Conceptual Design of OWC Wave Energy Converters Combined With Breakwater Structures

Ocean wave energy is one of several renewable sources of energy found in the ocean. The energy in the oscillatory ocean waves can be used to drive a machinery that converts the energy to other forms. Depending on the type and their location with respect the coast and offshore, a number of devices have been and are being developed to extract the wave energy for conversion into electricity. The most common devices are referred to as the oscillating water column (OWC), hinged contour device, buoyant moored device, hinged flap and overtopping device. Particularly popular are OWCs and moored floating bodies. The idea of integrating breakwater and wave energy converters emerged in the Indian wave energy program. Graw (1996) discussed this idea and pointed out the advantage of shared costs between the breakwater and the wave energy device. Because long waves are usually experience stronger reflection at coasts and breakwaters, they provide good conditions for the operation wave energy devices which work efficiently when the reflection is high. There are examples that OWC devices have been installed in water as shallow as 3 m. This paper reviews the options of integrating OWCs with different kinds of breakwaters like the perforated or non-perforated caisson breakwater, and non-gravity piled and floating types. The purpose of each of the concepts will also be highlighted.