# Iain Staffell Back to [[Topics/Climate Change Science and Policy Debate/Climate Change Science and Policy Debate|Climate Change Science and Policy Debate]] · [[Topics/Climate Change Science and Policy Debate/Research and Evidence|Research and Evidence]] **Role:** Energy researcher, Imperial College London; co-author of the peer-reviewed wind-degradation study. - Lead author of **Staffell & Green 2014, "How does wind farm performance decline with age?"**, *Renewable Energy* 66:775 ([doi](https://doi.org/10.1016/j.renene.2013.10.041)). The co-author is Richard Green. - **Finding:** UK wind-farm output declines ~1.6% a year, about a 12% loss over 20 years. That is comparable to other generators and much less than the REF/Hughes estimate.