Comparative Performance and Economic Analysis of Gas Turbine Combined Cycle Integrated with Hydrogen Production under Various System Configurations

As carbon-free fuels, especially hydrogen, and their production technologies gain attention, the need for research on systems integrating hydrogen production process and power generation is increasing. In this study, steam methane reforming(SMR) and water electrolysis(WE) were integrated with a gas turbine combined cycle(GTCC). The systems were classified in terms of the integration configuration(independent or thermally integrated) and the fuel supplied to the GTCC(hydrogen or syngas). Their performance and economic feasibility were analyzed under a fixed turbine inlet temperature condition, in comparison to a conventional GTCC. According to our analysis, the thermally integrated SMR-GTCC fueled with syngas achieved an 18.8% increase in power output with only a 2.8%p efficiency loss, representing the smallest efficiency penalty among the considered systems. Moreover, it reached the break-even point at the lowest electricity selling price of 162.8KRW/kWh, making it the most cost-effective option. In contrast, the WE-GTCC reduced CO₂ emissions per unit of power by 99.4%, demonstrating the highest environmental benefit. In summary, the SMR-GTCC provides superior efficiency and economic performance, whereas the WE-GTCC offers an advantage in carbon reduction.