Wave Energy 01

Content  How it is produced?  Advantages and Disadvantages of this resource..  Proportion of the resource used world wide and in India.  Where and How much? 2

3

Introduction  Waves are created by the gravitational action of sun and the moon and also by the interaction of wind with the surface of the sea.  Wave power is practically endless and classified as a Renewable energy source.  Wave energy can be extracted and converted into electricity by wave power machines. They can be position either on the shoreline or in deeper waters offshore. 4

A Global Wave Energy Resource Assessment 5

6

APPROACHES TO CAPTURE WAVE ENERGY 7

Buoyant moored devices  The device floats on or just below the surface of the water and is fasten to the sea floor.  A wave power machine needs to resist the motion of the waves in order to generate power: part of the machine needs to move while another part remains still.  In this type of device, the connection is static and is arranged in such a way that the waves motion will move only one part of the machine.  Electricity is generated from the somersaulting action of a floating object which can be mounted to a floating raft or to a device fixed on the ocean floor. 8

10

Oscillating Water Columns (OWC)..  Oscillating water column devices use a familiar concept for generating electricity – driving the turbines  As water oscillates in a column, wind travels back and forth in the chamber and drives the turbine  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 depresses the air column. 11

Hinged contour device  Here, the resistance to the waves is created by the alternate motion of the waves, which raises and lowers different sections of the machine relative to each other, pushing hydraulic fluid through hydraulic pumps to generate electricity. 13

14

15

ADVANTAGES & DISADVANTAGES 16

Advantages  A much greater level of power is concentrated in the motion of waves than in the movement of air  Whereas the power density at a good wind energy site may be of the order of a few square meter, the power density in a corresponding area of wave motion may be up to 100 times greater.  It produces no greenhouse gases or other waste.  It needs no fuel. 17

Advantages…..  Wave energy has this advantage over wind or solar energy that the energy has been naturally concentrated by buildup over-time and space and transported from the point at which it was originally present in the winds  Wave power devices do not use up large land masses like solar or wind  It produces electricity constantly  These devices are relatively pollution free, and because they remove energy from the waves, the water is left in a relatively calm state in their stir 18

Disadvantages  The major disadvantage of wave energy, as compared to wind, is that the energy is available in the ocean  Therefore the extraction equipment must operate in a marine environment which will have to be taken into account during its construction and its maintenance,lifetime and reliability should be considered since the energy may have to be transported through a great distance to the shore. 19

Disadvantages…  There is relative scarcity of accessible sites of large wave activity.  Economic factors such as the capital investment, costs of maintenance, repair and replacement  Wave energy converters must be capable of withstanding very severe peak stresses in storm 20

UK – Largest User of Wave Energy  Britain: Britain is sitting on the biggest source of marine energy in Europe  Tapping tidal and wave energy could one day produce about 10% of the world's electricity consumption, so the incentive to develop turbines, hydrofoils and ducts which can convert this energy into watts is enormous  While the costs of wind power have decreased by 80% in the last 25 years with design improvement and economies of scale, marine power is starting from a lower base and Britain is a world leader in this technology

22

23

24

WAVE POWER POTENTIAL ALONG THE INDIAN COASTLINE 25

Wave power potential along the Indian coastline Location (Non-monsoon) Wave power (kW/h) N and coast 85 E (off Madras) N and coast 85 E (off Vishakhapatnam) N and E (off Calcutta) N and 70 E coast (off Cochin) N and 70 E coast (off Mumbai) N and E (off Cape Comorin) Location (Monsoon) Wave power (kW/h) N and coast 85 E (off Madras) N and coast 85 E (off Vishakhapatnam) N and E (off Calcutta) N and 70 E coast (off Cochin) N and 70 E coast (off Mumbai) N and E (off Cape Comorin) 7.80

27

28