The present thesis consists of 10 research papers published during the period 1997-2002 together with a summary report. The objective of the work described in the thesis is to develop models and methods for calculation of high accuracy predictions of wind power generated electricity, and to implement these models and methods in an on-line software application. The economical value of having predictions available is also briefly considered. The summary report outlines the background and motivation for developing wind power prediction models. The meteorological theory which is relevant for the thesis is outlined and the background for the models and methods which are proposed in the various papers is described. The software system, Zephyr, which has been developed is also described in the summary report. The main part of the papers have been written in conjunction with two research projects where the Department of Informatics and Mathematical Modelling and the Department of Wind Energy and Atmospheric Physics have been two major participants. The first project entitled Implementing Short-term Prediction at Utilities , founded by the European Commission under the JOULE programme. The second project is founded by the Danish Ministry of Energy under the Energy Research Programme, and is entitled (in Danish) Vindmølleparks Produktions Prediktor . Both projects have now finished.