This book explores the potential of magnetic superconductors in storage systems, specifically focusing on superconducting magnetic energy storage (SMES) systems and using the Spanish electricity system, controlled by Red Eléctrica de España (REE), as an example. The book provides a comprehensive analysis of the economic costs associated with the manufacture and maintenance of SMES systems, as well as a regulatory analysis for their implementation in the complex Spanish electrical system. The analysis also compares this system with the regulations of other countries, providing a comprehensive case study. The book examines the possible economic and environmental benefits of using magnetic superconductors in electrical systems and provides a technical study of the use of these systems in hybrid storage systems that complement each other to optimize network performance. The study is conducted from the perspective of new distribution networks, distributed generation, and the concepts of the smart city. The book also explores potential applications and developments, such as electric vehicles. Overall, this book offers an insightful and comprehensive analysis of the potential of magnetic superconductors in storage systems. It will be an invaluable resource for researchers, engineers, and policymakers interested in the future of energy storage systems