Perspectives in Solid Oxide Fuel Cell-Based Microcombined Heat and Power Systems

Fuel cell technology has undergone extensive research and development in the past 20 years. Even though it has not yet made a commercial breakthrough, it is still seen as a promising enabling technology for emissions reduction. The high electrical efficiency (Powell et al., 2012, "Demonstration of a Highly Efficient Solid Oxide Fuel Cell Power System Using Adiabatic Steam Reforming and Anode GasRecirculation," J. Power Sources, 205, pp. 377-384; Foger and Payne, 2014, " Ceramic Fuel Cells BlueGen-Market Introduction Experience," 11th European SOFC & SOE Forum 2014, Lucerne, Switzerland, Paper No. A0503; and Payne et al., 2009, " Generating Electricity at 60% Electrical Efficiency From 1-2 kWe SOFC Products," ECS Trans., 25(2), pp. 231-240) of an solid oxide fuel cell (SOFC)-based fuel cell system and the ability to operate on renewable fuels make it an ideal platform for transition from fossil-fuel dependency to a sustainable world relying on renewable energy, by reducing emissions during the transition period where fossil fuels including natural gas remain a major source of energy. Key technical hurdles to commercialization are cost, life, and reliability. Despite significant advances in all areas of the technology cost and durability targets (Papageorgopoulos, 2012, " Fuel Cells, 2012 Annual Merit Review and Peer Evaluation Meeting," U.S. Department of Energy, Washington, DC, accessed May 14, 2012, http://www.hydrogen.energy.gov/pdfs/review12/fc_plenary_papageorgopoulos_2012_o.pdf) have not been met. The major contribution to cost comes from tailor-made balance of plant (BoP) components as SOFC-based systems cannot be optimized functionally with off-the shelf commercial items, and cost targets for BoP and stack cannot be met without volume manufacturing (Foger, 2008, "Materials Basics for Fuel Cells," Materials for Fuel Cells, M. Gasik ed., Woodhead Publishing, Cambridge, UK, pp. 6-63). Reliability issues range from stack degradation and mechanical failure and BoP component failure to grid-interface issues in a grid-connected distributed generation system. Resolving some of these issues are a key to the commercial viability of SOFC-based microcombined heat and power (CHP) systems. This paper highlights some of the technical and practical challenges facing developers of SOFC-based products.