The document discusses wave energy conversion as a significant source of ocean energy, covering its principles, benefits, and various technologies utilized for energy production from ocean waves. It outlines different types of wave energy systems and their advantages and disadvantages, as well as the potential energy resources available worldwide. Additionally, it highlights various methods of harnessing wave energy, including oscillating water columns and floating devices designed to generate electricity.

1. WAVE ENERGY CONVERSION
(OCEAN ENERGY)

2. Learning Outcomes
2
After completion of this topic, students will able to
General objective
•discuss the various ocean energy sources
•interpret the energy transformation in wave energy
conversion
•discuss the working of various type wave energy plant
Specific objectives
•define the wave energy
•write benefits and application of wave energy system
•explain the types of wave energy plant

3. FUNDAMENTALS OF OCEAN
• 75% of the Earth Covered by water
• Ocean water stores much more heat than the
atmosphere
• World’s total estimated ocean energy are about
130 × 106 .
• Five Principal ocean: Indian ocean, Pacific
ocean, Arctic ocean, Antarctic ocean, Atlantic
ocean

4. OCEAN ENERGY
Ocean
Energy
Ocean
Thermal
EnergyOcean
Wave
Energy
Ocean
Tidal
Energy
Ocean
Geother
mal
Energy
Ocean
Salinity
Gradient
Energy
Ocean
Chemical
Energy
Ocean
Nuclear
Energy
Ocean
Biogas
energy

5. OCEAN ENERGY CONVERSION
TECHOLOGY
• Ocean Thermal Energy: Energy aquired into
ocean by solar radiation. Temperature
differences between the upper level and deep
level of water in sea (Difference in thermal
energy) are utilized.
• Ocean Biomass Energy: Ocean covered with
aquatic biomass like algae, kelp , water
hyacinths, animals etc. The ocen biomass may
be converted into methane (bio-gas) by wet
anaerobic digestion process.

6. OCEAN ENERGY CONVERSION
TECHOLOGY
• Ocean Tidal Energy: hydro energy available in
tides. Ocean tides occur due to gravitational
attractive forces from sun and moon. The level
of ocean water rises periodically during high
tides and drops during low tide. Head
difference during this high and low tide is
utilized for power production.
• Ocean Geothermal Energy: Geothermal field
are available in off shore of sea.

7. OCEAN ENERGY CONVERSION
TECHOLOGY
• Ocean Chemical Energy: Chemical energy in
ocean water. Ocean water contains the
Sodium, Hydrogen, Oxygen, Chlorine, iodine,
etc.
• Ocean Salinity Gradient Energy: Difference in
salinity between ocean and river water can be
utilized for electricity generation
Ocean Chemical
Energy
Photochemical Process
Or Photo Biological
Conversion Process
Useful Secondary
Energy (hydrogen
and nitrogen)

8. OCEAN ENERGY CONVERSION
TECHOLOGY
• Ocean Salinity Gradient Energy: When saline
water is separated from fresh water by a
charged semi permeable membrane, electric
potential developed between the electrode.
One cell produced 1W.
• Ocean Current Energy: Ocean current has high
kinetic energy which can be converted into
electrical energy by turbo generator.

9. OCEAN ENERGY CONVERSION
TECHOLOGY
• Ocean Nuclear Energy: Nuclear resources
available from ocean water and ocean bed.
• Ocean Wave Energy: Ocean wave occurs due
to rotation of earth wind flow over the ocean.
Wave have interval of 4 to 12 sec with crest
height of 3 m and above. Ocean wave machine
is rotated by wave energy. Wave machine
drives the generator rotor, pump to store the
water at high level, compressor to store the air
in compressed air storage plant.

10. WAWE ENERGY
• Energy of interchanging between potential and
kinetic energy in the wave
• Cycloid motion of wave particles carries energy
forward without much current
• Typical periodicities are one to thirty seconds, thus
there are low-energy periods between high-energy
points
• In 1799, Girard & son of Paris proposed using wave
power for powering pumps and saws
• California coast could generate 7 to 17 MW per mile
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11. TYPES OF WAVE AND ENERGY

12. WAWE ENERGY
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• Kinetic energy (movement)
exists in the moving waves of
the ocean. That energy can be
used to power a turbine. See
in Fig. This is only one type
of wave-energy system.
• Others actually use the up
and down motion of the wave
to power a piston that moves
up and down inside a
cylinder. That piston can also
turn a generator.

13. ADVANTAGES
• Advantages
• The energy is free - no fuel needed, no waste
produced.
• Most designs are inexpensive to operate and
maintain.
• Waves can produce a great deal of energy.
• There are minimal environmental impacts.

14. DIS-ADVANTAGES
• Disadvantages
• Depends on the waves - sometimes you'll get loads of
energy, sometimes nothing.
• Needs a suitable site, where waves are consistently strong.
• Must be able to withstand very rough weather.
• Disturbance or destruction of marine life
• Possible threat to navigation from collisions because the
wave energy devices rise only a few feet above the water.
• Degradation of scenic ocean front views from wave energy
devices located near or on the shore, and from onshore
overhead electric transmission lines.
Conclusion:
• Waves harness a lot of the sun’s power, but they are better
for surfing than generating electricity.

15. WORLD WAVE POWERR RESOURCES
• “Potential exploitable wave energy" resources worldwide to be 2 TW.
• For European countries cover more than 50% of the total power
consumption.
• The wave market is estimated at $32 billion in the United Kingdom
and $800 billion worldwide.
Figures in
kW/m

16. WAVE POWER HARNESS
METHOD
1. Wave energy is to bend or focus the waves into a narrow
channel of concentration, to increase their power and size. Then
waves can be channelled into a catch basin or used directly to
spin turbines. The energy of the waves is converted into
electricity by means of surge devices and oscillating column
devices. Wave energy conversion (WEC) is one of the most
feasible future technologies. These energy systems are not
developed and maturated commercially due to the complexities,
sea conditions, and difficulty of interconnection and
transmission of electricity through turbulent water bodies. In
addition, they may require higher operation and maintenance
costs in comparison to the land power systems due to their
location at sea.

17. WAVE POWER HARNESS
METHOD
2. A typical ocean wave energy harvesting system consists
of a wave power absorber, a turbine, a generator, and power
electronic interfaces. The absorber captures the kinetic
energy of the ocean waves. The absorbed mechanical
kinetic energy of the waves is either conveyed to turbines
or the absorber directly drives the generator. Turbines are
generally used with systems that feature rotational
generators.
In other methods, a linear motion generator is used, and this
can be directly driven by the power absorber or movement
of the device. Both linear and rotational generators produce
variable frequency and variable amplitude AC voltage.

18. WAVE POWER HARNESS
METHOD
Both linear and rotational generators produce variable frequency
and variable amplitude AC voltage. This AC voltage is rectified to
DC voltage in order to take advantage of the DC energy
transmission capabilities of salty ocean water.

19. OSCILLATING WATER COLUMN (OWC)
An oscillating water column
is a partially submerged,
hollow structure. It is open
to the sea below the water
line, enclosing a column of
air on top of a column of
water.
Waves cause the water
column to rise and fall,
which in turn compresses
and decompresses the air
column.

20. OSCILLATING WATER COLUMN (OWC)
Waves cause the water
column to rise and fall, which
in turn compresses and
decompresses the air column.
This trapped air is allowed to
flow to and from the
atmosphere via a turbine,
which usually has the ability
to rotate regardless of the
direction of the airflow. The
rotation of the turbine is used
to generate electricity.

21. OSCILLATING WATER COLUMN

22. OSCILLATING WAVE SURGE CONVETER
Oscillating wave surge converters extract energy from
wave surges and the movement of water particles within
them. The arm oscillates as a pendulum mounted on a
pivoted joint in response to the movement of water in the
waves.

23. OVERTOPPING/TERMINATOR DEVICE
Overtopping devices capture water as waves break into a
storage reservoir. The water is then returned to the sea passing
through a conventional low-head turbine which generates power.
An overtopping device may use ‘collectors’ to concentrate the
wave energy.

24. FLOATING DEVICE - ATTENUATOR
An attenuator is a
floating device which
operates parallel to the
wave direction and
effectively rides the
waves. These devices
capture energy from
the relative motion of
the two arms as the
wave passes them.

25. ATTENUATOR –PELAMIS
One of the most well-known examples of this is the
Pelamis, a series of long cylindrical floating devices
connected to each other with hinges and anchored to the
seabed.
The cylindrical parts
drive hydraulic rams in
the connecting sections
and those in turn drive
an electric generator. The
devices send the
electricity through cables
to the sea floor where it
then travels through a
cable to shore.

26. FLOATING DEVICE- POINT ABSORBER
A point absorber is a floating
structure which absorbs energy
from all directions through its
movements at/near the water
surface. In a vertical tube below
the water, waves rush in and
drive a piston, a buoyant disk
connected to hose pumps, up and
down to
pressurize seawater inside. The
pressurized water then drives a
built-in turbine connected to an
electrical generator

27. SUBMERGED PRESSURE DIFFRENTIAL
Submerged pressure differential devices are typically
located near shore and attached to the seabed.
The motion of the
waves causes the sea
level to rise and fall
above the device,
inducing a pressure
differential in the
device. The
alternating pressure
pumps fluid through a
system to generate
electricity.

28. BULGE WAVE DEVICE
Bulge wave technology consists of a rubber tube filled
with water, moored to the seabed heading into the waves.
The water enters through the stern and the passing wave
causes pressure variations along the length of the tube,
creating a ‘bulge’.
As the bulge travels
through the tube it
grows, gathering
energy which can be
used to drive a
standard low-head
turbine located at the
bow, where the water
then returns to the sea.

29. ROTATING MASS DEVICE
Two forms of rotation are used to capture energy by the
movement of the device heaving and swaying in the
waves. This motion drives either an eccentric weight or a
gyroscope causes precession.
In both cases
the movement
is attached to
an electric
generator insi
de the device.

30. TAPPERED CHANEEL WAVE POWER
These shoreline systems consist of a tapered channel which feeds into a reservoir
constructed on a cliff. The narrowing of the channel causes the waves to increase their
amplitude (wave height) as they move towards the cliff face which eventually spills
over the walls of the channel and into the reservoir which is positioned several meters
above mean sea level. The kinetic energy of the moving wave is converted into
potential energy as the water is stored in the reservoir. The water then passes through
hydroelectric turbines on the way back to sea level thus generating electricity.

31. WAVE AIR TURBINE

32. SALTER “DUCKS”
• Scottish physicist Prof. Stephen Salter invented “Nodding Duck”
energy converter in 1970
• Salter “ducks” rock up and down as the wave passes beneath it.
This oscillating mechanical energy is converted to electrical
energy
• Destroyed by storm
• The “duck” device bobs back and forth as waves pass, this
motion moves a pendulum that is connected to a generator that
produces electricity
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33. SALTER “DUCKS”