Harnessing of Tidal Energy

8/2/2019 Harnessing of Tidal Energy

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HARNESSING OF TIDALENERGY BY MEANS OF COST-EFFECTIVE AND EFFICIENTTURBINES


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SHREYAS KALKUR .M SOWMYA .P RAOUNIVERSITY VISVESVARAYA COLLEGE

OF ENGINEERING

MECHANICAL ENGINEERING

BANGALORE UNIVERSITY

K.R.CIRCLEBANGALORE-560001.


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WHAT IS TIDAL ENERGY?

Tidal energy(orpower) is a form of

hydropowerassociated with the

oceanic tides which can be utilized inthe generation of electricity or other

useful forms of power.

Sea tides possess Tidal energy in the

form of kinetic energy.


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The Current Situation

Tidal Energy is sustainable, clean, reliable,

widely distributed, and can offer significant

benefits to many marine nations.

Tidal Energy can be captured in an efficient

and cost-effective way.

Tidal energy can be availed throughout theyear and it is inexhaustible.


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PRINCIPLE OF GENERATION OF TIDAL

ENERGY

Tidal power is the only form of energy

which derives directly from the relative

motions of the Earth

Moon system, andto a lesser extent from the EarthSun

system.

The tidal forces produced by the Moonand Sun, in combination with Earth's

rotation, are responsible for the

generation of the tides.


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Tidal energy is generated by the relative

motion of the water which interact via

gravitational forces. Periodic changes of water levels, and

associated tidal currents, are due to the

gravitational attraction by the Sun and Moon. The magnitude of the tide at a location is the

result of the changing positions of the Moon

and Sun relative to the Earth, the effects of

Earth rotation, and the local shape of the sea

floor and coastlines.


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Because the Earth's tides are caused by the

tidal forces due to gravitational interaction

with the Moon and Sun, and the Earth'srotation, tidal power is practically

inexhaustible and classified as a renewable

energy source.

A tidal generator uses this phenomenon to

generate electricity. The stronger the tide,either in water level height or tidal current

velocities, the greater the potential for tidal

electricity generation.


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World Map of the Distribution of

Tidal Energy

Red areas show most intense tidal energy


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Developing Nations

that could receive

significant benefits

from Tidal Energy________________________________________

Indian Ocean: Comoros, Madagascar, Maldives, Seychelles.

Asia: China, India, Indonesia, Korea, Philippines, Vietnam.

Pacific Ocean: Fiji, Kiribati, Micronesia, Palau, Papua NewGuinea, Samoa, Solomon Islands, Timor, Tuvalu,Vanuatu.

Central and South America: Argentina, Brazil, Ecuador,Guyana, Panama, Surinam.

Atlantic Ocean: Cape Verde.

All coastal nations with tidal passes between coral reefsor offshore islands can also utilize tidal energy.


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Tidal Energy in India

India's first attempt to harness tidal power forgenerating electricity would be in the form of a

three MWplant proposed at theDurgaduani

creek in Sundarbans delta of West Bengal.

The Gulf of Kutchand Gulf of Cambay in

Gujaratand Ganga delta in the Sunderbansare the three sites identified as potential

areas for tidal power generation.


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CLASSIFICATION OF TIDAL POWER

Tidal stream systemsmake use of the kinetic energy of movingwater to power turbines, in a similar way to windmills that use

moving air. This method is gaining in popularity because of the

lower cost and lower ecological impact compared to barrages.

Barragesmake use of the potential energy in the difference in

height (or head) between high and low tides. Barrages areessentially dams across the full width of a tidal estuary, and

suffer from very high civil infrastructure costs, a worldwide

shortage of viable sites, and environmental issues.

Tidal lagoons, are similar to barrages, but can be constructedas self contained structures, not fully across an estuary, and are

claimed to incur much lower cost and impact overall.

Furthermore they can be configured to generate continuously

which is not the case with barrages.


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Efficient technology to capture

Tidal Energy

is already cost-effective


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Helical Turbine: A tidal stream system

Tidal energy can becaptured efficiently and

inexpensively using the

Helical turbinewhich

was invented and

developed by

Prof.Alexander Gorlov

(in picture) of the

Northeastern university

in Boston,

Massachusetts,U.S.


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Schematic view of the helical turbinemounted in a frame


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Features of the

Helical Turbine

Operation self-starting with flow as low as 0.6 m/s

smooth-running

rotates in same direction regardlessof the direction of flow, making it ideal

for tidal applications


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Features of the

Helical Turbine

35% Efficiency


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Features of the

Helical Turbine

Power increases 8 timeswhen velocity doubles

0

500

1000

1500

2000

2500

0 1 2 3 4 5 6 7 8 9 10

Free Flow (Ft/sec)

Power(watts)

Source: GCK Technology

I Knot =

1.69 ft/sec

I M/sec =3.28 ft/sec


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0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

12000

1300014000

SOLAR

WIND

HYDR

O

NUCLEA

RCO

AL OIL

GAS

TIDA

L

Features of the Helical Turbine

Installation Cost: dollars/kw

Source: GCK Technology, Inc.

Red: high estimate

Blue: low estimate


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IMAGES OF OTHER TIDAL POWER

SYSTEMS

SeaGen in Strangford

Lough-The worlds

first commercial axial

turbine tidal streamgenerator.


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MULTIPLEBENEFITS

FROMTIDAL

ENERGY


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Multiple Benefits from Tidal Energy._______________________________________________________________________________________________________

Practical Examples:

1) Electrification of isolated

communities

2) Power for the grid

3) Regrowth of coral reefs usingmineral accretion technology


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1) Electrification of Isolated Communities:

The Tide-Energy project

near the mouth of the Amazon

Rural residents with a 6-blade helical turbine

Th Tid E j h


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(a) 6-bladehelical turbine

(b) Pulley andbelt

(c) Automotivealternator

The Tide-Energy project near the

mouth of the Amazon:

a simple generating package

Th Tid E j t th th f th


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The Tide-Energy project near the mouth of theAmazon: simple, accessible, affordable

technology

Simple:

The helical turbine rotates on a shaft with a pulleythat runs an alternator by means of a belt.

The alternator charges batteries for householduse, as is usual with other intermittent sourcessolar and windwhen used off the grid.

Accessible:

About 90% of a tide-powered station can be builtusing locally-available labor, materials, and equipment.

Only the technically-refined helical turbine blades areoutside components.


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The Tide-Energy project near the mouth of the

Amazon: simple, accessible, affordable technology

Affordable:Under local natural and economic conditions:

The investment in installation and equipment of a

tide-energy station is only 50%of the comparable solaroption.

That investment is similar to the cost of a small, diesel-

powered boat, which thousands of people in the region

already own.

The operating costs of a tide-energy station are less

than 60%of those of the comparable diesel option.


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2) Power for the Grid

The Uldolmok Strait Pilot Project in Korea

1m x 2.5m GHT from GCK Technology, Inc.

Th Uld l k Ch l Pil t P j t i K


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The Uldolmok Channel Pilot Project in Korea

Results and perspectives:

Testing of the Gorlov Helical Turbine manufactured byGCK Technology, Inc. was performed by the Korea Ocean

Research & Development Institute (KORDI).

Successful tests were carried out In 2002 using a 1m

diameter Gorlov Helical Turbine which produced about10kW in a 4 knot flow.

As a result of these trials, a larger GHT (2.2m diameter,

2.5m length) was designed and manufactured by GCK and

successfully tested by KORDI in 2004

The GHT has also been successfully tested on floating

platforms off of Long Island, NY and in the Merrimack

River in Massachusetts.

3) Generation of hydrogen for fuel cells from the


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3) Generation of hydrogen for fuel cells from theelectrolysis of water from tidal currents that donot need to be in close proximity to end-users.

Detail ofthe Farm

ProjectedPowerFarm1 2

3

4

The Gorlov Helical Turbine modules can be assembled inlarge-scale power farms, as depicted in the artists

conception above.

4) Regrowth of Coral Reefs Using Biorock


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4) Regrowth of Coral Reefs Using BiorockTechnology: Karang Lestari coral reef and

fisheries restoration project, Indonesia


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Before: Severe erosion

Biorock shore protection project at Ihuru Island,Maldives, turned a severely eroding beach into 15meters (50 feet) growth in a few years


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Biorock reef in front of the beach uses electricity to

grow solid limestone rock on a steel frame and to

grow corals. This slows down waves, causes sand

to settle, and attracts fish.

A f l t


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A few years later:beach has grown15 meters (50 ft.).

Tidal energy cangrow Biorock reefs

to protect wholeislands from sealevel rise, while

restoring theircoral reefs and

fisheries


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Biorocks technology speeds the growth of coral reefs 3-5

times and increases survival from severe high temperature

16-50 times. This rapidly increases fish populations and

creates ecotourism attractions.

Biorocks technology can be used to regrow dying coral

reefs throughout the world, build coastal protection, restore

fisheries, and create mariculture resources.

Biorocks technology has been proven in field tests in morethan 20 Caribbean, Pacific, Indian Ocean, and SoutheastAsian countries.

Tidal Energy often found around coral reefs and atolls can

be used with Biorocks technology to regrow reefs in aninexpensive, low-maintenance way using the helical turbine.


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DISADVANTAGES AND LIMITATIONS

Right now tides do not produce a lot of electricity so its not

very efficient. Barrages across river estuaries can change the

flow of the water, and because of that it is the place for birds

and other wildlife to live, because of this, there are some

wildlife that could be in danger.

Needs a suitable site where waves are consistently strong.

Some designs are noisy.

Must be able to withstand very rough weather.

You will need to find a way of getting the electricity from the

sea to the land.


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Environmental Impact

Tidal Power systems cause negligible or no

adverse affects on the environment and

ecology.

A proposal for the Severn Barrage, if built, has

been projected to save 18 million tonnes of

coal per year of operation. This decreases the

output of greenhouse gases into theatmosphere.


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Conclusions

Tidal Energy is sustainable, clean, and

reliable.

Tidal Energy is widely distributed and

can offer significant benefits to manycoastal nations.

Tide Energy can be captured in a

practical, efficient, cost-effective way.

Tidal Energy deserves to be included on

the list of sources of sustainable energy

and it needs to be supported and funded.


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Documents

Harnessing of Tidal Energy