Sea Wave Energy - Renewable Energy Resources

A presentation on the topic Sea wave energy, consisting of an introduction, terminologies, formulas and the availability of wave energy.

1. SEA WAVE
ENERGY

2. CONTENTS
01
02
Sea Wave Energy
Power associated with sea waves
03
Motion in sea waves
04
Wave energy availability

3. Wave energy is a form of renewable energy that can be
harnessed from the motion of the waves.
Wave energy has the potential to be the largest source of energy
from our seas.
Depending on the lunar cycles, tides, winds, and weather, waves
can vary in size and strength.
The energy in ocean waves mainly comes in an irregular and
oscillating form at all times of the day and night.
The wave height, period, and direction are primarily dependent
on the wind properties (speed, direction, and duration) and also
the geometry of the sea (fetch length and depth).
SEA WAVE ENERGY

4. There is little loss of energy in deep-water ocean waves, so as they travel
to distant shores they continue to collect more and more wind energy.
Energy intensity may, however, have variation but it is available 24 h a
day in the entire year.
It contains tremendous energy potential and wave power devices extract
energy from either the surface motion of ocean waves or from pressure
fluctuations below the surface. As waves roll through the ocean, they
create kinetic energy, or movement.
This movement can be used to power turbines, which, in turn, create
energy that can be converted into electricity and power.
SEA WAVE ENERGY

5. When the wind blows across a smooth water surface, air
particles from the wind grab the water molecules they touch.
Stretching of the water surface by the force or friction between
the air and the water creates capillary waves (small wave
ripples).
Surface tension acts on these ripples to restore the smooth
surface, thereby forming waves.
MOTION IN SEA WAVES

6. Crest: The peak point (maximum height) on the wave.
Trough: The valley point (lowest point) on the wave.
Wave height (H): The vertical distance between the wave crest
and the next trough.
Amplitude (a): Defined as H/2.
Wavelength (l): The horizontal distance between two successive
crests or troughs.
Wave propagation velocity (v): The motion of seawater in a
direction.
Wave period (T): The time required for two successive crests or
troughs to pass a point in space.
Frequency (f): The number of peaks (or troughs) that pass a fixed
point per second, given by f = 1/T.
MOTION IN SEA WAVES

7. MOTION IN SEA WAVES

8. POWER ASSOCIATED WITH
SEA WAVES
Sea waves contain kinetic and potential energy. (E)
Energy is transported by the wave and can be harnessed for
power.

9. Energy of a Wave (E) of a wave per meter of crest and unit of
surface:

- (1)
ρ: Density of water
g: Gravitational acceleration
a: Amplitude of the wave (half of the wave height H)

10. Group Velocity

dispersion relation (k) is given as
Thus,
-(2)

11. The power that a meter of crest holds can be obtained by
multiplying the amount of energy transported (E) by the group
velocity (Vg)
Combining energy (1) and group velocity (2)​

12. Substituting Wave Period
Wave period T:​ Amplitude a:
Power P per unit of wavefront (kW/m) is given as,
Substituting,

13. Ocean waves have significantly higher energy
density than air, making them a powerful
renewable resource.
The U.S. has 23 GW of wave energy potential, with
Europe, particularly Ireland and Scotland, having
high energy densities.
Generally, extreme latitudes and west coasts of
continents are the best wave location.
Current technologies like Oscillating Water
Columns (OWS) convert wave motion into
electricity.
WAVE ENERGY AVAILABILITY

14. Early Innovations
1799: First wave-power patent by Monsieur Girard and
son.
19th Century: Wave energy device in Algeria.
Historical Installations
1917: 10 kW plant in the Baltic Sea.
(flap pilot plant)
Modern Projects
2004: Pelamis wave machine in the UK.
Significant Plants
5 MW: Wave energy plant on Isle of Islay, Scotland.
2 MW: Wave energy project off Vancouver Island,
Canada.
A few installation of wave power:
Pelamis Wave Machine

15. Wave power at selected sites along Maharashtra coast
OFF SHORE Avg.Wave Power kW/m COASTALAvg.Wave Power kW/m
Site Annual (Jun-August) Site Annual (Jun-August)
Vengurla Rock 8.01 20.61 Girye 5.90 14.21
Square Rock 6.79 16.64 Vijaydurg 5.86 13.58
Redi 6.35 16.57 Ambolgarh 5.74 13.48
Malvan Rock 6.91 16.73 Kunkeshwar 5.64 13.35
Kura Inset 5.79 13.74 PawaPoint 5.36 13.10
  Wagapur 5.70 13.10
Availability in India:

16. Thank You
Any Q & A?