Swiss SOFC integration activities: Stacks, systems, and applications

Solid Oxide Fuel Cell (SOFC) application development is very well represented in Switzerland by two companies. Sulzer Hexis AG is one of the world leaders in the commercialization of SOFC systems for single family houses. A smaller company, HTceramix, is active in novel processing routes for cells and in innovative stack designs. This article first presents the benefits of implementing SOFC in selected applications and markets. Then the current state-of-the-art in stacking is described for both Swiss stack designs, looking at power density, and electrical efficiency. It is remarkable that both stacks currently exhibit a unique characteristic in SOFC design: the absence of side sealing, which permits to significantly simplify the stack assembly and thus improve its reliability. Finally, the two generations of SOFC systems produced by Sulzer Hexis are presented. The HXS 1000 Premiere preseries system is evaluated on the basis of the extended demonstration program currently underway where 110 systems are in operation in single family houses and public buildings. The near-series system is then introduced with respect to the identified needs in reduction of investment and operating costs as well as size and weight.