Ocean wave energy is captured directly from surface waves or from pressure fluctuations below the surface. Waves are caused by the wind blowing over the surface of the ocean. In many areas of the world, the wind blows with enough consistency and force to provide continuous waves. There is tremendous energy in the ocean waves. Wave power devices extract energy directly from the surface motion of ocean waves or from pressure fluctuations below the surface.

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Wave power varies 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 States.
Ocean mechanical wave energy is quite different from ocean thermal energy. Even though the sun affects all ocean activity, tides are driven primarily by the gravitational pull of the moon, and waves are driven primarily by the winds. As a result, tides and waves are intermittent sources of energy, while ocean thermal energy is fairly constant. Also, unlike thermal energy, the electricity conversion of both tidal and wave energy usually involves mechanical devices such as turbines. See the illustrations below.

alternative-energy

Advantages
• The energy is free – no fuel is needed and no waste is produced
• Inexpensive to operate and maintain
• Can produce a significant amount of energy.


alternative-energy

 

Disadvantages
• Depends on the waves – variable energy supply
• Reeds a suitable site, where waves are consistently strong
• Some designs generate noise
• Must be able to withstand very rough weather
• Costly to develop
• Visual impact if above water or onshore
• Can disturb or disrupt marine life – including changes in the distribution and types of marine life near the shore
• Poses a possible threat to navigation from collisions due to the low profile of the wave energy devices above the water, making them undetectable either by direct sighting or by radar
• May interfere with mooring and anchorage lines with commercial and sport-fishing
• May degrade scenic oceanfront views from wave energy devices located near or on the shore, and from onshore overhead electric transmission lines.
Ocean Wave Technologies and Methods
While all wave energy technologies are intended to be installed at or near the water’s surface, they differ in their orientation to the waves with which they are interacting and in the manner in which they convert the energy of the waves into other energy forms, usually electricity. The following wave of technologies has been the target of recent developments.
• Wave Terminator devices extend perpendicular to the direction of wave travel and capture or reflect the power of the wave. These devices are typically onshore or nearshore. An oscillating water column is a form of terminator in which water enters through a subsurface opening into a chamber with air trapped above it. The wave action causes the captured water column to move up and down like a piston to force the air through an opening connected to a turbine.
alternative-energy-wave-terminatorsWave Terminator device
• A point absorber is a floating structure with components that move relative to each other 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.

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Point Absorbers
• Attenuator Wave Energy Devices are long multi-segment floating structures oriented parallel to the direction of the waves. The differing heights of waves along the length of the device cause flexing where the segments connect and this flexing is connected to hydraulic pumps or other converters.
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Attenuator Wave Energy Devices
• Overtopping devices 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. Specially built seagoing vessels can also capture the energy of offshore waves. These floating platforms create electricity by funneling waves through internal turbines and then back into the sea.

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alternative-energy-overtopping-devices

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Wave Overtopping Devices


To be continued in Part 8 Ocean Thermal Energy

RELATED ARTICLES:

Part 6 – Solar Power

Part 5 – Tidal Energy

Part 4 – Geothermal Energy

Part 3 – Concentrated Solar Power

Part 2 – Wind Power

Part 1 – Introduction

TWECS – Tornado Wind Turbine Design Previous post TWECS – Tornado Wind Turbine Design
The Worlds First Floating Wind Turbine Launched In Norway Next post The Worlds First Floating Wind Turbine Launched In Norway

5 thoughts on “Ocean Wave Energy – Alternative Energy Part 7”

  1. hello
    dear friend
    i don’t understand english very good
    I looked at your site was very good
    i’m inventor system convertor energy wave sea or ocean to
    electricity in model small
    do you can help to me
    i make it system in the size big?
    This is my system specifications below
    1- Made easy
    2- is Efficiency very good
    3-Easy to install and the sea
    Coast
    4-Cost than other similar device.Is very low
    5-Maintenance is very easy and with cost low
    thank you ahmad from iran
    Thank you so much.
    My sincere regards
    ahmad mortazavi
    please reply
    goodluch

  2. Did you know that Romania has a technical solution with the highest efficiency to capture wave power?.
    Patent 108893 entitled Dynamic Engine for Sea Wave Energy Catching. A pioneering invention. It is estimated that “dynamic engine” has the ability to catching wave energy at a rate of over 80% while the other technical solutions known worldwide, are not able to capture wave energy with a higher percentage of about 10-15%.
    Cosma Vasile Rominia E-mail cosma.vasile@yahoo.com

  3. Patent RO 108893 publised on internet.
    For accurate information please visit: Brevet RO no. 108893. MOTOR DYNAMIC FOR WAVE CATCHING

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