Supergrids and the new challenges to face

In recent years electrical energy systems have undergone radical changes. The earliest innovations in MV and LV distribution systems brought about the development of smart grids, i.e. intelligent networks that, among countless other benefits, allow to exploit the renewable energy dispersed on the territory which would not otherwise be recovered. More recently, there have been momentous changes also in the HV and EHV electrical transmission systems that had already turned into Mega Smart Grids, i.e. large, high-voltage networks where some typical functions of smart grids had been implemented. In the future, in order to take advantage of the large energy amounts from renewable sources, such as wind in the North Sea and PV in the Sahara Desert, the different European mega smart grids may turn into one huge network called Supergrid, which will not only have important intelligent features but also a large number of submarine HVDC connections. The paper highlights the new opportunities offered by Supergrids, as well as some of the problems to be faced, such as voltage stability in huge systems whose mere size would have been unthinkable just a dozen years ago.