EnerDigit - A joint programming initiative to establish transnational innovation eco-systems for the designing, implementing and testing of interoperable technical and business services for energy systems, unleashing the potential of digital transformation for the energy transition This ERA-Co-fund Action aims to enhance the transnational collaboration in digital transformation of energy systems and networks. It helps unleashing the potential of digitalisation for the energy transition towards a de-carbonised, secure and resilient European energy system. The initiative coordinates relevant RDD programmes in the involved European and associated countries and regions, implementing at least two joint calls for RDD proposals. It contributes to the implementation of the EU SET-Plan, particularly Actions 3 and 4. Beyond the funding of transnational RDD projects, it accelerates the development of transnational innovation ecosystems by initiating a Transnational Validation Ecosystem with existing and upcoming living labs, allowing start-ups and innovative companies to test their solutions in different frameworks. It also promotes the development of interoperable solutions, enabling wider impact and use of applications, systems and services, by piloting a European Collaboration Platform for Interoperability Testing, providing an open, independent development and test environment for developers, manufacturers and suppliers of components and solutions for smart energy systems. A highly ambitious consortium establishes an Impact Network with Associated Partners, acting as intermediaries towards regional and local stakeholders, start-up supporters and incubators as well as to follow-up financers and investors in order to enhance need driven technology policy. This ERA-Net co-fund action is exploiting on sustainable coordination structures already established by the Joint Programming Platform Smart Energy Systems (JPP SES) and will be integrated there as a new "Focus Initiative".