Power-to-Gas: Bridging the Electricity and Gas Networks introduces the concept of Power-to-Gas (P2G) technologies in the Whole Energy System framework and related Vector-Coupling Technologies (VCTs). The boo provides a comprehensive approach to the economic, technical and environmental evaluation of P2G technology to make more effective use of the surplus power of renewable units. It covers converting electricity to hydrogen or methane, and the challenges, analytical solutions and future trends of P2G applications. Moreover, the reference features technology overviews and literature reviews in each chapter, along with concepts, appropriate definitions, fundamentals and contexts in the energy systems. Finally, modeling issues and requirements for analysis Gas and Power Vector-Coupling Technologies are presented and supported by real-world case studies and experimental examples. By uniquely analyzing issues from the whole energy system perspective, this book plays a pivotal role in supporting researchers and academicians in electrical, mechanical and energy engineering in their long-term decarbonization strategies.