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). Looking at coupling the power sector with the gas sector, covering a comprehensive and in-depth analysis of available technologies for bridging the gap and meeting the energy trilemma. Providing a comprehensive approach to the economic, technical, and environmental evaluation of P2G technology in order to make more effective use of the surplus power of renewable units, this book covers converting electricity to hydrogen or methane, 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 modelling issues and requirements for analysis Gas and Power Vector-Coupling Technologies are presented and supported by real-world case studies and experimental examples, for the use of P2X Vector-Coupling Technologies. 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.