Bridging a bi-directional connection between electricity and fuels in hybrid multienergy systems

Abstract A flexible conversion between electrical energy and fuels is significant technical support for the decentralization of the energy systems. On one hand, fuels can be stored seasonally without any self-charging losses. On the other hand, fuels, particularly liquid fuels, can be transported through well-developed transportation network to form connections between distributed hybrid systems (DHSs). To realize a flexible conversion between electricity and fuels, advanced fuel cells and electrolyzers (power-to-gas or power-to-liquid) are the key technologies. In this chapter, we introduce the working principles of fuel cells and electrolyzers, as well as their contributions to DHS. For each technology, current status, potential applications, and challenges are comprehensively reviewed and discussed.