In the coming decades, copper scarcity is likely to result in deteriorating ore quality, which in turn will lead to a higher GER (gross energy requirement) for copper production. In this study, this increasing GER and the effect it has on the EROI (energy return on investment) of wind turbine technologies have been analysed. The GER of copper in a 2050 100% renewable energy system will be a factor 2-7 larger than it is today, depending on technological progress, the recycling rate and the future electricity demand. Because of an increasing in-use stock of copper, recycling will play a relatively small role even when the recycling rate is high. The future EROI of wind turbines is approximately 15% less than is currently often taken into account, mainly due to network losses. The GER of increasingly scarce materials can potentially be used as a more meaningful indicator for abiotic depletion in LCA studies than the current mineral reserve based practice. (C) 2012 Elsevier Ltd. All rights reserved.