Stepping-up Wave Energy Extraction in All Degrees of Freedom by Combining Pendulum and Gyroscopic Effects

Reaching carbon neutrality targets, set by the European Commission, requires to increase the energy extraction ability of existing wave energy converters (WECs). Two already successful devices are considered in this paper, both exploiting inertial coupling between the inner electromechanical system and the hull motion: the ISWEC (Inertial Sea Wave Energy Converter), and the PeWEC (Pendulum Wave Energy Converter). Both technologies work best when the spreading factor of the wave is infinite (i.e. all wave components are coming from the same direction), and/or the hull is aligned with the incoming wave direction, so that the motion of the hull remains in a plane. A recent patent proposes a technological solution that conveniently combines gyroscopic and pendulum effects to effectively exploit motion also outside the plane, namely from all degrees of freedom (DoFs) and in the three-dimensional space. This paper starts from the analytical formulation of the electro-mechanical conversion system dynamics, considering at presented in linear form. Consequently, the relative importance of main mechanism design parameters is analyzed, discussing their impact on the overall performance. Furthermore, preliminary results are produced and discussed.