SOFC Lifetime Assessment in Gas Turbine Hybrid Power Systems

Abstract

The adoption of solid oxide fuel cell (SOFC) technology in power generation has been limited, in no small part, by material degradation issues affecting the stack lifetime, and hence, the economic viability. A numeric study was conducted to determine if the life of an SOFC could be extended when integrated with a recuperated gas turbine system. Dynamic modeling tools developed at the National Energy Technology Laboratory (NETL) for realtime applications were applied to evaluate life to failure for both a standalone SOFC and a hybrid SOFC gas turbine. These models were modified using empirical relations to experimental degradation data to incorporate degradation as a function of current density and fuel utilization. For the control strategy of shifting power to the turbine as fuel cell voltage degrades, the SOFC life could be extended dramatically, significantly impacting the economic potential of the technology.