The shift to a low-carbon European Union (EU) economy raises the challenges of integrating renewable energy sources (RES) and cutting the CO2 emissions of energy intensive industries (EII). In this context, hydrogen produced from RES will contribute to decarbonize those industries, as feedstock/fuel/energy storage. Among the different technologies for low carbon H2 production, high temperature electrolysis (HTE) enables the production of green hydrogen with extremely high efficiency. The solid oxide cells (SOC) are typically operated in the 650-to-850°C temperature range, and arranged in pile-ups or stacks to increase the overall power density and address (pre-) industrial markets.
The technology has recently entered a phase of aggressive industrialization. However, significant efforts are still required to turn the high efficiencies into a competitive levelized cost of H2. As long as such cost remains largely controlled by that of stack manufacturing, stack degradation and the relationship with operating conditions remain a crucial subject of research and development. Moreover, recent advances have shown that to properly evaluate stack lifetimes, actual testing beyond 5 kh is critical [1,2]. A better understanding of degradation over the 5-to-10 kh range [3–5] could thus enable the development of both accelerated stress tests (AST) to reduce the necessary test duration, as well as optimized operational strategies to extend stack lifetimes.