The great amount of wind power recently connected to electric power systems makes necessary new grid analysis tools and control strategies. Some of these tools are short term wind power prediction programs, which have been recently developed and are already in use in many System Operators and wind power producers. Prediction programs also allow the participation of wind energy in the electricity market by keeping the economic losses due to power imbalances for wind generators within acceptable values, specially if the uncertainty of the predictions is evaluated and used in the bidding process. Such participation intends to make the power system operation easier. Distributed control of power system, and specially optimised control of clusters of wind generators is another measure that is being taken in order to maintain the levels of power system security and to minimise the consequences of possible and temporary wind power curtailments, due to grid security reasons, on the affected wind farms. The contents of this book include a detailed description of short term wind power prediction programs, an evaluation of the economic losses due to imbalances incurred by wind generators participating in an electricity market, and an optimisation strategy aimed at minimising the consequences of power curtailments.