The development of new wind energy projects requires a thorough analysis of land use issues and constraints. At ETH Zurich, an analytical approach has been developed using a Geographic Information System (GIS) to define the location of suitable sites for wind projects and to predict their economic exploitable energy production. The purpose is to estimate the average Annual Energy Production (AEP), with a GIS customized tool, based on physical factors (environmental and anthropological constraints), the wind resource distribution and the technical specifications of the large-scale wind turbines currently present in the US market. Economics data and regulatory parameters are also included. The wind energy potential of the state of Iowa has been estimated: the resulting average AEP of Iowa is 914 TWh and the potential total installed capacity is 302 GW. A sensitivity analysis of the influence of the Power Purchase Agreement (PPA) shows that a PPA of 6.5 c$/kWh would enable to exploit the 85% of the buildable land with an IRR greater than 15%. This approach is applicable to both larger and more limited regions in order to support energy planners and wind farm developers to set energy strategies and to scout new profitable lands. (C) 2012 Elsevier Ltd. All rights reserved.