Energy security has recently become a policy priority for the European Union due to growing concerns about environmental challenges and the fact that EU covers about half of its energy needs through imports. Policy-makers in Europe are struggling with the need to achieve energy security and promote a transition towards decarbonised energy sources without undermining wellbeing and patterns of consumption. The collaborative EU MILESECURE-2050 VII Framework project provides new scientific knowledge on these issues, using multiple perspectives which extend to 2050, and develops new European models, which support and enable energy security at the European, national and local scales. In particular, this article focuses on the analysis developed at the local scale, related to a set of case studies on energy/social systems in transition. The methodological foundation of this work is shortly illustrated as well as the main findings. These highlight the leading role of the human factor in supporting the transition toward low carbon society.