Spatial distribution of offshore wind statistics on the coast of Portugal using Regional Frequency Analysis

This paper investigates the spatial characteristics of wind speed statistics in oceanic areas of Portugal. The main goal is to apply a regionalization method to define statistically homogeneous regions and then analyze the probabilistic moments, the wind power density, percentiles and extreme values within each region. The Regional Frequency Analysis based on L-moments was implemented using five years of atmospheric simulations. The domain convers latitudes 36.0 degrees N to 422 degrees N and longitudes 11.0 degrees W to 7.2 degrees W, with resolution of 0.081 degrees X 0.097 degrees and 6 h. The investigation using the L-moment ratios resulted in four regions: north (1), center (2), southwest (3) and south (4) of Portugal. A discussion about the potential associated with each region, in terms of the wind energy available and the extreme events severity, enriches the final analyses. Region 1 has the benefit of the highest mean wind power density, equal to 909 W/m(2), but it presented the most extreme winds with return value of 25.4 m/s for the return period of 20 years. It was observed that extreme winds are reduced moving south, together with the wind power densities, which are analyzed in detail. The spatial and regional characteristics of wind power densities and extreme values are deeply explored. (C) 2018 Elsevier Ltd. All rights reserved.