1. Ocean Energy Kim Cobb with slides from Dr. Alam, MIT

2. 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

3. 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

4. -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 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

5. Source of Ocean Wave Energy

6. How much of earth does the ocean cover? 3/4 How much of the world’s energy consumption can be covered by wave energy? 50% How many barrels of oil worth of energy coming into ocean every day? 250 billion

8. Wave Energy Extraction Technologies Point Absorber (OPT, Finavera) Oscillating Water Column (Energetech/Oceanlinx) Attenuator, Pelamis WP Overtopping, Wave Dragon

9. Power From Ocean Waves kW/m crest length

10. 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.

11. What is an example of a heaving device? What is an example of an oscillating water column? A buoy A generator system

12. Point absorber buoys: most common

14. Ocean Power Technology Ocean Power Technology buoy, to best tested this month off Oregon will power 50 homes. Federal permit obtained for grid-connection. capacity = 150 kW

15. Oscillating Water Column Installations: LAND NOTE: Plant Bowen (Georgia Power) operates at 3,200,000 kW

16. Oscillating Water Column Installations: OCEAN

17. “Overtopping” Wave Energy

18. “Sea Snake” Wave Energy 121m long, 3.5m tall!

20. Tidal Energy Conversion

21. Ocean Renewable Power Company installed first grid-connected tidal device in Cobbscook Bay, Maine in June, 2012. Powers 25 homes.

22. What is the device that the Ocean Renewable Power Company installed in 2012? Tidgen What is a pitching device? When ocean water moves the buoy platforms and creates energy.

23. Ocean Thermal Energy Conversion

24. 210 kW OTEC test plant, 1993-1998, Hawaii

25. Future OTEC plant: grow food and fuel?

26. 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

27. Ocean Energy: PROS and CONS?