To effectively align with the Paris Agreement's objective of achieving a carbon-neutral economy by 2050 and robustly mitigating anthropogenic climate change, while simultaneously ensuring energy security and advancing energy efficiency, there is an urgent imperative to significantly increase the share of renewable energy generation. Moreover, amidst the global energy crisis, the gas turbine industry has made significant strides towards developing turbines capable of running solely on 100% hydrogen by the year 2030. Under such circumstances, there is heightened motivation to reach deeper into the study of hydrogen-powered gas turbines and their more complex systems. Currently, the primary focus of research and analysis on hydrogen-fuelled gas turbines revolves around two main themes. Firstly, there is a concentration on emission reduction, driven by the urgency of addressing prevailing ecological challenges. Secondly, there is significant emphasis on analysing flame stability within the combustion chamber to optimize hydrogen combustion processes. However, this study presents an energy and exergy analysis of complex gas turbine systems fuelled by a mixture of hydrogen and methane. With the growing interest in transitioning to cleaner energy sources, understanding the performance of such systems is crucial. The research investigates the efficiency and effectiveness of gas turbine configurations utilizing hydrogen-methane mixtures, considering various operational parameters and environmental factors. By employing rigorous energy and exergy analyses, insights into the thermodynamic behaviour of these systems are provided. For this purpose, four different variants of gas turbine configurations were investigated: - classical system, - regenerative gas turbine, - gas turbine with compressor intercooling, - gas turbine with inter-stage turbine burner. To carry out the calculations and investigate these characteristics, Aspen HYSYS and Ebsilon Professional mathematical modelling programs were utilized. The findings contribute to advancing the understanding of hybrid fuel utilization, especially hydrogen-fuelled combustion, in different configurations of gas turbines, paving the way for optimized designs that align with sustainable energy objectives.