Optimisation of the Pendulum Wave Energy Converter With Spline-Based Hull Shape

Wave energy offers substantial potential but has yet to reach commercial viability due to high costs and reliability challenges. This study advances the Pendulum Wave Energy Converter (PeWEC), an inertial device featuring a fully enclosed Power Take-Off (PTO) to enhance survivability in harsh marine environments. To improve techno-economic performance, this research introduces a spline-based hull parametrisation, offering greater geometric flexibility than previous simplified arc-based designs.An upgraded optimisation model is presented, employing a genetic algorithm to minimise the ratio of Capital Expenditure (CapEx) to Annual Energy Production (AEP). The design space encompasses hull geometry, mass distribution, and PTO settings, subject to robust physical constraints. A frequency-domain approach simulates device dynamics across 128 representative sea states for a case study off Pantelleria Island, Italy.Computational results demonstrate the efficiency of the model, with parallelised runs completing within 96 hours. Comparative analyses indicate that spline-based designs significantly outperform benchmark arc-based geometries. Specifically, the spline parametrisation unlocks up to 33\% increase in maximum energy yield compared to the limit of the arc-based designs for a comparable investment. These findings validate that advanced hull shaping is critical for accessing superior techno-economic configurations.