Wave Power Use for Island Power Supply by a Backward Bent Duct Buoy

Abstract The Backward Bent Duct Buoy (BBDB) started as a Twin Fuselage BBDB, and was developed to Cylinder float BBDB. Water tank teat indicated a significant output increasing. A sea test in Mikawa bay in the inland sea area was conducted in 1995, and produced 300 watts from a 45 cm wave of 2.7 sec period from a 2.86 m BBDB. Using the Froude Simulation law, and scaling by 10, a wave in the open sea will generate 1,000 Kw from a 28.0 m BBDB. Introduction Wave power use is not yet completed except navigational light buoy, but solar power(l50 Watts/ m2) is highly concentrated towave power through wind blows on wide sea surface, and it is stored as swell on sea surface, Table I shows wind and wave Conditions Associated with fully developed sea states. Table I Wind and Wave Power Density by wind speed. (available in full paper) In case of 15 m/s in wind speed, wave power through I m width IS equal to solar power in 500 m22 and wind mill area of 50 m 2. Therefore, wave power use will be economical way than solar cell or windmill to use natural energy since energy density is higher. The other hand, wavegives a very strong breaking force to wave power facility constructed on shore, floating wave power device has a merit to avoid such destructive force by following to wave. Long life and safety mooring were certified by Floating type Wave Power Generator Kaimei by JAMSTEC, Floating platforms by Oil Industry and Fairway Buoy use on sea etc. The other hand, floating type wave power generator is easy to construct by ship-yard facility, than shore base facility which must be constructed on random shore line. In order to get an economical and safety floating type wave power device, Backward Bent Duct Buoy (BBDB) was developed in this 10 years by corporative study work of Japan, China, Denmark and Ireland. Further interest of India, Philippine and others is given to this study at recent time. We will ex-plains recent tank study, sea trial and further view for island's and land's power. Principle of BBDB and circumstance of development. The are various proposals for a Wave Power Generation buoy; Oscillating Water Column (OWC) with buoy is popular, Center Pipe Buoy (Figure 1) is used for navigation buoy, and a turbine generator is used on it. It is known that air output is increased by increasing length of the center pipe. but extending it to vertical direction brings a handling difficulty. For OWCdevice it is known to open the mouth to wave coming direction but Mr Koichi Nishikawa and Mr Takahiko Masuda proposed that Backward Bent Duct Buoy (Figure 2) which has horizontal long duct to open to backward.