GECAD is a Research Unit having as mission the development of scientific research and innovation for the incorporation of Intelligence in Engineering and Computing Complex Systems. Intelligent Energy Systems is the International and National reference of Excellence of GECAD, namely in areas like Smart Grids, Electricity Markets, Distributed Resources, Demand Response, Energy Efficiency and Intelligent Buildings.Research is performed in other areas like Affective Computing, Ambient Intelligence, Artificial Intelligence, Cyber-Physical Systems, Group Decision Support, and Internet-of-Things. Energy is the main field of application of GECAD R&D, however other fields like Industry, Cities, Security, and Tourism are also considered. GECAD is very effective in participating in R&D projects and in publishing in Top-level scientific journals.