Book excerpt: Nowadays, Smart Grid has become an established synonym for modern electric power systems. Electric networks are fed less and less by large, centrally planned fossil and nuclear power plants but more and more by millions of smaller, renewable and mostly weather-dependent generation units. A secure energy supply in such a sustainable and ecological system requires a completely different approach for planning, equipping and operating the electric power systems of the future, especially by using flexibility provisions of the network users according to the Smart Grid concept. The book brings together common themes beginning with Smart Grids and the characteristics of power plants based on renewable energy with highly efficient generation principles and storage capabilities. It covers the advanced technologies applied today in the transmission and distribution networks and innovative solutions for maintaining today’s high power quality under the challenging conditions of large-scale shares of volatile renewable energy sources in the annual energy balance. Besides considering the new primary and secondary technology solutions and control facilities for the transmission and distribution networks, prospective market conditions allowing network operators and the network users to gain benefits are also discussed. The growing role of information and communication technologies is investigated. The importance of new standards is underlined and the current international efforts in developing a consistent set of standards are updated in the second edition and described in detail. The updated presentation of international experiences to apply novel Smart Grid solutions to the practice of network operation concludes this book.