Assessing the performance of short design waves for an asymmetric hinged WEC

As governments worldwide set ambitious offshore renewable energy targets to achieve Net-Zero, the need for cost-effective device design is critical. Although global deployment of wave energy remains limited, it may feature in future ORE plans due to its potential for rapid growth and its value across diverse applications, including offshore decarbonisation, ocean sensing, aquaculture and autonomous vehicle charging. Accurate prediction of ultimate limit states is essential for the survivability and cost-competitiveness of floating platforms, yet current design standards rely on long irregular sea state simulations. Design waves offer a faster alternative, using targeted wave profiles to produce extreme responses. This study evaluates several design wave approaches against the traditional design method for a hinged wave energy converter using physical model data. The data consistently shows a steep-fronted wave profile, indicating that nonlinear wave development close to breaking may strongly influence extreme responses for this device. NewWave and response-conditioned design waves are generally under-conservative, and constrained variants provide mixed results. In contrast, steepness-conditioned profiles, tuned via focus point adjustment, capture extremes more effectively and produce the closest agreement with the benchmark data. These findings highlight steepness-conditioning as the most promising approach for this device, motivating further investigation across additional sea states.