Correlation analysis between UK onshore and offshore wind speeds

The work presented in this paper is an analysis of the correlation between wind speeds at offshore and coastal/inland sites to determine the expected accuracy of long term correction techniques for offshore resource assessment such as measure-correlate-predict (MCP). In particular, data from offshore mast masts at three different heights and five different surface stations have been studied. Different coastal-offshore, inland-offshore and coastal-onshore combinations have been analysed. Correlations based on one half of the available data and prediction accuracy based on the second half of the data are presented. The correlation coefficient, the Root Mean Square Error (RMSE) and the Mean Absolute Percentage Error (MAPE) were used as metrics in this case. Although RMSE of predictions is greatest for offshore sites, the MAPE is lowest for two of the three regions studied. An MAPE of 25-30% may be expected in terms of wind speed prediction accuracy based on statistical (turbulent) variation.