Solid Oxide Electrolysis: A Technology Status Assessment

The report evaluates solid oxide electrolyzer cell (SOEC) technology, highlighting its superior electrical efficiency when integrated with external heat sources, such as those found in steel, chemical, and nuclear plants. While the technology is more mature than often perceived—leveraging experience from the gigawatt-scale solid oxide fuel cell (SOFC) industry—it faces challenges regarding stack durability due to high-temperature thermal stress and the need to scale from small modules to hundred-megawatt systems. The report finds that raw material supply chains are not a bottleneck and that gigawatt-scale manufacturing is feasible within 18 to 36 months.

• SOECs offer a significant efficiency advantage over alkaline, PEM, or AEM electrolyzers when they can access an external source of process heat for steam generation, potentially reducing electricity demand by 6 kWh per kilogram of hydrogen.
• The technology's maturity is often underestimated because SOECs are nearly identical in design and manufacture to solid oxide fuel cells (SOFCs), which have already been deployed at a gigawatt scale.
• A primary commercial hurdle for SOEC manufacturers is scaling their product offerings from small modules (single-digit megawatts) to large-scale systems with capacities in the hundreds of megawatts.
• High-temperature operation (500°C to 1000°C) increases efficiency but accelerates stack failure due to thermal stresses, such as nickel migration, nickel sintering, and electrolyte cracking.
• Manufacturing capacity for SOECs is not a bottleneck; gigawatt-scale production could be established within 18 to 36 months, and there is no shortage of necessary raw materials.
• SOEC technology is particularly well-suited for integration with industrial facilities that produce high-grade process heat, including ammonia, chemical, and steel plants, as well as refineries.
• While current academic literature suggests an average stack life of 2.5 years, experience from SOFCs suggests stacks can operate for up to 80,000 hours (nearly 9 years), with expectations for SOEC to reach 7–8 years by 2030.
• SOECs avoid the use of critical and expensive platinum group metals like platinum and iridium, though they require rare earth metals such as zirconium, lanthanum, yttrium, and scandium.

APA

Flis, G., & Wakim, G. (2023). Solid Oxide Electrolysis: A Technology Status Assessment. Clean Air Task Force. https://cdn.catf.us/wp-content/uploads/2023/11/15092028/solid-oxide-electrolysis-report.pdf

Chicago

Flis, Gniewomir, and Ghassan Wakim. Solid Oxide Electrolysis: A Technology Status Assessment. Clean Air Task Force, 2023. https://cdn.catf.us/wp-content/uploads/2023/11/15092028/solid-oxide-electrolysis-report.pdf.

Wikipedia

{{cite report |last1=Flis |first1=Gniewomir |last2=Wakim |first2=Ghassan |title=Solid Oxide Electrolysis: A Technology Status Assessment |publisher=Clean Air Task Force |date=November 2023 |url=https://cdn.catf.us/wp-content/uploads/2023/11/15092028/solid-oxide-electrolysis-report.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{flis2023solid, author = {Flis, Gniewomir and Wakim, Ghassan}, title = {{Solid Oxide Electrolysis: A Technology Status Assessment}}, institution = {Clean Air Task Force}, year = {2023}, month = nov, url = {https://cdn.catf.us/wp-content/uploads/2023/11/15092028/solid-oxide-electrolysis-report.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }