The course presents an interdisciplinary perspective of the energy sector, with a special focus on the electric power sector, linking the engineering, economic, legal and environmental viewpoints. The course reviews the whole electricity supply value chain, from the analysis of the key primary energy sources (hydrocarbons, nuclear and renewable ones) to the description of the main electricity activities (generation, transmission, distribution and retail) and the different regimes in which they operate (regulated monopolies or under competitive conditions), with a special focus on the review of the fundamentals needed to approach the market designs currently implemented worldwide. The knowledge acquired in the course will provide the comprehensive understanding of electric power systems that will be needed for research in this field, as well as for future professional activities in the energy sector, whether in industry, government or consulting.