What is a Wave?
The oscillatory movements that occur on the sea surfaces are called “waves.” Wave is caused by wind, landslides on the sea floor, earthquakes, volcanic activities, and tidal events.
The wave is made up of up and down movement of water particles. But the main factor that creates the waves is the shape of the sea surface. Winds blow from the surface of the sea and thus raise the water and create the rotational motion. When the lower part of the waves hit the beach, they rub and their speed decreases. However, the upper part of the wave continues to move. Then its upper part is toppled and foaming occurs where it is toppled. Waves: They are classified according to the forces (capillary or gravity) that constitute them, their period, the depth of the medium in which they spread.
What is Wave Energy?
Wave energy is a powerful and unlimited renewable energy source that takes advantage of the kinetic energy created by the waves formed in the seas. It is a recently developed energy generation management that uses the force of waves through wind to generate electricity.
The body of water oscillating on the sea surface releases a great deal of energy.
Let’s assume that a 100,000-ton ship moves 1 meter up and down on waves in 10 seconds. The resulting energy in this case is:
100.000 x 1 x 2/10 = 20.000 Ton.m / sec. As → 1 kW = 102 kg.m / s
The energy generated here is 20.000 Ton.m / sec / 0,102 Ton.m / sec → ≈ 200.000 kW
An energy equivalent to a 200 MW power plant emerges.
Turkey coasts, fisheries, tourism, military installations due to 1 / 5th wave energy can be achieved by taking advantage of the technical potential is estimated at 18.5 billion kWh. A total of approximately 10 TWh / year of energy can be obtained from only one series / series of small scale converter in waters with an annual wave power of 4-17 kW / m. This is economically produced 12.5% of the hydroelectric potential of Turkey.
Electricity Generation Systems with Wave Energy
In Coastal Strip applications, energy generation structures are fixed or buried on the shore. It is easier to maintain and build than other applications, and there is no need for deep water connections or long underwater electrical cables. However, the wave energy that can be obtained may be less due to the wave regime with less power. The widespread use of such practices is limited by factors such as coastline geology, tidal level and protection of the coastal structure.
Oscillating water column-OWC
These systems have a water column and an air column above it. The bottom door allows water to enter. The air compressed by the water passes through the narrow section and moves the turbine at the outlet. As the wave retracts, this movement, which will discharge the air inside, will cause the turbine to move again. If a normal turbine is used in this system, the turbine propeller will rotate in different directions as the water enters and leaves the room. In this case, the propeller will stop and work, so it will reduce energy production. However, when the Wells turbine is used, the special structure of this turbine always provides one-way rotation without loss of time and provides more efficient energy production.
TAPCHAN (Shrinkable Channel) System
These systems consist of a gradually narrowing channel with a wall height of 3-5 meters above the water level, feeding the reservoir built on the edge of the cliff. The narrowing of the channel causes the wave height to increase and the rising waves from the channel walls
drains into it.
Since the water is stored in the reservoir, the kinetic energy of the moving wave transforms into potential energy.
The stored water is delivered to the turbine. Since it has few moving parts, it has low maintenance cost and high reliability. Energy can be stored in this system until it is needed. However, their systems are not suitable for all coastal areas.
Pendular is in the form of a rectangular box with one side opening to the sea. A pendulum cover is hinged over this opening. The cap moves back and forth with a wave action. This motion is used for the operation of the generator and hydraulic pump.
Applications Used in the World
- UK -Orkney wave power station
- Portugal -Agucadoura wave field
- England – Islay Limpet
- Spain – Citruki Breakwater wave field
- America -Azura wave energy station
- Israel -SDE sea wave power station