This book is aimed at university students in engineering, in particular graduated students in the electrical engineering area who want to learn more about topics such as the operation of electricity markets and the related policy decisions. The book starts with providing the fundamental theory of economics and regulation in relation to the electricity sector and then recalls the theory of nodal prices for the valuation of electrical energy at a power system buses. Numerical examples are used to clarify the implications of the theoretical models presented. Along with the theoretical aspects of valuating electricity, the book addresses the organisation of markets, including the real case example of the Italian power exchange, the options for capacity markets, the valuation of investments in transmission capacity and the congestion management, briefly recalling the current state of European markets integration. Environmental externalities are addressed while focusing on the current state of emission trading systems and the support for renewable energy. Finally, price formation and financial products supporting electricity trading are discussed.