The cumulative energy demand and the energy yield ratio can be seen as an indicator of environmental impacts to estimate the depletion of energy resources considering a whole lifecycle. For two wind energy converters (1.5 and 0.5 MW) these figures have been calculated. For calculating energy yield ratio, the yearly energy output of three sites has been selected: coastal, near coastal and inland. The cumulative energy demand of the wind energy converter varies from 13,795 to 13,927 GJ. The energy yield ratio is between 70 and 40 depending on the selected site. (C) 2004 Elsevier Ltd. All rights reserved.