The technology being developed by Wavegen is called 'oscillating water column'. The movement of the waves is used to move air in and out of a chamber. This air is passed through a turbine to generate electricity.
The schematic below is a cross section of a device called the LIMPET, already installed by Wavegen on the Scottish island of Islay. The Siadar scheme would look different to this but use the same principle.
Wavegen Technology
