Enhancing the Cost-Competitiveness of Green Ammonia-Based Power Systems: Hybrid Solid Oxide Fuel Cells and Gas Turbines

Ammonia (NH₃) is considered one of the most compelling energy carriers for sustainable power systems. The solid oxide fuel cell (SOFC)–gas turbine (GT) hybrid system, fueled by green NH₃-based hydrogen, is regarded as a promising sustainable power generation technology because of its high energy efficiency and low carbon emission. However, despite its significant potential, there have been limited discussions about (i) process configurations that consider the power generation characteristics of SOFC and GT and (ii) the economic performance. To address these limitations, this study proposes three economically optimized SOFC–GT hybrid systems and conducts comprehensive economic analyses. Notably, the heat-integrated parallel system, in which SOFC and GT are configured in parallel, and steam cycle is integrated into the SOFC off-gas stream, demonstrated the highest economic competitiveness among the suggested systems. The system reduces the cost of operating the SOFC, improves the cost-efficiency of the GT, and decreases power consumption for air compression, consequently representing a 6.9% reduction in the levelized cost of electricity and a 22.8%p increase in economic profitability under market uncertainties when compared to the base case with a typical hybrid system.