How is Marine Power Harnessed?

What is marine power?
Marine power involves harnessing the power of the sea both its waves and its tides. These power systems work by harnessing the movement and energy contained in the oceans and seas and converting it into electrical power.

Wave energy
As ocean waves are created by the interaction of wind with the surface of the sea, waves have the potential to provide a significant contribution to global energy requirements. These proposed technologies may be deployed either on the shoreline, in coastal waters or in deeper offshore locations.

Currently, there are only two wave power devices operating in the UK. Total capacity currently stands at 1.25 megawatts. The first type of device is the LIMPET (Land Installed Marine Powered Energy Transformer), a 500-kilowatt shoreline oscillating water column on the Scottish island of Islay. The second, the 750-kilowatt Pelamis sea snake, is an example of a hinged contour device. It is the first deep-water grid-connected trial and is currently installed at the European Marine Energy Centre in Scotland, where it is undergoing testing.

Wave technology is yet to achieve a commercial status, but future developments will harness this power source in increasing rates in the UK as the direction of the prevailing winds and the size of the Atlantic Ocean, means the UK has wave power levels that are among the highest in the world. Wave energy has the potential to provide in excess of 50 terawatt hours per year.

Tidal energy
Tidal energy exploits the natural ebb and flow of coastal tidal waters caused principally by the interaction of the gravitational fields of the earth, moon and sun. The coastal water level fluctuates twice daily, alternatively filling and emptying natural basins along the shoreline. The currents flowing in and out of these basins can be exploited to turn mechanical devices to produce electricity.