Overtopping Terminators
As waves arrive, they overtop the device and are restrained in the reservoir. As the water escapes energy is captured via a turbine generator. This device works well at capturing energy in deeper water environments, however it has a large footprint and produces the least amount of energy per unit area of any current wave power generation system.
Oscillating Water Columns
As waves enter and exit the chamber, air is forced past a turbine which is used to harness energy on both the rise and fall motions. Oscillating water columns are one of the most frequently installed and most studied technologies being used today. It produces energy that can easily be sent to the grid but this device is difficult to scale up to an appreciable size and suitable locations are difficult to find.
Attenuators
Attenuators are oriented in the direction of incoming waves so as to cause articulated components to bend and drive generators. They are typically moored to the ocean floor on one end. These devices work by the absorber principle, utilizing floats help extract the energy. These devices can produce large amounts of electricity but suffer from a very large initial cost and are often very large and unsightly.
Point Absorbers
Point absorbers capture energy from the up and down motion of waves. They harness power most effectively from waves with long wavelengths and periods. Power can be generated using either a hydraulic system or by linear induction (Note: The sea snake design seen above is also a point absorber). This design offers the smallest footprint and the highest efficiency. Disadvantages include the complexity of the drive mechanisms and difficulty of mooring in an offshore environment.