Wind climate analysis and modelling is of most importance during site selection for offshore wind farm
development. In this regard, reliable long-term wind data are required. Buoy measurements are
considered as a reference source in relevant applications including evaluation and calibration of wind
data obtained from less reliable sources, combined assessment, blending and homogenization of multisource
wind data, etc. Most of these applications are based on regression techniques elaborated by using
the principle of ordinary least squares (OLS). However, wind data usually contain several outliers, which
may question the validity of the regression analysis, if not properly considered. This study is focused on
the implementation of the most important robust regression methods, which can identify and reveal
outliers, and retain at the same time their efficiency. Long-term reference wind data series obtained from
buoys at six locations in the Mediterranean Sea are used to calibrate hindcast (model) wind data by
applying robust methods and OLS. The obtained results are compared according to several statistical
measures. The effects of the calibration methods are also assessed with respect to the available wind
power potential. The results clearly suggest that least trimmed squares and L1-estimator perform in all
respects better than OLS.