Wave Energy - Devices

Types of devices

Attenuators are devices facing the waves direction, going up and down the waves in a snake-like motion. The mechanical pressure applied in the joints of the device is converted into electricity.

Point Absorbers are made of a mobile floating structure mounted on a pole. The floating structure moves up and down with the waves, converting the mechanical power into electricity.

Oscillating wave surge converters consist of an oscillating arm mounted on a pivoted joint. The device works with the wave surges and the circular movement of water within them that pushes the device's arm forward and backward.

An Oscillating Water Columns (OWC), generally installed on the shoreline, are partially submerged structures open to the sea below the water line. Waves make the water inside the column to rise and fall, causing the compression and decompression of the air inside the structure. The air can only circulate in and out of the structure via a turbine that rotates under the pressure of this airflow and generates electricity.

Overtopping devices, also called 'terminators', are placed on the surface and capture water brought by the waves that will overflow the device. The captured water goes back to the sea though a turbine that generates power. They can be placed on the shoreline or offshore.
Submerged Pressure Differential devices use the pressure differential created by the waves passing above the device that cause the sea level to rise and fall. The alternating pressure pumps fluid through a system to generate electricity.

Bulge wave technology consists of a rubber tube filled with water, moored to the seabed heading into the waves. The water enters through the stern and the passing wave causes pressure variations along the length of the tube, creating a ‘bulge’. As the bulge travels through the tube it grows, gathering energy which can be used to drive a standard low-head turbine located at the bow, where the water then returns to the sea.

Rotating Mass devices use the heaving and swaying movements of the device in the waves to drive either an eccentric weight or a gyroscope causes precession. In both cases the movement is attached to an electric generator inside the device.