Survey of Energy Resources 2007
Wave Country Notes
Ireland has some of the best wave resource in the world and wave energy research has been undertaken there since 1980, with much of the work being conducted at University College Cork (UCC) and Queen's University Belfast (Northern Ireland), although other universities, such as Limerick, are now playing an increasing role. More recently, the Marine Institute and Sustainable Energy Ireland (SEI) has funded work, for example a wave and tidal energy resource study, as well as helping to develop an ocean strategy (http://www.sei.ie/getFile.asp?FC_ID=1747&docID=913) and supporting several device developers.
Clearpower Technology's Wavebob is a self-reacting point absorber. It comprises two floating bodies mounted vertically that have different responses to waves. This produces relative motion between the bodies, from which energy can be extracted using hydraulics to power a motor and generator. The different frequency responses give the device a greater bandwidth, with scope for tuning over a wider range of sea conditions than is possible with a conventional single buoy point absorber. A 1/4th scale device was deployed in the sea in 2006.
Hydam Technology has developed the McCabe Wave Pump. This is a floating device comprising two narrow pontoons that point into the waves and which are attached using hinges to either side of the central generating platform. As waves pass down the length of the device, the pontoons move with respect to the central platform and power is extracted from this movement using hydraulic rams. Although this can be used to generate electricity (~ 400 kW), the device has been designed primarily to produce potable water using reverse osmosis. A prototype scheme was tested in 1996 and a commercial demonstration scheme has more recently been constructed and deployed.
Ocean Energy's OE Buoy is a 'backward bent duct buoy', which is a floating OWC with the opening to the OWC pointing away from the incoming waves towards the land. A 1/4th scale device was deployed off the west coast of Ireland in late 2006 and further testing is planned for 2007, before construction of a 1 MW prototype (www.oceanenergy.ie).