Abstract: One possible technology for offshore wave energy conversion is the use of uplift or buoyancy forces. Such systems can be divided into resonant converters, with the possibility of increased performance through a point-absorber effect, and simple non-resonant floats.
Although non-resonant devices offer advantages of simplicity, very little work appears to have been conducted to evaluate their performance. In order to assess the potentialof such devices, a simple hydrostatic theory for power conversion was developed. It could be shown that the efficiency of such a converter becomes a function of the geometry, and the mode of operation.
Physical model tests were conducted, and maximum conversion efficiencies of up to 40% were reached. The good agreement of the experimental efficiencies with the theoretical values indicated that the simple hydrostatic theory can be utilized to quantify the performance of a non-resonant buoyancy type converter. The acceptably high possible efficiencies in combination with a survivability strategy which minimizes structural loadings indicate that the concept of non-resonant buoyancy converters has development potential.
