The special edition of IEEE Power and Energy Magazine (March/April 2014) is devoted to the unprecedented revolution in the European power sector, which is facing tremendous changes and challenges in improving its sustainability and the security of supply, including implementing the integration of the internal, E-28 energy market and its liberalization. Aging assets in need of decommissioning and upgrading the entire electrical power infrastructure (generation, transmission, and distribution) is also a considerable concern across the European energy landscape. Indeed, secure, sustainable, available, and affordable energy is fundamental to modern societies and to the wellbeing of citizens, in addition to industrial competitiveness. The European power system serves more than 500 million people – distributed over a large territory – with an annual consumption of over 3,000 TWh. The corresponding generation portfolio is still primarily composed of traditional plants using fossil, hydroelectric, and nuclear energy sources. Renewable energies are undergoing accelerated development with a significant share/penetration of wind energy. Total installed wind power in Europe was 106 GW at the end 2012, of which about 5 GW were from offshore sources. For solar photovoltaic (PV) energy, the installed capacity in the EU at the end of 2012 was close to 70 GW, representing about 68% of the world’s installed PV capacity. The transmission and distribution infrastructure investments (for renewal and expansion including the accommodation of renewable energy sources and distributed generation) are expected to represent several hundreds of billions of euros by 2030. The current high-voltage transmission grid ismade up of approximately 300,000 km of overhead lines and cables. It has historically been developed on a national basis, with a limited number of interconnections at the boundaries of neighboring countries initially built for security support via small energy exchanges, and not intended to support the open market. The recent opening and expansion of cross-border markets has drastically changed this situation, leading to a fast and continuous increase in cross-border exchanges and emphasizing the need for new infrastructure enabling better European market integration. Distribution grids at medium and low voltages cover about 5 million km of lines and cables, and are managed by about 5,000 distribution operators in all EU countries. In Europe, a large fraction of the PV and wind generation is connected at the distribution level, and this requires a major shift in the operation of distribution networks. To fulfil European climate and energy policies, the electrical system is experiencing a period of rapid and radical evolution focused on the development of renewable energies. The EU power grid can be a facilitator of the development of this new renewable portfolio through the harmonization of different energy sources and consumption patterns as well as through economies of scale; but it is facing major challenges in planning, developing, and deploying the appropriate technological solutions to respond to the political objectives and support the goal of a decarbonized and sustainable economy.