The "Comunidad Autonoma de Madrid" (Autonomous Community of Madrid, in the following Madrid Region), is a region located at the geographical centre of the Iberian Peninsula. Its area is 8.028 km(2), and its population about five million people. The Department of Economy and Technological Innovation of the Madrid Region, together with some organizations dealing on energy saving and other research institutions have elaborated an Energy Plan for the 2004-12 period. As a part of this work, the Fluid Mechanics Laboratory of the Superior Technical School of Industrial Engineers of the Polytechnic University of Madrid has carried out the assessment of the wind energy resources [Crespo A, Migoya E, Gomez Elvira R. La energia eolica en Madrid. Potencialidad y prospectiva. Plan etiergetico de la Comunidad de Madrid, 2004-2012. Madrid: Comunidad Autonoma de Madrid; 2004]; using for this task the WAsP program (Wind Atlas Analysis and Application Program), and the own codes, UPMORO (code to study orography effects) and UPMPARK (code to study wake effects in wind parks). Different kinds of data have been collected about climate, topography, roughness of the land, environmentally protected areas, town and village distribution, population density, main facilities and electric power supply. The Spanish National Meteorological Institute has nine wind measurement stations in the region, but only four of them have good and reliable temporary wind data, with time measurement periods that are long enough to provide representative correlations among stations. The Observed Wind Climates of the valid meteorological stations have been made. The Wind Atlas and the resource grid have been calculated, especially in the high wind resource areas, selecting appropriate measurements stations and using criteria based on proximity, similarity and ruggedness index. Some areas cannot be used as a wind energy resource mainly because they have environmental regulation or, in some cases, are very close to densely populated towns. In the finally selected areas, it is assumed that there are hypothetical wind farms, consisting of 2 MW turbines in appropriate configurations, in which the turbines are about 11 diameters apart. Its energy production will give an estimation of the wind energy potential of the Madrid Region. (c) 2006 Elsevier Ltd. All rights reserved.