On the errors in annual energy yield estimation due to monodirectional wave spectra assumption

The wave energy sector has made significant progress, and its potential is tangible. However, in order to make wave energy production a key tool in the energy transition, it is crucial to minimize the uncertainty associated with the energy production assessment. Trustworthy evaluations are reachable only through detailed analyses based on reliable, accurate and representative wave data. The use of synthetic parameters exclusively derived from a frequency spectrum leads to the neglect of directional information and the combination of wind waves and swells is treated incorrectly. This study investigates errors associated with relying solely on the frequency spectrum and points out the relevance of directionality. The island of Pantelleria serves as a case study, and the results show that PeWEC (PendulumWave Energy Converter) performance is overestimated when the monodirectionality of the waves is assumed. Neglecting the directional information contained in the frequency-direction spectra results in an overestimation of energy production of 40%.