Ocean Energy Conversion 1

8/6/2019 Ocean Energy Conversion 1

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Ocean Energy Conversion

escribes all forms of enewable energy derived from

he sea

•wave energy•tidal energy•ocean current energy•salinity gradient energy

•ocean thermal gradientenergy



Ocean Energy Conversion

• – .ides 0 03 TW

• –ave 1 to 10 TW

• – .arine Current 5 0 TW

• – .alinity 2 6 TW

• - .hermal Gradient 2 0 TW

•

. %Only 0 1 of the total energy possessed by the ocean



TIDES

Ø ,he relative motions of the moon arth and sun allows he ocean

urface to be raised and lowered in n equal ime intervals based on he number of interacting .ycles

Ø

ØØØ aused by the rotation of the

arth within the ravitational ields of the moon and the sun

Ø

Ø•



TIDES

-alf Day Cycle

aused by the gravitational field of themoon

esults to a period of 12 hours and 25 inutes between successive high waters

-4 Day Cycle

aused by the superposition of the ravitational fields of the moon and the sun

•



TIDAL ENERGY

-Tidal energy is energy that could be obtained

. ,from the changing sea levels In other words tidal energy is a direct result of tide.shifting from low to high



TIDAL ENERGY CONVERSION

v imilar to a conventional hydroelectric power plant

v nvolves a dam across an estuary

v .idal range above 5 meters

v ,nvolves the use of prefabricated caissons made of

oncrete and steel

v enerates power through turbogenerators or sluices



TIDAL ENERGY CONVERSION

b b g e n e r a t i o n

• from the basin to the sea

l o o d g e n e r a t i o n

• from the sea to the basin

-w o w a y g e n e r a t i o n

• ,from sea to basin from basin to sea

*VIDEO 1



WAVES

caused by the wind blowing over the surface of the ocean



WAVE ENERGY CONVERSION

, ,Includes technologies existing and experimental/ that harvest energy from ocean sea waves




A t t e n u a t o r s

v ong multisegment floating structures

v ove parallel to the direction of the waves

v he variation of heights of the waves

auses motion to the ength of the device




The PELAMIS WEC*video 2




v e r t o p p i n g d e v i c e s

v eservoirs are created to collect the aters brought by ncoming waves

v he force of gravity pushes the water down funnel

v he flow of this water going back to the cean will cause a orque of the turbine

hich is coupled to an electric generator




Overtopping WEC




u o y t y p e

v arnesses wave energy from all directions t a fixed position

v deal locations would be at areas where

ave heights are high

v sealed tube with a cavity filled ither with air or water

v he cavity decompresses or compresses

elative to the ’ave s height




Buoy type WEC




Oscillating water column device

v perates in the same way as the wind turbine

vv closed chamber is placed just close to

he shore where great waves could reachvv he difference in the height of water

nside the chamber brought about by the

ncoming wave causes the air pressure to varyvv turbine is placed on top of the chamber

hich is its only opening




scillating Water Column Device

*video 3



TIDAL CURRENT

h e m o v e m e n t o f t h e s e a w a t e r c a u s e d b y

t i d e s



CURRENT ENERGY

CONVERSIONv arvests in the same way as a wind turbine

does

v -his is through the use of open flow rotors

v ,s the current strike the rotor blade it

rives the rotor to .otate



CURRENT ENERGY

CONVERSION

y d r o o c e a n c u r r e n t g e n e r a t o r

* video 4



OCEAN THERMAL GRADIENT ENERGY

e n e r a t e d b y t h e d i f f e r e n c e b e t w e e n c o o l e r e e p a n d w a r m e r s h a l l o w o r s u r f a c e o c e a n

w a t e r s



OCEAN THERMAL ENERGYCONVERSION

v ’akes use of ocean s natural thermalgradientvv he difference in the temperature

-rives a power roducing cycle

vv ,t normal conditions the surface and

ottom water are °eparated by about 20 C( ° )6 Fvv ,deal in tropical coastal areas roughly

long the equator




-p e n C y c l e O T E C

v utilize the surface water to rotate the

turbine vv heat exchanger system is used where the

surface water - is placed on a low pressure container

vv Steam generated rotates the turbine




Open Cycle OTEC




v ,nstead of water fluids with ower boiling points ike ammonia are

sed to produce steamvv he temperature of the surface

ater is enough o vaporize the- -ow boiling point fluid

vv he water on the ocean floor is

sed to ondense vapor

l o s e d C y c l eO T E C




CLOSED CYCLE OTEC




y b r i d O T E C

•• u r f a c e w a t e r i s f l a s h

v a p o r a t e d t o b o i l t h e

-o w b o i l i n g p o i n t f l u i d

* video 5



SALINITY GRADIENT

h e n a f r e s h w a t e r f r o m s t r e a m s

n d r i v e r s m i x e s w i t h t h e

a l t w a t e r f r o m t h e s e a



SALINITY GRADIENT ENERGYCONVERSION

e v e r s e d e l e c t r o d i a l y s i s

resh water and salt solution are stacked into lternating cathode and anode exchange membranes

he difference in the ion concentration of the reshwater and seawater produces chemical

otential difference over each membrane



Reversed electrodialysis



SALINITY GRADIENT ENERGYCONVERSION

r e s s u r e R e t a r d e d O s m o s i s

nergy from the pressure difference between eawater and freshwater

eawater is collected into a pressure hamber

semi permeable membrane is used to let the resh water move and eventually increase the olume in the chamber



Pressure retarded osmosis



Ocean Energy in the Philippines

- ( )10 megawatt Cabangan ocean energy thermal conversion Otec project in Zambales

- ( )100 megawatt MW ocean thermal energy resource potential in San,Jose Antique

, ,theoretical capacity of 170 000 megawatts over a 1 000 square kilometer ocean resource area

, , , , ,Laoag Zambales Mindoro Isabela Panay Negros and parts of Mindanao, , , , ,Camarines Northeastern Samar Surigao Batan Island Catanduanes, , , ,Tacloban San Bernardino Strait Babuyan Island Ilocos Norte

.Siargao Island and Davao Oriental existing study on tidal current systems in the Hinatuan Passage in

Surigao and San Bernardino Strait- (Philippines 22 24 1



“The Philippines is one of the premier locations withinthe world for our technology due to the extremethermal difference between the warm surface water

and the deeper cold water… and we have a deep shelf here in the Philippines, …“We feel that the oceanshere are the oil of the Philippines and so we hope tolocate them… to help reduce the cost of energy and

that’s our goal over the next several years”.

,Derek Murray VP of the parent.company Deep Ocean Power Inc

Ocean Energy Conversion 1

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