Thermodynamic and Exergy Analysis of Reversible Solid Oxide Cell Systems

Abstract

Reversible solid oxide cell (SOC) technology could enable efficient storage of renewable energy. In literature, reversible systems have not yet been widely investigated. The main goal of the present work is to address differences and similarities among simple SOFC and SOEC systems based on the same variables. Scope of the analysis is to identify useful operating regimes for a bi-directional system, using a thermodynamic analysis. Both energetic and exergetic point of views are adopted to estimate system and components performances. Preliminary results from the ongoing research are presented in this paper. Different operating conditions are evaluated via sensitivity analysis. Results are presented first for a reversible cell and then for a complete system. Looking at system operation it is feasible to design a reversible SOFC / SOEC system. At atmospheric pressure the total reversible system energy efficiency is around 30%. This value could be increased with system modifications.