Ocean wave energy is a renewable resource that converts the motion of sea waves into electricity by means of wave energy converters (WECs). With one of the highest energy densities among renewable sources and strong complementarity with wind and solar, it is regarded as a promising contributor to the future energy mix, particularly for coastal and island communities. Unlike more mature renewables, however, the field has not yet converged toward a single dominant technology: a wide variety of device concepts is still being explored, which makes their modelling, control, and estimation especially open and challenging research problems.

WECs operate in a highly dynamic and uncertain environment, continuously excited by waves that cannot be measured directly. Extracting the maximum possible energy is not a conventional stabilisation or set-point-tracking problem: it calls for economic, energy-maximising control formulations, typically based on predictive strategies. These strategies deliberately push devices beyond the validity range of their simplified hydrodynamic models, so that accurate control-oriented modelling, real-time estimation, and robust autonomous operation become tightly coupled challenges, combining hard fundamental problems with high potential impact on the energy transition.