Metrics for Wave Energy Converter Hull Geometry Optimisation

Wave Energy Converter (WEC) structures have been widely studied in the past decade, due to their high potential for device cost reduction. In this context, various hull geometry optimisation studies have been performed to maximise power and reduce costs, where costs were mostly represented through the device size in terms of mass, volume or surface area. In the present study, the suitability of the different objective functions is analysed, with the goal of finding an optimal hull shape with relevant cost considerations when using a flexible geometry definition. The results are given for a particular location off the West Shetland shelf to the north of Scotland. Impedance matching control at the energy period is assumed, and this means that mass distribution has no effect on the device oscillation. The differences in shape and annual energy production are presented for optimal devices oscillating in surge, and in surge, heave and pitch. Devices are optimised for maximal annual energy production, and its ratio to various size characteristics based on volume and surface area.