Fundamental changes are currently taking place in mod- ern energy systems and, particularly, in electrical ones. Infras- tructures have to satisfy conflicting requirements: providing reliable and secure services to an increasing number of customers, taking into account a rational use of energy and the protection of the environment. This last requirement drives major changes in electrical and energy systems where increasingly renewable en- ergy sources need to be connected to the grid. It is generally ac- knowledged that these sources need to be massive and distributed, in order to provide a non-negligible part of the consumed electri- cal energy . It is also generally agreed that such integration of renewables into existing grids depends on the successful combi- nation of specific processes (e.g. demand side/response manage- ment, real-time consumption management, real-time local energy balance, accurate forecasting of renewables at continental, coun- try and regional scales) and new technologies (e.g. smart meters, agent-based distributed controls). Currently, there is a major effort from different research com- munities, in particular those of applied mathematics, control the- ory, computer science and, of course, power systems, to propose, discuss and validate new methodologies for the planning, opera- tion and control of future electrical and energy systems. It is within this context that Sustainable Energy, Grids and Networks (SEGAN) has been launched.