SOFC System Demonstrations

In the context of setting up a fully operational 20 kW SOFC system demonstrator at FZJ a new concept for packaging the hot parts of the system (meaning parts operating above 400 °C) has been developed. 

The benefits and feasibility of hybrid systems have been established with conceptual studies and small-scale demonstrations fueled with natural gas. If large-scale, greater than 100-MW, fuel cell/turbine hybrid systems are to become a reality a reduction in fuel cell costs and scalability to larger units is required. The SECA program demonstrated 3 to 10 kW SOFC systems with costs of less than 800/kW in 2005. 

Demonstration highlight The world s largest SOFC system, a 100 kW Siemens-Westinghouse SOFC installed at a Dutch cogeneration plant in 1998. 

Thus far, tubular design cells are the most reliable cells against thermal stresses and chemical degradation of the performance. Siemens Power Generation has demonstrated the performance and reliability of SOFC systems with tubular cells [6], The 100 kW CHP system has been operated for more than 20000 h, and it was reported that no degradation of the system was observed. To prove the feasibility of a GT/SOFC hybrid system, a 220-kW hybrid system with an SOFC generator integrated with a micro gas turbine has been demonstrated at the University of California this system has shown a conversion efficiency of around 49% (HHV). 

Furthermore there have been demonstrations of fuel cell APUs in cmiventionally driven passenger cars. Important activities have been done by Delphi with a gasoline SOFC system [54] or by DaimlerChrysler with a gasoline PEM. 

The direct internal reforming of pre-reformed natural gas has been demonstrated in SOFC systems, but the other approaches described above have mostly been implemented only in button cells. Thus, there is a need for stack-level sunulations and demcaistrations to more fully vet these approaches. 

Rechberger J, Schauperl R, Hansen JB, Larsen PK (2009) Development of a methanol SOFC APU demonstration system. In ECS Transactions, vol 25, pp 1085-1092... 

Solid oxide fuel cell technology has been reviewed from the point of view of lowering the operation temperatures. This process is closely related with the development of new materials, processing techniques, and stack designs. The most striking fact is that the recent achievement by Kyocera may indicate the start of a new era in the development and demonstration of SOFC systems for stationary applications. 

Research and development toward commercialization of high-temperature fuel cells including MCFC and SOFC systems have also grown considerably since 1980, with a bevy of demonstration units in operation and commercial sales of MCFC systems. Figure 1.22 shows the estimated number of fuel cell systems built for all applications (excluding educational kits) per year. In 2004, the cumulative number of independent power-generating systems topped 11,000, with 10,000 of those units built in the preceding decade. 

This chapter first considers the trends in the energy markets that are driving towards utilisation of SOFC technology for electricity generation in various applications, Then SOFCs are compared with combustion engine generators and the potential application areas of SOFC systems are explored in detail. Designs and performance of SOFC systems are then analysed, followed by examples of SOFC systems and their demonstrations. 

Since 1986, Siemens Westinghouse has tested at least 12 fully integrated SOFC systems on customer sites, ranging from 0.4 kW to 220 kW [47]. The most recent demonstrations were a 100 kW atmospheric SOFC system, operated in Westervoort, the Netherlands, by a consortium of Dutch and Danish energy companies and a 220 kW SOFC/GT hybrid system, installed and tested at the National Fuel Cell Research Center on the campus of the University of California-Irvine for Southern California Edison [48-51]. These two systems are discussed below. 

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