Long-Term Wind Speed Forecasting Based on Seasonal Trends

Over the last three decades, significant research has been carried out in the field of wind power forecasting with operational tools, however, making their presence noticeable in the last 15 years. So far, most of the work done has focused on short term forecasting of wind conditions. This is mainly due to the operational need for trading electricity a few days or a few hours ahead of gate closure due to the daily fluctuating nature of the demand and the finite response time of generation plant. However, System Operators (SOs), generators and suppliers have a need for longer term predictions of the power traded in order to maximize financial profits, schedule maintenance, etc. This paper presents a time series analysis of historical observations of wind speed in order to project future wind speed trends. The results suggest that the seasonal trend in wind speeds is the most important factor but that there is some monthly autocorrelation in the data which can improve forecasts. The approach proposed for forecasting wind speeds a month ahead may be deemed useful to suppliers for purchasing base load in advance and to SOs for power systems maintenance scheduling up to a month ahead.