The first presentation was on the impact of production volume and stack scale-up on SOFC manufacturing cost. Jan Thijssen of LLC presented research which suggests that a production volume of 50 MW per year, SOFC stack costs of $750/kW could currently be achieved. At higher volumes, of over 100 MW per year, costs of less than $200/kW were envisaged. Furthermore, cell scale-up has the potential to reduce stack cost by around 25%.

In his research the balance between processing costs and materials costs varied with cell scale-up and higher volumes. Processing costs drop markedly with higher volume production, but not so much with scale-up. However materials costs do not drop quite as much with scale-up or with high volume production.

The next presentation focussed on technical work carried out by Lawrence Berkeley National Laboratory where a new “chip cell” has been developed for use in small and portable SOFC designs. The team has developed a novel way of binding cells together using “window frames” – a stainless steel frame housing one cell on the front and another on the back. When put together in a stack, the steel frames touch but not the actual cells, giving the cells greater freedom to contract, expand and warp. This yields impressive results when subjected to rapid thermal cycling with negligible seal or structure deterioration even after 400 cycles at an operating temperature of 650 degrees C going down to 100 degrees C over the course of 100 hours – a cycling profile which can only be described as abusive.

After the break was a presentation by Robert Braun of the United Technologies Research Centre on their SOFC stack and system development. They are focussing on small and lightweight designs, and this is the first time that their research has been presented at the Seminar. Using Haynes nickel alloy interconnectors instead of ferritic stainless steel, their target efficiency is around 30% using liquid fuel in a 1kW Topsoe stack, with peak loads being met by an integrated battery.

CellTech Power LLC was up next, presenting their liquid tin alloy (LTA) SOFCs which they have been developing since 1998. The benefit of LTA SOFCs compared to traditional SOFCs is that they can utilise JP-8 diesel directly, with no requirement for water, air or a reformer. Furthermore, sulphur is not a poison in these systems, but a fuel – so there is no desulphuriser needed. CellTech has been working on reducing the normally lower power densities achieved by LTA SOFCs compared with those of conventional SOFCs, with some success although they stress that there are further gains to be made in this area. They are planning to develop units for portable power applications in the region of 100W to 500W at first, without discounting the possibility eventually of MW-scale applications.

Finally, an excellent presentation by Jari Kiviaho outlined the Finnish Platform for SOFC Research and Development. SOFC activities in Finland are divided into two streams – the Wartsila Corporation Fuel Cell Programme, which focuses largely on R&D, and the Finnish National SOFC Programme (FINSOFC) which aims at developing commercial products and encouraging the growth of sustainable fuel cell markets. Part of this latter goal includes the creation of a “Handbook” detailing SOFC CHP unit demonstration information such as relevant as EU legislation and directives, heat management, installation, servicing, and codes and standards. Finland’s National Fuel Cell Technology Programme is due to start in early 2007, and it will be fascinating to chart the growth of the fuel cell industry in one of the most technologically forward-looking countries in Europe. 

Mike