260 likes | 483 Views
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
E N D
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 • 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
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 Theoretical global resource of ocean energy: 8,000-80,000 TWh/yr for wave energy 800 TWh/yr for tidal current energy 2,000 TWh/yr for salinity gradient energy 10,000 TWh/yr for ocean thermal energy World’s electricity consumption 17,000 TWh/yr
Oscillating Water Column (Energetech/Oceanlinx) Wave Energy Extraction Technologies Point Absorber (OPT, Finavera) Overtopping, Wave Dragon Attenuator, Pelamis WP
Power From Ocean Waves kW/m crest length
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. Power From Ocean Waves
capacity = 150 kW Ocean Power Technology buoy, to best tested this month off Oregon will power 50 homes. Federal permit obtained for grid-connection.
Oscillating Water Column Installations: LAND NOTE: Plant Bowen (Georgia Power) operates at 3,200,000 kW
“Sea Snake” Wave Energy 121m long, 3.5m tall!
Ocean Renewable Power Company installed first grid-connected tidal device in Cobbscook Bay, Maine in June, 2012. Powers 25 homes.
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