The Concerted Action supports the implementation of the RES directive. In particular, the Concerted Action facilitates sharing experience and good practice of implementation, finding common approaches as well as cross-learning and cooperation. The work carried out within the CA-RES is designed to meet the needs of RES Directive implementing organisations. The action will provide added value compared with measures taken by each MS acting on its own. The Concerted Action will help make knowledge available to all participants through access to a network of national experts engaged in implementation of the Directive. The CA-RES4 will do this through a structured framework that will facilitate the exchange of information and experience through a series of meetings and other communication tools. It will provide participants with an opportunity to learn from others implementation process and policy approaches and build national policy capacity, but also to explore opportunities for bi-lateral or multi-lateral cooperation and identify areas for possible future convergence and harmonised approaches amongst participating countries. The CA-RES4 builds upon the success and structures of the previous phases of the CA. The CA-RES community has developed during the course of the previous phases into a unique network of experts and will be strengthened. The objective is to provide participating countries with the most pertinent information that may lead them on the most efficient path towards an effective implementation of the RES Directive 2018/2001/EC in the EU. The expected impact of the Action consists of a more harmonized approach and improved implementation of the RED II in participating countries, a strengthened network of experts as well as the transfer of good practices between countries.