‘Inverse’ Concept - Wave Energy Generation by Motion and Green Water Maximisation

This paper presents the initial investigations into the ‘Inverse’ concept for wave energy conversion, based on the maximisation of motions and green water. The ‘Inverse’ concept combines aspects of ‘overtopping’, ‘heaving’ and ‘pitching’ wave energy conversion concepts, but also adds specific aspects such as the use of green water. Instead of reducing the motions and green water as is done in normal offshore hydrodynamics, the ‘Inverse’ concepts tries to maximise the motions and green water to generate energy from the waves. Results are presented of frequency domain calculations for the motion (de-) optimisation. Improved Volume Of Fluid (iVOF) simulations are used to simulate the green water flow on the deck. It is concluded that the potential of the ‘Inverse’ concept is clear. As a result of the double connotation of the word ‘green’, this renewable energy concept could also be called the ‘green water’ concept. Further work needs to be carried out on the further optimisation of the concept.