An Introduction to

Ocean Renewable Energies

Presented by

S. Aboozar TabatabaiRutgers, the State University of New Jersey, Institute of Marine and Coastal Sciences

November 2010

الرحیم الرحمن الله بسمPhysical Oceanography

Class Presentation

Introduction

Federal Agency for Science and Innovation, 2008, Moscow, RussiaU.S. Energy Information Administration , International Energy Outlook 2010

Energy… Present and Future

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U.S. Energy Information Administration , International Energy Outlook 2010

Oil Price: light, sweet crude 2008 ($/barrel)

World primary energy

consumption (quadrillion Btu)

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Are we behind?!

2009 Annual Report, Ocean Energy Systems Implementing Agreement (OES-IA)

Member countries in Ocean Energy Systems Implementing Agreement

Internationally, the number of developed Internationally, the number of developed ocean energy technologies more than doubled ocean energy technologies more than doubled

from 2003 (35) to 2006 (81). However, the from 2003 (35) to 2006 (81). However, the federal government only acknowledged ocean federal government only acknowledged ocean renewables in the Energy Policy Act of 2005. renewables in the Energy Policy Act of 2005. 11

Internationally, the number of developed Internationally, the number of developed ocean energy technologies more than doubled ocean energy technologies more than doubled

from 2003 (35) to 2006 (81). However, the from 2003 (35) to 2006 (81). However, the federal government only acknowledged ocean federal government only acknowledged ocean renewables in the Energy Policy Act of 2005. renewables in the Energy Policy Act of 2005. 11

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International Energy Agency, Policy Report, 2006

Silver Medal?... Is that the best we got?!6

Good News ! Ocean renewable energies have begun to capture

the attention of US lawmakers…

• More investments

• Some more courses and programs in universities…

• tax credits

• . . . Way to go!

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Why Ocean?• The ocean is the world's largest solar collector and can

provide huge amount of energy (kinetic and thermal) which is absolutely clean (zero CO2 emission), sustainable, strategic, and predictable.

• Changes in salinity, thermal gradients, tidal sea level change and currents, or ocean waves can be used to generate electricity.

• The number of ocean energy technology concepts has increased to +100 known devices.

• Available global Ocean Energy resource is in the same order of magnitude of the present electricity production worldwide (even more!).

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Table compiled from International Energy Agency, Policy Report, 2006 9

Global Marine Renewable Energy Resources

<IEA-OES Report, 2008>

(Jun Zhang, 2012)

Wave Energy vs Tidal Energy

• Waves are produced by winds blowing across the surface of the ocean. However, because waves travel across the ocean, their arrival time at the wave power facility may be more predictable than wind.

• In contrast, tidal energy, which is driven by the gravitational pull of the moon and sun, is predictable centuries in advance.

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(Conventional) Tidal Energy

Technologies for harnessing energy from tides by building barrage across estuary are well developed, but this type of conversion process could have significant impact on local ecosystem.

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World’s largest tidal power plant in the Rance estuary

near St Malo, France

Peak rating of 240 Megawatts, generated by

24 turbines

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SihwaSihwa will be the world’s largest tidal power will be the world’s largest tidal power plant.plant.

It will be the world’s largest tidal power plant with a total power of 260 MW and an annual power generation of 543 GWh.

Sihwa, South KoreaUnder Construction

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Tidal Current Energy

Significant number of technologies for harnessing energy from tidal current are being developed worldwide. Some of them are at or near full-scale development and undergoing sea trials.Significant number of technologies for harnessing energy from tidal current are being developed worldwide. Some of them are at or near full-scale development and undergoing sea trials.

SeaGen

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Rotech Tidal Turbine (RTT)

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Wave Energy OWC

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Other wave Devices

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CETO

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Salinity Gradient EnergyTwo approaches:1.“Pressure Retarded Osmosis (PRO)”: relies on water molecules moving through a membrane, which issemi-permeable. When salt water is contained on one side of the membrane & fresh water is on its other side, fresh water is osmotically drawn into the salty side. This drives up the pressure in the "salty” chamber, & the sea water can then be sent through a turbine that generates power.(Dr Rolf JarleAabergStatkraft EnergiAS, Norway2004)

(Jun Zhang, 2012)

Salinity Gradient Energy

The world's first osmotic plant with capacity of 4 kW was opened by Statkraft on 24 November 2009 in Tofte, Norway

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Salinity Gradient Energy2. “Reverse ElectroDialysis (RED)”: In RED, a concentrated salt solution & a fresh water are brought into

contact through an alternating series of anion exchange membranes (AEM) and cation exchange membranes (CEM)

The difference in chemical potential between both solutions is the driving force for this process. The chemical potential difference generates a voltage over each membrane and the overall potential of the system is the sum of the potential differences over the sum of membranes.

Reference http://mtg.tnw.utwente.nl/teaching/assign/blue/

(Jun Zhang, 2012)

Ocean Thermal Energy Conversion (OTEC)

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Open-cycle OTEC

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Thank you for your attention.

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