Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI) delivered the Offshore Floating Wave Power Device MIGHTY WHALE to Japan Marine Science and Technology Center (JAMSTEC) in July 1998. The functions of the device are 1) wave energy conversion into electric power, and 2) wave height dissipation.
MIGHTY WHALE was developed jointly by JAMSTEC and IHI. It was constructed at IHI's Aioi Works, and was moored at its test site off Gokasho Bay in Mie Prefecture. The device is 50m in length and 30m in width, and is currently the world's largest floating wave power device. In appearance the device resembles a whale, and hence the name MIGHTY WHALE.
MIGHTY WHALE has three air chambers at the front (part of the mouth). Each air chamber has an opening nozzle at the top where an air turbine with a power generator is installed. The under water front wall of each air chamber is open to allow entry of wave power energy. Waves entering the air chamber cause up and down motions of the water level of the chamber, producing high velocity oscillating air flow through the opening nozzle. These air flows drive an air turbine, the type of which is Wells turbine featuring stable rotation of the same direction in oscillating air flows. An air turbine drives an electric power generator. The output of generators is utilized to drive an air compressor. In the future, compressed air produced by the device could be utilized to pump water from deep sea, or to purify sea water by aeration. Such a device could be utilized in fish farming and marine leisure.
An additional feature of the device is that its longitudinal cross section is shaped like an airplane wing. This form enables the device to face the predominant wave direction in open sea.
JAMSTEC plans to carry out open-sea performance verification tests on this prototype device for two years.
