Ocean Energy
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Ocean Energy im Cobb ith slides from Dr. Alam, MIT
description
Ocean Energy. Kim Cobb with slides from Dr. Alam, MIT. Overview of Ocean Energy. ocean energy is replenished by the sun and through tidal influences of the moon ’ s and sun ’ s gravitational forces near-surface winds induce wave action and cause wind-blown currents at - PowerPoint PPT Presentation
Transcript of Ocean Energy
Ocean Energy
Kim Cobbwith slides from Dr. Alam, MIT
Overview of Ocean Energy
-ocean energy is replenished by the sun and through tidal influences of the moon’s and sun’s gravitational forces
-near-surface winds induce wave action and cause wind-blown currents at about 3% of the wind speed
-tides cause strong currents into and out of coastal basins and rivers
-ocean surface heating by some 70% of the incoming sunlight adds to the surface water thermal energy, causing expansion and flow
-wind energy is stronger over the ocean due to less drag, although technically, only seabreezes are from ocean energy
How much energy and what types?-250 Billion barrels of oil worth of energy coming into ocean every day
-80 million barrels of oil per day produced
kinetic
potential
-250 Billion barrels of oil worth of energy coming into ocean every day
-80 million barrels of oil per day produced
How much energy and what types?
Theoretical global resource of ocean energy:
8,000-80,000 TWh/yr for wave energy800 TWh/yr for tidal current energy2,000 TWh/yr for salinity gradient energy10,000 TWh/yr for ocean thermal energy
World’s electricity consumption 17,000 TWh/yr
Source of Ocean Wave Energy
Wave Energy Extraction TechnologiesPoint Absorber(OPT,Finavera)
Oscillating Water Column (Energetech/Oceanlinx)
Attenuator, Pelamis WP Overtopping, Wave Dragon
Power From Ocean Waves
kW/m crest length
Power From Ocean Waves• Wave energy is strongest on the west coasts and increases toward the poles.• At approx. 30 kW/mcl in the Northwest (yearly avg.), a single meter (3.3 feet) of wave has the
raw energy to power about 23 homes.
Point absorber buoys: most common
Ocean Power Technology buoy, to best tested this month off Oregonwill power 50 homes. Federal permit obtained for grid-connection.
capacity = 150 kW
Oscillating Water Column Installations: LAND
NOTE: Plant Bowen (Georgia Power) operates at 3,200,000 kW
Oscillating Water Column Installations: OCEAN
“Overtopping” Wave Energy
Tidal Energy Conversion
Ocean Renewable Power Company installed first grid-connected tidal device in Cobbscook Bay, Maine in June, 2012. Powers 25 homes.
Ocean Thermal Energy Conversion
210 kW OTEC test plant, 1993-1998, Hawaii
Future OTEC plant: grow food and fuel?
Ocean Energy: Where are we today?
Wave Energy (grid-connected):-0.4MW and 0.5MW OWC off the coast of Pico and Islay by 2008-2.25MW Pelamis off Portugal by 2008-0.5MW section of Wave Star Energy off Denmark by 2009-7MW Wave Dragon off Wales by 2010
Tidal:- barriers: 240MW France in 1966 and 20MW in Canada-Current: 1.2MW off Ireland by 2009, 1MW France
Thermal:-0.2MW Hawaii 1993-1998
Ocean Energy: PROS and CONS?
