Power-to-Gas Energy Storage by Reversible Solid Oxide Cell for Distributed Renewable Power Systems

The conflict between energy utilization and environmental problems is deepening, urging society to promote the utilization of renewable energy in the future energy structure. In this paper, the processes of power-to-gas (PtG) are described in detail for improving the utilization and flexibility of renewable energy. The reversible solid oxide cell (RSOC) technology is considered as a promising route for PtG, especially power-to-methane (PtM). The working principle, electrochemical performance, and dynamic behaviors of RSOC and methane production characteristics are reviewed and manifested by summarizing the existing literature and the authors' experimental data. From the data, the application of RSOC in the distributed energy system is specifically demonstrated. The basic structure and power management strategies of the distributed systems combining renewable energy and natural gas are simulated and optimized by trade-offs among system efficiency, power quality, and renewable power penetration as well as system cost. It is found that RSOC is able to better integrate the renewable power, heat, and gas in the distributed system to fully utilize various energy sources and achieve a more efficient PtM conversion.