Techno-enviro-economic analysis of solid oxide electrolysis cell architectures

Solid oxide electrolysers (SOE) are able to produce hydrogen, an important building block in decarbonizing hard-to-abate sectors, with class-leading efficiencies. However, scaling up SOE technology remains challenging due to high costs and short lifetimes, which differ among the different SOE cell architectures. This work compares and contrasts the economic and environmental impact of scaling up different SOE cell architectures to a 1MW stack module. A parallelized and experimentally validated model was used to optimize each architecture across a broad range of material and microstructure combinations. Among the evaluated architectures, the anode-supported architecture achieved the highest current density, however, its high degradation rate currently makes it the least viable option. It must address the degradation, even if it is achieved by decreasing current density. The metal-supported architecture stands out as the cheapest architecture, but due to the low current densities and thus, increased material demand to manufacture the comparatively larger stack modules, its geopolitical supply chain risk is high. It requires stabler and more heat-resistant stainless steel to limit degradation and operate at 650 °C to decrease stack size and material supply chain risk by 20%. Remarkably, the electrolyte supported architecture using a 150 µm 1Ce10SSZ electrolyte is the most favourable at 103 ton CO 2 emissions, 254 € of material supply chain risk and 0.42M$ stack costs. Its stability and low geopolitical supply chain risk perhaps warrant a renewed focus on the electrolyte-supported architecture. • A large parametric sweep over millions of different microstructures in the quest for optimal solid oxide electrolysis architectures. • The three solid oxide electrolysis architectures are compared on costs, CO 2 emissions from manufacturing and the critical material supply risk disruption for 1MW stack modules. • Electrolyte supported solid oxide cell with a 150 μ m 1Ce10SSZ electrolyte after 4 years of operation, shows the lowest impact over all three categories. • Possible improvements in microstructure design and operation strategies are outlined for each of the architectures in reducing costs, CO 2 emissions from manufacturing and the critical material supply risk disruption.