The document presents the methodology elaborated by JRC within the framework of its participation to the work of the Smart Grids Task Force, Expert Group on Smart Grid Infrastructure Deployment (Expert Group 4). The then adopted Regulation 347/2013 on guidelines for trans-European energy infrastructure provides for the establishment of a EU-wide list of "Projects of Common Interest", a label identifying key energy infrastructure projects in EU. Within this framework, Expert Group 4 had the mandate to define an evaluation framework for projects proposals in the field of smart grids. On the basis of its experience on Cost Benefit Analysis of smart grid projects, JRC developed a multi-criteria assessment framework including: a) a checklist to check that project proposals meet the requirements set out by the Regulation; b) a techno-economic assessment through Key Performance Indicators to capture the key features of each project; c) a Cost Benefit Analysis of each projects.