Several initiatives were launched in the last decade in the European Union (EU) to align the Pan European power grid development with the EU's policy targets, particularly in the energy and climate change fields. The build of new infrastructures, which was initially mainly pushed by the need for increased cross border trading and integration of the wholesale electricity markets, is nowadays also strongly driven by the demand for integrating diversified, low-carbon energy sources (e.g. renewable wind and solar sources). The possible evolutions of the power grid in the medium-to-long term (up to 2050) highly depend upon different scenarios for: renewable energy deployment (primarily in terms of technologies, performances and geographical siting); extension of the European electricity network towards neighbouring power grids (e.g. Russia, Northern Africa and Middle East); penetration of distributed energy sources calling for a smarter system development especially at lower voltage levels. These factors, by defining the preferential patterns for the cross-European and intercontinental power flows, will outline critical structural and operational needs for the European power grid of the future. The present paper discusses the emerging challenges facing the European transmission grid, while contributing to meeting the EU energy and climate change policy goals. This work focuses on the European extra?high voltage system - generally considered as an already smart electricity system expected though to evolve towards higher transfer capacity architectures (so-called super grid); the challenges of smartening up the power distribution systems are addressed only in so far as transmission-distribution interfaces are concerned, illustrating tensions and complementarities of the smart and super grid concepts. In this light the paper presents: the main policy objectives and visions for electricity in the European Union; key figures and trends relating to the European energy and electricity systems in a worldwide context; technological options and design challenges for the pan-European transmission grid. The paper ends summarising needs and potential solutions for the EU transmission grid in view of its long-term evolution.