This report identifies and describes the regulatory frameworks and policy instruments relevant for RES Prosumer initiatives in the EU and nine participating Member States.2 Taking the current state of the art on the legal challenges and opportunities for RES prosumers, this document explains recent developments of EU legislation related to renewable energy production and self-consumption (i.e. prosumerism). The analysis of the policy and regulatory frameworks of nine EU Member States (i.e. Belgium/Flanders, Croatia, France, Germany, Italy, Portugal, Spain, Netherlands and United Kingdom/Great Britain) provides information necessary for understanding how the different regulatory frameworks are constraining or enabling the development of individual and collective forms of RES prosumerism. It will also be a useful tool for assessing whether and, if so, how prosumer provisions of the recent EU legislation are already integrated in the Member States’ national regulatoryframeworks. The study focusses on countries ... : H2020 project PROSEU - Prosumers for the Energy Union: Mainstreaming active participation of citizens in the energy transition. Deliverable 3.1 ...