Abstract
Six private companies and research institutes & universities jointly started a consortium research for practical use of the oscillating water column system (OWC) in 2011. Projecting-walls (PW), installed both side of the opening, were found out to make frequency dependency reduced. At the same time, hydraulic experiment for the single OWC facility installed on the line of breakwater showed sudden drop down of the efficiency of the primary conversion against a certain wave period. This occurred due to the interposition with reflection waves from the ambient surface of breakwater. Reduction of wave reflection improved this drop significantly.
The consortium with 2 new members tried a new application of PW-OWC system to the existing coastal embankment in the Sakata Port. The line of this embankment shows no bad effect of reflection waves, as the embankment has a series of two air chambers in front-back direction inside to reduce wave-reflection. An experiment facility of wave power conversion was finally installed on this embankment in December, 2014. After the official safety inspection by METI, the field experiment was started to obtain the data of waves and generated electricity since January, 2015. The PW-OWC system installed on the existing facility is expected a possible design of the practical application
