Abstract: The need of standard wave climate and energy resource statistics appears to be necessary to enable comparison of wave energy converters (WECs) performance through numerical modelling and tank testing. In this paper a proposal of a methodology for wave energy resource characterization is made based on the usual wave height, period, direction and power parameters. In addition, other spectral wave parameters relating to spectral width and wave grouping are used namely to select a representative sample of sea states. A wave climate and energy resource off Portugal north-western coast based on buoy measured data is proposed together with a set of thirty six energy spectra.