High temperature electrolysis (HTEL) is characterized by high efficiency and low operating costs compared
to other electrolysis technologies, such as PEM and alkaline electrolysis. For this reason, this technology
represents a promising approach for the production of green hydrogen. The core element for the production
of green hydrogen are HTEL cells and HTEL stacks. These represent a key to the large-scale and costeffective
production of green hydrogen at high base load. However, to serve the hydrogen market with
large-scale HTEL cells and stacks in the future, further development steps are required regarding lifetime,
material costs, efficiency, manufacturing technologies as well as production upscaling.

The project "HTs: HTEL-Stacks - Ready for Gigawatt" within the technology platform "H2Giga" addresses
the development and research focus exactly on these topics and thus contributes significantly to the realization
of the goals of the National Hydrogen Strategy and the associated upscaling of electrolysis technology to the megawatt
scale. Within the framework of the project, Sunfire, as an electrolyser manufacturer, is responsible for
overall coordination and is working together with companies from industry and research on issues relating
to the industrialization of HTEL cells and stacks.

The work at KIT comprises experimental and model-based investigations on samples provided by the
partners. Electrochemical tests of cells and repeat units, high resolution electron microscopy of materials
and interfaces and supporting modelling activities will be used to evaluate the developed HTELcomponents
and suggest measures to improve performance and durability. The achieved understanding of
mechanisms and interactions on the cell and stack level will enable a straightforward improvement of high
temperature electrolysers.