Add to ORKGThe European Union (EU) Regulatory Framework concerning Distributed Generation (DG) may have a decisive impact on the development of European distribution systems towards Smart Grids. To address this issue, the present paper firstly reviews this Regulatory Framework. Secondly, focus is on the current state of penetration of DG technologies deployed in the EU Member States, comparing then the level of penetration of distributed generation with the existing number of Distribution System Operators (DSO). Finally, considering that different elements can be included when referring to Smart Grids as a concept, several architectures do exist, having some discrepancies between themselves. Two representative case studies of two different Smart Grid ...