The European Union (EU)’s member states committed themselves to lowering by 20% the greenhouse gas (GHG) emissions (compared to 1990s levels) and are discussing new initiatives and actions targeting a 80% GHG reduction by 2050 [1][2]. It is clear that significant effort and changes have to be considered to achieve the EU’s decarbonization objectives while guaranteeing a competitive and secure energy supply. Among others, the EU energy policy road maps and initiatives entail building reinforced international partnerships and physical power interconnectors with neighbouring regions/systems, with a view at diversifying electricity resources portfolio through higher and efficient penetration of renewable energy sources (RES). The uneven geographical distribution of RES potentials, in a scenario of massive renewables integration in the European transmission grid, is expected to lead to increasing north–south power flows mainly triggered by onshore/offshore wind farm installations in the North Seas and south–north power flows mainly brought about by South European and possibly North African solar power plants. In order to accommodate these prospective flows and ensure a better balancing of large-scale RES production across far apart EU and extra-EU regions a reinforced transmission grid – generally named as Supergrid or Electricity Highway [1][12][19][21] – is expected to be developed in the coming decades, also beyond current ENTSO-E (European Network of Transmission System Operators for Electricity) system, thus allowing electricity to flow over long distances and be consumed/stored where more appropriate.