This book discusses current and essential issues regarding: EUROPEAN NETWORKS OF TRANSMISSION SYSTEM OPERATORS, ELECTRICITY QUALITY, ENERGY EFFICIENCY, ELECTRICITY RATIONALIZATION and ELECTRICITY STORAGE. In the current context of technological development and increased energy needs, efficient electricity management has become an essential component to ensure sustainability, economic efficiency, environmental protection and energy security. Electricity, an indispensable form of energy, fuels industries, institutions, housing and transport. That is why the way it is produced, distributed and consumed must be carefully planned and regulated. Electricity management is no longer an option, but a necessity. In a changing world with limited resources and an increasingly affected environment, only through responsible energy management can we ensure a sustainable future. This requires the collaboration of authorities, companies and citizens in a joint effort of efficiency, innovation and responsibility.