This book offers a comprehensive approach to energy systems integration (ESI) that optimizes the design and operation of energy systems, maximizing the benefits of all components while minimizing potential negative impacts. By coordinating the production, distribution, and utilization of energy from diverse sources, ESI ensures the most efficient and cost-effective fulfillment of end-users' needs. The true value of ESI lies in its ability to harmonize interconnected systems, enabling the production and supply of energy in its various forms to achieve reliability, environmental sustainability, and economic viability at appropriate scales. Through the analysis and design of integrated energy systems, often referred to as multi-energy systems (MES), decision-makers and industry professionals gain valuable insights into the optimal strategies required to fulfill these objectives while considering contextual conditions and operational constraints. The book explores the design, modeling, supervising, and controlling of energy systems but also examines how these approaches can be seamlessly integrated into future MES through innovative and ESI processes. Through its comprehensive analysis and forward-thinking approach, this book serves as a vital resource for researchers, practitioners, and policymakers seeking to navigate the complexities of energy systems integration and leverage the potential of renewable energy for a sustainable future.