Characteristics of wind power are different and therefore its integration leads to some important challenges concerning the electricity system. Due to weather dependence, the availability of the energy generated from wind power differs fundamentally from that generated conventionally from fossil fuels. In an electricity system with an important share of wind power, new methods for balancing supply and demand are needed. Wind power forecasting plays a key role in tackling this challenge. Good wind power predictions increase the value of the wind power making it more competitive.