Power grid informed techno-economic analysis of the optimal PeWEC design

The role of ocean energy is expected to expand significantly in the coming years, driven by the need to meet the European Commission’s SET Plan targets. Traditional wave energy converters (WECs) optimisation approaches prioritise minimising the Cost of Energy (CoE), but they often overlook grid integration challenges. However, mismatches between variable Renewable Energy Sources (vRES) production and actual grid demand arise due to factors like load shedding, storage limitations, and frequency requirements. This discrepancy is especially pronounced in off-grid systems with high vRES penetration. Therefore, it is crucial for WECs developers to consider the power grid’s behaviour, ensuring that devices can generate electricity when it is most needed. This study examines the discrepancy between the wave energy cost derived from total energy production and that based on the energy actually delivered to the grid. The analysis examines WECs optimised solely for minimising the cost of energy alongside those which align with grid demand, emphasising the need to integrate grid information into the design process. Findings reveal a clear trade-off between devices that achieve optimal wave energy cost and those that minimise the Total Annual Energy System Cost (TAESC). Significant differences in operational continuity, curtailment, and power output are observed when comparing the device with the lowest CoE and the one with the best TAESC. This indicates that the economic viability of a WEC depends on designing a system capable of efficiently harnessing energy from the more frequently occurring, albeit less energetic, sea states rather than focusing solely on high-energy conditions.