Reversible Cell Systems in the Energy Transition: A Comparative Assessment of Their Potential for Renewable Integration

This study examines reversible electrochemical cell technologies as promising solutions for long-duration energy storage and renewable energy integration. It focuses on two main approaches: reversible solid oxide cells (rSOCs) and PEM-based reversible systems. Reversible cells can operate both as electrolyzers, producing fuels from electricity, and as fuel cells, generating electricity from stored fuels. rSOCs stand out due to their high-temperature operation, high efficiency, and fuel flexibility. They can produce hydrogen, syngas, and synthetic fuels while enabling efficient power-to-X applications. Their round-trip efficiency ranges from approximately 54% to 74%, with even higher values achievable through advanced system integration. PEM-based systems offer fast responses, lower operating temperatures, and greater commercial maturity. However, they rely on expensive catalysts and are generally limited to pure hydrogen use. The study highlights the potential integration of rSOCs with industrial processes such as methanation, methanol production, and ammonia synthesis. Future research will focus on modeling rSOCs under varying operating conditions to improve performance, durability, and commercial viability.