orientated atanangleso thatthegeneratoris

sitting ontop ofthebarrage.

8/6/2019 Class d wr

7/12

Different Generator Types

1.Tidal Fences

2.Tidal Lagoons

3.Tidal Turbines

8/6/2019 Class d wr

8/12

Tidal Fences

Tidal fencesare composed of individual, verticalaxisturbineswhichare mounted withinthe fencestructure,

knownasacaisson.

Kind oflikegiantturnstyleswhich completelyblockachannel, forcingall ofthewaterthroughthem.

Unlikebarragetidalpowerstations,tidal fences canalso beused inunconfined basins,suchas inthe channelbetween

the mainland and anearby offshore island, orbetweentwoislands.

8/6/2019 Class d wr

9/12

8/6/2019 Class d wr

10/12

Tidal Turbines

Proposed shortlyafterthe oil crisis ofthe 1970s,tidalturbineshave onlybecomereality inthelast decade,when

a 10-15kW 'proof of concept' turbinewas operated on Loch

Linnhe.Resemblingawind turbine,tidalturbines offer

significantadvantages overbarrageand fencetidalsystems,

includingreduced environmentaleffects.

Tidalturbinesutilizetidal currentsthatare movingwithvelocities ofbetween 2 and 3 m/s (4 to 6 knots)to generate

between 4 and 13 kW/m2. Fast moving current (>3 m/s)

can causeunduestress ontheblades inasimilarwaythat

verystronggale forcewinds can damagetraditionalwind

turbinegenerators,whilstlowervelocitiesareuneconomic.

8/6/2019 Class d wr

11/12

Tidal Turbines (cont.)

SeaFlow,a 300 kW prototypeturbinewastheworldsfirst offshoretidalturbineand was installed off Lynmouth,

Devon in May 2003.

Cost 3.4 millionand was funded bya consortium ofprivatecompaniesand the UKand Germangovernments.

8/6/2019 Class d wr

12/12

Conclusions

Tidalpowerisarenewable,potentially zero emission(during operation)energysource.

Tideshavetheadvantage ofbeing completelypredictable,unlikesolarand wind power.

Differenttypes of Tidal Generatorssuit differentareasandenergyneeds.

Thereareenvironmental concernsthatneed to beaddressedwhen developingthistechnology further.