Long-Term Experience with a 5/15kW-Class Reversible Solid Oxide Cell System

A 5/15 kW-class reversible Solid Oxide Cell (rSOC) system was developed and experimentally investigated at the Forschungszentrum Jülich GmbH. The main component of this system is the well-established Jülich Integrated Module, which consists of four 10-layer SOC sub-stacks with an active cell area per layer of 320 cm². The other necessary system components, such as the evaporator, condenser and blowers are compactly arranged in the vicinity of the Integrated Module. The system’s total operation time was more than 9000 h, in detail 2607 h in fuel cells, 6043 h in electrolysis and 448 h in hot standby mode. In fuel cell mode, a power of 5374 W_DC at 0.5 A cm⁻² at a fuel utilization of 97.3% was delivered, which resulted in a DC electrical system’s efficiency of 62.7% (LHV). Furthermore, in electrolysis mode, a power of −14347 W_DC was consumed at 0.89 A cm⁻². At this operating point, the system’s DC efficiency reached 70% at a steam utilization of 85%.