Publications

Survey of Energy Resources 2007

Wave Country Notes

Japan
Despite having low wave-power levels, extensive research on wave energy has been undertaken in Japan, which deployed one of the first wave-energy devices (the floating OWC, 'Kaimei'), followed by another floating OWC (the 'Mighty Whale' in 1989). Particular emphasis has been placed on the development of air turbines and on the construction and deployment of prototype devices (primarily OWCs), with numerous schemes having been built:

• a 40 kW OWC was deployed in 1983 on the shoreline structure at Sanze for research purposes. It has since been decommissioned;
• a five-chambered 60 kW OWC was built as part of the harbour wall at Sakata Port in 1989;
• 10 OWCs were installed in front of an existing breakwater at Kujukuri beach, Chiba Prefecture. The air emitted from each OWC was manifolded into a pressurised reservoir and used to drive a 30 kW turbine. This scheme was operational between 1988 and 1997;
• a 130 kW OWC was mounted in a breakwater in Fukushima Prefecture in 1996. This used rectifying valves to control the flow of air to and from the turbine;
• a floating OWC known as the Backward Bent Duct Buoy was deployed in Japan in 1987. This continues to be developed in co-operation with institutes in China and Ireland;
• the Pendulor wave energy device has been developed by the Muroran Institute of Technology. Wave action causes pendulum oscillations of a plate ('pendulor') at the entrance to a box, this movement being used in conjunction with a hydraulic power take-off to generate electricity.

The only significant wave-energy device currently being studied is an OWC deployed at Niigata in 2005.