The Smart and Sustainable Grids research unit is an interdisciplinary group at the IIT which is focused on the analysis and development of models for the simulation and optimization of future electricity networks. These networks will enable us to ensure the viability of the model of sustainable energy required by society in the 21st century. This model is characterised by the centrality of the role of renewable energies with distributed characteristics, by a flexible energy demand and the capacity to meet that demand, and by a quality of service which meets the expectations of the digital society. We offer an important range of activities, making a significant research contribution both nationally and internationally: Externally financed research and development projects which include European projects, national CENIT projects, and a number of projects commissioned by private institutions and companies. A contribution to the scientific knowledge base in the form of PhDs, articles in the most important journals in this field and participation in international conferences. The development of our own software for the simulation of large networks. This software has a range of applications and can be sold under licence. The most relevant is the Reference Network Model, designed for the planning of large scale distribution networks and for assessing the impact of Distributed Energy Resources. An important teaching role in the PhD and Postgraduate programme in Electrical Engineering in the Escuela Técnica Superior de Ingeniería (ICAI) - including the Master’s Degree in the Electricity Sector and a close collaboration with the training courses of the EES-UETP.