definition, different working technology, global and India level production

1. G.L BAJAJ INSTITUTE OF TECHNOLOGY & MANAGEMENT,
GR. NOIDA
DEPARTMENT OF MECHANICAL ENGINEERING
Prepared By
Mr. VISHAL SHANKAR SRIVASTAV
(Asst. Prof. ) 1
Topic – Wave Energy Conversion

2. Content
• Introduction
• Working
• Types
• Advantages and disadvantages
• Applications
• References
2

3. Introduction
Waves are most commonly caused by wind.
Wind-driven waves, or surface waves, are created by the friction between wind and
surface water[1].
As wind blows across the surface of the ocean or a lake, the continual disturbance
creates a wave crest [1].
Waves are move in a circular motion. However, water does not actually travel in
waves. Waves transmit energy, not water, across the ocean[1].
Wave energy consists of kinetic energy resulting from wave propagation and potential
energy resulting from lifting of water mass with respect to mean sea level[2].
The wave energy depends upon amplitude of the wave and period of the motion.
Wave power is commonly expressed in kilowatt per meter, that is, the rate of energy
transfer across a line of l m length parallel to the wave front[2].

4. Working Technology
Fig:1 OWC wave energy conversion[3] Fig:2 Waves creation technology
Oscillating Water Column Technology (OWC)

5. Oscillating Water Column Technology (OWC)
• The oscillating water column partly submerged concrete or steel structure,
which has an opening to the sea below the water line, thereby enclosing a
column of air above a column of water.
• As waves impinge on the device, they cause the water column to rise and fall,
which alternately compresses and depressurizes the air column.
• This air is allowed to flow to and from the atmosphere through a turbine,
which drives an electric generator .
• Both conventional (i.e. unidirectional) and self-rectifying air turbines have
been proposed.

6. 2: Oscillating Wave Surge Technology (OWS) or Float or buoy
systems
• Oscillating wave surge converters (OWSCs) are
a class of wave power technology that exploits
the enhanced horizontal fluid particle movement
of waves in the nearshore coastal zone with
water depths of 10-20 m.
• That use the rise and fall of ocean swells to
drive hydraulic pumps.
• The object can be mounted to a floating raft or
to a device fixed on the ocean bed.
• A series of anchored buoys rise and fall with the
wave.
• The movement is used to run an electrical
generator to produce electricity which is then
transmitted ashore by underwater power cables.
Fig:3 OWS wave energy conversion[4]

7. Advantage
1. It’s highly predictable
2. It’s eco friendly.
3. It is highly suitable to develop power in remote islands, on drilling
platforms and on ship where other alternatives are impossible.
4. Wave energy conversion devices help in reducing the erosion of costal
region.
5. Waves are continuously formed and power can be extracted continuously.
No storage of power is required.

8. Disadvantage
1. Too costly.
2. Sea water is corrosive and life of equipment used in conversion
devices is limited.
3. Variability in wave magnitude can damage equipment.
4. Damage to sea life ecosystem.

9. Wave Energy Plants and Potential in India[5]
• India is estimated to have a potential of 40-60 GW of Wave Energy around
it cost with the current state of technology.
• The wave energy potential is estimated to be 5-15 MW per metre of
coastline.
• There are no big wave energy plants in India except the pilot plant at
Vizinjham Fisheries Harbour near Trivandrum in Kerala.
• Maharashtra government has built project would generate 15 to 20 kilowatt
of electricity located at Borya and Budhal villages in coastal Ratnagiri
district.
• Sagar Shakti is a 1 MW OTEC plant built off the Tuticorn coast which
utilizes the temperature different wave energy device.

10. Global Position of Wave Energy [6]
• The best wave conditions for exploitation are in medium-high latitudes and
deep waters (greater than 40 m deep), since wave energy is found to reach
power densities of 60-70 kW/m in those location.
• For example, countries like Australia, Chile, Ireland, New Zealand, South
Africa, the UK and the US have excellent wave resources with average power
densities of 40-60 kW/m. Global estimates for wave energy potential are still
relatively uncertain.
• In 2012, the Intergovernmental Panel on Climate Change (IPCC) reported a
theoretical potential of around 29,500 terawatt-hour per year (TWh/yr)
considering all areas with wave energy densities higher than 5 kW/m.

11. References :
1. https://oceanservice.noaa.gov/facts/wavesinocean.html
2. NON-CONVENTIONAL ENERGY RESOURCES, by - G.S.
Sawhney, PHL learning publication -2012
3. https://images.app.goo.gl/nj884pNDAog2dGXn8
4. https://images.app.goo.gl/jaSjKZqDKrJBi2Ke9
5. https://www.irena.org/documentdownloads/publications/wave-
energy_v4_web.pdf