Sea Energy
Energy from the sea
Ocean wave energy is harnessed directly from the surface waves or from pressure fluctuations below the surface waves.
Waves are caused by the wind blowing over the seas surface. In all areas of
the world, if the wind blows with enough consistency and force then it will
provide continuous waves. There is tremendous energy in the ocean waves
and wave power devices extract energy directly from the surface motion of ocean waves or from pressure fluctuations below the surface.
Wave power does vary considerably in different parts of the world, and wave energy can't be harnessed effectively everywhere. Wave-power rich areas of the world include the western coasts of Scotland, northern Canada, southern Africa, Australia, and the north-western coasts of the United Statesthese are the most recognised areas
Ocean Wave Technologies
A variety of technologies have been proposed to capture the energy from waves. Some of the more proposed commercially viable designs are undergoing demonstration testing on a commercial scale.
Wave technologies can be installed in near shore, offshore, and far offshore locations
Offshore systems are situated in deep water, typically of more than 40 meters (131 feet).
While all wave energy technologies are intended to be installed at or near the water's surface, the different technologies vary in their orientation to the waves and in their operation of how they convert the wave energy to electrical power.
It is thought that the following wave technologies have been the highlighted as promising for future commercial use.
Terminator devices
These are extend perpendicular to the direction of wave and capture or reflect the power of the wave. These devices are typically onshore or near shore; however, floating versions have been designed for offshore applications.. The wave action causes the captured water column to move up and down like a piston to force the air though an opening connected to a turbine which converts it to electrical power.
A point absorber
This is a floating structure with components that move due to wave action (e.g., a floating buoy inside a fixed cylinder). The relative motion is used to drive electromechanical or hydraulic energy converters.
Attenuators
These are long multi-segment floating structures fixed parallel to the direction of the waves. The different heights of waves along the length of the device, and the movement are connected to hydraulic pumps or other converters that change the wave energy into electrical power.
Overtopping devices
These have reservoirs that are filled by incoming waves to levels above the
average surrounding ocean. The water is then released, and gravity causes it to fall back toward the ocean surface. The energy of the falling water is used to turn hydro turbines. Very similar to hydro power stations
Environmental Considerations
Possible environmental considerations that need to be considered:-
· Positive or negative impacts on marine habitat
· Toxic releases from leaks or accidental spills of liquids used in those systems with working hydraulic fluids. Can we stop any leaks very quickly, very important if the equipment is fitted off shore in deep water.
· Conflict with other sea space users, such as commercial shipping and recreational boating.
· Who has the responsibility to ensure a safe system?
· Currently no electrical courses available in this area.
· What level of electrical training will be required to ensure a quality system?
Date Created 2010-07-13 11:02:55.0
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