|Green power from the sea – harnessing wave energy
The water of the world’s oceans is always in motion. Without being interrupted, waves constantly break at the coastline, sometimes strong, sometimes weaker. There is an enormous energy potential that is available around the clock and free of charge. The potential for wave energy is huge and the drive to harness the power of the waves is gaining momentum.
The Oscillating Water Column
This ingenious design to harness wave energy is normally situated on the coast or is fixed offshore. It consists of an enclosed chamber with an opening beneath sea level. Wave action causes water to move up and down within the chamber. This causes air to be displaced and escape through an opening in the roof. The escaping air turns a turbine that is placed within the hole and consequently generates power.
The Oscillating Bodies
These types of facilities are usually found offshore and utilize the movement of the ocean by means of a semi-submerged generator on which a fixed counter bearing moves sideways or up and down.
Overtopping devices work on the same principles as hydroelectric dams but are situated offshore. Similar to a hydrodam these devices have a reservoir that is filled up with water as the waves break over the sides. The reservoir is filled up to levels above the surrounding ocean. The water falling back to the ocean drives a turbine that in turn generates energy.
Future of Wave energy
To be able to harness wave energy at a cost competitive level to that of fossil fuels have been extremely difficult. A coal powered station can produce power 24 hours a day. Wave farms are dependent on the ocean and when the seas are calm, these farms aren’t efficient.