Energy systems can be vulnerable to climate change. This paper summarizes the contribution of their authors to a few strategic studies, research workshops, development forum and international conferences related to Climate and Energy. It presents a review of the impacts that climate change may have throughout the energy chain and identifies current knowledge gaps and areas for future research development. One of the greatest challenges is how to assess impacts which may occur as a consequence of the projected increase in the intensity of extreme weather events: the majority of current methodologies rely on past experience but this may not be a sufficiently good guide for planning and operational activities in the coming decades. Also, climate impact assessments on energy planning and operation need to take into account a greater number of scenarios, as well as investigate impacts on particular energy segments. Therefore, we identify energy segments for which little climate impact research has been conducted. Finally, because climate impact assessment for energy systems is a relatively new research field, it is expected that methodological developments will increase in the near future with a consequent broadening of the knowledge base on the subject. (C) 2011 Elsevier Ltd. All rights reserved.